The Rising Threat of Drug Resistant Pseudomonas aeruginosa- A Nightmare for Intensive Care Unit Patients

Introduction: Multidrug Resistant (MDR), Extensively Drug Resistant (XDR) and Pan Drug Resistant (PDR) variants manifest a high level of intrinsic resistance to antimicrobial drugs by the help of efflux pump, biofilm formation and aminoglycoside modifying enzymes. The potentiality of Pseudomonas spp. to produce variety of drug resistance mechanism has led to evolution of drug resistant phenotypes this poses a challenge for clinicians in the treatment of severe infection among Intensive Care Unit (ICU) patients. Aim: To determine the phenotypic profiling of b-lactamases and burden of MDR, XDR and PDR Pseudomonas aeruginosa (P. aeruginosa) in ICU patients. Materials and Methods: The present cross-sectional prospective study was carried in the Department of Microbiology, Santosh Medical College and Hospital, Ghaziabad, Uttar Pradesh, India, after permission from Institutional Ethics Committee (IEC). A total of 115 isolates of P. aeruginosa were isolated from 502 human clinical samples from January 2019 to February 2021 and all the clinical samples were non duplicate. Antimicrobial Susceptibility Testing (AST) was performed for all isolates by standard KirbyBauer disc diffusion method on Mueller Hinton Agar (MHA). Phenotypic profiling of Extended Spectrum b-Lactamase (ESBL), Metallo b-Lactamase (MBL) and Ampicillinase C (AmpC) was performed by disc potentiation test; Imipenemase (IMP) - Ethylenediamine Tetraacetic Acid (EDTA) combined disc test and Cefoxitin Cloxacillin Double Disc Synergy Test (CC-DDST), respectively. The obtained results were statistically analysed in numbers and percentages using MS Excel 2013 version. Results: Out of 502 total human clinical samples, 115 isolates were P. aeruginosa giving the prevalence rate of 23%. Among 115 Pseudomonas isolates, 60 (52%) were MDR phenotypes, 8 (7%) were XDR phenotypes and there was no PDR phenotypes isolated in present study as all isolates were sensitive to Ticarcillin/Clavulanic acid, Colistin and Polymyxin B. Out of 115 isolates, 59 (51%) were ESBL producers, 26 (23%) were MBL producers, and 6 (5%) were AmpC producers. Conclusion: Strict antibiotic policies and regular surveillance programme of antimicrobial resistance must be tailored to fend off the emergence of drug resistant Pseudomonas aeruginosa.