Prevalence of ESβL, AmpC and Colistin-Resistant E. coli in Meat: A Comparison between Pork and Wild Boar.

Martina Rega,Alice Vismarra,Ilaria Carmosino,Viviana Frascolla,Cristina Bacci,Paolo Bonilauri

doi:10.3390/microorganisms9020214

Abstract

A global increase in Escherichia coli (E. coli) resistant to cephalosporins (extended-spectrum β-lactamases (ESβLs) and AmpC β-lactamases) has been recorded in the last 20 years. Similarly, several studies have reported the spread of colistin resistance in Enterobacteriaceae isolated from food and the environment. The aim of the present study was to evaluate the prevalence of ESβL, AmpC and colistin-resistant E. coli isolated from pork and wild boar meat products in the Emilia Romagna region (North Italy). The isolates were analysed phenotypically (considering both resistant and intermediate profiles) and genotypically. The prevalence of genotypically confirmed ESβL and AmpC E. coli was higher in pork meat products (ESβL = 11.1% vs. AmpC = 0.3%) compared to wild boar meat (ESβL = 6.5% vs. AmpC = 0%). Intermediate profiles for cefotaxime (CTX) and ceftazidime (CAZ) were genotypically confirmed as ESβL in pork meat isolates but not for wild boar. Four E. coli from wild boar meat were resistant to colistin but did not harbour the mcr-1 gene. E. coli isolated from wild boar meat seem to show aspecific antimicrobial resistance mechanisms for cephalosporins and colistin. The prevalence of resistant isolates found in wild boar is less alarming than in pork from farmed domestic pigs. However, the potential risk to consumers of these meat products will require further investigations.

Highlights

Antimicrobials are necessary agents to fight diseases in humans, animals, plants and crops
The aim of the present study was to define the prevalence of extended-spectrum β-lactamases (ESβLs), AmpC and colistinresistant E. coli in pork and wild boar meat products in order to define their potential transmission along the food chain and to evaluate any difference in resistance profile eventually present when considering their origin
The phenotypic results showed that 7 E. coli pork meat isolates out of 314 (2.2%; CI 95% = 0.6–3.9) were ESβL, 3 (0.9%; CI 95% = 0–1.9) were AmpC and 5 (1.6%; CI 95% = 0.2–3.0)

Summary

Introduction

Antimicrobials are necessary agents to fight diseases in humans, animals, plants and crops. Their use is complicated by the development of antimicrobial resistance (AMR) [1]. Since 2008, the World Organization for Animal Health (Oie) has published guidelines with the aim to encourage prudent use of antimicrobials [5]. It is estimated that resistance to second and third generations of cephalosporins will double by 2030 [3]. Human infections caused by cephalosporin-resistant Escherichia coli (E. coli), for example, are increasing, and a significant risk factor is represented by the use of these drugs in farming [3]. E. coli become resistant to cephalosporins due to their ability to produce β-lactamases, enzymes that hydrolyse the β-lactam ring and deactivate the molecule [6]

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