Antibiotic susceptibility of organisms causing urinary tract infection in patients presenting to a teaching hospital

Urinary tract infections (UTI) are common. It causes severe morbidity and mortality, and it is important to know the causative organisms in the hospital and community for optimum management of UTI.

This is a prospective hospital based study to identify the organisms causing UTI and their antibiotic susceptibility. Consecutive patients presenting with symptoms of UTI had their clean catch midstream urine analysed. Antibiotic susceptibility was tested by Kirby-Bauer's disc diffusion method as described by National Committee for Clinical Laboratory Services (NCCLS) guidelines.

Out of 1726 patients, 549 (31.8%) showed bacterial growth. Escherichia coli was most common (72.5%), followed by Klebsiella pneumoniae (11.3%), Staphylococcus aureus (3.1%), coagulase negative Staphylococcal species (2.7%) and others (10.1%). There was a female dominance of 3.2:1 compared to males, except in the 61 and above age range. Infections were most common in young adults (21-30 years). The most effective antibiotic was Nitrofurantoin followed by Norfloxacin, Ciprofloxacin and Ofloxacin. Some isolates were resistant to Norfloxacin, Ampicillin, Cotrimoxazole and Ciprofloxacin.

The most common causative organism for UTI was Escherichia coli, and the best first line antibiotic was Nitrofurantoin. Organisms are developing resistance to antibiotics such as Norfloxacin, Ampicillin and Ciprofloxacin.