Microorganisms Associated with Oral Cavities Before and After Tooth Brushing Among Students of Imo State University, Owerri, Nigeria

Abstract

The oral cavity harbours a complex community of bacteria that may affect oral and systemic health. Poor oral hygiene favours bacteria growth, responsible for oral disorders such as halitosis, dental caries and periodontal infections. Tooth brushing still is one of the most efficient ways of lowering oral bacteria load.The study was carried out to examine the microorganisms associated with the oral cavities of students before and after teeth brushing among students of Imo State University, Owerri, Nigeria. Oral swab was obtained from the students of Imo State University before and after brushing using sterile swab sticks. The samples were cultivated on Nutrient agar, MacConkey agar, Mannitol Salt agar and Salmonella-Shigella agar by normal microbiological procedures. Bacterial enumeration was carried out by serial dilution and pour plate technique. Colony morphology, Gram stain, motility and biochemical assays (catalase, citrate, coagulase, oxidase, indole, methyl red, Voges-Proskauer and sugar fermentation) were used for the identification of the isolates. Total heterotrophic plate counts ranged from 3.2 × 10⁴ to 6.0 × 10⁷ CFU/g before brushing and significantly (p < 0.001) decreased to 3.2 × 10¹ to 6.0 × 10^4 CFU/g after brushing. Before brushing, bacterial isolates include Escherichia coli, Klebsiella spp., Proteus spp., Pseudomonas spp., Shigella spp. and Staphylococcus aureus. Only Klebsiella spp., Pseudomonas spp. and Staphylococcus aureus remained after brushing. The incidence rates of Escherichia coli, Pseudomonas spp., and Klebsiella spp. were 23% before brushing and 35% after brushing, respectively. Tooth brushing resulted in a considerable reduction of bacterial load and variety in the oral cavity. The survival of some harmful organisms after brushing underlines the necessity of good oral hygiene practice and the need for regular instruction on oral health care for university students.

Keywords: Oral Microbiota; Tooth-Brushing; Bacterial Burden; Oral Hygiene; University Students; Nigeria

Citation

Njoku-Obi Treasure, Chibueze NM, Nwanjo SO. Microorganisms Associated with Oral Cavities Before and After Tooth Brushing Among Students of Imo State University, Owerri, Nigeria. WebLog J Emerg Med. wjem.2026. f3002. https://doi.org/10.5281/zenodo.21430148