Analysis of urine culture isolates from seven laboratories of Sri Lanka: National Laboratory Based Surveillance of Sri Lanka College of Microbiologists in 2014

Introduction: National Laboratory Based Surveillance of Antimicrobial Resistance in urinary isolates conducted by the Sri Lanka College of Microbiologists was started in 2011 in collaboration with the Ministry of Health of Sri Lanka. Methods: Pooled susceptibility data of urine culture isolates with a colony count of ≥10 5 CFU/ml from samples of non-catheterised patients received in 2014 were analysed using WHONET 5.6 software. Results: The majority of the isolates (3975/4979:79.8%) were Gram negative enteric organisms, commonly known as coliforms. The other bacterial isolates identified were Enterococcus spp. (254), Pseudomonas spp. (194), coagulase negative staphylococci (59), Staphylococcus aureus (36), Acinetobacter spp. (35) and Group B β-haemolytic streptococci (18). The coliforms isolated from adults attending outpatient clinics (n=277) had 55.2% susceptibility to cephalexin and cephradine, 54% to amoxycillin/clavulanic acid, 65.1% to nitrofurantoin, 48.3% to norfloxacin, 63.4 % to cefotaxime, 86.4% to gentamicin, 97.4% to imipenem and 100% to meropenem. The isolates from adult hospitalized patients (n=1297) had 39.5% susceptibility to cefotaxime, 87.9% to meropenem, 62.6% to gentamicin and 31.9% to ciprofloxacin.  Coliforms isolated from paediatric outpatients (n=182) had 58.5% susceptibility to cephalexin and cephradine, 58.5% to amoxycillin/clavulanic acid, 80% to nitrofurantoin, 85% to cefotaxime, 86.5% to gentamicin and 89.7% to meropenem. Those from paediatric hospitalized patients (n= 663) had 64.6% susceptibility to cefotaxime, 90.5% to meropenem and 80.2% to gentamicin. Conclusion: Coliforms, the commonest category of organisms isolated had high resistance rate in hospitalized patients whereas the resistance was less in outpatients, especially in the paediatric age group.