Increasingly difficult treatment of multidrug-resistant (MDR) bacteria has become a global problem of the 21st century. Within a group of multiresistant bacteria, the Acinetobacter baumannii convincingly occupies the position at the top of the group designated as ESKAPE pathogens. In this study, 61 isolates of A. baumannii were recovered from different samples originating from various departments of the University Clinical Hospital Mostar during 2018. All of the isolates were identified using conventional phenotypic methods and the VITEK® 2 Compact System, and were confirmed by MALDI-TOF mass spectrometry. The minimum inhibitory concentrations (MICs) were determined by the microbroth dilution method using MICRONAUT-S MDR MRGN-Screening and VITEK 2 Compact System. All strains were resistant to carbapenems and classified in eight different resistotypes according to their antibiotic resistance and macrorestriction pulsed-field gel electrophoresis profiles, with all belonging to IC II. One isolate displayed resistance to colistin (MIC ≥16 mg/L). The presence of blaOXA genes encoding OXA-type carbapenemases was investigated by multiplex PCR and the Eazyplex® SuperBugAcineto system and showed 100% compatibility with the detection of acquired oxacillinases. Molecular characterization of the isolates tested in this study revealed the OXA-23- and OXA-40-like groups of acquired oxacillinases. Sequencing of two PCR products of the OXA-40-like group confirmed the presence of OXA-72. Survival assays with two selected isolates of A. baumannii encoding different mechanisms of carbapenem resistance revealed that one isolate was able to survive on a fragment of white laboratory coat during 90 days of monitoring. To the best of our knowledge, this is the first article to present the results of a comprehensive phenotypic, genotypic, and molecular analysis of A. baumannii isolates from the leading clinical hospital center in the southwestern part of Bosnia and Herzegovina, including data for the survival of this pathogen on the white laboratory coats used as compulsory medical clothing.
Keywords: Acinetobacter baumannii; OXA-23; OXA-72; laboratory coat; loop-mediated isothermal amplification; survival assay.