Source: UNIV OF MINNESOTA submitted to NRP
ASSESSING AND MANAGING THE OUTCOMES ASSOCIATED WITH ANTIMICROBIAL TREATMENT OF CLOSTRIDIAL DERMATITIS IN TURKEY PRODUCTION
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
ACTIVE
Funding Source
Reporting Frequency
Annual
Accession No.
1029852
Grant No.
2023-68015-39283
Cumulative Award Amt.
$999,990.00
Proposal No.
2022-08926
Multistate No.
(N/A)
Project Start Date
Jun 1, 2023
Project End Date
May 31, 2026
Grant Year
2023
Program Code
[A1366]- Mitigating Antimicrobial Resistance Across the Food Chain
Recipient Organization
UNIV OF MINNESOTA
(N/A)
ST PAUL,MN 55108
Performing Department
(N/A)
Non Technical Summary
Clostridial dermatitis (CD) in turkeys remains one of the most important diseases in turkey production. This bacterial disease requires the majority of antibiotic use in turkey production. Unfortunately, effective CD prevention measures are imperfect and difficult to implement, and thus the U.S. turkey industry is challenged to reduce the antibiotic therapy this disease requires. To help the U.S. turkey industry reduce the need for antibiotics, we must find ways of reducing the incidence of Clostridial dermatitis. However, we will never eliminate this disease entirely, and therefore we must also help veterinarians ensure they are practicing good antibiotic stewardship when treatment is needed.We believe that the only way we will see major improvements in antibiotic stewardship and consequent reductions in antibiotic resistance associated with turkey will be through a highly integrated collaboration with the U.S. turkey industry. This project was designed in collaboration with veterinarians at many of the largest turkey companies in the U.S. The companies that will participate in this project produce more than 75% of turkey annually in the U.S.One of the outcomes of this project is to develop dynamic web-based dashboard tools that will enable industry collaborators to evaluate options for reducing the incidence of Clostridial dermatitis. The tools will show the user outcomes such as expected reductions in antibiotic resistance associated with each intervention option as well as the costs associated with each of these strategies. Tools such as these will help ensure the long-term sustainability of U.S. turkey production because the end-users of these tools will be able to identify effective interventions that have an effect on multiple outcomes of concern while also maximizing the return on investment of these strategiesThe best way to reduce the use of antibiotics is to reduce the need for antibiotics. As stated previously, the best way to reduce the need for antibiotics in U.S. turkey production is to decrease the incidence of clinical CD. This project is highly collaborative with veterinarians and other professionals within the U.S. turkey industry and should greatly improve our understanding of the key disease that necessitates the majority of antibiotic use in turkey production.
Animal Health Component
65%
Research Effort Categories
Basic
25%
Applied
65%
Developmental
10%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
3113230117040%
3113230110030%
3114010107020%
7234010117010%
Goals / Objectives
Clostridial dermatitis (CD) in turkeys is caused by Clostridium septicum and C. perfringens and remains one of the most important diseases in turkey production. The majority of antimicrobial use in turkey production is directed towards CD. Penicillin and lincomycin are the two medically important, water-soluble antimicrobials most commonly used for the treatment and control of CD. Unfortunately, prevention measures are imperfect and difficult to implement; thus the U.S. turkey industry is challenged to reduce the antimicrobial therapy this disease requires.Given these challenges, the long-term goals of this project are not only to help the U.S. turkey industry reduce the need for antimicrobials through reductions in the incidence of Clostridial dermatitis, but when antimicrobials are needed, to help veterinarians ensure they are practicing good antimicrobial stewardship and are using antimicrobials responsibly. The supporting objectives are to:1) Analyze genomes of Clostridium spp. isolates collected from commercial turkey production systems and identify defining genomic traits linked to CD, including virulence factors, antimicrobial resistance genes and other phylogenetic/genomic traits;2) Examine the short- and long-term effects of antimicrobial use for the treatment and control of clinical CD on commercial turkey production systems and their microbiota;3) Deliver intervention options for managing CD in turkey production through a diversity of extension and outreach activities, including the development of software tools to aid stakeholders in comparing CD management options.
Project Methods
In Objective 1 we will conduct a cross-sectional observational study across many turkey companies and farms to examine the genetic diversity of Clostridium in the U.S. turkey industry and the possible link of specific strains or genomic traits within Clostridium to clinical Clostridial dermatitis (CD). We will also quantify the amount of Clostridium in the litter at the time of sampling. Isolates of Clostridium will be cultured using standard methods and then sequenced using Illumina MiSeq. Microbiomes of the turkey litter will be assessed using MiSeq 2x300 bp and various analyses. The bacterial load of Clostridium septicum and perfringens in the turkey litter will be quantified with qPCR assays. Genome-wide association studies (GWAS) will be used to identify differential genetic content between defined groups of isolates. Comparisons of interesting will include 1) between CD-associated and non-CD-associated isolates, 2) between isolates collected at various timepoints throughout CD treatment (Obj 2), and 3) between isolates of different phylogenetic clades.In Objective 2 we will conduct a longitudinal observational study across farms and companies that are affected with clinical CD. Farms will be sampled prior to the initiation of antimicrobial therapy, during therapy, and then at various time points after the conclusion of therapy. In Objective 2a, we will investigate how antimicrobial treatment affects the quantity of different resistance genes and microbial composition (microbiome) of the litter. Resistance genes will be quantified using a customized microfluidic qPCR that we have developed. The microbiome will be analyzed similarly to Objective 1. In Objective 2b, we will examine how antimicrobial treatment affects the Clostridium population within the barn and whether specific traits within the Clostridium population are predictive of treatment success. Further, we will quantify the load of Clostridium in the litter of the sampled barns to determine if treatment success is linked to load. The laboratory methods will be the same as in Objective 1. Finally, we will compare the Clostridium isolates from the litter with those from lesions in the same flock to determine the specific bacterial traits that are associated with clinical illness.In Objective 3 we will deliver intervention options for managing CD in turkey production through a diversity of extension and outreach activities. First, we will develop half-day symposia and hour-long webinars that target two different audiences: poultry scientists/veterinarians and poultry producers/managers. Information relevant to veterinarians, nutritionists, and scientists will be presented at the annual meeting of the American Association of Avian Pathologists (AAAP). Training workshops and modules for poultry managers will be presented at meetings of the U.S. Poultry and Egg Association, for example at the International Production and Processing Expo (IPPE), a key meeting for the poultry industry. Second, we will develop multi-criteria decision analysis (MCDA) models to enable end users to compare a variety of disease management options, weigh these options by the importance of different criteria, and then visualize the estimated outcomes of each of these management decisions. The MCDA models will be developed in Logical Decisions software. We will develop a user-friendly, web-based interactive dashboard to quantitatively evaluate a wide array of management interventions for CD; this dashboard will be built using the open-source Shiny package within R. Specifically, we envision the dashboard having two sections. In one section, the user will be able to use the MCDA model to evaluate different management options after weighting the importance of different criteria. In the second section of the dashboard, the user will be able to visualize the predicted, quantified outputs of the chosen disease management strategy.

