Whole-Genome Analysis of Two Copies of Gene Carrying Strain Acsw19 Isolated from Sichuan, China.

Purpose: To characterize the genetic feature of the carbapenems resistant strain Acsw19 isolated from municipal sludge. This strain was found to carry two copies of -like gene, and -like gene along with other 8 antimicrobial resistance genes, 3 plasmids, 15 genomic islands and 8 prophages.

Methods: A carbapenem-resistant strain Acsw19 isolated from municipal sludge was subjected to whole-genome sequencing (WGS) via the PacBio and Illumina MiSeq platforms. Thereafter, the characteristic was analyzed by a series of bioinformatics software.

Results: The results showed that the genome of Acsw19 was consisted of a 3,433,749 bp circular chromosome and 3 circular plasmids, pAcsw19-1 (11,161 bp), pAcsw19-2 (351,885 bp) and pAcsw19-3 (38,391bp), respectively. Resistome analysis showed that Acsw19 carried 12 antimicrobial resistance genes, including 6 [-like, , , () and ] in the plasmid pAcsw19-2 and 6 ( -like, , , and ) in the chromosome genome. Specifically, the -like gene shared 86.33%, 71.7% and 71.9% similarities with the and gene, and the -like gene shared 94.4%, 95.39% and 96.36% similarities with , and , at the nucleotide level, respectively. Phylogenetic analysis showed that the -like gene and -like gene had the closest evolutionary relationship with and , respectively. These results indicated that the -like and -like genes identified in the current study should be the novel variant resistance genes.

Conclusion: Carrying of two copies of , like, -like and along with other 8 antimicrobial resistance genes, 3 plasmids, 15 genomic islands and 8 prophages strain might increase the possibility of spreading of resistance genes.