Progress 11/20/13 to 09/22/15
Outputs
Target Audience: Farmers Veterinarians Food Scientists Other Scientists Changes/Problems:Though the original goal of this study was to use Salmonella as the model pathogen, we were unable to isolate Salmonella from a test sample >100 goats. This may have been because the isolation protocols were not sensitive enough or the target goats were shedding Salmonella below the detection limit for the isolation protocols. This was consistent with our anticipated pitfall of the original proposal. Given my long-term research goal to understand the factors leading to bacterial contamination of both lamb and goat meat, and to identify on-farm and post-harvest management strategies for reducing microbiological food safety hazards in small ruminant food systems in the United States, I changed the model pathogen to E.coli with the objective of identifying and characterizing both E. coli O157 and non-O157 E. coli shed by in a new host (sheep) brought to auctions. I chose sheep because data on the source of foodborne pathogen contamination and exposure risk levels of lamb to bacterial contamination at United States processing or retail facilities are limited. Consequently, the modified approach involves testing fecal samples for E. coli O157 and Non-O157 in 500 sheep. The goal of this study was to quantify the prevalence and to identify virulence genes common to Shiga toxin-producing E. coli (STEC) in sheep sold at a livestock sale barn in Missouri. Five hundred anal-rectal fecal swabs from sheep originating from 63 unique flocks delivered to a sale barn auction were collected and tested using standard microbiological and molecular techniques for STEC detection. Samples were collected from range of 1 and 24 sheep per flock over a nine-week period between September and November 2014. Approximately 18% (88/500) of the samples tested were positive for at least one STEC based on presence of an STEC O-side chain, the detection of at least one-stx and eae genes. E. coli O157:H7 was not detected in any of the samples tested suggesting a majority of STEC shed by the sheep in the sale barn during our sampling period belonged to the non- O157 serogroups (16.4%). E. coli O145 (6.8%) and O26 (6.2%) were the most prevalent serotypes in the samples tested. Four percent (20/500) of the samples tested had multiple STEC serotypes. Further studies are needed to facilitate the development of effective improvements in food safety strategies in the small ruminant industry. What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest? A publication is under preparation for submission to an appropriate peer-reviewed journal Conference Papers and Presentations Status: Other Year Published: 2015 Citation: Ravichandran N, Pithua P (sponsor), and Jacob M. "Prevalence of shiga-toxigenic Escherichia coli (STEC) serotypes in pre-harvest sheep in Missouri". Proceedings and Abstracts, the 38th Annual Phi Zeta Research Day. Abstract #62, p35. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Salmonella was absent from a test sample >100 goats either because the isolation protocols were not sensitive enough or the target population where shedding Salmonella at levels below the detection limit for the isolation protocols. However, when we extended the study to include Shiga toxin producing E. coli (STEC), we found strong evidence of bacterial fecal shedding and carcass contamination at small ruminant slaughter plants with E. coli O157 and other non-O157 STEC. In goats slaughtered at a Missouri plant, non-O157 STEC serotypes was detected in approximately 0% of hides, 1.85% (i.e., E. coli O111) of pre-evisceration carcasses and 1.45% (i.e., E. coli O103) of the fecal samples tested [Pithua, unpublished data]. These data support the conclusion that goat meat may serve as an important vehicle for human exposure to STEC and other foodborne pathogens in the United States; however, there may be a regional difference in prevalence estimates. There are no published studies on the prevalence of Salmonella prevalence in US meat goats. Preliminary data from this project has also been used to seek additional funding support from USDA-NIFA to identify and characterize potential foodborne pathogens in small ruminants entering different regions of the US food supply and to test the efficacy of a commercial siderophore receptor and porin protein vaccine for lowering the fecal shedding of Salmonella and E. coli O157:H7 in goats [Pithua P (PI) "Food safety and defense in small ruminant food systems."USDA-NIFA. Status Not Funded].
Publications
|
Progress 10/01/14 to 09/22/15
Outputs
Target Audience:
Nothing Reported
Changes/Problems:Though the original goal of this study was to use Salmonella as the model pathogen, we were unable to isolate Salmonella from a test sample >100 goats. This may have been because the isolation protocols were not sensitive enough or the target goats were shedding Salmonella below the detection limit for the isolation protocols. This was consistent with our anticipated pitfall of the original proposal. Given my long-term research goal to understand the factors leading to bacterial contamination of both lamb and goat meat, and to identify on-farm and post-harvest management strategies for reducing microbiological food safety hazards in small ruminant food systems in the United States, I changed the model pathogen to E.coli with the objective of identifying and characterizing both E. coli O157 and non-O157 E. coli shed by in a new host (sheep) brought to auctions. I chose sheep because data on the source of foodborne pathogen contamination and exposure risk levels of lamb to bacterial contamination at United States processing or retail facilities are limited. Consequently, the modified approach involves testing fecal samples for E. coli O157 and Non-O157 in 500 sheep. Five hundred anal-rectal fecal swabs from sheep originating from 63 unique flocks delivered to an sale barn auction were collected and tested using standard microbiological and molecular techniques. Samples were collected from range of 1 and 24 sheep per flock over a nine-week period between September and November, 2014. Approximately 18% (88/500) of the samples tested were positive for at least one STEC based on presence of an STEC O-side chain, the detection of at least one-stx and eae genes. E. coli O157:H7 was not detected in any of the samples tested suggesting a majority of STEC shed by the sheep at the sale barn during our sampling period belonged to the non-O157 serogroups (16.4%). E. coli O145 (6.8%) and O26 (6.2%) were the most prevalent serotypes in the samples tested. Four percent (20/500) of the samples tested had multiple STEC serotypes. What opportunities for training and professional development has the project provided?One graduate student [ MPH -Veterinary Public Health) is currently undergoing hands on research training under this project involving data collection, collation, analyses, microbiological methods, literature search and scientific writing as part of this project. 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?
