Genomic characterization of a clinical Acinetobacter baumannii ST1928 isolate carrying a new ampC allelic variant blaADC-196 gene from China.

Abstract

OBJECTIVES\nThe prevalence of multidrug-resistant Acinetobacter baumannii is of serious concern in the hospital settings. In this study, we report the genome sequence and genomic characterization of a clinical A. baumannii isolate belongs to a novel sequence type, which harbors blaOXA-383 and a new ampC allelic variant blaADC-196 genes simultaneously from China.\n\n\nMETHODS\nWhole genomic DNA from A. baumannii A42 was extracted and sequenced using the Illumina HiSeq 4000 platform. De novo genome assembly was performed using Unicycler and the draft genome was annotated using the NCBI Prokaryotic Genome Annotation Pipeline. Genomic analyses were performed through various bioinformatics webserver from the Center of Genomic Epidemiology and BacWGSTdb (http://bacdb.org/BacWGSTdb).\n\n\nRESULTS\nThe genome size was calculated as 3,800,237 bp, with 3,610 protein-coding sequences and GC content of 38.9%. The A. baumannii A42 belonged to a rare sporadic clone ST1928. Antimicrobial resistome consisted of genes encoding resistance to beta-lactams (blaOXA-383 and a new ampC allelic variant blaADC-196) and the virulence factor gene for including biofilm-associated protein (bap), acinetobactin biosynthesis protein (basA-J), penicillin-binding protein (pbpG), and biofilm synthesis N-glycosyltransferase (pgaA-D), as well as 16 genomic islands and multiple insertion sequences were identified in the genome of A. baumannii A42.\n\n\nCONCLUSION\nThis is the first report of the genome sequence of A. baumannii ST1928 clinical isolate carrying a novel class C β-lactamase gene from China. The genome sequence data can be used as a reference sequence for comparative studies and would facilitate further understanding of the antibiotic resistance mechanisms of A. baumannii at the genomic level.