Isolation and identification of species from the water systems of ICUs and transplant wards of hospitals and determination of the susceptibilities of isolates to conventional antifungals.

BACKGROUND

The rising prevalence of nosocomial infections, particularly those caused by airborne fungal spores in operating rooms and intensive care units (ICUs), has become a significant public health concern. species in water systems pose a severe threat to immunocompromised patients and can disseminate as aerosols through devices such as faucets and showers. This study aimed to isolate and identify species from the water systems of the ICUs and transplant units at Imam Khomeini Hospital Complex and Shariati Hospital in Tehran, Iran, as potential sources of future outbreaks. Additionally, the study sought to determine the susceptibilities of the isolates to conventional antifungal agents.

METHODS

Sterile swabs and open plates containing Sabouraud dextrose agar (SDA) with chloramphenicol were used to collect water samples from sink surfaces, shower trays, faucets, and around the drains of sinks, as well as from bathroom areas. Swab samples were cultured, and the open-plate samples were evaluated for the growth of species. The validation of all sp. isolates was performed using DNA sequencing of the translation elongation factor 1-alpha (TEF-1α) gene. The antifungal susceptibility patterns of each isolate were tested against voriconazole, itraconazole, posaconazole, caspofungin, and amphotericin B using the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method for filamentous fungi.

RESULTS

species were recovered from six out of 362 water system samples, representing 1.65% of the total. Five isolates were identified as from the complex, while one isolate was identified as from the complex. All isolates were obtained from sinks (three isolates) and faucets (three isolates) at Imam Khomeini Hospital. Antifungal susceptibility testing revealed that posaconazole, voriconazole, and amphotericin B were the most effective drugs against all isolates, with no instances of resistance to these antifungal agents observed. However, non-wild-type isolates were noted for the other drugs tested.

DISCUSSION

The isolation of pathogenic species from water samples collected in the ICU wards of the Imam Khomeini Hospital Complex underscores the urgent need to implement effective control and prevention measures in hospital water systems.