Molecular Detection of OXA-type Carbapenemases among Acinetobacter baumannii Isolated from Burn Patients and Hospital Environments

Abstract

Background:Acinetobacter baumanniiis known as one of the major causes of nosocomial infections, especially in intensive care units and burn patients. The emergence of antimicrobial resistance in burn wound bacterial pathogens is a severe health crisis. Detection of carbapenem resistance and genetic elements inA. baumanniiassociated with burn patients and hospital environments play a key role in the control and alerting in clinical settings.Purpose:In this study, the prevalence of OXA-type carbapenemases was investigated inA. baumanniistrains isolated from burn patients and from a hospital environment in Tehran, 2021.Methods:A total of 85 non-duplicateA. baumanniiisolates (53 from various surfaces of the hospital environment and 32 from burn patients) were recovered in the Burns Hospital in Tehran. TheA. baumanniiisolates were screened for antibiotic susceptibility and the presence of the most common OXA-type carbapenemase genes.Results:A. baumanniiwas isolated from 38.5% of hospital patient burn wounds and 22.1% of surfaces, including burn units (15.6%) and intensive care units (52.4%). Antibiotic susceptibility results showed that (100%) of burn patient isolates were resistant to imipenem, while (100%) of ICU isolates and (96.8%) of burn isolates were resistant to imipenem. All clinical isolates were identified as MDR and XDR, whereas all (100%) and 98.1% of environmental isolates were identified as MDR and XDR, respectively. All studiedA. baumanniiisolates carriedblaOXA-51-likegene. Moreover, 50 (94.3%) and 49 (92.5%) of environmental isolates, 32 (100%) and 30 (93.7%) of burn patient isolate harboredblaOXA-23-likeandblaOXA-24/40–likegenes, respectively. None of the isolates carried theblaOXA-58orblaOXA-143genes and all isolates had at least 2 OXA-type carbapenemase genes.Conclusion:Our results suggest that surfaces in the hospital environment, particularly in ICUs, are contaminated with MDR or XDRA. baumanniistrains. They may be considered a potential reservoir for the colonization of hospital patients. In addition, OXA-type carbapenemases, including OXA-23-like and OXA-24/40-like, appear to be one of the major mechanisms of carbapenem resistance in the clinical and environmentalA. baumanniistrains.