Emerging Challenges: High frequency of Antiseptic Resistance Encoding Genes and Reduced Biguanide Susceptibility in Antibiotic-Resistant Acinetobacter baumannii in Iran

Acinetobacter baumannii (A. baumannii) is a prevalent infectious agent regularly reported from hospital intensive care unit (ICU) patients. Annually, Multi-drug-resistant (MDR) isolates present a significant clinical challenge. The present study aimed to determine the prevalence of antiseptic resistance genes and the level of resistance to quaternary ammonium and biguanide compounds in A. baumannii isolates obtained from patients of north Khorasan province.All obtained A. baumannii isolates were examined for in vitro susceptibility to antiseptic agents and the presence antiseptic resistance encoding genes including qacE, qacEΔ۱, and blaOXA-۲۳.The broth microdilution method detected the Minimum Inhibitory Concentrations (MIC) against antiseptic compounds. The majority of A. baumannii infections were observed in ICU patients (n=۶۳, ۸۴%). MDR and extensively drug-resistant (XDR) phenotypes were present in ۵۳.۲% and ۴۶.۷% of cases, respectively. Among ۷۵ isolates, ۴۸ (۶۴%) had at least one resistance gene. This includes ۲۴ (۳۲%) isolates with only the qacE gene and ۵ (۶.۷%) isolates with the qacEΔ۱ gene. Coexistence of qacE and qacEΔ۱ genes were found in nine (۲۵.۳%) isolates. The mean minimum inhibitory concentration (MIC) of chlorhexidine digluconate (CHG) was statistically significantly higher in isolates harboring antiseptic resistance genes than in isolates without such genes (۸۱.۴ µg/ml versus ۲۷.۹ µg/ml, P=۰.۰۰۱).The increased MIC against antiseptic agents among A. baumannii isolates is a big medical concern. The presence of antiseptic-resistant genes and increased minimum inhibitory concentration (MIC) levels against antiseptic agents in MDR and XDR A. baumannii emphasizes the critical need for comprehensive monitoring of all A. baumannii isolates in hospital settings to ensure efficient infection control.

کلیدواژه ها:

Acinetobacter baumannii ، Multi Drug Resistant ، Biguanide compound ، qacE ، qacEΔ۱