Aerococcus urinae strain isolation, identification, and characterization.

Twenty-four clinical isolates of Aerococcus urinae were collected from transurethral catheter urine samples of 21 female patients between 2013 and 2016. Following Loyola University Medical Center (LUMC) Institutional Review Board approval, patients gave verbal and written consent for chart abstraction and urine collection with analysis for research purposes. Patients were recruited as part of separate studies (5, 23, 28, 29). Matrix-assisted laser desorption ionization–time of flight mass spectrophotometry (MALDI-TOF MS) with the MALDI Biotyper 3.0 software program (Bruker Daltonics, Billerica, MA) was used to identify the bacterial strains, as described elsewhere (2).

The 24 clinical A. urinae strains were isolated from women with and without lower urinary tract symptoms (Table 1). Nine strains were collected from seven patients diagnosed with overactive bladder (OAB), nine strains were from eight patients diagnosed with UUI, and three strains were from three patients diagnosed with stress urinary incontinence (SUI). One A. urinae strain was cultured from a case of UTI, as defined by patient symptoms and culture of >100,000 CFU/ml of A. urinae as the sole uropathogen, verified by the clinical microbiology lab using MALDI-TOF MS as described above. Finally, two strains were cultured from two asymptomatic control patients. Of note, the three hyperflocking strains were isolated from different patients, collected months apart.

In addition to the 24 clinical strains of A. urinae, strains from 3 other Aerococcus species were selected for the genome comparison analysis described below. All three were isolated via the same method and during the same time period as indicated for the 24 A. urinae strains. Aerococcus christensenii (UMB0884) was cultured from an asymptomatic control patient, while Aerococcus sanguinicola (UMB0139) and Aerococcus viridans (UMB0240) were cultured from two different patients with OAB.