RESUMEN
BACKGROUND: Cockroaches are the most prevalent domestic pests of a worldwide distribution. They were recognized as possible vectors of pathogenic bacteria, viruses, fungi and parasites in residential dwellings and hospital environments. The present study isolated and identified yeasts and filamentous fungi from digestive tract of American cockroaches, collected from three different residential regions of Iran. METHODS: Seventy cockroaches were sampled using direct collection (hand catch), vacuum cleaner and sticky traps in Ahvaz, Iran in 2009-2010. Their medically important fungal microorganisms were isolated from digestive tract using standard mycological methods. Filamentous fungi were identified by macroscopic and microscopic examination. Yeasts were identified by API ID32C-32100 kit. RESULTS: A high percentage of cockroaches (88.6%) were detected to carry fungi of medical importance. Overall, 23 fungi species/genera were isolated from the American cockroaches' alimentary tract. The fungi isolated from cockroaches, from the residential regions were species of Aspergillus, Rhizopus, Penicillium, Mucorales, Alternaria, Cladosporium, Mycelia, Chrysosporium, Candida, Rhodotorula, Zygosaccharomyces, and Debaryomyces. Candida spp. (41.4%), Aspergillus spp. (37.1%) and Rhodotorula spp (27.1%) were the most common fungi recovered on cockroaches. Candida albicans and Candida glabrata were the commonest species of the genus Candida. In addition, Aspergillus niger and A. flavus were the most frequent species of the genus Aspergillus. CONCLUSION: American cockroaches may carry pathogenic fungi in the urban areas of Ahvaz.
RESUMEN
Musca domestica L., 1758 is capable of transferring a number of pathogenic viruses, bacteria, fungi, and parasites to animals and humans. The objective of this study was to isolate and identify medically important filamentous fungi and yeasts from adult M. domestica collected from two wards of three hospital environments in Ahvaz city, Khuzestan Province, southwestern Iran. The common house flies were caught by a sterile net. These insects were washed in a solution of 1% sodium hypochlorite for 3 min and twice in sterile distilled water for 1 min. The flies were individually crushed with sterile swabs in sterile test tubes. Then 2 ml of sterile normal saline (0.85%) was added to each tube, and the tube was centrifuged for 5 min. The supernatant was then discarded, and the remaining sediment was inoculated with a sterile swab in the Sabouraud's dextrose agar medium containing chloramphenicol. Isolation and identification of fungi were made by standard mycological methods. In this research, totally 190 M. domestica from hospital environments were captured. In total, 28 fungal species were isolated. The main fungi isolated were Aspergillus spp. (67.4%), Penicillium sp. (11.6%), Mucorales sp. (11%), Candida spp. (10.5%), and Rhodotorula sp. (8.4%). Among the house flies caught at the hospitals, about 80% were found to carry one or more medically important species of fungi. This study has established that common house flies carry pathogenic fungi in the hospital environments of Ahvaz. The control of M. domestica in hospitals is essential in order to control the nosocomial fungal infections in patients.