Aerococcus urinae and Globicatellasanguinis Persist in Polymicrobial Urethral Catheter BiofilmsExamined in Longitudinal Profiles at the Proteomic Level

摘要

Aerococcus urinae (Au) and Globicatella sanguinis (Gs) are gram-positive bacteria belonging to the family Aerococcaceae and colonize the human immunocompromised and catheterized urinary tract. We identified both pathogens in polymicrobial urethral catheter biofilms (CBs) with a combination of 16S rDNA sequencing, proteomic analyses, and microbial cultures. Longitudinal sampling of biofilms from serially replaced catheters revealed that each species persisted in the urinary tract of a patient in cohabitation with 1 or more gram-negative uropathogens. The Gs and Au proteomes revealed active glycolytic, heterolactic fermentation, and peptide catabolic energy metabolism pathways in an anaerobic milieu. A few phosphotransferase system (PTS)–based sugar uptake and oligopeptide ABC transport systems were highly expressed, indicating adaptations to the supply of nutrients in urine and from exfoliating squamous epithelial and urothelial cells. Differences in the Au vs Gs metabolisms pertained to citrate lyase and utilization and storage of glycogen (evident only in Gs proteomes) and to the enzyme Xfp that degradesd-xylulose-5′-phosphate and the biosynthetic pathways for 2 proteincofactors, pyridoxal 6′-phosphate and 4′-phosphopantothenate (expressed only inAu proteomes). A predicted ZnuA-like transition metal ionuptake system was identified for Gs while Auexpressed 2 LPXTG-anchored surface proteins, one of which had a predicted pilinD adhesion motif. While these proteins may contribute to fitness and virulencein the human host, it cannot be ruled out that Au andGs fill a niche in polymicrobial biofilms without being thedirect cause of injury in urothelial tissues.