Laboratory Survey of Significant Bacteriuria in a Family Practice Clinic – Is the Spectrum of Causative Agents Changing?

Abstract

Urinary tract infection correlates with significant bacteriuria. Empiric and definitive therapy depends on the sensitivity pattern of the causative agents, so it is essential to keep abreast of changes in the causative organisms. This study was carried out to determine the causative agents of significant bacteriuria and their antibiotic sensitivity pattern. Mid stream urine specimens were collected from all patients attending the Family Medicine Clinic of the Lagos State University Teaching Hospital, Ikeja Lagos in July and August of 2005. The urine specimens were transported on ice to the Medical Microbiology and Parasitology Department of the College of Medicine, Idi-Araba. Significant bacteriuria was determined by the standard loop method. Culture was performed on MacConkey agar (oxoid) and blood agar base (Oxoid) and Isolates were identified by standard laboratory methods. Antibiotic sensitivity was by disc diffusion method. Four hundred and fifty urine specimens surveyed for bacteria were from 251 females (55.8%) and 199 males (44.2%) with age range 13 to 89 years. Ninety four patients (20.9%) had significant bacteriuria and 14 were symptomatic, making the prevalence rate of symptomatic bacteriuria 3.1%. Out of 91 patients who had been on antibiotics, a significantly higher proportion (52%) had bacteriuria while only 13.4% of those who had not been on antibiotics had bacteriuria. Klebsiella and Enterobacter species were more commonly isolated than E. coli. Most of the isolates were resistant to cotrimoxazole (89%), tetracycline (69.1%) and amoxicillin (88.1%). Sensitivity rates to the urinary antiseptics ranged from 54.2 to 55.9%. Many of the bacteria were sensitive to ofloxacin(92.9%), ciprofloxacin(84.7%), cefotaxime(72.9%), ceftriaxone(86.4%) and ceftazidime(88.1%). Sensitivity to the aminoglycosides ranged from 57.7 to 59.3%. The spectrum of isolates in this study and the high rate of antibiotic resistance suggest that many patients in this population will probably benefit more from treatment of UTI based on routine antibiotic sensitivity testing rather than empiric therapy..

Keywords: Asymptomatic bacterivria, significant bacterivria, antibiotic sensitivity, antibiotic resistance, laboratory survey.

Nigerian Journal of Health and Biomedical Science Vol. 6 (1) 2007: pp. 52-57