Carbapenem-Resistant Acinetobacter baumannii: Resistance, Virulence, and Possible Dissemination Between Different Hospitals in Western Iran

The capacity for biofilm formation, along with the acquisition of antimicrobial resistance, could be the primary factors enhancing the persistence and spread of Acinetobacter baumannii (AB). We aimed to identify the trends in molecular epidemiology of AB isolated from western Iran. Ninety-nine pathogenic AB isolates were collected from patients in three major hospitals in Sanandaj and Kermanshah (the capitals of Kurdistan and Kermanshah provinces in western Iran, respectively) in one year. Isolates were tested for the presence of class D and B carbapenemases, integrons, and biofilm-associated genes, and their genetic diversity was initially investigated using enterobacterial repetitive intergenic consensus (ERIC) analysis, followed by multilocus sequence typing (MLST) and plasmid profiling. Of the 99 isolates, 91.9% showed resistance to carbapenems. The most common class D and class B carbapenemases were OXA-24-like and VIM type, respectively. The bap, bfmR, and ompA biofilm-related genes were present in all isolates. Class 1 integron was only identified in 10.1% of isolates and contained the sugar dehydrogenase gene cassette. By ERIC, Cluster C was found in three hospitals, and Clone A in two hospitals. By MLST, isolates in Cluster C and Clone A were assigned to ST78 and ST2125, respectively. Plasmid profiling of Cluster C and Clone A isolates showed similar plasmid profiles. Our research offers insights into the epidemiology of AB circulating in western Iran during recent years. The results may suggest a possible inter-hospital spread of these strains; however, further research is needed. We document for the first time the emergence of ST2125 and ST78 in Iran.