Asymptomatic bacteriuria is a common clinical entity in pregnancy but the prevalence due to S. saprophyticus, an established uro-pathogen in sexually active women, remained largely unknown in Nigeria. The prevalence of asymptomatic significant bacteriuria due to S. saprophyticus was therefore determined among 431 pregnant women in a tertiary health institution, Southwestern Nigeria. Clean catch specimens of mid stream, early morning voided urine, collected on two occasions with an interval of four weeks, were subjected to microbial analysis and quantitative culture. All cultures with significant growth (≥105 CFU/ml) were characterized and S. saprophyticus identified using conventional biochemical scheme. A total of 862 duplicate urine samples were analyzed; 19.5% were positive for the same bacteria on two consecutive samples, giving a prevalence rate of 19.5% for asymptomatic bacteriuria. S. saprophyticus was recovered from consecutive urine of 2.6% of the women, 54.5% of whom had significant pyuria. The isolates were all susceptible to vancomycin, gentamicin and fluoroquinolones, but 18.2% were methicillin resistant strains. From the result of this study, all pregnant women should be routinely screened for S. saprophyticus urinary carriage. Key words: Asymptomatic, Bacteriuria, Staphylococcus saprophyticus, Nigeria
