Diversity of Plasmids and Genes Encoding Resistance to Extended Spectrum Cephalosporins in Commensal Escherichia coli From Dutch Livestock in 2007-2017.

Daniela Ceccarelli,Dik J Mevius,Cindy Dierikx,Ben Wit,Arie Kant,Joost Hordijk,Alieda Van Essen-Zandbergen,Kees T Veldman

doi:10.3389/fmicb.2019.00076

Abstract

Extended-spectrum β-lactamase (ESBL) and plasmid-mediated AmpC β-lactamase (pAmpC) genes confer resistance to extended spectrum cephalosporin’s. The spread of these genes is mostly facilitated by plasmid-mediated horizontal transfer. National surveillance activities to detect ESBL/pAmpC-producers in commensal bacteria from livestock are in place in the Netherlands since several years. This study aimed at reporting gene and plasmid diversity of commensal ESBL/pAmpC-producing Escherichia coli isolated from healthy animals during surveillance activities between 2007 and 2017. A collection of 2304 extended-spectrum cephalosporin-resistant (ESC-R) E. coli isolated from feces of broilers, dairy cattle, slaughter pigs, turkeys, ducks, and veal calves was investigated and ESBL/pAmpC genes were determined. Gene location of a selection of 473 E. coli isolates was determined and typing of plasmids linked to the ESBL/pAmpC genes was performed. Twenty-two different ESBL/pAmpC genes were identified with blaCTX-M-1 being the most prevalent gene in livestock (43.7%), followed by blaCMY -2 and blaSHV -12, independent of the animal source. Prevalence of typically human associated blaCTX-M-15 was highest in cattle. Less than 10% E. coli isolates owed their ESC-R phenotype to promoter mutations of the chromosomal ampC gene. Majority (92%) of ESBL/pAmpC genes analyzed were plasmid located, with IncI1α being the most represented plasmid family in isolates from all animals, followed by IncF (veal calves, dairy cattle and slaughter pigs), IncK (broilers and laying hens), IncX1 in broilers, and emerging IncX3 in broilers and dairy cattle. Prevalence and molecular diversity of ESC-R E. coli isolated from livestock over an 11-year period revealed a composite scenario of gene-plasmid combinations.

Highlights

Extended-spectrum β-lactamases (ESBLs) and plasmid-mediatedAmpC β-lactamases are able to hydrolyse a large variety of β-lactam antibiotics, including cephalosporins and monobactams
National surveillance activities to detect ESBL/pAmpC-producers in commensal bacteria from livestock are in place in the Netherlands since several years
E. coli isolated from feces of broilers, dairy cattle, slaughter pigs, turkeys, ducks, and veal calves was investigated and ESBL/pAmpC genes were determined

Summary

Introduction

Extended-spectrum β-lactamases (ESBLs) and plasmid-mediatedAmpC β-lactamases (pAmpCs) are able to hydrolyse a large variety of β-lactam antibiotics, including cephalosporins and monobactams. The successful spread of ESBL/pAmpC genes is mostly due to their localization on plasmids, resulting in easy transmission between bacteria (Rozwandowicz et al, 2018). Enterobacteriaceae have emerged globally in livestock animals during the last decades (Carattoli, 2008), with the consequent concern of animals being a putative source of ESBL/pAmpC-producing bacteria for humans either by direct contact or consumption of contaminated food products, as reviewed by (Ewers et al, 2012). The impact of transmission from livestock and the food chain on infections in humans is still debated (Madec et al, 2017; Dorado-Garcia et al, 2018), the ESBL/pAmpC reservoir in commensal bacteria from livestock has been increasingly investigated for its potential risk to public health (Michael et al, 2015)

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