Urinary tract infections: Should we think about the anaerobic cocci?

Abstract

Anaerobic cocci are common anaerobic isolates. Numerous genera of anaerobic cocci have been reported in both urinary tract microbiota, mainly of females, and in cases of urinary tract infections (UTIs), predominantly in patients with comorbidities, when no facultatively anaerobic bacteria were detected from the urine samples. UTIs caused by anaerobic cocci have been reported in >7% in some studies. As the routine diagnostic methods may be insufficient to detect and identify the anaerobic cocci in patients with UTIs, enhanced quantitative urine culture (EQUC) can give better results. EQUC is performed by plating urine samples onto different media to be incubated in both aerobic and anaerobic conditions with a prolonged incubation time. Other newer methods such as 16S rRNA gene sequencing, qualitative PCR and Next Generation Sequencing can also be considered. Anaerobic cocci such as Peptoniphilus, Parvimonas, Anaerococcus and Finegoldia spp. were found in patients with bacteremia of urinary source. A fatal outcome has been reported in a diabetic patient with emphysematous pyelonephritis caused by Finegoldia magna and Candida parapsilosis due to a delay in seeking hospital care during the COVID-19 pandemic. In specific cases such as of chronic infections, immunosuppression, comorbidity, advanced age, following urological tract manipulations and negative culture results for usual uropathogens, it may be advisable to use suprapubic aspiration cultured in both aerobic and anaerobic condition or EQUC using media which support the relative slow growing anaerobic cocci as well.

Keywords: Anaerobic cocci; Detection; Enhanced quantitative urine culture; Treatment; Urinary tract infections.