In Silico Characterization of bla _NDM -Harboring Conjugative Plasmids in Acinetobacter Species

Abstract

Conjugative plasmids harboring the bla NDM gene play a vital role in disseminating carbapenem resistance. In this study, we first report a conjugative plasmid, pNDM-YR7, in Acinetobacter junii .

A novel replication initiation region encoded in a widespread Acinetobacter plasmid lineage carrying a blaNDM-1 gene

“…This plasmid also encodes proteins involved in maintenance and transfer and 19 proteins with unknown functions. Our bioinformatics analysis did not reveal any gene encoding a Rep protein for the initiation of plasmid replication on the pAhaeAN54e plasmid or the other members of the pNDM-YR7 clade [14]; in this work, we identified the minimal region of the pAhaeAN54e plasmid necessary for plasmid replication by an experimental approach. This 834 bp region has an unusual organization in that it encodes three small peptides that are required for plasmid replication and maintenance.…”

“…The blaNDM genes are frequently present in plasmids. In a recent work, Tang and coworkers studied a set of 62 Acinetobacter plasmids containing blaNDM genes [14]. The phylogenetic analysis of these strains revealed that these plasmids belong to two different clades: the pNDM-JN01-like clade and the pNDM-YR7-like clade.…”

“…The second clade (pNDM-YR7 clade) consists of medium-sized conjugative plasmids (39.36 kb to 49.65 kbthat carry a MOBQ family relaxase gene, encode TrwB/TraD subfamily type IV coupling proteins, and possess VirB-like type IV secretion system gene clusters. Interestingly, no gene encoding a replication initiation protein (Rep) was identified in the members of this second family [14].…”

“…The blaNDM genes are linked to a wide variety of plasmids, including IncC, IncFII, IncFIB, IncH, IncL/M, and IncX3, and untyped plasmids; however, it always occurs near insertion sequences, (IS5, IS26, ISAba125, IS3000, and ISCR1); transposons, like Tn3, Tn125, and Tn3000, or transposon relics [9][10][11][12][13][14].…”

“…Recently, Tang and coworkers described two large Acinetobacter plasmid clades harboring blaNDM genes [14]. One of the clades consists of plasmids with a gene encoding a Rep protein of the Rep_3 superfamily.…”