ASSESSMENT OF AIRBORNE BACTERIAL ISOLATES FROM BUSINESS CENTERS IN PHYSICAL SCIENCE COMPLEX, UNIVERSITY OF BENIN

ABSTRACT

The microbial quality of indoor air in a given space at a particular time period is said to be determined by the quality of air entering the space, the number of occupants in the space, their physical activities and resultant aerosol generation, human traffic and ventilation of the area. The aim of the study was to identify the airborne bacterial isolates from business centers, determine the antibacterial susceptibility pattern, the multiple antibiotics resistance index and the public health significance of the isolates. The study of the sources of bacteria in two main areas of built (house and community places), and open-air environments is discussed here. Airborne samples were collected from three (3) selected business centres in Physical Science Complex, University of Benin, Benin City, Edo State using settle plate method. The plates were placed at a distance of 1m above the ground, away from direct contact with moving air and timed for 15 minutes after which they were covered and taken back to the laboratory. Various biochemical tests were carried out and results were recorded. These characteristics and results of biochemical tests were used to identify the possible bacterial organism isolated. The highest bacterial count of 5.5710³ cfu/m³ was observed and recorded in Week Three at Location One while the lowest bacterial count of 1.0310³ cfu/m³ was observed and recorded in Week One at Location Three. The organisms isolated were: Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Bacillis cereus, Streptococcus sp., Micrococcus sp., Nocardia sp. and Corynebacterium sp.MAR index greater than 0.2 indicates high risk source of contamination where antibiotics are often used. Passive overnight ventilation is an energy-efficient way to simultaneously cool building mass and avoid overnight and weekend microbial community stagnancy. The high level of contamination and bacterial load in the various Locations observed in this study could be reduced by increase in the hygienic status of the occupants, the buildings and the surrounding environment. Restriction should be made on the number of occupants that are allowed indoors at any given point in time and proper ventilation strategies should be implemented to minimize or reduce air congestion.