CURRENT AND SPORADIC DISEASE PROBLEMS IN POULTRY

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
311	3299	1090	20%
311	3299	1100	20%
311	3299	1101	20%
311	3299	1160	20%
311	3299	1170	20%

Progress 10/01/07 to 09/30/19

Outputs
Target Audience:Poultry industry; Poultry veterinarians; Scientists in the field of poultry enteric diseases Changes/Problems:Enteric disease in poultry continue to be a problem and new enteric pathogen continue to emerge and re-emerge. For this reason, we submitted the application for renewal of this project with the following goals. We will continue to determine host/viral factors responsible for microbiota disruption; impact of microbiota disruption on poultry performance; and role of microbiota in outbreak and severity of poultry enteric diseases. We will continue to isolate and characterize enteric viruses from field in collaboration with industry and Ohio Department of Agriculture. What opportunities for training and professional development has the project provided?This project partially supported training of 2graduate student and 2research associate. In addition to training on specific research, they presented the finding at the international meetings. They also published the paper in peer-reviewed journals. How have the results been disseminated to communities of interest?The results were shared with the turkey industry and veterinarians (from Ohio, Michigan, and Indiana) in our semiannual meetings. In addition, the results were presented at the international meetings and manuscript was published in peerreviewed journal. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Turkey arthritis reovirus (TARV) infections have been recognized since 2011 to cause disease and significant economic losses to the U.S. turkey industry. Reoviral arthritis has been reproduced in commercial-origin turkeys. However, determination of pathogenesis or vaccine efficacy in these turkeys can be complicated by enteric reovirus strains and other pathogens that ubiquitously exist at subclinical levels among commercial turkey flocks. We accomplished the followings: 1) we established and published specific-pathogen-free (SPF) turkey model for reoviral arthritis; and 2) we demonstrated turkey arthritis reovirus virulence correlates with the degree of normal gut and respiratory microbiome disruption. Establishment of specific-pathogen-free turkey model for reoviral arthritis Turkeys from a specific-pathogen-free (SPF) flock were evaluated for use as a turkey reoviral arthritis model. One-day-old or 1-week-old poults were orally inoculated with TARV (O'Neil strain) and monitored for disease onset and progression. A gut isolate of turkey reovirus (MN1 strain) was also tested for comparison. Disease was observed only in TARV-infected birds. Features of reoviral arthritis in SPF turkeys included swelling of hock joints, tenosynovitis, distal tibiotarsal cartilage erosion, and gait defects (lameness). Moreover, TARV infection resulted in a significant depression of body weights during the early times post-infection. Age-dependent susceptibility to TARV infection was unclear. TARV was transmitted to all sentinel birds, which manifested high levels of tenosynovitis and tibiotarsal cartilage erosion. Simulation of stressful conditions by dexamethasone treatment did not affect the viral load or exacerbate the disease. Collectively, the clinical and pathological features of reoviral arthritis in the SPF turkey model generally resembled those induced in commercial turkeys under field and/or experimental conditions. Summary/Impact. SPF turkeys are a reliable model for reoviral arthritis. The SPF turkey reoviral arthritis model will be instrumental in evaluation of TARV pathogenesis and reoviral vaccine efficacy. SPF model of turkey reoviral arthritis and dysbiosis in reovirus infected turkeys Reoviruses that cause arthritis in avian species are most commonly transmitted through fecal-oral route and replicate in the gut before translocation to different organs including the hock joints. The respiratory tract is a secondary port of entry and replication site for avian reovirus. Our studies of clinically healthy commercial and SPF turkeys have demonstrated that both gut and respiratory systems are inhabited by complex communities of resident microorganisms (microbiome) that might interact with infecting pathogens and influence the degree of pathogenesis and clinical disease. We investigated two TARV isolates, Reo/Turkey/OH/FAHRP/2016 (FA) and TARV O'Neil (ON), for their impact on gut and respiratory microbiome in SPF turkeys. 1-week-old poults were orally inoculated with TARV or virus-free medium and monitored for 4 weeks to detect clinical disease manifestations, cloacal virus shedding, tendon viral titers, and bacterial microbiota disruptions (dysbiosis). Compared to ON virus, FA virus caused a milder weight gain depression, a markedly lower tendon viremia, and lower cloacal virus shedding. Gut and respiratory bacterial communities were profiled using 16S rRNA amplicon sequencing to gain more insight into TARV pathogenesis. Hierarchical clustering revealed that FA virus caused remarkable disruption of core bacterial taxa abundance in trachea and only minor disruptions in the cecum, ileum, and sinus compared to mock-infected birds. In contrast, ON virus was associated with major microbiota disruptions in all four anatomical sites examined. The degree of enhancement/suppression of the abundance of several core taxa by the two TARVs corresponded well with cloacal virus shedding, viral titers in tendons, and body weight suppression. Suppression of weight gain by TARV was associated with suppression of potentially growth-enhancing bacterial taxa like Lactobacillus agilis in ileum. Summary/Impact. Using the SPF turkey model, we show that TARV infection results in dysbiosis of respiratory and intestinal microbiome, which persists long after clearance of the virus. The long term goal of this project is to determine host/viral factors responsible for dysbiosis, impacts of microbiota disruption on immunity and production performance of turkeys, and the role of microbiota in outbreak and severity of reoviral arthritis.

Publications

Type: Journal Articles Status: Published Year Published: 2019 Citation: Ngunjiri JM., Ghorbani A, Jang H, Waliullah S, Elaish M, Abundo MC, KC M, Taylor KJM, Porter RE, Lee CW. (2019). Specific-Pathogen-Free Turkey Model for Reoviral Arthritis. Veterinary Microbiology, 235, 170-179.
Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Ngunjiri JM, Ghorbani A, Taylor KJM, Abundo MC, Jang H, Elaish M, KC M, Ji H, Lee CW. Turkey arthritis reovirus virulence correlates with the degree of normal gut and respiratory microbiome disruption. 99th Conference of Research Workers in Animal Diseases, Chicago, IL. December 2-4, 2018.
Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Taylor KJM, Ngunjiri JM, Abundo MC, KC M, Ji H, Ghorbani A, Jang H, Elaish M, Lee CW. Disruption of turkey core gut and respiratory microbiome by reovirus and influenza virus. 99th Conference of Research Workers in Animal Diseases, Chicago, IL. December 2-4, 2018.

Progress 10/01/17 to 09/30/18

Outputs
Target Audience:Poultry industry; Poultry veterinarians; Scientist in the field of poultry enteric disease Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project partially supported training of 1 student and 1research associate. In addition to training on specific research, they presented the findings at the international meetings. Manuscript is being prepared for publication. How have the results been disseminated to communities of interest?The results were shared with the turkey industry and veterinarians (from Ohio, Michigan, and Indiana) in our semiannual meetings. In addition, the results were presented at the international meetings and manuscript will be submitted for publication in peer-reviewed journals. What do you plan to do during the next reporting period to accomplish the goals? We will determine 1) host/viral factors responsible for microbiota disruption; 2) impact of microbiota disruption on poultry performance; and 3) role of microbiota in outbreak and severity of reoviral arthritis. We will continue to isolate and characterize enteric viruses from field in collaboration with industry and Ohio Department of Agriculture.

Impacts
What was accomplished under these goals? Turkey arthritis reovirus (TARV) virulence correlates with the degree of normal gut and respiratory microbiome disruption TARV-mediated arthritis was reproduced in SPF turkeys. Disease was indicated by clinical manifestations and pathologic features such as staggered movement, dropped keel bone, swelling of hock joints, gastrocnemius and digital flexor tendons, mild to severe valgus, distal tibiotarsal cartilage pitting and erosion, high gait scores, and weight gain depression The degree of enhancement/suppression of several core taxa by the two TARVs corresponded well with tendon viremia and body weight depression. Two tested viruses were isolated from severe clinical cases in commercial turkey farms, but one of theviruses showed a mild pathotype in SPF turkeys, suggesting that the concept of "one pathogen - one disease" does not fully explain TARV-associated arthritis. Thus, our holistic approach of understanding this complicated disease will help to develop unconventional preventive measures. Understanding the Respiratory Microbiota of Poultry - Surveillance of commercial and SFP poultry Complex microbial communities that occupy the respiratory and gut system have a significant influence on the immune status and animal health. There is a need to define the baseline microbiota in order to facilitate studies that will illuminate the microbiome's role in host susceptibility and response to pathogens and vaccines. We first characterized the bacterial communities that were present in gut and the upper and lower respiratory tract including sinus, trachea, air sacs and the lungs. In the second study, we evaluated field-utilized respiratory swab collection methods which produced extensive data where microbiome from tracheal swab and wash are distinct from each other while the tracheal and choanal swabs share a high degree of similarity. We also have sampled healthy flocks of commercial chickens and turkeys along the different phases of production. We found that age and body-site had the greatest impact on the bacterial microbiome of those birds. The core respiratory microbiota differed greatly from core gut microbiota in diversity and temporal dynamics, yet several members of the genus Lactobacillus were ubiquitous, suggesting a common function of this genus in both systems. We also showed that known avian pathogens can emerge and persist at subclinical levels in an optimally performing flock. Controlled experiments using SPF chickens are ongoing focusing on the effects of viral infections (reovirus, IBDV) and antiviral vaccines on commensal bacteria. Future work will establish core microbiome biomarkers of viral infections and the long-term impacts of viral infections on microbiome, and poultry performance.

