A New OXA-66-harboring Acinetobacter Baumannii Sub-Clonal Complex 195 is Spreading Widely in Guangzhou, China, A Multicenter Study

Abstract

Objectives The clonal spread of Acinetobacter baumannii (A. baumannii) is an emerging problem. We analyzed the molecular epidemiology of A. baumannii isolated from 5 teaching hospitals in Guangzhou, China. Methods 138 A. baumannii isolates were collected. Multilocus sequence typing (MLST) was used to assess the genetic relationships among the isolates. The blaOXA-51-like gene was amplified and then sequenced. Results Most of the isolates (55.8%, 77/138) were obtained from intensive care units (ICUs). The respiratory system was the most common site where A. baumannii was found (72.5%, 100/138). A. baumannii remained susceptible to polymyxin and tigecycline, but the susceptibility to other antimicrobial agents was below 30%. We used MLST to group the A. baumannii isolates into 8 existing sequence types (STs) and 17 new STs. With the predicted founder ST195 (accounted for 35.5% of all isolates, 49/138), Clonal complex (CC) 195 was the most prevalent and widely spread STs in the hospital environment. All ST195 isolates harbored OXA-66 according to the blaOXA-51-like gene sequencing. But each hospital had its unique epidemiological feature. Conclusions OXA-66 gene harboring CC195 was the most epidemic STs in Guangzhou, China. Health care facilities should develop their own management strategy.