Molecular Epidemiology of Acinetobacter baumannii Isolates Using Single-Locus Sequence Typing of blaOXA-۵۱-like and ampC Genes as a Cost-Effective Method

Background: Acinetobacter baumannii is a crisis-causing opportunistic pathogen with a high capacity for clonal spread. blaOXA-۵۱-like and ampC sequence-based typing (SBT) is a cost-effective and reliable technique to identify global and widespread lineages of A. baumannii strains. This research aimed to study circulating A. baumannii clones using single-locus sequence typing (SLST) as a reliable and cost-effective method.Materials & Methods: A total of ۱۱۹ A. baumannii clinical isolates were collected from hospital inpatients from February to September ۲۰۲۴. The antibiotic resistance profile of A. baumannii isolates was determined, and genotyping was performed using SBT of blaOXA-۵۱-like and ampC genes.Findings: All A. baumannii isolates were specified as multidrug-resistant (MDR), and ۷۸.۱% were identified as carbapenem resistant. Resistance to colistin was observed in ۵% of isolates with a minimum inhibitory concentration (MIC) of ≥۱۲۸ μg/mL. SBT of the blaOXA-۵۱-like gene revealed four various blaOXA-۵۱-like allele variants: including blaOXA-۶۹ (n=۴۷, ۳۹.۵%), blaOXA-۶۴ (n=۲۱, ۱۷.۶%), blaOXA-۳۸۳ (n=۴۴, ۳۷%), and blaOXA-۴۴۱ (n=۷, ۵.۹%). SBT of the ampC specified two alleles, including ampC-۱ (n=۴۷, ۳۹.۵%) and ampC-۲۵ (n=۲۱, ۱۷.۶%), and ۵۱ (۴۲.۹%) isolates showed an undetermined allele variant of the ampC gene. blaOXA-۶۹ /ampC-۱ and blaOXA-۶۴ / ampC-۲۵ pertained to sequence type ۱/ clonal complex ۱ (ST۱/CC۱) and ST۲۵/CC۲۵, respectively. Conclusion: SBT of the blaOXA-۵۱-like and ampC genes revealed a relatively high prevalence of the international ST۱/CC۱ clone in MDR A. baumannii isolates in our region. However, the blaOXA-۳۸۳ allele variant, which could possibly be associated with endemic clones, also had an approximately significant frequency.

کلیدواژه ها:

Acinetobacter baumannii ، Molecular epidemiology ، Genotyping ، multidrug-resistance