Case Series: Emerging Pathogens Aerococcus urinae and Aerococcus sanguinicola at a Canadian tertiary care hospital

Abstract Introduction/Objective Background: Aerococcus urinae and sanguinicola are emerging opportunistic pathogen linked with urinary tract infections. Unmanaged Aerococcus infections have the propensity to precipitated into urosepsis. The ongoing gestalt of managing these infections needs standardization. We reviewed A. urinae and sanguinicola isolates from our clinical microbiology laboratory to better characterize its spectrum of clinical presentation, sources of infection, microbiological characteristics, and antimicrobial management. Methods/Case Report Methods: The electronic microbiology database was utilized to review the retrospective clinical data of patients that grew positive cultures for Aerococcus urinae and sanguinicola on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) in Saskatchewan from January to July 2023. Demographic variables, site of presentation, microbiological parameters surrounding culture and sensitivities, and antimicrobial management were recorded. The results were analyzed on SPSS 28 software. Results (if a Case Study enter NA) Results: This cohort (n=115) had a median age 82 years [Range: 7 to 103] with a female predilection (F:M = 78:37). A. urinae and sanguinicola were primarily involved in UTI (n=96), obstructive uropathy (n=9), and urosepsis (n=6). The hypothyroidism (26.9%, n = 31) rate in this population was 3-fold higher than the age-matched background rate for our province. Aerococcus infections were predominantly monomicrobial (73.9%, n= 85 out of 115) and showed sensitivity for ceftriaxone, penicillin G, and vancomycin. Antimicrobials were seldom used in the UTI cohort (31.2%, n=30 out of 96). Amoxicillin-clavulanate (29.8%, n=25 out 84) was the most popular choice at patient discharge in monomicrobial Aerococcus infections only. Conclusion Conclusion: Aerococcus urinae and sanguinicola are emerging uropathogen. Despite this, the clinical significance of these Aerococcus species remains undervalued. Our case series shows that untreated or recurrent A. urinae and A. sanguinicola infections can precipitate into urosepsis. Clinicians should utilize the antimicrobial susceptibility profiles for these Aerococcus species to provide appropriate antimicrobial coverage and manage these pathogens effectively. Further studies should explore the link between hypothyroidism and these aerococcal infections.