High Prevalence of Virulence and <i>bla_OXA</i> Genes Encoding Carbapenemases Among <i>Acinetobacter baumannii</i> Isolates from Hospitalised Patients in Three Regions of Poland

Infections caused by <i>Acinetobacter baumannii</i> are increasing worldwide. We evaluated the antibiotic resistance profile, biofilm production, and the frequency of 12 genes encoding carbapenemases and 13 virulence factors in 90 isolates from patients of three hospitals in various regions of Poland. Antibiotic resistance survey was performed using the disc-diffusion method, genes encoding resistance to carbapenems and virulence factors were detected with PCR, and biofilm formation was tested using microtiter plates. A total of 52.2% of isolates were resistant to all tested antibiotic groups (penicillins with β-lactamase inhibitors, cephalosporins, carbapenems, aminoglycosides, fluoroquinolones, and trimethoprim plus sulfamethoxazole). Among the genes encoding carbapenem resistance, the <i>bla</i>_OXA-23 (68.9%), <i>bla</i>_OXA-40 (83.3%), and ISAba-<i>bla</i>_OXA-51 (18.9%) were detected. The <i>ompA</i>, <i>ata,</i> and <i>recA</i> genes responsible for biofilm formation, adhesion, and stress response, respectively, occurred in all isolates. Genes responsible for the production of other adhesins (<i>bap</i>—94.4%, <i>espA</i>—4.4%, <i>chop</i>—37.7%), biofilm formation (<i>pbpG</i>—90.0%), production of siderophore (<i>basD</i>—97.7%), toxins (<i>lipA</i>—92.2%, <i>cpaA</i>—1.1%), glycoconjugates (<i>bfmR</i>—84.4%), and inducing host cell death (<i>fhaB</i>—71.1%, <i>abeD</i>—93.3%) were also found. A total of 68.8% of isolates produced biofilm. The isolates from Masovia had more virulence genes than isolates from the other regions; moreover, all isolates from Masovia and West Pomerania were multidrug-resistant (MDR), including resistance to carbapenems.