Genomic Characterization of Clinical Extensively Drug-Resistant Acinetobacter pittii Isolates.

Peechanika Chopjitt,Rujirat Hatrongjit,Shigeyuki Hamada,Yukihiro Akeda,Anusak Kerdsin,Kazunori Tomono,Parichart Boueroy,Ratchadaporn Ungcharoen,Nuntiput Putthanachote

doi:10.3390/microorganisms9020242

Abstract

Carbapenem-resistant Acinetobacter pittii (CRAP) is a causative agent of nosocomial infections. This study aimed to characterize clinical isolates of CRAP from a tertiary hospital in Northeast Thailand. Six isolates were confirmed as extensively drug-resistant Acinetobacter pittii (XDRAP). The blaNDM-1 gene was detected in three isolates, whereas blaIMP-14 and blaIMP-1 were detected in the others. Multilocus sequence typing with the Pasteur scheme revealed ST220 in two isolates, ST744 in two isolates, and ST63 and ST396 for the remaining two isolates, respectively. Genomic characterization revealed that six XDRAP genes contained antimicrobial resistance genes: ST63 (A436) and ST396 (A1) contained 10 antimicrobial resistance genes, ST220 (A984 and A864) and ST744 (A56 and A273) contained 9 and 8 antimicrobial resistance genes, respectively. The single nucleotide polymorphism (SNP) phylogenetic tree revealed that the isolates A984 and A864 were closely related to A. pittii YB-45 (ST220) from China, while A436 was related to A. pittii WCHAP100020, also from China. A273 and A56 isolates (ST744) were clustered together; these isolates were closely related to strains 2014S07-126, AP43, and WCHAP005069, which were isolated from Taiwan and China. Strict implementation of infection control based upon the framework of epidemiological analyses is essential to prevent outbreaks and contain the spread of the pathogen. Continued surveillance and close monitoring with molecular epidemiological tools are needed.

Highlights

Acinetobacter calcoaceticus-baumannii complex (ACB complex) includes A. baumannii, A. calcoaceticus, A. pittii, A. nosocomialis, A. seifertii, and A. dijkshoorniae [1,2,3]
Of the total 832 carbapenem-resistant carbapenemresistant ACB (CRACB) isolates used in this study, 826 were identified as A. baumannii (99.3%), and 6 (0.7%) were identified as
All the A. pittii isolates in this study were resistant to carbapenem and showed presence of blaNDM-1, blaIMP-1, and blaIMP-14 genes, as well as oxacillinase genes like blaOXA-10, blaOXA-58, and blaOXA-23

Summary

Introduction

Acinetobacter calcoaceticus-baumannii complex (ACB complex) includes A. baumannii, A. calcoaceticus, A. pittii, A. nosocomialis, A. seifertii, and A. dijkshoorniae [1,2,3]. They are the primary bacteria causing nosocomial infection [1,2,3]. A. baumannii is known as the most clinically relevant and common nosocomial infection worldwide. Carbapenem-resistant A. pittii (CRAP) has been extensively reported and disseminated worldwide [4,5]. It is associated with human infection and intestinal carriage and is recognized as a significant cause of nosocomial infection in various countries,

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