A Study on the Prevalence of Indoor Mycoflora in Air Conditioned Buses

Aim: To study the presence of indoor mycoflora in A/c Buses to know the commuters risk of exposure to fungal spores.
Place and Duration: Chennai Mofussil Bus Terminus (CMBT), Koyambedu, Chennai, India. Study was conducted from November 2011 to April 2012.
Methodology: Airborne fungi from 50 A/c buses were studied using Reuter Centrifugal Sampler (Biotest, Germany), fungi from the surfaces of air vents through swab sample and bus seats by rubbing sterile petridishes on the seats. Sabourauds Dextrose Agar (SDA) was used for the isolation of fungi from different buses. The collected data were statistically analyzed.
Results: A total of 38 species classified in 21 genera were recorded. Among which, Zygomycetes was represented by 4 species, Ascomycetes and Coelomycetes by single species each and the remaining belongs to Hyphomycetes. The genus, Aspergillus was represented by maximum number of species (11 species) followed by Penicillium (5 species). A total average of 713 CFU/m3 of air was recorded within the buses. Aspergillus niger was the first dominant fungi in the order of dominance followed by Chrysonilia sitophila, Alternaria alternata and Aspergillus flavus in that order. From the surface of bus seats, Aspergillus niger, A. flavus, Rhizopus stolonifer and A. japonicus were recorded as dominant. However, different mycofloral composition was recorded from air vents. Cladosporium chlorocephalum and Curvularia lunata dominated the surface of air vents.
Conclusion: The study demonstrates the presence of potential fungal species which pose exposure risk to the immune compromised commuters.