Abstract
New Delhi metallo-beta-lactamase (NDM)-producing Acinetobacter spp. have been reported worldwide and become a global threat to clinics. This study aimed to characterize the genomic features of the carbapenem-resistant Acinetobacter pittii strain AP8900 harboring chromosome-borne bla(NDM-1). The genome of strain AP8900 was fully sequenced using Illumina and PacBio platforms. Genome analyses revealed that the chromosome-borne bla(NDM-1) of strain AP8900 was located on the Tn125 bracketed by two copies of ISAba125 in the same orientation. So far, only five strains of A. pittii with complete genomes harboring chromosome-borne bla(NDM-1) were found (four from China and one from the USA), all carrying nearly identical Tn125 carried by the strain AP8900. Furthermore, the Tn125 of strain AP8900 in this study was also distributed in other species, mainly Acinetobacter spp. Notably, the Tn125 carried by AP8900 also found in Proteus mirabilis, Klebsiella pneumoniae, and Morganella morganii. In addition, two antibiotic resistance plasmids were found in strain AP8900, and the configuration "sul2- glmM" was found on both pAP8900-1 (ISAba1-sul2-glmM-ISVsa3-IS1006) and pAP8900-2 (∆ISAba2-sul2-glmM-IS17). This study delivers comprehensive insights into the characteristics and diversity of chromosome-borne bla(NDM-1) in A. pittii. The complete genome of A. pittii AP8900 strain from southern China provides important data for the analysis of antimicrobial resistance in this region.