In vitro activity of piperacillin/tazobactam against pseudomonas species in paediatric population

Aim: to determine the susceptibility of piperacillin/tazobactam against pseudomonas species methods: this cross sectional observational study was conducted during april 2011 to march 2012 at microbiology department of the children's hospital and institute of child health,lahore. a total number of 10761 samples were collected and processed for microbiological investigations. the organisms were identified by routine laboratory tests including biochemical tests. results: out of 10,761 samples 2,375(22%) were positive for bacterial growth,among them 200(9.2%) were pseudomonasspp. and 2,175(90.8%) were other than pseudomonasspp. the highest proportion of pseudomonas spp. was isolated from urine samples 69(34.5%) followed by blood 60(30%),swab 50(25%) and 21(10.5%) from the samples of sputum,secretion and tips. from a total 200 positive cultures of pseudomonas spp. urology ward accounted for the highest proportion 44(18%),followed bymedical ward 36(18%). the proportions of other wards were as: opd 30(15%),neonatology 29(14.5%),icu 16(8%),hematologyoncology ward 14(7%),surgical ward 13(6.5%),developmental ward 7(3.5%),m/e 6(3%) and orthopedics ward 5(2.5%). pseudomonas spp. was found highly sensitive to piperacillin/tazobactam (87.5%). sensitivity to other antimicrobial discs was meropenem (86.5%),sulbactam/cefoperazone (82.5%),amikacin (74.5%),ciprofloxacin (64.5%),cefotaxime (17.5%),ceftriaxone (20.0%),ceftazidime (60.5%),pipemedic acid (21.75%),nitrofurantoin (18.8%) and norfloxacin (46.4%). sensitivity of norfloxacin,nitrofurantoin. conclusion: piperacillin/tazobactam is the most active combination against pseudomonas spp. and remains a very active beta-lactam when tested in vitro against clinical isolates of pseudomonas spp.