📱 eBook en inglés ARCHIVES OF CLINICAL MICROBIOLOGY: PCR ANALYSIS OF MUTTON AND CHICKEN SAMPLES FOR THE PRESENCE OF SHIGA TOXIGENIC E. COLI

Shigatoxigenic Escherichia coli strains are major food-borne pathogens that are trans- mitted through contaminated meat and meat products. Apart from cattle, sheep and goat are important natural reservoirs. Faecal contamination during slaughter and fur- ther processing along with poor hygienic practices accounts for the presence of STEC in raw meat. A total of 200 samples (50 each of mutton and chicken and 50 samples each of mutton and chicken swabs) collected from various sources were subjected to PCR analysis for the presence of Shigatoxigenic E. coli using primers specifc to STEC virulent genes, shiga toxin (stx1 and stx2) and enterohaemolysin (hlyA) with amplif- cation size of 614bp, 779bp and 361bp respectively. Out of 200 samples, 58 showed presence of STEC (20 mutton, 24 mutton swabs, 7 chicken and 7 chicken swabs out of 50 samples each). Of the 58 STEC positive samples, 42 (72.4%) showed presence of stx1, 16 (27.5%) showed stx2, 21 (36.2%) showed hlyA gene and 8 (13.7%) showed both stx1 and stx2. Among 58 STEC positive isolates, 8.6% (1 mutton, 2 mutton swab and 2 chicken swabs) isolates were possessing all the 3 virulent genes. The sensitivity of PCR method for STEC was 1.7cfu. Enrichment with mTSB broth containing novo- biocin gave good results compared to mEC broth with novobiocin. It is advisable to use more rapid, sensitive and specifc PCR method to detect virulent STEC from diferent food sources.