Publications

Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Ngunjiri JM, Abundo MC, Jang H, Elaish M, Mahesh KC, Ghorbani A, Youmans BP, Johnson TJ, Lee CW. Understanding the respiratory microbiome of commercial turkeys and chicken layers. Conference of Research Workers in Animal Diseases Meeting. Chicago, IL. Dec. 35. 2017.
Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Abundo MC, Ngunjiri JM, Taylor K, Lee CW. Microbiome in the upper and lower respiratory tract and standardization of sample collection methods in clinically healthy poultry. Annual Convention of American Veterinary Medical Association. Denver, CO. July 13-17, 2018.
Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Ngunjiri JM, Lee CW. Understanding the respiratory microbiome of poultry. 4th Annual PRD-CAP Meeting. Kansas City, MO. October 24, 2018.

Progress 10/01/16 to 09/30/17

Outputs
Target Audience:Poultryindustry; Poultry veterinarians; Scientist in the field of poultry enteric disease Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project partially supported training of 2 research associates. In addition to training on specific research, they presented the finding at the international meetings. Manuscript is being prepared for publication. How have the results been disseminated to communities of interest?The results were shared with the turkey industry and veterinarians (from Ohio, Michigan, and Indiana) in our semiannual meetings. In addition, the results were presented at the international meetings and manuscript will be submitted for publication in peer-reviewed journals. What do you plan to do during the next reporting period to accomplish the goals?Different preventive measure will be developed based on the comparative pathogenicity studies. We will continue to work on microbiome to enhance our understanding of how changes in gut and respiratory microbiome affect reoviral pathogenesis in turkeys. We will continue to isolate and characterize enteric viruses from field in collaboration with industry and Ohio Department of Agriculture.

Impacts
What was accomplished under these goals? Reoviral arthritis emerged in the U.S. commercial turkeys in 2011 and outbreaks have continued to occur in the Midwest resulting in significant financial losses to the turkey industry. As an important step toward developing preventive measures including vaccines, the study was conducted in order to establish an SPF turkey model to assess Turkey Arthritis Reo-Virus (TARV) pathogenesis and to better understand the host-pathogen-environment interaction in disease manifestation. We accomplished the followings: 1) Establishment of a specific-pathogen-free (SPF) turkey model of reoviral arthritis to facilitate future development of preventive measures including vaccines: 1 day old or 1 week old poults were orally inoculated with a reo-virus isolated from tendons of a clinically lame commercial turkey and monitored for 16 weeks. Clinical manifestations and pathological features of arthritis were more pronounced in SPF turkeys compared to commercial turkeys used in previous studies. 2) Surveillance of commercial turkeys for reovirus and gut microbiome. A commercial turkey flock was followed from hatch up to 16 weeks of age, to monitor changes in gut bacteria through 16S rRNA analysis and reovirus prevalence through serology. Bacterial diversity was highly influenced by age and gut location. Bacterial communities were very dynamic in young birds (1-5 weeks) and more stable in older birds (8-16 weeks). The dominant classes of bacteria included: bacteroidia in cecum, clostridia in both cecum and ileum, and bacilli in ileum. Determination of the correlation between reovirus prevalence and gut bacterial community was complicated by the presence of high reovirus antibody titers in all birds. 3) Comparison of microbiome composition and diversity in commercial turkeys, SPF turkeys, and reovirus-infected SPF turkeys. To better understand the pathobiology of arthritis reovirus infection in turkeys, 16S rRNA analysis of gut and respiratory microbiomes was conducted. Reovirus infection in SPF turkeys had a noticeable influence on the beta-diversity of bacteria communities in the gut and was associated with change in the relative abundance of dominant bacterial classes. In summary, our study has provided critical data for SPF turkeys as a model for the study of turkey arthritis reovrius pathogenesis and the developed model will be used to develop reoviral vaccine. In addition, complex microbial communities (microbiome) that inhabit the gut and respiratory tracts have significant influence on the development, immune status, and animal health. Our work will enhance the understanding of how changes in gut and respiratory microbiome affect reoviral pathogenesis in turkeys.

Publications

Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: John M. Ngunjiri, Sumyya Waliullah, Hyesun Jang, Mohamed Elaish, Amir Ghorbani, Mahesh KC, Michael C. Abundo, Chang-Won Lee . Specific pathogen-free (SPF) turkey model for emerging reoviral arthritis. Conference of Research Workers in Animal Diseases Meeting. Chicago, IL. Dec. 46. 2016.
Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: John M. Ngunjiri, Amir Ghorbani, Hyesun Jang, Mohamed Elaish, Sumyya Waliullah, Mahesh KC, Michael C. Abundo, Chang-Won Lee. Specific Pathogen Free Turkey Model for Emerging Reovirus and Assessment of Microbiome in Reovirus-infected Turkeys. American Society for Virology. 36th Annual Meeting. Madison, Wisconsin, June 24-28, 2017.

Progress 10/01/15 to 09/30/16

Outputs
Target Audience:Turkey industry; Poultry veterinarians; Scientist in the field of poultry enteric disease Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project partially supported training oftwo research associates. In addition to training on specific research, they presented their findings at the international meeting. Manuscript is being prepared for publication. How have the results been disseminated to communities of interest?The results were shared with the turkey industry and veterinarians (from Ohio, Michigan, and Indiana) in our semiannual meetings. In addition, the results were presented at the international meetings and manuscript will be submitted for publication in peer-reviewed journals. What do you plan to do during the next reporting period to accomplish the goals?We will continue to isolate and characterize enteric viruses from field in collaboration with industry and Ohio Department of Agriculture. The pathogenicity of isolated virus from turkeys will be determined experimentally in vivo. Different preventive measure will be developed based on the comparative pathogenicity studies.

Impacts
What was accomplished under these goals? Reoviral arthritis emerged in the U.S. commercial turkeys in 2011 and outbreaks have continued to occur in the Midwest resulting in significant financial losses to the turkey industry. As an important step toward developing preventive measures including vaccines, the study was conducted in order to establish an SPF turkey model to assess TARV pathogenesis. We accomplished the followings: We reproduced reoviral arthritis by oral inoculation of O'Neil strain while a typical enteritis reovirus (MN1 strain) did not induce the disease in SPF turkeys. Arthritis was indicated by clinical manifestations and pathological features such as staggered movement, dropped keel bone, swelling of hock joints, gastrocnemius and digital flexor tendons, mild to severe valgus, high gait scores, and distal tibiotarsal cartilage pitting and erosion. Turkey reovirus (O'Neil strain) infection caused a significant weight gain depression during the early stages of infection. The weight gain depression was exacerbated by early infection (1 day compared with 7 days of age) and dexamethasone-induced stress. Recently we isolated new reovirus from affected turkey farm in Ohio. The newly isolated strain will be used in comparative pathogenesis study with other reovirus isolates. Our study has provided baseline data for SPF turkeys as a model for the study of turkey arthritis reovrius pathogenesis and themodel will be used to develop reoviral vaccine and other preventive measures.

Publications

Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: John M. Ngunjiri, Sumyya Waliullah, Hyesun Jang, Chang-Won Lee. Pathogenesis of Emerging Turkey Arthritis Reovirus. Proceedings of the Sixty-Fifth Western Poultry Disease Conference. April 24-27, 2016 Vancouver, BC, Canada. pp192-194.

Progress 10/01/14 to 09/30/15

Outputs
Target Audience:Turkey industry; Poultry veterinarians; Scientist in the field of poultry enteric disease Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project partially supported training of 2 research associate. In addition to training on specific research, they prepared and submitted a abstract to an international meeting for presentation using data obtained from this study. How have the results been disseminated to communities of interest?The results were shared with the turkey industry and veterinarians (from Ohio, Michigan, and Indiana) in our semiannual meetings. In addition, the results will be presented also at the internation meeting in 2016 and manuscript submitted for publication in peer-reviewed journals. What do you plan to do during the next reporting period to accomplish the goals?We will continue to isolate and characterize enteric viruses from field in collaboration with industry and Ohio Department of Agriculture. The pathogenicity of isolated virus from turkeys will be determined experimentally in vivo. Additional effort will be made to reproduce the reoviral arthritis in SPF turkeys immunosuppressed by dexamethasone treatment to mimic the field condition.

Impacts
What was accomplished under these goals? Avian reoviruses are ubiquitous in commercial poultry and have been frequently isolated mainly from intestines of chickens and turkeys that are clinically normal. However, reoviral arthritis emerged in the U.S. commercial turkeys in 2011 and outbreaks have continued to occur in the Midwest. Although the mortality is rather low, significant economic loss results from a low weight uniformity in the affected flock. Currently, no commercial vaccines are available for turkeys. Further, the efficacy of autogenous vaccines being sporadically used in the field is unclear and has not been experimentally validated. We conducted in vivo studies using specific-pathogen-free (SPF) turkeys to provide solid experimental baseline data to better understand the pathogenesis of reovirus and develop appropriate control strategies. We found that reovirus isolated from arthritis case can be detected in the hock joint more frequently than typical enteric reovirus which correlated with earlier and higher seroconversion in terms of detection rate and antibody titer. Further information that could lead to better understanding of pathogenesis and novel control strategies will be of significant impact. Our study will fill this void in order to identify features that need to be fine-tuned to generate the most effective preventive measures for reoviral arthritis.

