"Roar" of blaNDM-1 and "silence" of blaOXA-58 co-exist in Acinetobacter pittii.

Shuru Zhou,Xuemin Guo,Guoxiong Zhang,Xin Chen,Jie Wang,Xiaobin Meng,Dongsheng Zhou

doi:10.1038/srep08976

Abstract

Acinetobacter pittii 44551 was recovered from a patient with gout combined with tuberculosis and was found to harbor the carbapenemase genes blaNDM-1 and blaOXA-58 on two different plasmids pNDM-44551 and pOXA58-44551, respectively. pNDM-44551 displayed high self-transferability across multiple bacterial species, while pOXA58-44551 was likely co-transferable with pNDM-44551 into A. baumannii receipts. pNDM-44551 was a close variant of the previously characterized pNDM-BJ01, and the blaNDM-1 gene cluster was arranged sequentially as orfA, ISAba14, aphA6, ISAba125, blaNDM-1, bleMBL, ΔtrpF, dsbC, tnpR, and zeta. pOXA58-44551 was a repAci9-containing plasmid, and blaOXA-58 was embedded in a 372F-ISAba3-like-blaOXA-58-ISAba3 structure. The mobile genetic platforms of blaNDM-1 and blaOXA-58 herein showed some differences from their previously characterized variants. The production of NDM-1 in strain 44551 contributed the majority to its high resistance to carbapenems, while the blaOXA-58 stayed silent most likely due to the lack of an upstream promoter to drive its transcription. Increased surveillance of Acinetobacter co-harboring blaNDM-1 (active) and blaOXA-58 (either active or silent) is urgently needed.

Highlights

Acinetobacter pittii 44551 was recovered from a patient with gout combined with tuberculosis and was found to harbor the carbapenemase genes blaNDM-1 and blaOXA-58 on two different plasmids pNDM-44551 and pOXA58-44551, respectively. pNDM-44551 displayed high self-transferability across multiple bacterial species, while pOXA58-44551 was likely co-transferable with pNDM-44551 into A. baumannii receipts. pNDM-44551 was a close variant of the previously characterized pNDM-BJ01, and the blaNDM-1 gene cluster was arranged sequentially as orfA, ISAba[14], aphA6, ISAba[125], blaNDM-1, bleMBL, DtrpF, dsbC, tnpR, and zeta. pOXA58-44551 was a repAci9-containing plasmid, and blaOXA-58 was embedded in a 372F-ISAba3-like-blaOXA-58-ISAba[3] structure
The present study describes the genetic environment, transferability, and antibiotic susceptibility of blaNDM-1 and blaOXA-58 harbored on different plasmids in a single clinical A. pittii isolate from China
BlaNDM-1 and blaOXA-58 were found to be harbored on two different plasmids in a single clinical A. pittii isolate named 44551, with the former gene expressing well and the latter one silent

Summary

Introduction

Acinetobacter pittii 44551 was recovered from a patient with gout combined with tuberculosis and was found to harbor the carbapenemase genes blaNDM-1 and blaOXA-58 on two different plasmids pNDM-44551 and pOXA58-44551, respectively. pNDM-44551 displayed high self-transferability across multiple bacterial species, while pOXA58-44551 was likely co-transferable with pNDM-44551 into A. baumannii receipts. pNDM-44551 was a close variant of the previously characterized pNDM-BJ01, and the blaNDM-1 gene cluster was arranged sequentially as orfA, ISAba[14], aphA6, ISAba[125], blaNDM-1, bleMBL, DtrpF, dsbC, tnpR, and zeta. pOXA58-44551 was a repAci9-containing plasmid, and blaOXA-58 was embedded in a 372F-ISAba3-like-blaOXA-58-ISAba[3] structure. Found in Klebsiella pneumoniae in 2008, blaNDM has been identified globally in many bacteria and received great attention partly due to its high transferability across different bacterial species, its frequent co-occurrence with other resistance genes, and the global spread of blaNDM-carrying strains[10,11,12,13,14,15]. Coexistence of blaNDM and blaOXA has been described in Acinetobacter, e.g. blaOXA-23 and blaNDM-1 in A. baumannii from India[19] and the Czech Republic[20], and blaNDM-1, blaOXA-23 and blaIMP in A. baumannii from China[21] It remains unclear whether and how these co-existing carbapenemase genes are expressed to www.nature.com/scientificreports contribute to drug resistance. The present study describes the genetic environment, transferability, and antibiotic susceptibility of blaNDM-1 and blaOXA-58 harbored on different plasmids in a single clinical A. pittii isolate from China

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Results

Conclusion