Insight into carbapenem-resistance and virulence of Acinetobacter baumannii from a children's medical center in the east China

Carbapenem-resistant Acinetobacter baumannii (CRAB) appeared more and more frequently in children and caused a great threat to global public health. It is urgent to investigate the carbapenems-resistance and virulence of CRAB for clinicians to choose appropriate antibiotics. A retrospective study for 77 nonduplicated CRAB isolates was conducted. The carbapenems-resistance and virulence genes were characterized by Polymerase Chain Reaction (PCR) and gel electrophoresis. In present study, A. baumannii mainly came from intensive care unit, mostly isolated from sputum samples. The carbapenems-resistant rate of A. baumannii in 2018–2020 increased significantly compared with that in 2016–2017. All isolates had the carbapenems-resistant genes. They were highly resistant to a variety of antibiotics, but were relatively sensitive to fluoroquinolones and tetracyclines. The bla VIM and bla OXA-23 were detected in all isolates, whereas bla OXA-51, bla IMP and bla NDM were present in 98.70%, 67.53% and 31.17% of isolates. Notably, 1 isolate A. baumannii was identified as multidrug-resistant A. baumannii (MDR-AB), and 76 other extensivelydrug-resistance (XDR) isolates were also detected. Virulence genes were present in 100% of all isolates, including genes in iron acquisition system (basJ), secretion systems (ompA, plcD), quorum sensing system (abaI) and biofifilm formation (csuA). adeH, pgaA, ptk were present in 98.70%, 98.70% and 94.80% of isolates. CRAB prevalent in east China carried a large number of drug resistance and virulence genes. Fluoroquinolones and tetracyclines may be effective antibiotics for the treatment of CRAB infection in children. An in-depth understanding of the resistance and virulence of CRAB is conducive to timely guiding empirical drug use and controlling infection.