Local characteristics of molecular epidemiolgy of Acinetobacter baumannii in Jilin Province (northeast China)

Abstract

Abstract A. Baumannii is an opportunistic nosocomial pathogen which have severe antibiotic-resistant. However, the epidemiology is less clearly understood in Jilin province and China. Thus, 89 A. baumannii isolates from a single hospital in Jilin province between 2013-2017 were performed by multi-locus sequence typing (MLST), and all Chinese strains with definite STs in MLST database were analyzed by silico phylogenetic tools. A total of 22 Sequence types (STs) in Jilin were identified and 10 STs were found to be novel. The top three predominant sequence types are ST195 (n=34, 38.2%), ST208 (n=14, 15.7%) and ST540 (n=13, 14.6%). ST369 is predicted to be group founder and ST195, ST540 are subgroup founders of the majority STs in Jilin Province. The majority of all Jilin isolates showed clonality and close relationship with the majorities from other regions of China. But occupation of individual STs in Jilin were different from that of other domestic regions. Excepting domestic transmission, some newly discovered singleton showed close relationship with strains from other countries, which suggest that nation-cross transmission is one of important origin of Jilin strains. And the aggregation trend and close genetic relationship of dominant STs proved that predominant STs continue to mutate in the process of transmission. Drug resistance facilitated transmission of Jilin A.baumannii isolates because more than 94% of isolates are resistant to at least one carbapenem and the STs with strong resistance to carbapenems usually has more isolates. In conclusion, high diversity and different occupation of STs, and occupation of novel STs proved that epidemiology of A. baumannii in Jilin has special regional characteristics, and drug resistance facilitated transmission of domestic strains and foreign strains.