Detection of Shiga Toxin-producing Escherichia coli in Ground Beef: Evaluation of Contamination Levels in Butcheries of The Metropolitan Zone in Asuncion, Paraguay

MARTINEZ, A; PADOLA NL; ROJAS N; RODRIGUEZ, F; ACUÑA,P; GUILLEN, RM

Journal of Pure and Applied Microbiology

JPAM

Lugar: Bhopal; Año: 2019 vol. 13

0973-7510

Shiga toxin-producing Escherichia coli (STEC) can cause from watery diarrhea to severe diseases, suchas thrombocytopenic purpura (TP) or hemolytic uremic syndrome (HUS). Ruminants are the mainreservoir; most of the time humans are infected through the ingestion of contaminated meat. Thegoal of this study was the detection of stx1 and stx2 genes through the standardization of a real timePCR method that uses SYBR green, and then we used this method to analyze the presence of STEC inground beef from butcheries of the metropolitan zone of Asuncion, Paraguay. We analyzed 48 groundbeef samples from 24 butcheries. They were processed by standard methods of culture and DNAextraction. Real-time PCR reactions were standardized for the detection of stx1 and stx2. Both geneswere detected in the 48 samples studied. The concordance between this method and a conventionalPCR technique was excellent, showing kappa concordance indexes of 0.76 for stx1 and 0.87 for stx2.Even though the high levels of contaminated ground beef detected, all the isolates were LEE negativesand O157 negatives, which are less related to outbreaks and severe diseases. The most commonvirulence profile was stx1/stx2/saa/exhA. With this finding, we have proven the need for preventiveprocedures in the slaughter process and the handling process of meat products.