Biodeterioration of Classroom Wall Surfaces in the University of Port Harcourt, Nigeria

Abstract

Aim: This study investigated the biodeterioration of classroom wall surfaces in the University of Port Harcourt, Nigeria. Study Design: Scrapings from selected classroom wall surfaces were analyzed for their microbiological and physicochemical parameters. Isolated bacteria were screened for their antibiotics susceptibility. Place and Duration of Study: This study was carried out at the University of Port Harcourt between March - June 2018. Methods: The population of culturable bacterial and fungal biodeteriogens was determined by plating. Physicochemical parameters were determined using standard methods. Antibiotic susceptibility pattern of the bacterial isolates was determined using the disc diffusion method. Results: The total culturable heterotrophic bacterial counts ranged from 6.48 to 8.23 log CFU/g while the total fungal counts ranged from 5.00 to 7.28 log CFU/g. The bacterial isolates identified by biochemical characterization and their frequency of occurrence are Micrococcus spp. (7.3%), Citrobacter spp. (3.2%), Bacillus spp. (39.1%), Serratia spp. (3.2%), Corynebacterium spp. (10.9%), Staphylococcus aureus (20.1%), Proteus spp. (9.2%) and Shigella spp (7.0%). The fungal isolates and their frequency of occurrence are Aspergillus flavus (39.1%), Penicillium spp. (20.1%), Microsporium canis (14.3%), Coccidioides spp. (10.9%), Aspergillus fumigates (3.2%) and Tricophyton spp (3.2%). All antibiotics used showed activity against all bacterial isolates except Proteus spp. From the results of the physicochemical parameters, pH values ranged from 6.15 to 9.01, nitrate ranged from 5.30 to 14.83 mg/kg, phosphate ranged 2.19 to 5.94 mg/kg, sulphate ranged from 12.97 to 19.07 mg/kg and Total Organic Carbon ranged from 74.89 to 119.43 mg/kg. Conclusions: This study has shown the potential public health risk associated with classroom building deterioration owing to the presence of pathogenic microorganisms. Therefore, measures towards prevention and mitigation of classroom building biodeterioration should be in place.