Carriage of ESBL/AmpC-producing or ciprofloxacin non-susceptible Escherichia coli and Klebsiella spp. in healthy people in Norway.

Sophie Berg,Ulf R. Dahle,Charlotte R. Ulstad,Morten Lindbæk,Margrete Solheim,Astrid L. Wester

doi:10.1186/s13756-016-0156-x

Abstract

BackgroundAsymptomatic carriage has been recognised as an important risk factor for infection caused by antibiotic resistant bacteria. A 14% global prevalence of Extended-Spectrum Beta-lactamase (ESBL) carriage was recently reported, but large intra-and interregional variations were observed. We investigated the faecal carriage rates of ESBL-, AmpC-producing and ciprofloxacin non-susceptible Escherichia coli and Klebsiella spp. in healthy Norwegians.MethodsRectal samples were obtained from 284 volunteers, together with demographic data and information on recent travel history. The rectal samples were screened by selective plating and E. coli and Klebsiella spp. identified using MALDI-TOF. Phenotypic and molecular characterization of resistant isolates was also performed.ResultsESBL- or AmpC-producing E. coli and Klebsiella spp. were isolated from 4.9% and 3.2% of the study population, respectively. Carriage of ciprofloxacin non-susceptible isolates was detected in 9.9% of the volunteers. Molecular typing of ESBL/plasmid-mediated AmpC (pAmpC)-producing isolates suggested an allodemic situation rather than the dissemination of a specific clone in the Norwegian community. In concurrence with previous findings, travel to South-East Asia was associated with increased risk of carrying resistant E. coli or Klebsiella spp., highlighting the contribution of factors such as increased global mobility in erasing the boundaries between healthcare and community settings when it comes to spread of resistant bacteria.ConclusionsOverall, our study recognised Norway as a low-incidence country for faecal carriage of resistant bacteria among healthy individuals. Furthermore, our work denoted the importance of healthy humans as a reservoir for transmission of antibiotic resistant E. coli and Klebsiella spp.Electronic supplementary materialThe online version of this article (doi:10.1186/s13756-016-0156-x) contains supplementary material, which is available to authorized users.

Highlights

Asymptomatic carriage has been recognised as an important risk factor for infection caused by antibiotic resistant bacteria
From 284 volunteers, we found that 4.9% were colonised with Extended-Spectrum Beta-lactamase (ESBL)- and 3.2% with AmpC-producing E. coli or Klebsiella spp
We found that all ESBL/plasmid-mediated AmpC (pAmpC)-producing and > 50% of the ciprofloxacin non-susceptible isolates, including all ciprofloxacin non-susceptible Klebsiella isolates were multi-drug resistant (MDR)

Summary

Introduction

Asymptomatic carriage has been recognised as an important risk factor for infection caused by antibiotic resistant bacteria. A 14% global prevalence of Extended-Spectrum Beta-lactamase (ESBL) carriage was recently reported, but large intra-and interregional variations were observed. We investigated the faecal carriage rates of ESBL-, AmpC-producing and ciprofloxacin non-susceptible Escherichia coli and Klebsiella spp. in healthy Norwegians. The emergence of extended-spectrum betalactamases (ESBL and plasmid-mediated AmpC; pAmpC) and different mechanisms of ciprofloxacin resistance have rendered such infections notoriously challenging to treat and cure [4, 5]. Faecal carriage of ESBL probably represents the most important reservoir for infections with ESBL-producing Enterobacteriaceae [6, 7]. Differences in the prevalence of gut colonization with ESBL-producing bacteria are observed both between and within regions, and the rates of colonization with ESBL-producing bacteria are generally increasing [8, 9].

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