Antibiotic Susceptibility Profiles and Bacteriological Risks Associated With Used Toothbrushes: A Case Study of Some Apparently Healthy University Students in Southwestern Nigeria

Abstract

Toothbrushes play a significant role in disease transmission and increase the risk of infection since they serve as reservoirs for microorganisms in healthy, oral-diseased and medically ill adults. Investigation was carried out on the antibiotic susceptibility profiles of bacteria isolated from used toothbrushes. Thirty toothbrushes used for at least 5 weeks by thirty University students were collected. Heads of the brushes were soaked in 10 ml of sterile tryptone soya broth (TSB) and agitated by vortex mixing. The bacterial suspension was serially diluted. Plate count agar, MacConkey agar and Mannitol salt agar media were used for the isolation of non-fastidious bacteria, coliforms and staphylococci, respectively, employing the spread plate technique. Biochemical characterization of isolates was carried out using standard methods. Survival ability of bacterial contaminants on the used toothbrushes was also investigated at the 24th hr, 72nd hr and 144th. The disk diffusion method was employed for the determination of the antimicrobial susceptibility profiles of the bacterial isolates. Seven genera of microorganisms were encountered and these include Staphylococcus, Escherichia, Klebsiella, Pseudomonas, Lactobacillus, Leuconostoc and Proteus. Pseudomonas aeruginosa was most prevalent as shown by mean total plate count of 5.0 x 102 CFU ml-1 while E. coli had the lowest prevalence (1.2 x 102 CFU ml-1). It was discovered that S. aureus, S. epidermidis, E. coli and Proteus sp all survived at 144th hr indicating high survival ability, while Lactobacillus sp only survived at 24th hr. There were variations in the susceptibility patterns of the isolates to the various antibiotics. It was determined that 62.5% of the isolates showed susceptibility; twenty percent (20%) of isolates were intermediately susceptible and the remaining 17.5% were resistant. It was concluded that most bacterial isolates from toothbrushes were susceptible to antibiotics but the percentage resistant should be of great concern as it poses high health risk and may generate the spread of antibiotic-resistant bacteria within the family and beyond. Organisms such as some members of the enterobacteriaceae which are not normally associated with oral flora isolated from used toothbrushes investigated in this study should also be of interest.