Detection of antibiotic resistance genes in bacterial isolates from most touched surfaces of public transports in Sagamu, Ogun state, Nigeria

Background and Aims: The role of fomites in the transmission of infectious diseases is becoming more important because of the possibility that contaminated surfaces act as reservoirs of diseases. The aim of this study was to ascertain the level of bacterial contamination and the prevalence of antibiotic-resistant genes on the most touched surfaces on public transport.Methods: One hundred samples were collected from door handles and armrests of buses and tricycles, respectively at Isale-Oko motor garage, Sagamu. Bacteria were isolated from the samples and identified following standard microbiological techniques. Antibiotic susceptibility testing was done with the Kirby-Bauer disc diffusion method. The presence of antibiotic-resistant genes vanA, drfA, dfrG genes, and extended-spectrum betta-lactamase (ESBL) genes in Gram-negatives were screened by polymerase chain reaction (PCR) method.Results: Out of the samples tested, 91% were positive for bacterial contamination. Among the 91 positive samples, 126 bacteria were identified, comprising 98 Gram-positive and 28 Gram-negative bacterial isolates. Staphylococcus aureus had the highest overall frequency of occurrence with 62 (49.2%) isolates. Among the Gram-positives, azithromycin resistance was present in 35(56.5%) S. aureus and 19(52.8%) Staphylococcus epidermidis. Salmonella species was the most resistant to ciprofloxacin (100%). dfrG was the most detected among trimethoprim-resistant genes occurring in 11(55%) of multidrug-resistant S. aureus and 6(54.6%) of S. epidermidis. vanA gene was present in S. aureus (20%). dfrA was present in only Klebsiella pneumoniae and Esherichia coli. E. coli and Shigella species carried 𝑏𝑙𝑎𝑇𝐸𝑀 while 𝑏𝑙𝑎𝑆𝐻𝑉 was found in Pseudomonas aeruginosa.Conclusion: The most-touched surfaces of public transportation can serve as a substantial source of spread for potentially harmful bacteria.