IN VITROACTIVITY OF GATIFLOXACIN AGAINST GRAM NEGATIVE CLINICAL ISOLATES IN A TERTIARY CARE HOSPITAL

Purpose :The study was carried out to test the in vitroactivity of gatifloxacin (GT) against the commonly isolated gram negative pathogens from clinical specimens and compare the same with that of two other fluoroquinolones-ciprofloxacin (CIP) and levofloxacin (LVX) and four non-quinolone agents- cefotaxime (CF), ceftriaxone (CTX), ceftazidime (CAZ) and amoxyclav (AMC). The study included 77 gram negative isolates. Methods :The in vitroactivity of gatifloxacin was evaluated by the Kirby-Bauer disc diffusion method and the MIC was determined by the agar dilution method as per the NCCLS guidelines. Results :Of the organisms tested, 62.8% of the isolates belonging to the family Enterobacteriaceaewere sensitive to GT, compared to 36.1 to LVX, 27.8 to CIP, 41.61 to AMC and 32.2% to the cephalosporins tested. For P.aeruginosa, the figures were 41.2, 41.2, 23.5 and 35.3% for GT, CIP, LVX, and the III generation cephalosporins, respectively. Conclusion :Gatifloxacin was more effective than the other two fluoroquinolones and the non-quinolone antibiotics against the members of Enterobacteriaceae. However, GT and CIP were found to be equally effective against P.aeruginosa.