Investigation of clonal relationships between healthcare-associated acinetobacter baumannii strains isolated from Turkey's Eastern Anatolia region hospitals and Çukurova region

Healthcare-associated infections (HAIs), Acinetobacter baumannii strains, which are increasingly isolated and cause losses of patients due to treatment failures, are at the top of the World Health Organization (WHO)'s list of resistant bacteria that urgently require the discovery of new antibiotics owing to the rapid spread of antibiotic resistance. It is assumed that the spread can be prevented in line with the current data through surveillance systems worldwide. In this study, it was aimed to identify the phylogenotypic relationships between the Acinetobacter baumannii strains isolated from the clinical samples of patients who were monitored in hospitals of our region and hospitals in the border provinces of the Eastern Anatolia Region and diagnosed with HAI. Our study included 166 Acinetobacter baumannii isolates obtained from patients who were diagnosed with HAI between September 2019 and January 2020; 84 in Van, Iğdır, Kars, Ağrı, and Ardahan state hospitals in the Eastern Anatolia Region and 82 in Adana City Hospital and Mersin University Hospital in the Çukurova Region. All isolates were resistant to carbapenem. They were detected and confirmed with conventional culture methods through which they were revealed to be carbapenem-resistant A. baumannii (CRAB), and specific blaOXA-51-like genes with the PCR method. Their antibiotic susceptibility was determined by the liquid microdilution method. The phylogenetic relationship between the isolates was examined by the Pulsed-field gel electrophoresis (PFGE) method. Apart from carbapenems, the highest antibiotic resistance was observed in ciprofloxacin by 92.6%, and the lowest resistance was observed in gentamicin by 69.5%. Resistance rates were observed to be higher in metropolises such as Adana, Mersin, and Van. As a result of the analysis of PFGE band profiles, it was revealed that the isolates were gathered in 51 clusters, 20 of which had a single member in each. The most crowded cluster was the L cluster, consisting of 30 members, all of which belonged to the Eastern Anatolia Region and were gathered in 21 pulsotypes (L1-L21). It was followed by the Z7 cluster consisting of 15 members, all of which belonged to Mersin and were gathered in 9 pulsotypes (Z7z1-Z7z9). The fact that CRAB strains are observed to have different incidences along with regional differences, but similar clones can also be observed in different hospitals in our country indicates that CRAB clones will dominate hospitals and societies all over the world. Furthermore, we think that our study will make an extremely significant contribution to the surveillance of these infections in the eastern border provinces of Turkey since no literature on phylogenetic relationships and surveillance studies on this subject has been encountered in the provinces of Ağrı, Iğdır, Kars, and Ardahan, also called the Serhat Region, before.