The prevalence, antibiotic resistance and mecA characterization of coagulase negative staphylococci recovered from non-healthcare settings in London, UK

Zhen Xu,Ronald R Cutler,Yuting Liu,Hermine V Mkrtchyan,Jiazhen Chen,Raju Misra,Wenhong Zhang,Haroun N Shah

doi:10.1186/s13756-018-0367-4

Abstract

BackgroundCoagulase negative staphylococci (CoNS) are important reservoirs of antibiotic resistance genes and associated mobile genetic elements and are believed to contribute to the emergence of successful methicillin resistant Staphylococcus aureus (MRSA) clones. Although, these bacteria have been linked to various ecological niches, little is known about the dissemination and genetic diversity of antibiotic resistant CoNS in general public settings.MethodsFour hundred seventy-nine samples were collected from different non-healthcare/general public settings in various locations (n = 355) and from the hands of volunteers (n = 124) in London UK between April 2013 and Nov 2014.ResultsSix hundred forty-three staphylococcal isolates belonging to 19 staphylococcal species were identified. Five hundred seventy-two (94%) isolates were resistant to at least one antibiotic, and only 34 isolates were fully susceptible. Sixty-eight (11%) mecA positive staphylococcal isolates were determined in this study. SCCmec types were fully determined for forty-six isolates. Thirteen staphylococci (19%) carried SCCmec V, followed by 8 isolates carrying SCCmec type I (2%), 5 SCCmec type IV (7%), 4 SCCmec type II (6%), 1 SCCmec type III (2%), 1 SCCmec type VI (2%), and 1 SCCmec type VIII (2%). In addition, three isolates harboured a new SCCmec type 1A, which carried combination of class A mec complex and ccr type 1.MLST typing revealed that all S. epidermidis strains possess new MLST types and were assigned the following new sequence types: ST599, ST600, ST600, ST600, ST601, ST602, ST602, ST603, ST604, ST605, ST606, ST607 and ST608.ConclusionsThe prevalence of antibiotic resistant staphylococci in general public settings demonstrates that antibiotics in the natural environments contribute to the selection of antibiotic resistant microorganisms. The finding of various SCCmec types in non-healthcare associated environments indicates the complexity of SCCmec. We also report on new MLST types that were assigned for all S. epidermidis isolates, which demonstrates the genetic variability of these isolates.

Highlights

Coagulase negative staphylococci (CoNS) are important reservoirs of antibiotic resistance genes and associated mobile genetic elements and are believed to contribute to the emergence of successful methicillin resistant Staphylococcus aureus (MRSA) clones
The prevalence of antibiotic resistant staphylococci in general public settings demonstrates that antibiotics in the natural environments contribute to the selection of antibiotic resistant microorganisms
We report on new Multi-locus sequence typing (MLST) types that were assigned for all S. epidermidis isolates, which demonstrates the genetic variability of these isolates

Summary

Introduction

Coagulase negative staphylococci (CoNS) are important reservoirs of antibiotic resistance genes and associated mobile genetic elements and are believed to contribute to the emergence of successful methicillin resistant Staphylococcus aureus (MRSA) clones. These bacteria have been linked to various ecological niches, little is known about the dissemination and genetic diversity of antibiotic resistant CoNS in general public settings. That the high virulence of S. aureus has been evidenced in many studies [2], it is believed that coagulase-negative staphylococci (CoNS) act as an important reservoir of antimicrobial resistance genes and resistance-associated mobile genetic elements, which can transfer between staphylococcal species.

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Conclusion