MOLECULAR ANALYSİS OF ANTİBİOTİC RESİSTANCE CHARACTERİSTİCS OF ACİNETOBACTER SPP. ISOLATED FROM FECAL AND CLİNİCAL SPECİMENS İN EASTERN TURKEY

Ömer AKGÜL*

Aim: Acinetobacter baumannii has recently become a prominent source of nosocomial infections. A. baumannii can present as an opportunistic infection, especially in hospitalized individuals with weakened immune systems. A. baumannii can spread throughout the human body via multiple pathways and may lead to lethal infections. The aim of our study is to perform a molecular examination of the antibiotic resistance traits of Acinetobacter spp. isolated from stool and clinical specimens. Material and Method: From January 2018 to December 2020, clinical infection specimens (comprising sputum, puncture fluid, urine, blood, and device-associated samples) were gathered at Van Training and Research Hospital. Furthermore, 6000 fecal specimens were collected from August 2018 to December 2020. All isolated bacteria were identified as Acinetobacter species by recA gene analysis, biochemical procedures, and 16S ribosomal RNA (rRNA) sequencing, alongside conventional microbiological techniques. The genomic regions selected for investigation in the isolates were amplified utilizing polymerase chain reaction and ERIC-PCR techniques. Findings: A total of 285 carbapenem-resistant Acinetobacter isolates were collected during the study period, comprising 180 from clinical infection specimens and 105 from fecal research specimens. Subsequent identification indicated 201 A. baumannii and 84 non-baumannii Acinetobacter species. Among the non-baumannii Acinetobacter species, 12 isolates and 5 A. baumannii isolates exhibited resistance to colistin. All carbapenem-resistant Acinetobacter isolates were identified as multidrug-resistant (MDR). Twelve non-baumannii Acinetobacter and five A. baumannii isolates exhibited resistance to colistin, with seven non-baumannii Acinetobacter strains from fecal samples testing positive for the mcr-1 gene. Discussion: Colistin is regarded as a last-resort treatment for infections caused by carbapenem-resistant Gram-negative bacteria. The emergence of the mcr gene has resulted in more significant challenges in therapeutic treatment. The existence of two significant clinical resistance genes, namely blaNDM and mcr-1, in non-baumannii Acinetobacter gut colonization is notable. The variety and prevalence of antibiotic resistance genes found in Acinetobacter species within stool samples suggest that the gut may serve as a substantial reservoir for resistant opportunistic bacteria.