Publications

Type: Journal Articles Status: Published Year Published: 2015 Citation: Awe OO, Kang KI, Ibrahim M, Ali A, Elaish M, Saif YM, Lee CW. Age-Related Susceptibility of Turkeys to Enteric Viruses. Avian Dis. 59(2):207-12. 2015

Progress 10/01/13 to 09/30/14

Outputs
Target Audience: Turkey industry; Poultry veterinarians; Scientist in the field of poultry enteric disease Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? This project supported training of1 Ph.D students. In addition to training on specific research, the student prepared and submitted a manuscript to an international journal using data obtained from this study. This student succesfully completed his PH.D. study. How have the results been disseminated to communities of interest? The results were presented at the regional meetings (OSU) and manuscript was submitted for publication in peer-reviewed journals. In addition, the results were shared with the turkey industry and veterinarians (from Ohio, Michigan, and Indiana)in our semiannual meetings. What do you plan to do during the next reporting period to accomplish the goals? We will continue to isolate and characterize enteric viruses from field in collaboration with industry and Ohio Department of Agriculture. The pathogenicity of isolated virus from turkeys will be determined experimentally in vivo. The current diagnostic methods for identifying enteric virus infection will be evaluated and validated especially for avian coronaviruses.

Impacts
What was accomplished under these goals? Several different enteric viruses have been identified as the causes of gastrointestinal infections in poultry. Enteric virus infections are well characterized in poults, but limited studies have been conducted in older birds. To better understand the age related susceptibility of the enteric viruses, we investigated the susceptibility of 2-, 7-, 12-, 30-, and 52-week-old turkeys to turkey coronavirus (TCoV) and turkey astrovirus (TAstV) was evaluated, as well as the effect of combined infection of TAstV and TCoV in 2-week-old poults and turkey hens. From cloacal swabs and intestines, TCoV was consistently detected by RT-PCR throughout the experimental period (1-21 DPI) from all age groups. In contrast, the last detection point of TAstV gradually decreased to 21, 16, and 12 DPI in birds inoculated at 2, 7, and 12 weeks of age, respectively, and viral RNA was rarely detected from cloacal swabs or intestinal contents in turkey hens within 3 DPI. Infection with TAstV alone did not affect body weight in poults or egg production in hens. The combined infection of TAstV and TCoV did not induce more severe clinical signs and pathology than the TCoV alone infection. However, a severe prolonged decrease in egg production (about 50%) was observed in turkey hens in the combined infection group compared to a transient egg production drop in TCoV alone infected hens. Our findings clearly reveal the age related susceptibility of turkeys to enteric viruses in relation to the specific pathogen and also the co-infection status. Our extensive study provides critical baseline data to further investigate the underlying mechanism regarding the age related TAstV susceptibility and the pathogenesis of the TAstV and TCoV co-infection in layer hens.

Publications

Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Kang KI, Awe O, Ibrahim M, Elaish M, Ali A, Rauf A, Saif YM, Lee CW. Assessing susceptibility to turkey astrovirus & coronavirus in various aged turkeys. Annual Meeting. American Society of Virology. Fort Collins, CO. 2014.
Type: Theses/Dissertations Status: Published Year Published: 2014 Citation: Studies on turkey enteric viruses: age related prevalence and impact on production performance. Dissertation. 2014, June. The Ohio State University.

Progress 01/01/13 to 09/30/13

Outputs
Target Audience: Turkey industry; Poultry veterinarians; Scientist in the field of poultry enteric disease Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? This project supported training of1 Ph.D students. In addition to training on specific research, the student presented the results at the two national meetings. How have the results been disseminated to communities of interest? The results were presented at the regional (NCADC) and national (AVMA) meetings and two manuscriptsare being prepared for publication in peer-reviewed journals. In addition, the results were shared with the turkey industry and veterinarians (from Ohio, Michigan, and Indiana)in our semiannual meetings. What do you plan to do during the next reporting period to accomplish the goals? 1. We will continue to survey, isolate and characterize enteric viruses from field in collaboration with industry and Ohio Department of Agriculture. 2. The pathogenicity of isolated virus from turkeys will be determined experimentally in vivo. 3. The current diagnostic methods for identifying enteric virus infection will be evaluated and validated.

Impacts
What was accomplished under these goals? Although several viruses have been detected from turkeys with enteric disease, little is known about their true impact in turkey enteric health especially in older birds. Since longitudinal surveillance study of enteric viruses is limited, prevalence of enteric viruses in three turkey commercial operations in Ohio was determined. Fecal samples were collected from each operation starting from placement to slaughter (21 weeks of age). Samples were screened for the presence of astrovirus, avian rotaviruses (AvRVs) groups A and D, reovirus, and turkey coronavirus (TCoV) by RT-PCR, and adenovirus and parvovirus by PCR. Results showed that parvovirus and astrovirus were the most prevalent enteric viruses (overall prevalence of 76% and 67% respectively). Parvovirus was consistently detected after 4 weeks of age from all farms with increased prevalence as age increases. All flocks were positive for astrovirus as early as 1 week old until slaughter with gradual decrease in prevalence. Rotaviruses were detected with high prevalence at 1 and 4 weeks of age. Interestingly, group A AvRV prevailed at first week of age, however, at 4 weeks of age, group D AvRV were the predominant genotype in all flocks sampled and both AvRV-A and -D were detected at 14 weeks of age in two farms. Avian reoviruses were intermittently detected in young ages but with increased detection in older turkeys, and adenovirus were sporadically observed at 9 weeks of age. All flocks were negative for TCoV at all ages. Our findings reveal that enteric viruses are prevalent both in healthy and diseased turkeys of wide age range. Our study provides critical baseline data to further investigate the effect of combined infection of different enteric viruses in turkey health and production.

Publications

Type: Other Status: Published Year Published: 2013 Citation: Awe O, Ali A, Mahmoud I, Shany SA, Elaish MN, Saif YM, Lee CW. Effect of poultry enteric viruses on egg production in layer turkey hens. 64th North Central Avian Disease Conference. March 11-12. 2013. St. Paul, Minnesota.
Type: Other Status: Published Year Published: 2013 Citation: Awe O, Ali A, Elaish M, Saif YM, Lee CW. Age related prevalence of enteric viruses in healthy commercial flocks. 150th AVMA Annual Convention. July 2023, 2013. Chicago, IL.

Progress 01/01/12 to 12/31/12

Outputs
OUTPUTS: Enteric virus infections cause enteritis in turkeys of varying ages. However, the effect of enteric viruses on egg production is not well understood. Earlier, we detected turkey coronavirus (TCoV) in the oviducts of turkey breeder hens that had drops in egg production. Hence, we initiated studies to determine the effect of TCoV alone and in combination with another enteric virus (astrovirus) on reproductive performance of experimentally inoculated turkey breeder hens. Thirty-week-old turkey hens in peak egg production were either mock-infected or inoculated orally with TCoV (Indiana strain NRC-47) alone or combination with astrovirus. In the cloacal swabs of hens inoculated with TCoV alone, TCoV was detected consistently upto 12 DPI with the higher rate of detection after 5 DPI (>90%). TCoV was also detected in the reproductive tract of birds at 7 DPI. A transient drop (25 - 35%) in egg production was observed in TCoV infected turkey hens between 4 and 7 DPI. Turkey hens co-infected with TCoV and astrovirus had a severe drop (51%) in egg production which never returned to a normal level of production. PARTICIPANTS: Prinicipal institution and individuals: Ohio Agricultural Research and Development Center / The Ohio State University. Y.M. Saif, L. Saif, C.W. Lee, A. Rauf, O. Awe, and M. Strother. TARGET AUDIENCES: Turkey industry; Poultry veterinarian; Scientist in the field of poultry diseases and virology PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Our results demonstrate the impact of single and combined infections of enteric viruses on reproductive performance of turkey hens causing transient or severe drop in egg production. Considering the significant economic impact of any drop in egg production in turkey breeder flocks, it is important to establish a causal relationship. Our study will lead to development of control strategies to prevent egg production drops in addition to preventing enteric problem.

Publications

Lee CW, Awe O, Murgia M, Rauf A, Ali A, Saif YM. Effect of Coronavirus Infection on Reproductive Performance of Turkey Breeder Hens. AVMA Annual Convention. August 3-6, 2012. San Diego, California.

Progress 01/01/11 to 12/31/11

Outputs
OUTPUTS: Earlier, we detected turkey coronavirus (TCoV) in the oviducts of turkey breeder hens that had drops in egg production. Hence, we initiated studies to determine the possible role of TCV in egg production drops. In our experimental studies, we observed transient drop in egg production in turkey coronavirus infected turkey hens between 4 and 7 days post infection in addition to severe gross pathology in the intestine. TCoV was detected consistently in the intestine and fecal swabs throughout 14 days of experimental period. In addition, we were able to detect a small amount of TCoV in the reproductive tract of infected birds at 7 days post infection by RT-PCR. PARTICIPANTS: Veterinarians, Ohio Department of Agriculture, Ohio Poultry Team TARGET AUDIENCES: Animal producers and processors. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Considering the significant economic impact of any drop in egg production in turkey flocks, a causal relationship if established would lead to development of control strategies to prevent egg production drops in addition to preventing enteric problem.

