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

Mf Cerutti,Ks Zenato,C Pissetti,M Cardoso,Go Werlang,Tr Vieira

doi:10.1590/1806-9061-2019-1093

Mf Cerutti, Ks Zenato + Show 4 more

Open Access

https://doi.org/10.1590/1806-9061-2019-1093

Copy DOI

Abstract

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.

Highlights

According to estimates of the World Health Organization, almost one in ten people falls ill and 420,000 die every year from eating contaminated food (WHO, 2015)
Since there are still few studies in Brazil investigating STEC in meat products and, to the best of our knowledge, no report on Atypical Enteropathogenic (aEPEC) in chicken meat, the aim of this study was to assess the presence of STEC and aEPEC in frozen chicken carcasses sold in food stores
Among the 246 chicken samples evaluated for E. coli enumeration, no typical colonies were detected in 26.83%

Summary

Introduction

According to estimates of the World Health Organization, almost one in ten people falls ill and 420,000 die every year from eating contaminated food (WHO, 2015). Among the pathogens involved in foodborne disease, Shiga toxin-producing Escherichia coli (STEC)was responsible for more than 1 million illnesses, resulting in more than 100 deaths (WHO, 2015). Regarding STEC, the severity of the disease in humans contributes to its relevance, and infections have been associated with clinical illness ranging from mild non bloody diarrhea to hemolytic uremic syndrome, which often includes acute kidney failure. STEC comprises a large, highly diverse group of strains, which have the production of Shiga toxin (Stx) encoded by the genes stx or stx in common. Pathogenesis includes common steps, including entry into the human gut, attachment to the intestinal epithelial cells usually via an intimin protein encoded by the eae gene, and the production of toxin. Stx and the ability to adhere to intestinal epithelial cells are regarded as major STEC virulence traits (FAO/WHO, 2018)

Objectives

Methods

Results

Conclusion