IncA/C Plasmid Carrying bla(NDM-1), bla(CMY-16), and fosA3 in a Salmonella enterica Serovar Corvallis Strain Isolated from a Migratory Wild Bird in Germany

Abstract

A Salmonella enterica serovar Corvallis strain was isolated from a wild bird in Germany. This strain carried the IncA/C2 pRH-1238 plasmid. Complete sequencing of the plasmid was performed, identifying the blaNDM-1, blaCMY-16, fosA3, sul1, sul2, strA, strB, aac(6')-Ib, aadA5, aphA6, tetA(A), mphA, floR, dfrA7, and merA genes, which confer clinically relevant resistance to most of the antimicrobial classes, including β-lactams with carbapenems, fosfomycin, aminoglycosides, co-trimoxazole, tetracyclines, and macrolides. The strain likely originated from the Asiatic region and was transferred to Germany through the Milvus migrans migratory route.

FIG 1

Phylogenetic and homology trees of IncA/C plasmids. The phylogenetic and homology analyses were performed by aligning sequences of the following NDM-1-IncA/C plasmids (GenBank accession numbers): pNDM-1_Dok01 (AP012208), pMR0211 (JN687470), pKP1-NDM-1 (KF992018), pNDM-US (CP006661), pNDM102337 (JF714412), pNDM10469 (JN861072), pNDM-KN (JN157804), and pNDM10505 (JF503991). The phylogenetic (left) and homology (right) trees were obtained using the DNAman software (Lynnon BioSoft, Vaudreuil, Quebec, Canada) for quick alignment. Unrooted phylogenetic trees were generated by the maximum-likelihood method. The bar corresponds to the scale of sequence divergence.

FIG 2

Major structural features of pRH-1238 plasmid compared with pMR0211 and pNDM-1_Dok01 plasmids identified in P. stuartii and E. coli, respectively. Orange arrows indicate antibiotic resistance genes, and red arrows indicate transposon-related genes (tnpA and tnpR) or insertion sequences. The bla_NDM-1 gene is indicated by blue arrows. The repAciN gene is indicated by violet arrows. The white arrows indicate plasmid scaffold regions in common among IncA/C plasmids. The black bars indicate inverted repeat (IR) sites.

FIG 3

Comparison of the bla_NDM-1 gene environments between pRH-1238 plasmid and the genetic context of the genome of the P. aeruginosa MMA83. Orange arrows indicate antibiotic resistance genes, and red arrows indicate transposon-related genes (tnpA and tnpR) or insertion sequences. The bla_NDM-1 gene is indicated by blue arrows. The repAciN gene is indicated by the violet arrow. The white arrows indicate plasmid scaffold regions that are in common among IncA/C plasmids. The black bars indicate IR sites.