Evidence-based prescription of antibiotics in urology: a 5-year review of microbiology

OBJECTIVE To analyse the results of positive urine cultures over a 5-year period in a large hospital and urology department (amongst both inpatients and outpatients), assess the prevalence of different organisms and the resistance profiles of a range of antibiotics, and thus provide information on which organisms are likely to cause urosepsis. METHODS The use of antibiotics should be based on knowledge of which pathogens are present and what resistance patterns are emerging, particularly relevant in surgical disciplines like urology, as antibiotics are now routinely administered peri-operatively, whereby evidence-based prescription is preferable to generic guidelines. We therefore examined almost 25 000 positive urine cultures in our hospital over a 5-year period, and focused on the infections encountered amongst urology patients during this time. RESULTS A significant proportion of inpatient urinary infection (40%) is caused by Gram-positive bacteria such as Streptococcus faecalis, underlining the need for including Gram-positive cover during urological prophylaxis. The commonest pathogen remains Escherichia coli among both inpatients and outpatients. The ineffectiveness of common antibiotics such as ciprofloxacin and trimethoprim was identified, as was the increase in gentamicin resistance. CONCLUSION We propose using an aminoglycoside with a penicillin for high-risk cases (e.g. endoscopic stone surgery) while low-risk cases (e.g. flexible cystoscopy with no risk factors) might be managed without such prophylaxis. Pathogenic patterns and resistance rates should be monitored regularly.