Nothing Reported
Impacts
What was accomplished under these goals?
Salmonella was absent from a test sample >100 goats either because the isolation protocols were not sensitive enough or the target population where shedding Salmonella at levels below the detection limit for the isolation protocols. However, when we extended the study to include Shiga toxin producing E. coli (STEC), we found strong evidence of bacterial fecal shedding and carcass contamination at small ruminant slaughter plants with E. coli O157 and other non-O157 STEC. In goats slaughtered at a Missouri plant, non-O157 STEC serotypes was detected in approximately 0% of hides, 1.85% (i.e., E. coli O111) of pre-evisceration carcasses and 1.45% (i.e., E. coli O103) of the fecal samples tested [Pithua, unpublished data]. These data support the conclusion that goat meat may serve as an important vehicle for human exposure to STEC and other foodborne pathogens in the United States; however, there may be a regional difference in prevalence estimates. There are no published studies on the prevalence of Salmonella prevalence in US meat goats. Preliminary data from this project has also been used to seek additional funding support from USDA-NIFA to identify and characterize potential foodborne pathogens in small ruminants entering different regions of the US food supply and to test the efficacy of a commercial siderophore receptor and porin protein vaccine for lowering the fecal shedding of Salmonella and E. coli O157:H7 in goats [Pithua P (PI) "Food safety and defense in small ruminant food systems."USDA-NIFA. Status pending].
Publications
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2015
Citation:
Ravichandran N, Pithua P (sponsor), and Jacob M. "Prevalence of shiga-toxigenic Escherichia coli (STEC) serotypes in pre-harvest sheep in Missouri". Proceedings and Abstracts, the 38th Annual Phi Zeta Research Day. Abstract #62, p35.
- Type:
Journal Articles
Status:
Submitted
Year Published:
2015
Citation:
Ravichandran N, Jacob M, and Pithua P "Prevalence of E. coli O157 and non-O157 in sheep auctioned at a full service stockyard in mid-Missouri, USA" Food Control.
- Type:
Theses/Dissertations
Status:
Accepted
Year Published:
2015
Citation:
PREVALENCE OF SHIGA-TOXIGENIC ESCHERICHIA COLI (STEC) IN PRE-HARVEST SHEEP IN MISSOURI presented by Nivedita Ravichandran,
a candidate for the degree of Master of Public Health
|
Progress 11/20/13 to 09/30/14
Outputs
Target Audience:
Nothing Reported
Changes/Problems: Though the original goal of this study was to use Salmonella as the model pathogen, we were unable to isolate Salmonella from a test sample >100 goats. This may have been because the isolation protocols were not sensitive enough or the target goats were shedding Salmonella below the detection limit for the isolation protocols. This was consistent with our anticipated pitfall of the original proposal. Given my long-term research goal to understand the factors leading to bacterial contamination of both lamb and goat meat, and to identify on-farm and post-harvest management strategies for reducing microbiological food safety hazards in small ruminant food systems in the United States, I changed the model pathogen to E.coli with the objective of identifying and characterizing both E. coli O157 and non-O157 E. coli shed by in a new host (sheep) brought to auctions. I chose sheep because data on the source of foodborne pathogen contamination and exposure risk levels of lamb to bacterial contamination at United States processing or retail facilities are limited. Consequently, the modified approach involves testing fecal samples for E. coli O157 and Non-O157 in 500 sheep. To date, 241 sheep have been sampled and are undergoing laboratory analyses. Sampling for the remaining half are expected to be completed by November 2014. What opportunities for training and professional development has the project provided? One graduate student [ MPH -Veterinary Public Health) is currently undergoing hands on research training under this project involving data collection, collation, analyses, microbiological methods, literature search and scientific writing as part of this project. 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?
Nothing Reported
Impacts
What was accomplished under these goals?
Salmonella was absent from a test sample >100 goats either because the isolation protocols were not sensitive enough or the target population where shedding Salmonella at levels below the detection limit for the isolation protocols. However, when we extended the study to include Shiga toxin producing E. coli (STEC), we found strong evidence of bacterial fecal shedding and carcass contamination at small ruminant slaughter plants with E. coli O157 and other non-O157 STEC. In goats slaughtered at a Missouri plant, non-O157 STEC serotypes was detected in approximately 0% of hides, 1.85% (i.e., E. coli O111) of pre-evisceration carcasses and 1.45% (i.e., E. coli O103) of the fecal samples tested [Pithua, unpublished data]. These data support the conclusion that goat meat may serve as an important vehicle for human exposure to STEC and other foodborne pathogens in the United States; however, there may be a regional difference in prevalence estimates. There are no published studies on the prevalence of Salmonella prevalence in US meat goats. Preliminary data from this project has also been used to seek additional funding support from USDA-NIFA to identify and characterize potential foodborne pathogens in small ruminants entering different regions of the US food supply and to test the efficacy of a commercial siderophore receptor and porin protein vaccine for lowering the fecal shedding of Salmonella and E. coli O157:H7 in goats [Pithua P (PI) "Food safety and defense in small ruminant food systems."USDA-NIFA. Status pending].
Publications
|
|