Bacteriuria and Antimicrobial Susceptibility of Escherichia coli Isolated From Urine of Asymptomatic University Students in Keffi, Nigeria

Background: Asymptomatic bacteriuria can develop into symptomatic urinary tract infection. Objectives: This study investigated asymptomatic Escherichia coli bacteriuria among undergraduate students of Nasarawa State University, Keffi, Nigeria, and the antimicrobial susceptibility of bacterial isolates from these subjects. Patients and Methods: Four hundred urine samples were collected from consenting healthy male and female students. The bacterial load of each sample was determined by spread plate count on nutrient agar. E. coli was isolated and antimicrobial susceptibility of the isolates to common antibiotics was evaluated by the disc-diffusion method. Results: Of the urine samples, 80 (20%) showed significant bacteriuria, with a higher prevalence in females (25%) than in males (15%). While 60% of E. coli isolates from male samples were susceptible to pefloxacin or gentamicin, 3.3% were susceptible to amoxicillin/clavulanic acid. Twenty-seven (90%) E. coli isolates from male samples had multiple antibiotic resistance (MAR), with 37% being resistant to 5 antibiotics and possessing MAR indices of 0.5. Forty-nine (98%) of the E. coli isolates from female samples had MAR, with 13 (26.5%) being resistant to 6 antimicrobial agents and possessing MAR indices of 0.6. Conclusions: Significant bacteriuria is observed among the students of Nasarawa State University, with a higher prevalence in females than in males. Pefloxacin, ofloxacin, and gentamicin are effective against E. coli isolates from the urine of these students.