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Full-Text Articles in Life Sciences

Development And Validation Of High-Resolution Melting Assays For The Detection Of Potentially Virulent Strains Of Escherichia Coli O103 And O121, Frank J. Velez, Joseph M. Bosilevac, Sabine Delannoy, Patrick Fach, Ravinder Nagpal, Prashant Singh May 2022

Development And Validation Of High-Resolution Melting Assays For The Detection Of Potentially Virulent Strains Of Escherichia Coli O103 And O121, Frank J. Velez, Joseph M. Bosilevac, Sabine Delannoy, Patrick Fach, Ravinder Nagpal, Prashant Singh

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Virulent strains of Shiga toxin-producing Escherichia coli (STEC) serogroups O103 and O121 are considered adulterants in beef. Two high-resolution melting (HRM) real-time PCR assays were standardized for the specific detection and discrimination of potentially virulent and avirulent strains of E. coli O103 and O121. The O103 HRM assay offered the possibility to distinguish clearly STEC O103:H2 from STEC O103:H25. The two standardized assays were extensively validated using 215 pure culture strains, laboratory inoculated food samples, and naturally contaminated beef (n = 84) and pork (n = 84) enrichments collected from the red meat surveillance program. Both HRM assays showed 100% …


Validation Of High-Resolution Melting Assays For The Detection Of Virulent Strains Of Escherichia Coli O26 And O111 In Beef And Pork Enrichment Broths, Frank J. Velez, Joseph M. Bosilevac, Prashant Singh Oct 2021

Validation Of High-Resolution Melting Assays For The Detection Of Virulent Strains Of Escherichia Coli O26 And O111 In Beef And Pork Enrichment Broths, Frank J. Velez, Joseph M. Bosilevac, Prashant Singh

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Extensive validation of diagnostic assays using widely collected surveillance samples is critical for developing pathogen detection assays. The detection of potentially virulent E. coli strains is critical to the red meat industry. We previously developed two high-resolution melting (HRM) assays for detecting potentially virulent and avirulent E. coli O26 and O111 strains. Assays were validated using enriched beef (n = 36) and pork (n = 36) samples collected as part of a U.S. federal regulatory surveillance program. Data from this study showed more than 90% sensitivity and specificity for both the HRM assays, demonstrating suitability for the red meat industry …


Effects Of Poor Sanitation Procedures On Cross-Contamination Of Animal Species In Ground Meat Products, Sunjung Chung, Rosalee S. Hellberg Oct 2019

Effects Of Poor Sanitation Procedures On Cross-Contamination Of Animal Species In Ground Meat Products, Sunjung Chung, Rosalee S. Hellberg

Food Science Faculty Articles and Research

The presence of <1% of an undeclared species in ground meat is generally thought to be indicative of cross-contamination as opposed to intentional mislabeling; however, this has not been experimentally tested. The objective of this study was to quantify the effects of poor sanitation on the cross-contamination of animal species in ground meat products, with the example of undeclared pork in ground beef. Cross-contamination was quantified using real-time polymerase chain reaction (PCR). Three different sanitation treatments were tested with a commercial grinder (“no cleaning”, “partial cleaning”, or “complete cleaning”) in between grinding of pork and beef samples (13.6 kg each). A 100-g sample was collected for each 0.91 kg (2 lb) of beef processed with the grinder and each sanitation treatment was tested twice. For the “no cleaning” treatment, the first 100-g sample of ground beef run through the grinder contained 24.42 ± 10.41% pork, while subsequent samples (n = 14) contained <0.2% pork. With “partial cleaning,” the first sample of ground beef contained 4.60 ± 0.3% pork and subsequent samples contained <0.2% pork. Pork was not detected in ground beef following “complete cleaning.” These results indicate that incomplete cleaning of grinding equipment leads to species cross-contamination at levels of <1% in most cases. Proper sanitation procedures must be followed when grinding multiple species in order to prevent cross-contamination and product mislabeling.