CURRENT TRENDS OF ANTIBIOTIC RESISTANCE IN PSEUDOMONAS AERUGINOSA STRAINS IN TERTIARY CARE CENTER IN SOUTH INDIA

PURPOSE OF THE STUDY To study the Antibiotic susceptibility patterns of isolates of Pseudomonas aeruginosa from hospitalized patients. We also aim at finding out the Extended Spectrum Beta Lactamase (ESBL) and Metallo Beta Lactamase (MBL) production in the isolates. MATERIALS AND METHODS Out of 2552 bacterial culture positive isolates in a period of 4 months (September-December,2011), from various specimens of Inpatients ,197 (7.72 percent ) isolates of Pseudomonas aeruginosa were isolated. These 197 Pseudomonas aeruginosa strains taken up for the study. They were subjected to antibiotic susceptibility testing by disc diffusion test as per the Clinical and Laboratory Standards Institute (CLSI) guidelines. Ceftazidime resistant isolates were selected for the detection of ESBL and MBL production by phenotypic confirmatory test and Modified Hodge test respectively. Appropriate standard strains were used as controls for antibiotic susceptibility testing, ESBL and MBL detection. Statistical analysis was carried out using Statistical Package for Social Sciences (SPSS) and Epi-info softwares by a statistician. The proportional data of this study were tested using Pearsons Chi square analysis test 2.RESULTS Of the 197 isolates of Pseudomonas aeruginosa studied, 31(15.7percent ) were ESBL producers and 21(10.7 percent) were MBL producers. Over all susceptibility was 91.4 percent for Imipenem, 80.2 percent for Piperacillin-Tazobactam, 56.3 percent for Ceftazidime, 45.7 percent to Amikacin, 44.7 percent to Ciprofloxacin, 42.1 percent to Cefepime, 40.1 percent to Ofloxacin, 26.9 percent to Gentamicin and only 4.5 percent susceptibility to Piperacillin.CONCLUSION Our findings showed widespread emergence of drug resistance among the Pseudomonas aeruginosa isolates. Hence there is a need to do regular surveillance to detect resistance patterns and to use antibiotics judiciously and effectively, so as to prevent their spread.