Prevalence of OXA-Type β-Lactamase Genes among Carbapenem-Resistant Acinetobacter baumannii Clinical Isolates in Thailand.

Krit Thirapanmethee,Mullika Chomnawang,Preecha Montakantikul,Thayapa Srisiri-a-nun,Piyatip Khuntayaporn,Jantana Houngsaitong

doi:10.3390/antibiotics9120864

Krit Thirapanmethee, Mullika Chomnawang + Show 4 more

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https://doi.org/10.3390/antibiotics9120864

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Journal: Antibiotics	Publication Date: Dec 3, 2020
Citations: 22	License type: CC BY 4.0

Affiliation: Mahidol University

Abstract

Carbapenem-resistant Acinetobacter baumannii (CRAB) is a critical health concern for the treatment of infectious diseases. The aim of this study was to investigate the molecular epidemiology of CRAB emphasizing the presence of oxacillinase (OXA)-type β-lactamase-encoding genes, one of the most important carbapenem resistance mechanisms. In this study, a total of 183 non-repetitive CRAB isolates collected from 11 tertiary care hospitals across Thailand were investigated. As a result, the blaoxa-51-like gene, an intrinsic enzyme marker, was detected in all clinical isolates. The blaoxa-23-like gene was presented in the majority of isolates (68.31%). In contrast, the prevalence rates of blaoxa-40/24-like and blaoxa-58-like gene occurrences in CRAB isolates were only 4.92% and 1.09%, respectively. All isolates were resistant to carbapenems, with 100% resistance to imipenem, followed by meropenem (98.91%) and doripenem (94.54%). Most isolates showed high resistance rates to ciprofloxacin (97.81%), ceftazidime (96.72%), gentamicin (91.26%), and amikacin (80.87%). Interestingly, colistin was found to be a potential drug of choice due to the high susceptibility of the tested isolates to this antimicrobial (87.98%). Most CRAB isolates in Thailand were of ST2 lineage, but some belonged to ST25, ST98, ST129, ST164, ST215, ST338, and ST745. Further studies to monitor the spread of carbapenem-resistant OXA-type β-lactamase genes from A. baumannii in hospital settings are warranted.

Highlights

Acinetobacter baumannii is a Gram-negative coccobacillus that has the ability to acquire antibiotic resistance and to persist in hospital environments [1]
A total of 183 carbapenem-resistant A. baumannii (CRAB) isolates were collected from 11 tertiary care hospitals across Thailand during
The effect of the OXA β-lactamases in conferring carbapenem resistance has demonstrated a significant clinical impact on the ability to treat nosocomial infections

Summary

Introduction

Acinetobacter baumannii is a Gram-negative coccobacillus that has the ability to acquire antibiotic resistance and to persist in hospital environments [1]. This organism is considered an opportunistic pathogen responsible for nosocomial infections, especially in intensive care units [2]. A. baumannii is one of the ESKAPE pathogens, along with Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Enterobacter spp., which are responsible for the majority of nosocomial infections and are capable of “escaping” the bactericidal activity of antimicrobial agents [4,5]. A. baumannii can develop resistance to many classes of commonly used antimicrobial agents [6,7]. The emergence of carbapenem-resistant A. baumannii (CRAB), multidrug-resistant (MDR)

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