Aspergillus diversity in the environments of nosocomial infection cases at a University hospital

Introduction and Objectives: Aspergillus species as opportunistic infections have been increasingly reported in human and immunosuppressive patients per year worldwide. The main object was to use a rapid and cheap molecular method for monitoring of Aspergillus infections and epidemiological approaches. Materials and Methods: Different molecular methods such as restriction fragment length polymorphism based on amplification of ribosomal RNA have been employed to identify Aspergilli at the level of species. The subject of our study was a group of hospitalized patients with clinical and subclinical signs of infection. All of the collected clinical specimens were transported to the medical mycology lab and examined for Aspergillus identification. Results: Environmental specimens were collected from air and surfaces inspected for the Aspergillus hospital sources. At first, a growth characteristics and microscopic features on mycological media for the identification of Aspergillus species were performed. For the confirmation of Aspergillus isolates which similarly found in clinical and environmental sources, molecular method polymerase chain reaction/restriction fragment length polymorphism was carried out. From the mentioned specimens, 102 fungal isolates included Candida spp., Aspergillus spp. and other fungi. Among the clinical isolates; Aspergillus flavus (47%), Aspergillus fumigatus (29.4%) and Aspergillus niger (23.5%) were the most frequent species respectively. Also, Aspergillus isolates from environmental were Aspergillus niger (43.7%), Aspergillus flavus (41.7%), Aspergillus fumigatus (14.6%). Conclusion: Therefore, polymerase chain reaction-restriction fragment length polymorphism with a single restriction enzyme can be very useful in identification of Aspergillus spp., because of its facility in use, speed, robust, and high sensitivity of diagnosis.

Keywords:

Aspergillus , identification , molecular , hospital.