Escherichia coli in Chicken Carcasses in Southern Brazil: Absence of Shigatoxigenic (STEC) and Isolation of Atypical Enteropathogenic (aEPEC)

Abstract

The aim of this study was to investigate the presence of shiga toxin-producing Escherichia coli (STEC) and atypical enteropathogenic Escherichia coli (aEPEC) in frozen chicken carcasses sold at stores in southern Brazil. Typical E. coli colonies were enumerated in 246 chicken carcasses, and the presence of stx1, stx2, eae genes was investigated in their rinse liquid and in E. coli strains isolated from those carcasses.Strains of E. coli were also investigated for the presence of bfp gene. A median of 0.6 cfu.g -1 (ranging from <0.1 to 242.7 cfu.g -1 ) of typical E. coli colonies was found in the carcasses. Shiga toxin-encoding genes (stx1 and stx2) were not detected, indicating that the chicken carcasses were negative for STEC. The intimin protein gene (eae) was detected in E.coli isolated from 4.88% of the carcasses; all tested strains were negative for the bfp gene and were classified as aEPEC. Twenty-two aEPEC strains were tested for resistance to ten antimicrobials and subjected to macrorestriction (PFGE). All the tested aEPEC strains were fully susceptible to cephalosporins, ciprofloxacin and colistin. Resistance to sulfonamide (65%), ampicillin (55%), tetracycline (50%) and gentamicin (45%) were the most frequent. The PFGE profile demonstrated a low level of similarity among the resistant strains, indicating that they were epidemiologically unrelated. The results indicate that aEPEC strains can contaminate chicken meat, and their association with strains implicated in human diarrhea needs to be further investigated.

An overview of genetically modified foods: agreement, challenges and assessment of safety

“…Although ruminants, and particularly cattle, are regarded as the main reservoir for STEC (18, 19), there is evidence for non-ruminants, particularly poultry being significant spill-over hosts for STEC. These are animals that are susceptible to colonization by STEC but do not maintain such colonization in the absence of continuous exposure (17,(20)(21)(22).…”

Molecular Detection and Prevalence of Non-O157 Shiga Toxigenic Escherichia Coli in Selected Chicken Abattoirs and Retail Outlets in Osogbo, Osun State Nigeria

“…Although ruminants, and particularly cattle, are regarded as the main reservoir for STEC [18,19], there is evidence for non-ruminants, particularly poultry being signi cant spill-over hosts for STEC. These are animals that are susceptible to colonization by STEC but do not maintain such colonization in the absence of continuous exposure [17,20,21,22].…”