Occurrence of Free-living Amoebae in Nasal Swaps of Patients of Intensive Care Unit (ICU) and Critical Care Unit (CCU) and Their Surrounding Environments

BACKGROUND: The presence of potentially pathogenic Free Living Amoebae (FLA) in hospital environment could be a health hazard for high-risk patients such as immunosuppressed patients. This study was carried out to investigate the presence of potentially pathogenic FLAs in the environment and medical instruments of different hospital wards, and nasal swabs of immunosuppressed patients of a hospital in Tehran, Iran. METHODS: In this cross-sectional study, 60 environmental (26 samples) and nasal swab (34 samples) samples were collected between Dec 2015 and Feb 2016. The samples were assessed using culturing, staining and morphological methods based on page key. To decrease the bacterial and fungal contamination and better identification of FLAs, cloning was performed. RESULTS: Overall, 17 (28%) samples, including 13 environmental samples and 4 nasal swabs samples, were found positive for FLAs. The most frequent amoebae were Acanthamoeba spp. and two plates had mix contamination of Acanthamoeba spp. and Vahlkampfiids/Vermamoeba. Overall, Acanthamoeba species (58%), Vahlkampfiids (26%) and V. vermiformis (15%) were identified in clinical and environmental samples. CONCLUSION: The occurrence of these FLAs in environmental and clinical samples of hospital may threat health status of patients directly, particularly in immunosuppressed patients, and can transmit other pathogens. Thus, the increasing awareness of clinical setting staffs about FLAs and improvement of disinfection methods in hospitals is needed.