Antimicrobial Susceptibility Pattern of Pseudomonas aeruginosa with Special Reference to ESBL Producers from Various Clinical Samples at a Tertiary Care Center in Bihar

Background: P. aeruginosa is a Gram negative non-fermentative bacillus which is an opportunistic pathogen responsible for various nosocomial infections like UTI, wound infections or severe sepsis. P. aeruginosa is extensively found in hospital environment and is resistant to many antimicrobials due to acquired and intrinsic resistance factors. Production of Extended Spectrum β- Lactamases (ESBLs) is a major cause of antimicrobial resistance in P. aeruginosa which is now seen throughout the world. ESBL production offers resistance to most of the β-lactam antibiotics including 3rd generation cephalosporins and these strains also acquire resistance to other classes of antibiotics resulting in MDR strains. Because of the extensive distribution of the ESBL producing isolates throughout the world we aim this study to know the prevalence of ESBL producing P. aeruginosa isolates and their antimicrobial susceptibility pattern to guide the clinicians to formulate proper antimicrobial therapy in such infections. Methods: This prospective analytical study was conducted in the department of microbiology of Indira Gandhi Institute of Medical Sciences, Patna during the period of October 2014 to March 2015 to evaluate ESBL production and antimicrobial susceptibility of P. aeruginosa isolates from various clinical samples. Results: A total of 102 strains of P. aeruginosa was isolated from 1000 various clinical samples. 27 isolates (26.5%) of P. aeruginosa isolates were ESBL producers. All the isolates were sensitive to Colistin and Polymyxin B and Imipenem has the highest sensitivity among ESBL producing isolates and Ampicillin along with most the Cephalosporins showed very low sensitivity. Conclusion: We conclude that there is a significant prevalence of ESBL producing P. aeruginosa strains in our hospital which are mostly multi drug resistant(MDR) and constant monitoring of their changing antibiogram along with nosocomial infections caused by such strains is important to guide the proper antimicrobial therapy and reinforce infection control practices