Streptococcus urinalis: A potential case of male urethritis caused by a novel pathogen

Abstract

Urethritis is a frequent lower urinary tract infection often linked to sexually transmitted infections (STIs). While Neisseria gonorrhoeae and Chlamydia trachomatis are the main pathogens, other microorganisms such as Mycoplasma genitalium, Trichomonas vaginalis, and Ureaplasma urealyticum may also be involved. In over half of non-gonococcal urethritis (NGU) cases, no causative agent is identified. We present the case of a 37-year-old man with scrotal pain, painful ejaculation, dysuria, and urethral discharge following a single unprotected sexual encounter. Initial STI PCR was positive for Ureaplasma urealyticum, and azithromycin was prescribed. Symptoms persisted, and a urethral culture revealed Streptococcus urinalis, confirmed by MALDI-TOF MS and 16S rRNA sequencing. Gram staining showed numerous leukocytes and Gram-positive cocci in chains. A second urethral swab yielded the same organism. The isolate was fully susceptible to all tested antibiotics. Although S. urinalis has been described in urinary tract infections and sepsis, to our knowledge, this is the first reported case suggesting a possible role in male urethritis. While prostatitis or epididymitis cannot be ruled out, the repeated isolation of S. urinalis and persistent symptoms support its potential pathogenicity. This case adds to growing evidence implicating S. urinalis in genitourinary tract infections.