Introduction: Bacterial consortia are non-random patterns of bacterial communities that work synergistically to provide growth and survival advantages over planktonic, free-floating, microbes. In this study, we aim to characterize bacterial consortia identified by multiplex polymerase chain reaction (M-PCR) in symptomatic patients with polymicrobial urinary tract infections (UTI). Methods: We performed a retrospective analysis of 2493 UTI-symptomatic patients over the age of 60 from 37 geographically disparate urology clinics from July 2018 to February 2019. M-PCR was performed to detect 24 different bacterial species. A cutoff of 10 detections was used to distinguish a bacterial consortium from a random association of bacteria in a polymicrobial specimen. Results: Bacteria were detected in 68.8% (1710/2493) of specimens. Of these, 60.1% (1027/1710) were polymicrobial. Of these, bacterial consortia were found in 42.2% (433/1027). Eight bacteria formed 18 different consortia, which ranged in count from 2 to 4 bacterial species, Table 1. All consortia contained Gram-positive bacteria. Half of consortia contained gram negative bacteria, and no consortium had more than one Gram-negative bacterium. A. Schaalii and A. urinae, which are both Gram positive, were the most commonly detected bacteria within the consortia, 73.0% and 67.7%, respectively, and were found in 14 of the 18 consortia. A. Schaalii and A. urinae were found together in 55.9% of consortia polymicrobial specimens, but in only 33% of non-consortia polymicrobial specimens. In contrast, some bacteria, such as P. aeruginosa and S. aureus, were detected in polymicrobial infections but not in any consortia. Conclusion: The balance of bacteria in consortia is shifted not only toward Gram-positive bacteria but also toward specific Gram-positive bacteria. The high prevalence of A. schaalii or A. urinae in the consortia suggests that the organisms could be keystone bacteria in formation of pathogenic consortia.
Vollstedt A, Wang D, Luke N, Baunoch D, Wojno K, Cline K, et al. Defining and detecting bacterial consortia within urine samples of patients with symptomatic urinary tract infection. Paper presented at: The Annual Winter Meeting of the Society of Urodynamics, Female Pelvic Medicine & Urogenital Reconstruction; 2021 Feb 25-27; Virtual. Available at: https://sufuorg.com/docs/meetings/sufu2102/program-book-abstracts.aspx