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

Objectives The prevalence of multidrug-resistant Acinetobacter baumannii is of serious concern in hospital settings. Here we report the genome sequence and genomic characterisation of a clinical A. baumannii isolate from China belonging to a novel sequence type (ST) harbouring blaOXA-383 and a new ampC allelic variant blaADC-196 simultaneously. Methods Whole genomic DNA from A. baumannii A42 was extracted and sequenced using an Illumina HiSeq X10 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 web servers from the Center for Genomic Epidemiology as well as BacWGSTdb. Results The genome size was calculated as 3 800 237 bp, with 3610 protein-coding sequences and a GC content of 38.9%. A. baumannii A42 belongs to a rare sporadic clone ST1928. The resistome contains genes encoding resistance to β-lactams (blaOXA-383 and a new ampC allelic variant blaADC-196). Virulence factor genes encoding 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 also identified in the genome of A. baumannii A42. Conclusion This is the first report of the genome sequence of an 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 antimicrobial resistance mechanisms of A. baumannii at the genomic level.