Asymptomatic bacteriuria among outpatients with diabetes mellitus in an urban black population.

OBJECTIVE

To determine the prevalence of asymptomatic bacteriuria (ASB) in individuals afflicted by Diabetes mellitus; the antibiotic susceptibility of the microbial isolates and the association of host factors with ASB.

DESIGN

This was a prospective cross sectional study.

SETTING

Attendants of outpatient polyclinics at three main tertiary hospitals; namely, Harare, Chitungwiza and Parirenyatwa Hospitals.

SUBJECTS

176 participants.

MAIN OUTCOME MEASURES

Patients attending the polyclinics between 6.30 am and 9.30 am from Monday to Friday were randomly selected. Demographic data was obtained at enrollment using a standardized questionnaire. Fasting venous blood was withdrawn from the participants for glucose analysis. Clean-catch midstream urine samples from all men and women were cultured and the causal organisms were isolated and identified by standard microbiological methods. Antibiotic susceptibility testing was performed using a disc diffusion method. Potential host factors included age, type of diabetes, duration of diabetes, glucosuria and leukocyturia.

RESULTS

The prevalence of ASB was 32% in the diabetics and 11% in nondiabetic participants. The commonest bacterial organism isolated in participants afflicted by Diabetes mellitus was Escherichia coli (26%) followed by Staphylococcus aureus (21%), Streptococcus group B (14%), Streptococcus group D and non-lactose fermenting coliforms (7% respectively). Other isolates were Micrococcus and Pseudomonas (5% respectively), Klebsiella and Proteus (2% respectively). Gentamicin, nitrofurantoin, ampicillin and nicene were the most effective antimicrobials in the majority of isolates. Certain isolates exhibited some bacterial resistance to conventional antibiotics. Of the host factors, an association was found between bacteriuria and glucosuria (p < 0.001) and between leukocyturia and bacteriuria (p = 0.005).

CONCLUSION

The prevalence of ASB is increased in diabetes and the rather high blood glucose levels exhibited by these individuals may further complicate this condition. As some bacterial species exhibited resistance to some common antimicrobials, these results raise questions regarding future clinical reliability of some conventional antimicrobials when considering therapy for asymptomatic bacteriuria.