Publications

No publications reported this period

Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: In cooperation with researchers at the University of Cincinnati, we screened gut contents from healthy and diseased chicken and turkey flocks for viruses. Based on sequences, several diseased flocks had not previously identified picornaviruses. Two major groups of picornaviruses were identified and both originated from turkeys and chickens. Further studies are planned to attempt in vitro/in ovo propagation of these viruses and to experimentally initiate infection in chicks and poults. Studies continue on the role of parvoviruses in enteric disease of turkeys. A preliminary study indicated the potential of these viruses in causing enteric disease. Further detailed studies are planned. PARTICIPANTS: Veterinarians, Ohio Department of Agriculture, Ohio Poultry Team TARGET AUDIENCES: Animal producers and processors PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Identifying the cause(s) of enteric disease in poultry is a first step towards understanding the disease process and development of rational control strategies.

Publications

No publications reported this period

Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: In the past, we detected by electron microscopy featureless small round viruses (15-20 nm) from diarrheic turkey poults, but we were not able to definitely identify these particles and at times they were mistakenly designed as featureless astroviruses. We developed a PCR using primers targeting the NS protein of parvoviruses and used them to test gut contents from diarrheic poults stored in our collection. Some of these samples go back to the year 2000 and they originated from flocks in Ohio, North Carolina and Pennsylvania. Of 168 samples examined, 119 reacted positively with the PCR assay. Currently, we are purifying the virus preparation to be used for experimental studies on pathogenicity of the virus. PARTICIPANTS: Veterinarians, Ohio Department of Health, Ohio Poultry Team TARGET AUDIENCES: Animal producers and processors PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
The prevalence of parvoviruses in diarrheic poults could be of economic significance. In mammalian species, parvoviruses are a major cause of systemic disease. Further studies are conducted to elucidate the role of parvoviruses in disease in turkeys.

Publications

No publications reported this period

Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: We prepared large pools of coronaviruses/infectious bronchitis virus (IBV) and turkey coronavirus (TCV) in egg embryos and antisera were prepared against these viruses in chickens, turkeys, and guinea pigs. This work was done under a contract with the National Institutes of Health and the reagents were deposited with the American Type Culture collection for national and international distribution. PARTICIPANTS: Veterinarians, Ohio Department of Agriculture, Ohio Poultry Team TARGET AUDIENCES: Animal producers and processors. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
There are no standard reagents for diagnosis or studies of IBV and TCV. The reagents produced will be the universal standards that will facilitate diagnosis and studies on IBV and TCV. They will be distributed nationally and internationally for the above purposes.

Publications

Yassine, H., Lee, C.W., and Saif, Y.M. 2008. Antigenic and genetic relatedness of H3N2 influenza viruses of turkey origin and an H3N4 duck vaccine strain. 59th North Central Avian Disease Conference. St. Paul, Minnesota.
Pillai, S.P.S., Yassine, H.M., Saif, Y.M., and Lee, C.W. 2008. Pathogenicity and antigenicity of triple reassortants H3N2 influenza viruses in poultry. 59th North Central Avian Disease Conference. St. Paul, Minnesota.
Bricker, J.M. and Y.M. Saif. 2008. Erysipelas. In (Y.M. Saif et al, eds.) Diseases of Poultry, 12th edition, Blackwell Publishing, Ames, IA, p. 909-922.
Etterdossi, N. and Y.M. Saif. 2008. Infectious Bursal Disease In (Y.M. Saif et al, eds.) Diseases of Poultry, 12th edition, Blackwell Publishing, Ames, IA, Chapter 7, p. 185-208.
Jackwood, M.W. and Y.M. Saif 2008. Bordetellosis (Turkey Coryza). In In (Y.M. Saif et al, eds.) Diseases of Poultry, 12th edition, Blackwell Publishing, Ames, IA, Subchapter 19, p.774-788.
Saif, Y. M. 2008. Introduction of Viral Enteric Infections. In (Y.M. Saif et al, eds.) Diseases of Poultry, 12th edition, Blackwell Publishing, Ames, IA, Chapter 12, p. 329-330.
Saif, Y. M. 2008. Introduction of Other Viral Infections. In (Y.M. Saif et al, eds.) Diseases of Poultry, 12th edition, Blackwell Publishing, Ames, IA, Chapter 14, p. 405.
Lee, C.W., Cha, W., Saif, Y.M., and Rajashekara, G. 2008. Development of Multiplex Branched DNA and Microsphere-based Assays for the Detection of H5 and H7 Subtype Avian Influenza Virus. ASM 108th General Meeting, Boston, Massachusetts.
Saif, Y.M., Yassine, H.M., and Lee, C.W. 2008. Further investigation on H3N2 influenza A virus isolated from turkey flocks in the USA. 7th Intl Symp. on Turkey Disease, Berlin, Germany.
Wang, L., Pillai, S.P., Saif, Y.M. and Lee, C.W. 2008. Characterization of influenza virus variants with different sizes of the non-structural genes and their potential as live influenza vaccine in poultry. American Society for Virology. 27th Annual Meeting, Ithaca, New York.
Saif, Y.M., Yassine, H.M. and Lee, C.W. 2008. Influenza in turkeys: antigenic and genetic relatedness of H3N2 viruses. National Veterinary Service Laboratory (NCSL), Ames, Iowa.
Saif, Y.M., Editor-in-Chief, J.R. Glisson, A.M. Fadly, L. Nolan, L.R. McDougald, and D.E. Swayne, Associate Editors. 2008. Diseases of Poultry. 12th edition, Blackwell Publishing, Ames, Iowa.
Saif, Y. M. 2008. Introduction of Emerging Diseases and Diseases of Complex or Unknown Etiology. In (Y.M. Saif et al, eds.) Diseases of Poultry, 12th edition, Blackwell Publishing, Ames, IA, Chapter 33, p. 1261.
Yassine, H.M., Lee, C.W., Suarez, D.L., and Saif, Y.M. Saif. 2008. Genetic and antigenic relatedness of H3 subtype influenza A viruses isolated form avian and mammalian species. Vaccine, 26:966-977. Peebles, E.D., Willeford, K.O., Keirs, R.W., Nestor, ,K.E., Saif, Y.M., Wang, C., Matyi, C.J., Anderson, J.W., Kidd, M.T., and Pulikanti, R. 2008. Use of a caprine serum fraction-immunomodulator to reduce mortality in commercial and large-bodied turkey lines infected with Pasteurella multocida. Intl. J. of Poultry Science, 7:818-824.
Wang, L., Suarez, D.L., Pantin-Jackwood, M., Mibayashi, M.,Garcia-Sastre, A., Saif, Y.M., and Lee, C.W. 2008. Characterization of Influenza Virus Variants with Different Sizes of the Non-structural (NS) Genes and Their Potential as a Live Influenza Vaccine in Poultry. Vaccine, 26:3580-3586..
Pillai, S.P.S., Pantin-Jackwood, M., Jadhao, S.J., Suarez, D.L., Wang, L., Yassine, H.M., Saif, Y.M., and Lee, C.W. 2008. Pathobiology of triple reassortant H3N2 influenza viruses in breeder turkeys and its potential implication for vaccine studies in turkeys. Vaccine, (in press).
Lee, C.W. and Saif, Y.M. 2008 Avian influenza virus. Comparative Immunology, Microbiology & Infectious Diseases, (in press). Saif, Y.M. 2008. Virus Enteritis of Poultry. Proc. 8th Scientific Conference of the Egyptian Veterinary Poultry Association, The Egyptian Intl. Ag. Ctr., Cairo, Egypt, (P107-109).
Yassine, H.M., Zhang, Y.J., Lee, C.W., Byrum, B.A., O-Quin, J., Smith, K.A., and Saif, Y.M. 2008. Genetic characterization of triple reassortant H1N1 influenza virus. 145th AVMA Annual Convention. New Orleans, Louisiana.

Progress 01/01/06 to 12/31/06

Outputs
Specific primers were designed for chicken astrovirus and turkey coronavirus. Large pools of avian coronaviruses (infectious bronchitis virus and turkey coronavirus) and antisera against both viruses were prepared in chickens, turkeys, and guinea pigs. These reagents were prepared at the request of the National Institutes of Health and deposited with the American Type Culture Collection.

Impacts
Primers for chicken astrovirus and turkey coronavirus will facilitate diagnosis of the infections. Reagents for coronavirus will facilitate diagnosis and control of the infections.

Publications

Tang, Y., Q. Wang and Y.M. Saif. Development of a ssRNA internal control template reagent for a multiplex RT-PCR to detect turkey astroviruses. J. Virol. Meth. 126:81-86, 2005.

Progress 01/01/05 to 12/31/05

Outputs
An antigen-capture enzyme-linked immunosorbent assay and an RT-PCR for detection of turkey astroviruses were developed. AssRNA internal control template for multiplex RT-PCR to detect turkey astrovirus was also developed. Astroviruses from two different serotypes were characterized molecularly.

Impacts
Development of new sensitive tests for astroviruses facilitates the diagnosis of the disease, epidemiology of the infection and a variety of other studies.

Publications

Tang, Y., C.W. Lee, Y. Zhang, D.A. Senne, R. Dearth, B. Byrum, D.R. Perez, D.O. Suarez, and Y.M. Saif. Isolation and characterization of H3N2 influenza A virus from turkeys. Avian Dis. 49:207-213, 2005.
Tang, Y., M. V. Murgia, and Y.M. Saif. Molecular characterization of the capsid gene of two serotypes of turkey astroviruses. Avian Dis. 49:514-519, 2005.
Tang, Y., M.M. Ismail and Y.M. Saif. Development of antigen-capture enzyme-linked immunosorbent assay and RT-PCR for detection of turkey astroviruses. Avian Dis. 49:182-188, 2005.

