ABSTRACT
Investigating the air borne micro flora is an important criteria that must be taken into account when indoor learning environment are designed to provide a safe environment. Pathogenic airborne microbes are potential sources of diseases. This study aimed to investigate the micro flora of the indoor air with relevant emphases on the composition, microbial load and occurrence of bacterial and fungal species in a lecture room. Most University Students spend about 60-70% of their time in lecture rooms and exposure to these microbial contaminants in air has a direct impact on their health, performance and productivity. The research was carried out by sampling the air using settle plate method; from various lecture room in the Faculty. Culture media used were nutrient agar, mannitol salt agar, potato dextrose agar and MacConkey agar. Sampling was carried out every month for 2 months. The results showed that the lecture room with the highest bacterial, Coliform and Staphylococci count was PBB LR with values 4.8 ± 0.82 x 103 cfu/m3 , 4.30± 0.51 x 103 cfu/m3 and 3.52 ± 0.89 x 103 cfu/m3 respectively in the second month. The highest fungal count of 1.57 ±0.68 x 103 cfu/m3 was from MCB LR in the first month. The identified bacterial isolates were Lactobacillus delbrueckii, Aeromonas hydrophilia, Enterobacter intermedius, Staphylococcus epidermis, Serratia liquefacias, Pseudomonas sp, Micrococcus luteus, Acineobacter baumanii, Lactobacillus fermenti, Serratia marcese, Aeromonas veronii., Streptococcus sp., Staphylococcus aureus, Corynebacterium sp. The isolates Lactococcus delbrueckii had the highest frequency of occurrence. The Bacterial isolate Aeromonas veronii., had the highest virulence factors of 100%. The antibiotic susceptibility pattern showed that all Gram negative isolate was susceptible to Sparfloxacin antibiotic. Isolate with the highest MAR index of 0.6 was Aeromonas veronii. Identified fungal isolates were Penicillium sp., Aspergillus sp. and Alternaria sp. Proper ventilation systems, a good building design, regular environmental hygiene and constant monitoring of parameters like temperature and humidity which aid the growth of these organisms or their presence in the air should be observed.
