Urinary tract infections with Aerococcus urinae in the south of the Netherlands

Aerococcus urinae is an uncommon urinary tract pathogen that causes infections predominantly in elderly persons with local or general predisposing conditions. During a one-year study, the clinical features of Aerococcus urinae urinary tract infections (≤ 10⁵ cfu/ml) were investigated in two large medical microbiology laboratories in the Netherlands. The incidence of Aerococcus urinae urinary tract infections ranged between 0.31 and 0.44% for the two laboratories. The median age (range 35-95 years) of patients with this infection was 82.5 years for women and 77.5 for men. Men had significantly (p < 0.01) more local predisposing conditions than did women. Underlying systemic diseases such as diabetes mellitus, malignancy, and dementia were found in 67.5% of patients. Most patients (97.5%) had the classic signs of a urinary tract infection, but none of them developed serious symptoms. All isolates tested were susceptible to penicillin, amoxicillin, and nitrofurantoin, 78.3% were susceptible to norfloxacin, and all were resistant to sulfonamides. The majority of patients were treated with amoxicillin, amoxicillin with clavulanic acid, or norfloxacin.