[Encrusted Pyelitis Secondary to Corynebacterium urealyticum Infection: A Rare and Serious Complication].

Corynebacterium urealitycum is a gram-positive bacillus, usually found as a colonizer on the skin. However, a pathogenic role has been described in susceptible patients, where it can cause urinary tract infection, nephrolithiasis, pyelitis, and encrusted cystitis.

Methods: Retrospective cohort study of patients older than 18 years with positive urine cultures for C. urealyticumin the Laboratory of the Microbiology of the UC Health Network - CHRISTUS, between 2017 and 2020.

Results: 6 positive urine cultures were obtained, corresponding to 5 patients. One case presented as encrusted pyelitis, with an associated reinfection, one case as lower urinary tract infection, and three as asymptomatic bacteriuria. All patients had some relevant risk factor. All patients presented urine tests with triple phosphate crystals and alkaline pH between 7.5 and 9.0.

Conclusions: Patients with positive urine cultures for C. urelyticum represent a low percentage of all agents isolated from urine cultures. Although it may be asymptomatic, the development of encrusted pyelitis is a possible manifestation associated with an extended hospital stay. Urinalysis with alkaline pH and the presence of triple phosphate crystals is characteristic. More extensive clinical series and antibiotic susceptibility studies are necessary for a more standardized management of these patients. Finally, the authors' key lesson is remembering how unusual bacteria, such as C. urealyticum, can cause serious complications secondary to their phytopathogenic mechanism of urine alkalinization.