Risk Factors and Significance of Gentamicin Resistant Positive Urine Culture in Patients Undergoing Urological Surgery: A Short Report

We assessed patients who had pre-operative urine that grew gentamicin-resistant bacteria but were given gentamicin prophylaxis because urine result was not available. Our aim was to identify postoperative-sepsis rates, risk factors to acquire resistant-bacteria, and to optimize our prophylactic regime. Total 4,933 pre-operative urine-samples were reviewed and those positive for E.coli, Klebsiella or Proteus (n = 979) were analysed. Forty-four (4.4%) had gentamicin-resistant bacteria. Of those, 8 were immunosuppressed, 38 (86%) had a recent urological procedure and 29 (66%) had received recent antibiotics. Eighteen (41%) had a urinary catheter and 11 (25%) had double J stent. Three patients (7%) developed post-operative sepsis/febrile urinary tract infection. Although the majority of gentamicin-resistant samples represent colonization, the incidence of post-operative sepsis was significant. Amikacin may be a superior alternative. Our new protocol aims to pre-operatively identify patients at risk of prophylaxis failure with gentamicin and select amikacin as an alternative.