Prevalence and characteristics of Shiga-toxin producing Escherichia coli (STEC) isolated from beef slaughterhouse

Md Parvej,Jayedul Hassan,Md Mahmud,Md Rahman,K Nazir,Montasir Mamun,Marzia Rahman

doi:10.5455/javar.2018.e271

Abstract

Objective: Shiga-toxin producing Escherichia coli (STEC) is the most important foodborne bacterial pathogen worldwide and the bovine animals are assumed as a reservoir of this pathogen. The present study was conducted to assess the role of bovine animals as the source of STEC. Materials and methods: To assess the role of bovine animals as the source of STEC, we examined 100 samples (50 rectal swab and 50 beef samples) collected from the local beef slaughterhouses by cultural, morphological, biochemical tests and polymerase chain reaction. Finally, the drug resistance pattern of isolated organisms has been examined. Result: In the preliminary screening by polymerase chain reaction (PCR), E. coli was more prevalent in rectal swab (n=21/50) than beef samples (n=16/50). Among 39 isolated E. coli, 10 isolates were confirmed as STEC (Rectal swab=7, Beef=3) by PCR, where stx2 gene (n=7/10) was predominant than stx1 gene (n=3/10). Remaining 29 isolates did not react to stx primers in PCR. Presence of STEC in beef samples was significantly associated with the fecal contamination at P≤0.1 (0.074818) in PearsonÂ’s correlation coefficient method. In addition, most of the isolated STEC strains were resistant to one or more commonly used antimicrobials in the country. Conclusion: The bovine animals and its products could be an important source of multidrug-resistant STEC in the country.

Highlights

Escherichia coli is considered as the normal inhabitant of the gut microflora in mammals, in the exhausted or immunosuppressed host, nonpathogenic strains of E. coli can cause serious illness including diarrhea (Duriez et al, 2001; Hilbert et al, 2008)
Shigatoxin producing Escherichia coli is worldwide reported Diarrheagenic E. coli (DEC) pathotype and is the causal agent of hemorrhagic colitis with some severe sequelae including hemolytic uremic syndrome, which is due to the effect of Shigatoxin produced by the organism that acts on kidney, intestine and other parenchymatous organs (Gyles, 2007)
The organism does not produce any clinical illness in their natural reservoir but it produces a broad spectrum of clinical abnormalities in humans including mild diarrhea, hemorrhagic colitis, hemolytic uremic syndrome, bloody diarrhea and thrombotic thrombocytopenic purpura (Fey et al, 2000)

Summary

Introduction

Escherichia coli is considered as the normal inhabitant of the gut microflora in mammals, in the exhausted or immunosuppressed host, nonpathogenic strains of E. coli can cause serious illness including diarrhea (Duriez et al, 2001; Hilbert et al, 2008). Diarrheagenic E. coli (DEC) is the leading cause of foodborne diarrhea in developed as well as developing countries and this pathogen is an important etiology of morbidity and mortality worldwide (Mohammed et al, 2002). Shigatoxin producing Escherichia coli is worldwide reported DEC pathotype and is the causal agent of hemorrhagic colitis with some severe sequelae including hemolytic uremic syndrome, which is due to the effect of Shigatoxin produced by the organism that acts on kidney, intestine and other parenchymatous organs (Gyles, 2007). The organism does not produce any clinical illness in their natural reservoir but it produces a broad spectrum of clinical abnormalities in humans including mild diarrhea, hemorrhagic colitis, hemolytic uremic syndrome, bloody diarrhea and thrombotic thrombocytopenic purpura (Fey et al, 2000)

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Discussion

Conclusion