Progress 01/01/04 to 12/31/04

Outputs
The complete capsid protein regions (ORF2) of two turkey astroviruses were cloned and sequenced and the sequences were compared with 16 ORF2 sequences of astroviruses retrieved from a database. The phylogenetic tree showed TAstV 1987 was closely related genetically to TAstV-2, but TAstV 2001 was distantly related to the TastV-2.

Impacts
Understanding the pathogenesis and antigenicity, of astroviruses and the development of detection techniques will be helpful in control of the disease caused by the viruses.

Publications

Saif, Y.M. Coronavirus enteritis of turkeys: Yesterday, today and tomorrow. Proc. 5th Int. Symp. On Turkey Diseases, Berlin, Germany, pp. 30-33, 2004.

Progress 01/01/03 to 12/31/03

Outputs
The pathogenicity, antigenicity and detection of two turkey astroviruses were studied. Both viruses caused diarrhea and growth depression in SPF turkey poults. Some lesions were detected in lymphoid tissues. The two viruses were shown to belong to two different serotypes and their structural proteins were different. Polyclonal AC-ELISA was developed and it had high sensitivity than a monoclonal AC-ELISA. A multiplex and monoplex RT-PRC assays were developed and validated.

Impacts
Understanding the pathogenesis and antigenicity, of astroviruses and the development of detection techniques will be helpful in control of the disease caused by the viruses.

Publications

Saif, Y.M. Molecular Methodologies: Challenges and Opportunities. Proc. 75th Northeastern Conference on Avian Diseases (NECAD), Orono, Maine, June 12, 2003.
Saif, Y.M. Viral enteritis of poultry. Proc. XIII Congress of the World Veterinary Poultry Association, Co-sponsored by the AAAP/AVMA, Denver, CO, July 19-23, 2003.
Saif, Y.M. Infezioni virali enteriche dei tacchinotti. Proc. XLII Convegno Annuale Societa Italiana Patologia Aviare (S.I.P.A.), Forli, Italy, October 2-3, 2003, pp. 10-13.

Progress 01/01/02 to 12/31/02

Outputs
A study was designed to compare the replication potential of turkey coronavirus (TCV) and its effect in chickens and turkeys and to study the effect of single and combined infection of turkey poults with TCV and astrovirus. The pathogenicity of TCV in experimentally inoculated turkey poults and chickens was studied by observing the clinical signs and gross lesions. Two trials were conducted using 1-day-old and 4-week-old specific pathogen free turkey poults and chickens. One-day-old turkey poults developed clinical signs of enteritis at 48 hours postinoculation (PI). Poults euthanize at 3, 5, and 7 days PI had flaccid, pale and thin walled intestine with loose contents. The 4-week-old turkeys had no clinical signs or gross lesions. One-day-old and 4-week-old chickens developed no clinical signs or gross lesions although the TCV was detected in gut contents of the birds throughout the experimental period (14 days). In another experiment, mean plasma D-xylose concentrations in 3-day-old turkey poults inoculated with the TCV, turkey astrovirus, or a combination of both viruses were significantly lower than in the uninoculated controls.

Impacts
This is the first report of a BCV causing disease in turkeys and to provide information on the pathogenesis of the disease and the relatedness of the virus to avian coronaviruses. This information will be useful for control of enteric diseases in turkeys.

Publications

Saif, Y.M. and K.E. Nestor. 2002. Increased mortality in turkeys selected for increased body weight following vaccination with a live Newcastle disease virus vaccine. Avian Dis. 46:505-508.
Peebles, E.D., K.O. Willeford, K.E. Nestor, Y.M. Saif, and J.W. Anderson. 2002. Effective use of a caprine serum fraction to reduce mortality in a large-bodied turkey line infected with Pasteurella multocida. Proc. 91st Annual Poultry Science Assoc. Meeting, abstract 252, University of Delaware, Newark, Delaware August 11-14.

Progress 01/01/01 to 12/31/01

Outputs
The DB2 strain of bovine coronavirus (BCV) was shown experimentally to be infectious and to initiate clinical disease (enteritis) and lesions in the gastrointestinal tract of SPF poults but not in SPF chicks. The above results prompted us to investigate the antigenic and genomic relatedness of turkey origin coronavirus (TCV) and BCV using RT-PCR, nested RT-PCR and antigen capture ELISA. No relatedness between TCV and BCV was detected. On the other hand, the TCV were shown to be related to infectious bronchitis virus of chickens. The TCV was shown to cause disease in SPF turkey poults and the disease was aggravated when an astrovirus was combined with the TCV.

Impacts
This is the first report of a BCV causing disease in turkeys and to provide information on the pathogenesis of the disease and the relatedness of the virus to avian coronaviruses. This information will be useful for control of enteric diseases in turkeys.

Publications

Ismail, M.M., K.O Cho, L.A. Ward, L.J. Saif and Y.M. Saif: Experimental bovine coronavirus in turkey poults and young chickens. Avian Dis. 45:157-163, 2001.
Ismail, M.M., Y. Tang and Y.M. Saif. Pathogenicity of turkey coronavirus in turkeys and chickens. Proc. 52nd North Central Avian Disease Conference, p. 43, abstract, 2001.
Qureshi, M.A., Y.M. Saif, R.A. Ali, F.W. Edens, C.L. Heggen-Peay, and G.B. Havenstein. Comparison of PEMS-associated and classical astroviruses-mediated effects on performance and immune functions of turkey poults. Poultry Science, Vol. 80, supplement 1, abstract 538, 2001.

Progress 01/01/00 to 12/31/00

Outputs
A study was conducted to evaluate the virus neutralization (VN) test and ELISA for detection of antibodies to pneumovirus in turkey sera. We tested 260 sera obtained from the University of Minnesota (UM) where they were tested using an ELISA. Of 100 samples identified as positive by ELISA at UM, 99 were identified as positive by VN and ELISA in Ohio. Of 100 samples identified as negative by ELISA at UM, 5 were identified as positive by ELISA and of these 5 three were identified as suspicious by VN at Ohio. Of the 60 samples identified as suspicious at UM, 11 were ELISA positive, 9 were positive by VN and the rest were negative at Ohio. These results indicate a good agreement between the tests used.

Impacts
(N/A)

Publications

Saif, Y.M. 1999. Control y Prevencion de la Enfermedad Infecciosa de la Bursa. Proc. XVI Congreso Lationoamericano de Avicultura, pp. 37-38, abstract.

Progress 01/01/99 to 12/31/99

Outputs
The small round virus (SRV) was found to cause enteritis in turkey poults and spread from the gastrointestinal tract to lymphoid organs where its caused lymphoid depletion and organ atrophy. In vitro studies indicated that the infection results in depressed responsiveness of lymphoid cells. ELISAs were developed for detection of SRV antigen and antibodies and used for a limited field survey. The SRV was characterized physically and morphologically, and genomically. Sequence analysis indicated lack of similarity to enteroviruses and astroviruses. Bovine coronavirus induced enteric signs and lesions in turkey poults similar to those induced by turkey coronavirus but young chicks inoculated with the same virus were not affected.

Impacts
(N/A)

Publications

Yu, M., N.N. Ismail, M.A. Qureshi, R.N. Dearth, H.J. Barnes, and Y.M. Saif. Studies on the etiology of the poult enteritis and mortality syndrome and characterization of a small round virus. Proc. North Central Avian Disease Conference and Symposium on Emerging Respiratory Diseases, pp. 103-104, abstract, 1999.
Ismail, M.M., K.O. Cho, R.N. Dearth, L.J. Saif, and Y.M. Saif. Bovine coronavirus infection in chicks and turkey poults. Proc. North Central Avian Disease Conference and Symposium on Emerging Respiratory Diseases, p.100, abstract, 1999.

Progress 01/01/98 to 12/31/98

Outputs
Gut contents from poults from different turkey flocks in North Carolina affected with poult enteritis and mortality syndrome (PEMS) had coronavirus (CV), several serogroups of rotaviruses, and a small round virus (SRV). The SRV alone caused depression, significant reduction in growth rate, and enteric lesions and the virus was recovered from the GI tract. Both the SRV and a CV were adapted to turkey embryos. In 4 experiments, using the CV and SRV to challenge poults at different ages, all inoculated and contact birds developed diarrhea and GI lesions. There were also lesions of varying severity in the thymus, bursa of Fabricius, and spleen. Birds exposed to both viruses and young birds were more severely affected and young birds. Young birds had 36, 18, 10, 10% mortality in birds inoculated with a combination of the CV and SRV, SRV only, CV only and control group respectively. In other experiments, it was shown that the SRV has the potential to interfere with the immune response.

Impacts
(N/A)

Publications

No publications reported this period

Progress 01/01/97 to 12/31/97

Outputs
Major emphasis has been on the study of the Poult Enteritis and Mortality Syndrome (PEMS). The objectives are: 1)identification and characterization of infectious agents associated with the disease; 2)reproducing the disease; 3)developing diagnostic reagents and tests. A strain of E. coli from birds affected with PEMS is highly invasive in young poults and its possible contribution as a secondary infection should be considered. We examined 412 sera from 1-28 day-old turkeys experimentally inoculated with gut contents from PEM affected birds. Few birds(16) had neutralizing antibodies to serotype 1 but most of birds older than 3 wks had serotype 2 antibodies. A tissue culture adapted serotype 2 IBDV becomes pathogenic in chicken embryos after 5 passages but was not pathogenic in SPF poults. IBDV was not detected by PCR in bursas from naturally or experimentally PEMS infected birds. Gut contents and bursas from 9 flocks naturally infected with PEMS were examined using IEM and genome electropherotyping. We detected coronavirus, 3 serogroups of rotavirus, reovirus, a small round virus. None of these flocks had a single agent. Contents of the GI tract of birds affected with PEMS caused high morbidity and mortality in inoculated birds. A small round virus obtained from PEMS induced morbidity in inoculated and contact exposed poults. Polyclonal antibodies to 3 serogroups of rotaviruses, astrovirus, reovirus, coronavirus; and monoclonal antibodies to coronavirus were produced.

