Bacteriological assessment of the indoor air quality of the lecture rooms in the Faculty of Life Sciences, University of Benin, Nigeria

Objective: To assess the bacteria load of lecture rooms in the Faculty of Life Sciences, University of Benin, Benin City, Nigeria. Methods: Air sampling using settle plate method in lecture rooms was carried out for two months. The temperature and relative humidity of the sampled areas were determined while the bacteriological analyses were carried out using the standard microbiological methods. Virulent factors and antibiotics susceptibility profile of the isolates were analyzed. Results: The lecture room with the highest bacterial, coliform and Staphylococci count was plant biology and biotechnology lecture room with values 4.84 ± 0.82 × 10 3 , 4.30 ± 0.51 × 10 3 and 3.52 ± 0.89 × 10 3 cfu/m 3 , respectively, in the two months dectected. The identified bacterial isolates were Lactobacillus delbrucckii, Aeromonas (A.) hydrophilia, Enterobacter intermedius, Serratia liquefacias, Pseudomonas sp., Micrococcus luteus, Acineobacter baumanii, Lactobacillus fermenti, Serratia marcescens, A. veronii., Streptococcus sp., Staphylococcus aureus, Corynebacterium sp. The isolate with the highest frequency of occurrence was Staphylococcus aureus . Bacterial isolates with the highest virulence factors of 100 % was A. veronii. The antibiotic susceptibility profile showed that all Gram-negative bacterial isolates were susceptible to Sparfloxacin antibiotic. Isolate with the highest multiple antibiotic resistance index of 0.6 was Acineobacter baumanii . Conclusions: To maintain air quality, constant monitoring of parameters like temperature and humidity that promote the presence organisms in the air, reducing the number of occupants, ensuring a well-functioning ventilation system, and implementing regular cleaning routines should be practiced.