Evaluating the Frequency Distribution of Carbapenemase-Producing <i>Acinetobacter </i>Species: Insights from a Post-COVID-19 Study

Background: Acinetobacter species are common culprits of nosocomial infections and represent serious public health concern due to their growing resistance to antibiotics, including carbapenems, which are among the most effective treatments available. Antibiotic resistance is primarily driven by the production of extended-spectrum β-lactamases (ESBLs), particularly carbapenemases. Objective: The study evaluated carbapenem resistance and frequency of carbapenemase production in clinical Acinetobacter spp. Materials and Methods: This was a cross-sectional prospective study conducted for one year to identify Acinetobacter spp. from various clinical specimens, including blood, pus, body fluids and sputum. The Acinetobacter spp. isolates were identified based on their cultural, microscopic, and biochemical characteristics. The API-E20 kit was used where necessary. Antibiotic susceptibility testing (AST) to assess the resistance patterns of Acinetobacter spp. was performed using Kirby-Bauer method following the guidelines set by CLSI. Moreover, the Modified Hodge test (MHT) was employed to detect the carbapenemases production in the Acinetobacter spp. Results: A total of forty-five (n=45) Acinetobacter spp. isolates of clinical samples, including pus (n=9), blood (n=15), sputum (n=11), and body fluids (n=10) were identified. AST data revealed that >90% strains were resistant to penicillin and cephalosporins, including 80.85% isolates resistant to both imipenem and meropenem antibiotics, considered as CR-Acinetobacter spp. isolates. All these isolates were subjected to MHT, which showed that most of the isolates were producing carbapenemases. Conclusions: A high frequency of carbapenemase-producer Acinetobacter spp. were observed. The emergence of carbapenem resistant Acinetobacter spp. presents a significant challenge to the treatment of bacterial infections globally, with a particularly severe impact in developing countries. These findings underscore the urgent need for effective antibiotic stewardship programs in Sindh, Pakistan.