“Roar” of blaNDM-1 and “silence” of blaOXA-58 co-exist in Acinetobacter pittii

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.

Increased prevalence of carbapenem resistant Enterobacteriaceae in hospital setting due to cross-species transmission of the blaNDM-1 element and clonal spread of progenitor resistant strains

“…An imipenem-EDTA double-disc synergy test and a modified Hodge test were used to screen for the presence of Metallo-β-lactamases(MBLs) and carbapenemases, respectively, and were analyzed according to CLSI guidelines (Zhou et al, 2015). …”

Insights into the complete genomes of carbapenem-resistant Acinetobacter baumannii harbouring bla OXA-23, bla OXA-420 and bla NDM-1 genes using a hybrid-assembly approach

“…The genome ACN21 was devoid of bla OXA-23 , while the presence of bla NDM-1 and bla OXA-420 could be encoding for carbapenem resistance. In ACN21, bla NDM-1 resides in chromosome and bla OXA-420 in plasmids whereas previous studies reported the co-presence of bla NDM and bla OXA-58 on the same plasmid [31][32][33][34]. In CIAT 758, bla OXA-58 was carried on the plasmid (Table 1).…”

<p>Whole-Genome Analysis of Two Copies of <em>bla</em>_NDM-1 Gene Carrying <em>Acinetobacter johnsonii</em> Strain Acsw19 Isolated from Sichuan, China</p>

“…11,[19][20][21] In addition, the genes encoding bla NDM and bla OXA are known to be carried on some mobile genetic elements that inserted into the chromosome or plasmids, and it is suspected the mechanism of horizontal gene transfer (HGT) promotes the exchange of resistance genes among pathogenic microorganisms isolated from the clinical, environmental samples, and food animals. 11,[22][23][24][25] In this study, we mainly characterized the genetic feature of a carbapenems resistant strain Acinetobacter johnsonii Acsw19 isolated from municipal sludge. This strain was found to carry two copies of bla NDM-1 , cmlB1-like gene, and bla OXA-211 -like gene along with other 8 antimicrobial resistance genes, three plasmids, 15 genomic islands and 8 prophages.…”