Impacts
(N/A)

Publications

CALNEK, B.W., BARNES, H.J., BEARD, C.W., MCDOUGLAD, L.R. and SAIF, Y.M., 1997. Diseases of poultry. Iowa State University Press, Ames,
SAIF, Y.M. 1997. Emerging diseases and diseases of complex or unknown etiology: Introduction. Diseases of poultry (B.W. Calnek, H.J. Barnes, C.W. Beard, L.R. McDougald, Y.M. Saif, Eds.) Iowa State

Progress 01/01/96 to 12/30/96

Outputs
Studies were initiated in collaboration with scientists from North Carolina State University on the role of Escherichia coli isolates from turkey poults suffering from the newly recognized disease "poult enteritis and mortality syndrome (PEMS)". Three experiments were conducted to investigate the potential invasiveness of these isolates following experimental oral inoculation into turkey poults varying in age from 1 to 21 days. The results indicated the potential pathogenicity of these strains as indicated by the presence of the organisms in the blood, liver, spleen, air sacs and the lungs of orally inoculated birds. The ability of E. coli isolates to penetrate the gut barriers in avian species was not previously recognized and could have profound implications.

Impacts
(N/A)

Publications

Progress 01/01/95 to 12/30/95

Outputs
Clostridium perfringens (CP) is the causative agent of necrotic enteritis of poultry. The disease is suspected of developing as a result of sudden changes in the gut flora leading to an increase in the population of CP. Some antibiotics are commonly included in poultry feeds to promote growth and it was of interest to investigate the effect of these antibiotics on CP. Eleven antibiotics were examined for their effect on 48 field isolates "26 from chickens and 22 from turkeys" of CP. These isolates originated from pools of gut contents from different farms. Great variations were detected in the sensitivity of these isolates to the different antibiotics tested. Studies were initiated on the pathogenesis and epidemiology of coronavirus of turkeys. Diagnostic procedures and reagents are being developed.

Impacts
(N/A)

Publications

Progress 01/01/94 to 12/30/94

Outputs
Maternal rIgG titer in the small intestine was determined after in situ ligationof the individual segments; it was highest in the duodenum, followed by the ileum and jejunum. There was evidence that rIgG in the intestine was transferred from the blood and not directly from the yolk sac. Bidirectional movement of rIgG between circulation and intestine was also detected. Maternal rIgG was not detected in the intestinal washings of progency from hens naturally infected with rotavirus.

Impacts
(N/A)

Publications

Progress 01/01/93 to 12/30/93

Outputs
Circulating maternally derived anti-rotavirus IgG (rIgG) was found to play a significant role in protection of the intestinal mucosa of turkey poults against rotavirus infection during the first week of life. The protective immunity afforded by maternal rIgG was titer-dependent. Yolk had a high titer of rIgG at hatch. Maternal rIgG titers in intestinal mucosal washings were 200 to 500 fold less than in the circulation and was negligible in 13 day old poults. Maternal rIgG was detected in tracheal washings. Bile had higher titers of rIgG which declined rapidly after hatch. The source of rIgG in the intestine was determined to be from the circulation and not directly from yolk sac.

Impacts
(N/A)

Publications

Progress 01/01/92 to 12/30/92

Outputs
Enteroviruses are frequently associated with enteric disease in turkey poults. Studies were initiated to gain knowledge on the virus and the disease. An immunoperoxidase and immunofluorescent assays were developed to detect virus antigen. The virus was detected in enterocytes of the jejunum and ileum in experimentally infected poults. Scanning electron microscopy and histologic examination indicated most of the lesions to be in that area. The villi were shortened and crypt depth was increased. An antigen capture enzyme-linked immunosorbent assay was developed for detecting the virus in gut contents. The virus was found to have a single stranded RNA genome of approximately 7.5 Kb and a buoyant density of 1.33 g/ml in CsCl. The test compared favorably with immune electron microscopy. Poults receiving a combined viral infection of rotavirus and enterovirus were more severely affected than poults receiving either inoculum alone.

Impacts
(N/A)

Publications

Progress 01/01/91 to 12/30/91

Outputs
Two objectives were pursued: 1) the role of maternally derived antibodies in protecting mucosal surfaces (gut) in turkey poults; 2) the site of transfer of these antibodies to the gut. Poults from hens immunized with rotavirus and specific pathogen free poults were used. Different segments of the small intestine (SI) were ligated and flushed twice at 6 hours intervals and the flushings were tested for anti rotavirus IgG antibodies. The results indicated that the maternal antibodies transfer to the small intestine from the blood but not directly from the yolk sac. The antibodies modulated experimental rotavirus infection.

Impacts
(N/A)

Publications

Progress 01/01/90 to 12/30/90

Outputs
In a natural outbreak of enteric disease in turkey poults, Salmonella, group D rotavirus, astrovirus, and a small (18-24 nm) round virus were detected in the gut contents. Except for the small virus, the pathogenic potential of the other agents is recognized. Four- and 5-day-old specific-pathogen-free turkey poults were inoculated orally or by contact exposure to the small round turkey-origin enteric virus. At days 4 and 8 postinoculation (PI), the orally inoculated poults had significantly lower body weight gains than control poults. Poults at day 4 (orally inoculated) and 5 contact-exposed) PI had watery droppings, dilated thin-walled ceca filled with yellow foamy fluid, catarrhal small-intestinal secretions, pale intestinal serosa, and mild lymphocytic enteritis. In addition, at day 4 PI, poults were lymphopenic, had intracytoplasmic crystalline arrays of 17.1 /+-/ 1.1-nm viral particles in the jejunal villar enterocytes, and had an 18-to-24 nm virus in intestinal contents. Analysis of morphometric data revealed mild shortening of villi in the duodenum and elongation of crypts in the duodenum and ileum during the late stage of the syndrome (day 8 PI). These findings suggest that the 18-to-24-nm virus can produce an enteric disease syndrome and that the acute clinical manifestation of this syndrome is not the result of morphologic change such as intestinal villus atrophy.

Impacts
(N/A)

Publications

Progress 01/01/89 to 12/30/89

Outputs
Studies were initiated on "field outbreaks of a disease in Ohio commercial turkey flocks" noticed for the first time. Twelve outbreaks were investigated during 1989 in flocks varying in age from 6 to 12 weeks. Clinical signs consisted of lameness, loss of condition and increased mortality. Lesions consisted of synovitis with purulent material in joints, enlargement of the liver accompanied by dark greenish discoloration, enlargement of the heart accompanied by necrotic foci in the musculature and hydropericardium. The only consistent lesion observed in all flocks examined was the synovitis. Material from the joints had no bacteria or mycoplasma which are the recognized pathogens that commonly induce synovitis in turkeys. Inoculated chicken embryos developed lesions and many inoculated embryos died. Currently we are attempting to characterize the agent from the embryos. A small (18-24 mm) round virus was detected in the gut contents of commercial turkey poults from a flock in N. Carolina. The flock had increased mortality, enteritis and a variety of nonspecific clinical signs. The virus was purified and inoculated into SPF turkey poults & found to induce disease in these poults accompanied by reduced weight gain. Attempts are underway to characterize the virus. Nine group A rotaviruses recovered from commercially reared poultry were tested for subgroup (SG) antigens by monoclonal antibody ELISA and all lacked SG1 and SG2 antigens.

Impacts
(N/A)

Publications

Progress 01/01/88 to 12/30/88

Outputs
Studies on recent isolates (variants) of infectious bursal disease virus (IBDV) have concentrated mainly on their interactions with broilers. Recently, we isolated and characterized an IBDV variant from a large Midwestern mutilage commercial layer operation. Pullets in this operation were vaccinated for IBDV at 3 weeks of age but developed bursal lesions at 6 to 7 weeks of age. In experimental studies, the vaccine used on the farm was found to be ineffective in inducing protection against the field strain, whereas, inactivated vaccines made of the variant strains "MD and E" were protective.

Impacts
(N/A)

Publications

Progress 01/01/87 to 12/30/87

Outputs
Survey for prevalence of leiomyoma and leiomyosarcoma in differing genetic strains of Coturlix quail has been initiated. Early trials attempting histologic fixation of avian tissue with microwave irradiation did not produce satisfactory results.

Impacts
(N/A)

Publications

Progress 01/01/86 to 12/30/86

Outputs
Further observations were made on the prevalence and incidence of enteric viruses in diarrheic and normal turkey poults. Seldom was only one type of virus identified. No viruses were detected in the first few days of life. The combination of astrovirus and rota-like virus was the most common in diseased flocks. Normal poults had a much lower incidence of virus.

Impacts
(N/A)

Publications

Progress 01/01/85 to 12/30/85

Outputs
Further surveys of field samples from diarrheic turkey poults indicated that astroviruses were the most common agents detected in these poults. Examination of sections of intestinal tract from turkey poults experimentally infected with astroviruses revealed no marked histologic changes. There was some evidence that the microvilli of the enterocytes may be damaged.

