A survey of the microflora of the outdoor air environment of Keffi Metropolis, Nasarawa State, Nigeria

The microbiological quality of the air environment of Keffi metropolis was assessed by determining the concentrations and composition of bacteria and fungi present in the outdoor air. Air samples were collected from ten different locations of the metropolis by the plate sedimentation methods which involved exposing media-filled Petri plates to the air for 30 min. Trypticase soy agar (TSA) was used for the enumeration of total bacterial concentrations while malt extract agar (MEA) was used for the enumeration of total fungal concentrations. Standard microbiological methods were employed for the identification of the bacterial and fungal isolates. The results obtained show that the concentrations of bacteria in the different locations of Keffi ranged from 2.8 x 103 to 6.4 x 103 CFU/m3, while the concentrations of fungi ranged from 4.71 x 102to 4.60 x 103 CFU/m3. Six bacterial species belonging to six genera and nine fungal species belonging to seven genera were isolated at varying frequencies of distribution. The quantitative and qualitative analysis of the microbial flora of the outdoor air of Keffi metropolis has provided information on the airborne microorganisms. The fact that some of the bacterial and fungal species isolated are known to be pathogenic to humans has demonstrated that the microflora of Keffi metropolis has public health implication. Key words: Bacteria, fungi, microflora, air quality, Keffi, Nigeria.