Progress 06/01/23 to 05/31/24

Outputs
Target Audience:This project focused on one main target audienceduring this reporting period: veterinarians working with the turkey industry. We were forced to delay the start of this project due to disease issues, which will be discussed later. However, we maintained regular contact with the collaborating turkey veterinarians in this project to understand the challenges they continue to face with clostridial dermatitis and any possible solutions they have tried. Changes/Problems:We had a major challenge that delayed the start of this project. First, avian influenza virus was spreading throughout the U.S. poultry industry, especially turkeys. For this reason, access to farms was restricted. Then an outbreak of avian metapneumovirus in turkeys also started. These viruses are both still circulating. We decided to delay the start of the project because if any of our enrolled flocks were to break with either virus, the entire flock would be depopulated and the major investment of enrolling the flock would be lost. The turkey veterinarian collaborators were supportive of this delay. However, both viruses continue to circulate but we cannot wait any longer to start the study. The collaborating veterinarians have agreed that this fall would be a good time to get the project started with a full implementation by spring 2025. What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals?In the next reporting period, we will begin the field work in collaboration with the participating companies.For Objective 1, we will sequence the genomes of the isolates we are receiving from other labs around the country, but we will also begin sequencing the isolates we recover from the field studies of this project. As we conduct the field studies of Objective 2, we will be identifying the effects of antimicrobial use on the bacterial populations in the turkey barn. Finally, we will begin our extension activities. We intend to present an update of the work conducted in Year 1 at the Annual Meeting of the American Association of Avian Pathologists.

Impacts
What was accomplished under these goals? We had to delay the start of this project due to two different turkey diseases, as will be discussed in the Changes/Problems section of this Progress Report. We started the laboratory component of this project, as described below. PCR Assays We have used previously reported primers from the literature to develop a conventional PCR assay that allows us to speciateClostridium perfringensand Clostridium septicumisolates. The primers in our assay are species specific, and we have verified that they do not cross react with other species, including other organisms commonly found in poultry (i.e., Campylobacter, E. coli, Salmonellaand Enterococcus). In addition, we have worked on a quantitative PCR assay that will be used to quantify the total load of C. perfringensand C. septicumin litter samples. Unfortunately, many previously published primer sets for C. perfringensor C. septicumshow cross reactivity with each other. We have been able to identify a primer set that is specific to C. septicumand we demonstrated that these primersdo not cross react with C. perfringens or other organisms commonly found in poultry mentioned above. We are in the final steps of confirming the primers we have for C. perfringensare specific in a full qPCR assay. Isolates Received In collaboration with Megan Lighty at the Penn State Animal Diagnostic Lab we have received 31Clostridium isolates for sequencing from 29 distinct cases. Of the 31 isolates, 26 are Clostridium perfringensand five are Clostridium septicum.Fourteen cases were inchicken, 12 in turkey, and three cases with isolates were in other poultry species. These isolates will be sequenced to add to the database of Clostridium genomes in poultry.

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