Impacts
(N/A)

Publications

Progress 01/01/84 to 12/30/84

Outputs
The survey initiated last year to identify enteric viruses of turkeys was continued. To date, we have examined contents from diarrheic turkeys originating from 40 flocks in nine states by electron microscopy, immune-electron microscopy and RNA analysis. A variety of viruses were detected including rota-like viruses, rotaviruses, reoviruses, astroviruses, enteroviruses and adenoviruses. The rota-like viruses were the viruses most commonly associated with diarrhea. Some viruses were detected in normal turkeys and some flocks that were sampled repeatedly never had diarrhea although a variety of viruses were detected in gut contents. Experimental infection of SPF turkey poults with rotaviruses resulted in a very mild enteritis, whereas a combination of the rota-like virus and another small virus resulted in pronounced enteritis. Observations were made on a natural outbreak of erysipelas in several lines of turkeys maintained for genetic studies. There were line differences in mortality, suggesting genetic variation in resistance to the disease.

Impacts
(N/A)

Publications

Progress 01/01/83 to 12/30/83

Outputs
A new study was initiated to identify viral agents associated with enteritis in turkey poults and to define their role in initiating the disease. Samples were received from 6 states and the following viruses were detected singly and in combination: rotavirus, rota-like virus, astrovirus, reovirus and enterovirus. Electron microscopy, immune electron microscopy, ELISA, and RNA analysis were the procedures used for identification. The rota-like virus was the only agent identified in all samples submitted. One strain of this virus was used successfully to initiate diarrhea in 2 week-old SPF poults. Studies continued on drinking water vaccination of turkeys against erysipelas. Two doses administered 2-3 weeks apart of a live serotype la Erysipelas rhusiopathiae (ER) elicited protection in 7-9 week old turkeys but one dose did not elicit protection. Studies are in progress to identify the protective antigen(s) of ER and its (their) presence in different isolates.

Impacts
(N/A)

Publications

Progress 01/01/82 to 12/30/82

Outputs
Nine field isolates of ER were obtained from turkeys experiencing clinical erysipelas in Ohio, Indiana, and Iowa. Four were identified as serotype 1a, one as serotype 1b, one as serotype 2, and three as serotype 5. A live serotype la strain, when administered via the drinking water, afforded some protection in turkeys following challenge with a virulent strain (serotype 1a). A live serotype 2 strain (used in commercial bacterin production) failed to afford protection when administered orally following the same challenge. A commercial bacterin afforded consistent protection in turkeys following challenge with the virulent serotype la strain.

Impacts
(N/A)

Publications

Progress 01/01/81 to 12/30/81

Outputs
Studies continued on Erysipelas rhusiopathiae in turkeys. Antisera were prepared in turkeys against the major serotypes detected in natural outbreaks (serotypes la, lb, 2, 5, and 6). These antisera were used to type field isolates. Six isolates from natural outbreaks of the disease belonged to 3 serotypes (5, la, and lb). Studies continued on the feasibility of Using vaccines to immunize turkeys against the disease. Results from two experiments indicated that vaccination via the drinking water failed to induce immunity in susceptible turkeys. Moderate protection was induced when one dose of the vaccine was introduced intramuscularly and complete protection was obtained with two doses (administered 3 weeks apart). Full protection was afforded by the bacterin. Studies will be performed on the effect of age at vaccination time on the response of the turkey to the oral vaccine.

Impacts
(N/A)

Publications

Progress 01/01/80 to 12/30/80

Outputs
Work continued on Erysipelas rhusiopathiae infection in turkeys. A challenge procedure for turkeys was developed which consistently resulted in 60-80% mortality of susceptible birds. The procedure involved the use of dexamethasone. Three commercial live vaccines used for swine failed to confer protection in turkeys when administered orally or subcutaneously, whereas, a commercial bacterin did induce immunity. The live oral commercial vaccine strain was detected in several tissues and was shed in the feces up to 19 days post-exposure. Studies were initiated on the prevalence of different serotypes of Erysipelas rhusiopathiae in field outbreaks and on cross-protection between different serotypes.

Impacts
(N/A)

Publications

Progress 01/01/79 to 12/30/79

Outputs
Studies were initiated on Erysipelas rhusiopathiae infection in turkeys. The goal of these studies is to develop an oral vaccination program. Currently, available commercial bacterins require individual handling of turkeys. This procedure is time-consuming and requires an extensive amount of labor. Hence, the tendency not to vaccinate or to postpone vaccination beyond the recommended intervals for vaccination. A commercially available avirulent strain that is used for oral vaccination of swine was found to colonize the GI tract of the turkey. Preliminary studies indicated that this strain might be a suitable vaccine for turkeys. Erysipelas rhusiopathiae mutants are being developed to compare their immunogenicity with the commercially available vaccine.

Impacts
(N/A)

Publications

Progress 01/01/78 to 12/30/78

Outputs
Further experiments on the passive transfer of immunoglobulins from the turkey hen to the egg indicated that IgG is the major immunoglobulin transferred to the egg and should account for the most of the passive protection afforded the newly hatched poult. The amounts of immunoglobulins A and M were considered insignificant in overall immunoglobulin transfer into eggs.

Impacts
(N/A)

Publications

Progress 01/01/77 to 12/30/77

Outputs
Studies of basic mechanisms by which turkey immunoglobulins (Ig) are passively transferred from hen to egg were continued. IPGy1 labeled IgM had a half-life average of 2.67 days with fractional turnover of 25.52% of the plasma pool per day IgM associated radioactivity in eggs was insignificant in overall Ig transfer into eggs. IPGy1 labeled IgA (biliary) had a half-life average of 1.8 days with fractiona turnover 38.6% of plasma pool per day. IgA associated radioactivity in eggs was considered insignificant as was IgM. The elimination of injected IPGy1 labeled IgG (comparable to maternal IgG) in newly hatched poults was as follows: 30.53%, 10.31%, and 3.48% of the labeled IgG at 7, 14 and 21 days after hatching. Indirect immunofluorescence procedures were used to study the ontogeny of immunoglobulin surface receptors. The first organ to acquire Ig surface determinants was the bursa of Fabricius. IgM-bearing lymphocytes first appeared in the bursa of turkey embryos at 24 days. IgG appeared 3 days post-hatch. By the time IgG-bearing lymphocytes appeared, IgM-bearing lymphocytes had seeded out to the periphery of the bursal parenchyma. The disease produced by Mycoplasma gallisepticum in poults was more severe in birds maintained at 30% and 85% relative humidity than poults maintained at 60% relative humidity.

Impacts
(N/A)

Publications

Progress 01/01/76 to 12/30/76

Outputs
Studies were initiated to determine basic mechanisms by which immunoglobulin G is passively transferred from turkey hens into eggs. The half-life of IPGy1 labeled IgG was calculated to be 5.91 plus or minus 0.81 days and time of maximal passage of radioactivity from hen into eggs was 6.5 plus or minus 1.3 days. The following IgG determinations were made: plasma level (8.54 plus or minus 1.2 mg/ml), total plasma pool (0.557 plus or minus .08 gm/kg), total turnover rate (.067 plus or minus 0.02 g/kg/day or 11.92 plus or minus 1.83 percent of plasma pool/day). Passage of IgG into egg yolks was at a constant rate over an observation period of 46 days as determined by 2 methods. IgG was detectable in egg whites but at a low level. The biological significance of eggwhite IgG is questionable. Quantitative data on IgG levels in the total plasma volume of growing poults indicated a decline in IgG levels during the first 7 days of life (maternal IgG). Synthesis starts 7 days after hatching. This was indicated by an increase in mean total plasma IgG level from 18.63 mg on day 7 to 29.59 mg by day 11. Techniques have been developed for fluorescent labeling of turkey lymphocytes. These procedures will be used to study the ontogeny of immunoglobulin-bearing cells in the turkey embryo and the newly hatched poult. Preliminary trials indicated that high humidity had a beneficial effect on turkey poults exposed to Mycoplasma gallisepticum.

Impacts
(N/A)

Publications

Progress 01/01/75 to 12/30/75

Outputs
Live 24-hr brain-heart-infusion broth cultures of Pasteurella aerogenes were used in an attempt to immunize Corturnix quail to infection with Missouri strain9481 of Pasteurella multocida. 160 g. to 180 g. quail were injected intravenously and intramuscularly with 0.5 ml P. aerogenes 24-hr BHI culture at 4 wks and 6 wks of age. P. aerogenes culture was administered to one group in drinking water at the level of 200 ml culture per 3785 ml (1 gal) of water twiceat a 2-week interval. A week following the last exposure to P. aerogenes, inoculated and control groups of quail were placed in isolators and challenged with P. multocida in the drinking water at a level of 100 ml 24-hr BHI culture per 946.2 ml (1 qt). Mortality rate per group of 20 quail was as follows: IM vaccinated 100%, water vaccinated 90%, IV vaccinated 85%, unvaccinated controls 90%. Mortality occurred over a 4-5 day period following challenge. There was no evidence of inceased resistance or decreased mortality in P. aerogenes vaccinated quail subsequent to challenge with P. multocida.

