Candiduria in catheterized ICU patients: epidemiology, molecular identification, and antifungal susceptibility

Candiduria related to urinary catheters is frequently encountered in patients hospitalized in intensive care units. The diagnosis and management of catheter-associated candiduria in hospitalized patients is frequently a gray area for both physicians and microbiologists because of the paucity of clinical and microbiological data.

This cross-sectional study aims to enhance the understanding of candiduria among adult ICU patients with urinary catheters across three hospitals in Tehran, Iran. Yeast identification was performed using a two-step multiplex PCR, and antifungal susceptibility testing was performed following the CLSI M27, 4^th edition, recommendations.

Among the 110 enrolled ICU patients, 38 (35%) had significant candiduria. A total of 45 yeast isolates were collected. The distribution was as follows: Candida glabrata (23/45; 51%), C. albicans (14/45; 31%), and C. tropicalis (4/45; 9%). These three species accounted for 91% of the isolates. Antifungal resistance was detected: six isolates (two C. glabrata, two C. albicans, one C. krusei, and one C. tropicalis) were fluconazole-resistant, and one C. glabrata isolate was resistant to itraconazole, voriconazole, and caspofungin. All isolated species were susceptible to amphotericin B. Symptomatic candiduria occurred in 29% of cases (11/38); only 55% (6/11) were treated, and of those, 50% (3/6) experienced fluconazole treatment failure. One symptomatic patient developed candidemia shortly after acquiring candiduria. The mortality rate was 21% (8/38), with no apparent difference in death rates between symptomatic and asymptomatic candiduric patients.

Our findings reveal that high fluconazole failure rates among patients with symptomatic candiduria are concerning. Furthermore, speciation and antifungal susceptibility testing are crucial, as they guide clinicians in selecting the most effective agent and improving case management.