Isolation and antimicrobial susceptibility testing of Escherichia coli causing urinary tract infections

Objective: Escherichia coli is the greatest cause of primary urinary tract infections (UTI). Antimicrobial \nsusceptibility testing provides information that allows physicians to select the most appropriate antimicrobial \nagents for treating a specific infection. This study aimed to assess the current status of multidrug resistance \namong urinary Escherichia coli isolates in Kenya. \nMethodology and results: A total of 3,341 urine samples were collected from in and out-patients attending \nThika district hospital in Kenya between January and December 2008. The samples were cultured on \nCystein lysine electrolytes deficiency (CLED) media and the bacterial isolates recovered were tested \nagainst Trimethoprim-sulfamethoxazole, Cefuroxime, Augmentin®, Nitrofurantoin, Nalidixic acid, \nGentamycin, Cephaloxin, Norfloxacin, Ciproxin®, Ceftazidime, Amikacin, Ofloxacin, Centriaxone, \nPerfloxacin, Ticarcillin, Pipril and Roceph using Kirby Bauer disc diffusion technique. Among the 3,341 \nsamples examined, 24% had Escherichia coli isolates with 64% of them being from female patients \ncompared to 36% that were from men aged above 21 years. In children aged >10yrs, boys had the highest \nprevalence (55%) compared to girls (45%). Those in age categories <21yrs had the more isolates (73%) \nfollowed by 5-10yrs (46%), 1-4yrs (16%), and the least 11-20yrs (5%). Upto 75% of the isolates were \nresistant to Trimethoprim-sulfamethoxazole; all (100%) were susceptible to Ticarcillin, Peril/Tazo, Amikacin, \nOfloxacin and Roceph; and 80% of the isolates were susceptible to Cephalexin, Ceftriaxime, Nalidixic acid, \nGentamycin, Norfloxacin, Ciproxin®, Ceftazidime/fortum and Centraixone. \nConclusion and application of findings: Considering the relatively high rates of UTI and drug resistance \nobserved in this study, continued local, regional, and national surveillance is warranted. Antibiotics should \nonly be issued when prescribed by physicians.