Prevalence and susceptibility pattern of Acinetobacter baumannii and Pseudomonas aeruginosa from various clinical samples at a tertiary care center in Chennai, Tamil Nadu

Given their severity, inherent antibiotic resistance and potential to develop novel drug resistance, A. baumannii and P. aeruginosa infections are of utmost relevance among Gram-negative bacterial infections. Here, we studied the prevalence of A. baumannii and P. aeruginosa and their antibiotic susceptibility profile in a tertiary care center. A prospective study was conducted for clinical samples received at the Department of Microbiology, SRM Medical College Hospital and Research Centre between September 2021 and February 2022. The various clinical samples studied were blood, pus, urine, tissue, ear swab, vaginal swab and sputum. All the samples were processed according to standard conventional methods and non-fermenting Gram-negative bacteria obtained from these samples were included in the study. On microbiological analysis, most of the isolates were identified to be P. aeruginosa (72%) and A. baumannii (28%). The overall prevalence was higher among males 64% compared to females 36% in the age group of 46 – 60 years. The prevalence of MDR phenotype was high in A. baumannii (60%) compared to P. aeruginosa isolates (14%) in this study. This study shows that the MDR phenotype of A. baumannii is more prevalent in intensive care units. The emergence of colistin resistance among the study isolates is concerning. This suggests that the availability of local susceptibility data is essential to aid in the selection of appropriate antimicrobial drugs for effective treatment. Thus, the appropriate use of antibiotics is necessary to prevent the emergence of antimicrobial resistance.