Impacts
(N/A)

Publications

Progress 01/01/74 to 12/30/74

Outputs
Ketamine HCl anesthetic was found to be a satisfactory chemical restraint for minor surgical procedures, bacteriologic sampling and examination of Coturnix quail. Dose rate from 5 mg to 10 mg per 100 gms of body weight by intramuscularinjection produced satisfactory restraint for a duration of 20 to 60 minutes in 130 to 170 gm quail. Xylazine HCl anesthetic was tested in quail and found unsatisfactory as the margin between anesthetic level and toxic dosage was extremely narrow. 2-phenoxyethanol was tested for in vitro inhibition of Candida albicans and found ineffective. Chlorhexidine (biquanide) disinfectant was tested for in vitro inhibition of C. albicans and found effective in a rangeof 30ppm to 480ppm dilution. Gentamicin sulfate was tested for enhancement of C. albicans infection in day-old turkey poults. No significant difference in morbidity or mortality was noted between groups of poults treated with gentamicin and untreated control groups exposed to infective levels of C. albicans. Attempts to transmit Marble Spleen Disease by injection of tissue homogenates of liver and spleens from infected pheasants into Coturnix quail were unsuccessful.

Impacts
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Publications

Progress 01/01/73 to 12/30/73

Outputs
Aeronomas hydrophila isolated from naturally infected turkey poults does not cause significant problems alone. Experimental infection combining A. hydrophila and Salmonella infantis resulted in high morbidity and mortality thatneither organism alone produced. In another experiment, the organisms singly orin combination failed to produce disease in poults. No signs of toxicity were observed in 136 g. to 195 g. Coturnix quail injected IV with graduated doses (1 mcg. to 1 mg.) of E. coli endotoxin. No pathologic alterations were observed intissues from endotoxin-injected quail killed 6 days following inoculation. Prophylactic effects of gential violet (GV), sodium propionate (NaP), and formicacid (FA), singly and in combination, in drinking water and feed, in quail exposed to Candida albicans were continued. Levels tested were determined by the minimum amount necessary to completely inhibit C. albicans growth in Sabouraud's broth media. The levels are expressed as grams per 3.785 kilograms of drinking water or feed-water mixture: GV 0.11 g., FA 3.78 g. and NaP 18.9 g. None of the compounds tested, singly or in combination, even at double the described levels had any prophylactic effect on experimentally infected quail. Copper inhibited the growth of C. albicans in broth media when used at 3% displacement, v/v. A 6-inch length of 3/4 in. copper pipe in drinking containers filled with C. albicans-inoculated water did not decrease the morbidity in exposed quail but did significantly reduce mortality.

Impacts
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Publications

Progress 01/01/72 to 12/30/72

Outputs
Tests of prophylactic effects of gentian violet for experimental moniliasis in quail exposed to Candida albicans in the feed are in progress. Gentian violet in the drinking water was administered in dilutions of 1:100,000, 1:50,000 and 1:10,000 during a 21-day period of exposure to inoculated feed. Tests are not complete but results indicate that the incidence and severity of lesions were not significantly reduced by the administration of gentian violet. Drinking water dilutions of 1:10,000 were toxic as all quail in the test groups were deadwithin 2 weeks. Attempts to transmit ulcerative enteritis (Quail disease) to chickens and turkeys were not successful. A study of the effect of Escherichia coli endotoxin on the pathogenicity of Staphylococcus aureus for quail is being continued. Observations on incidence of crooked-neck syndrome in turkeys and quail are being continued. Studies were conducted on the treatment of turkey hatching eggs to eliminate Salmonella infection. Thirty-three strains of Salmonella belonging to 25 serotypes were introduced singly and in combination into groups of turkey eggs using a pressure differential procedure. Two days after infection half the number of eggs was dipped in a solution containing 1000ppm of the antibiotic gentamicin sulfate using a temperature differential procedure. After one week of incubation the eggs were examined and an infectionrate of approximately 80% was detected in the infected nontreated eggs, whereas the infection was eliminated from the treated eggs.

Impacts
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Publications

Progress 01/01/71 to 12/30/71

Outputs
Prophylactic effects of nystatin (N), ethylene-diamine dihydriodide (ED), Benlate (trademark) (B), sodium propionate (SP), and gential violet (GV) were evaluated on experimental moniliasis in Jananese quail. Three- to 5-day-old quail were concurrently exposed to drinking water inoculated with Candida albicans and fed rations containing the test compounds for periods of 21 to 22 days. 1116 quail were used in 18 test and 6 control groups. ED and B were not effective in reducing incidence or decreasing the severity of lesions. The percentage of incidence and severity of lesions were significantly reduced in quail receiving combined SP and GV. N was more effective in the reduction of incidence and severity of lesions in exposed quail than any of the chemo-therapeutic compounds tested. A study of the prevalence of Histoplasma capsulatum in 100 samples of poultry manure from OARDC farms and selected Ohio producers was completed. Histoplasma was isolated from 4 locations on OARDC farms and from 7 commercial farms. The public health hazard of Histoplasmosis should be considered in planning disposal systems for poultry manure. Genetic studies of crooked-neck in turkeys and quail are being continued. Studies have been initiated on Blue-comb infection of turkeys. A hemagglutinating (HA) activity was detected in cecal filtrates from turkeys with Blue-comb symptoms and lesions but not in a few normal turkeys examined. Studies were initiated tofind the significance of this HA activity.

Impacts
(N/A)

Publications

Progress 01/01/70 to 12/30/70

Outputs
The effect of parenteral B(12), folic acid, and vitamin K on sulfaquinoxaline-induced lesions of aplastic anemia in chickens was determined. The above vitamins injected individually or in combinations had no effect on theoccurrence of aplastic anemia, clinical signs, gross pathologic lesions and mortality in chickens. A study of the effect of "Sevin" (1-naphthyl N-methylcarbamate) insecticide on chickens and pheasants was completed. Neithergross nor histopathologic lesions were found in any of the experimental birds sprayed with 1 ounce of half, double, or recommended concentrations of "Sevin". Genetic studies of crooked-neck syndrome in turkey poults are still in progress.Studies of experimental aspergillosis in chickens and candidiasis in quail and the effects of drugs on the infections have been initiated. A pressure differential procedure was developed and used successfully to infect hatching turkey eggs with Arizona organisms. Eggs naturally or experimentally infected with Arizona were dipped in antibiotic solutions using a temperature differential procedure in an attempt to eliminate the infection. Spectinomycin and lincomycin had little value in controlling the infection. Gentamicin was found effective in eliminating the infection from the eggs and had no detrimental effect on hatchability, early growth or mortality of poults.

Impacts
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Publications

Progress 01/01/69 to 12/30/69

Outputs
Studies of whole blood levels of ascorbic acid in chickens with various forms ofleukosis complex were completed and data are in process of evaluation. A study was initiated on the pathology of traumatic gastroenteritis in turkey poults caused by ingestion of pine shavings litter. Pine fragments were embedded in the proventriculus, gizzard and duodenum, with lacerations and hemorrhages accompanied by melenic masses in the intestinal lumen of 2- to 3-week-old poults. Excessively high light intensity, 500 to 750 ft. candles, was suggestedas an initiating factor causing litter eating by the poults. A study of the effect of supplemental ascorbic acid, iron, copper and B(1)(2) on packed cell volume, whole blood ascorbic acid levels and hemorrhagic manifestations of sulfaquinoxaline-induced hemorrahgic syndrome in chickens was completed. The supplement did not significantly alter the mortality, packed cell volume, and whole blood ascorbic acid levels of the experimental birds. The hemorrhagic manifestations were significantly less in one group receiving the supplement butthe phenomenon could not be entirely attributed to the use of ascorbic acid.

Impacts
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Publications

Progress 01/01/68 to 12/30/68

Outputs
Studies of combined Staphylococcus aureus and Eimeria sp. infections conducted in chickens. Infection with Eimeria sp. did not enhance pathogenicity of S. aureus when administered orally in chickens. Observations on possible synergismbetween Infectious Laryngotracheitis Virus and Hemophilus gallinarum infections in chickens were made. Experimental infections with both agents resulted in a more severe disease than when either was used alone. Pathologic and microbiologic studies of crooked-neck in turkeys were conducted in a commercial flock. The principal lesion observed was an osteodystrophy of cervical vertebrae. A genetic defect was suggested as the cause of the syndrome. Streptobacillus moniliformis was isolated from turkeys with a naturally occurring infectious purulent synovitis. Rat-bite wounds were observed in affected birds and isolation of S. moniliformis from rats in cohabitation suggests a source of infection. Turkey poults experimentally infected by parenteral injection with virulent organisms. Inoculations of lambs and pigs did not produce infection. Histopathologic studies and concurrent cultural procedure indicated that isolation of etiologic agent was necessary for differential diagnosis. Studies of ascorbic acid levels in whole blood of chickens with aplastic-anemia and forms of the leukosis complex initiated.

Impacts
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Publications

Progress 01/01/67 to 12/30/67

Outputs
Pilot experiments investigating the pathogenic mechanisms of avian Staphylococcosis were initiated. Experimental infections have not duplicated the natural occurring syndrome nor illucidated the mechanism of transmission as observed in field outbreaks. The effects of hypersensitivity, mechanical and chemical trauma, and Eimeria sp. infection were investigated as possible contributors to the pathogenesis of Staphylococcus aureus infection in broilers.Hypersensitivity did not appear to contribute to the pathogenicity of S. aureus.Mechanical or chemical trauma may be a significant factor. Studies of combined S. aureus and Eimeria sp. are still in progress.

Impacts
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Publications