Detection of the Phenicol-Oxazolidinone Resistance Gene poxtA in Enterococcus faecium and Enterococcus faecalis from Food-Producing Animals during 2008-2018 in Korea.

Seok-Hyeon Na,Soon-Seek Yoon,Suk-Kyung Lim,Abraham-Fikru Mechesso,Hee-Young Kang,Su-Jeong Kim,Dong-Chan Moon,Mi-Hyun Kim,Ji-Hyun Choi

doi:10.3390/microorganisms8111839

Seok-Hyeon Na, Soon-Seek Yoon + Show 7 more

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https://doi.org/10.3390/microorganisms8111839

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Journal: Microorganisms	Publication Date: Nov 23, 2020
Citations: 19	License type: CC BY 4.0

Affiliation: Animal and Plant Quarantine Agency

Abstract

We aimed to investigate the presence of the phenicol–oxazolidinone resistance gene poxtA in linezolid-resistant enterococci from food-producing animals and analyze its molecular characteristics. We collected 3941 Enterococcus faecium and 5088 E. faecalis isolates from all provinces of South Korea from 2008 to 2018. We found linezolid resistance in 0.79% (94/3941) of E. faecium and 1.22% (62/5088) of E. faecalis isolates. Overall, 23.1% (36/156) of the linezolid-resistant isolates had the poxtA gene, including 31 E. faecium and five E. faecalis isolates. The poxtA-positive enterococci were mainly isolated from chicken (86.1%; 26/36). Fifteen poxtA-harboring isolates co-carried another linezolid-resistance gene, optrA. Eight E. faecium isolates had an N130K mutation in the ribosomal protein L4, while no mutations were observed in E. faecalis isolates. The poxtA gene was transferred into 10 enterococci by conjugation. Multi-locus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) analysis indicated that poxtA-carrying isolates were heterogeneous. Three E. faecium isolates belonged to CC17 (ST32, ST121, and ST491). To our knowledge, this is the first report on the poxtA gene in Korea. Prudent use of antimicrobials and active surveillance on antimicrobial resistance are urgently needed to reduce the risk of dissemination of the linezolid-resistant isolates in humans and animals.

Highlights

Oxazolidinones, including linezolid and tedizolid, have been used for the treatment of severe bacterial infections caused by clinically important Gram-positive pathogens, such as vancomycinresistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) [1]
The poxtA gene was detected in 33.0% (31/94) of E. faecium and 8.1% (5/62) of E. faecalis
We detected the phenicol–oxazolidinone resistance gene poxtA in linezolid-resistant enterococci isolated from food-producing animals

Summary

Introduction

Oxazolidinones, including linezolid and tedizolid, have been used for the treatment of severe bacterial infections caused by clinically important Gram-positive pathogens, such as vancomycinresistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) [1]. Linezolid is known to interfere with the peptidyltransferase site of the bacterial ribosome. This leads to a disruption of protein synthesis and inhibition of bacterial growth [4]. Since the first discovery of the poxtA gene in Staphylococcus aureus by a basic local alignment search tool (BLAST) search of GenBank [6], it has been detected in enterococcal isolates from humans and animals in many countries, including China [8,9,10], Italy [11], Tunisia [12], and Pakistan [13]

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