Bacterial diversity and antibiotic susceptibility profile of the isolates from public vehicles in Butwal Sub-Metropolitan City, Rupandehi, Nepal

Public transportation systems are vital for urban mobility but are susceptible to bacterial contamination due to high passenger density, frequent shared surface contact,minimal ventilation, and unsatisfactory cleaning practices promoting transmission of pathogenic and antibiotic resistant bacteria.,The main aim of this study was to explore the bacterial diversity associated with selected public vehicles and determine the antibiotics susceptibility patterns of bacterial isolates.A descriptive cross-sectional study was carried out from July 2023 to July 2024 at Paschimanchal Bus Terminal Stop, Butwal Sub-Metropolitan City, Rupandehi, Nepal. A total of 324 swabs were gathered from high-contact surfaces in AC buses, micro buses, and wingers using systematic sampling. Standard laboratory methods were used to identify bacterial cultures and their antibiotic susceptibility.Out of 324 surface swabs from 81 public vehicles, 262 (80.86%) showed bacterial growth. Among 262 isolates 148 (56.48%) were Gram positive and 114 (43.51%) Gram-negative. Predominant Gram positive isolates were CoNS 72 (27.48%), S.aureus 52 (19.84%) and Bacillus spp. 21 (8.02%), while Gram negative included E.coli 32 (12.21%), Klebsiella spp. 26 (9.92%) and Pseudomonas spp. 21 (8.02%). CoNS (44.44%, 32/72) and S.aureus (42.31%, 22/52) were significantly more frequent in Micro buses (P < 0.05). High antibiotic sensitivity was found for Gentamicin (100%, 12/12 for Micrococcus sp.; 97.22%, 70/72 for CoNS) and Meropenem (100%, 26/26 for Klebsiella spp.). Resistance was highest to Cetriaxone (100%, 9/9 for Citrobacter spp.) and Amoxicillin-clavulanic acid (69.2%. 18/26 for Klebsiella spp.) The extensive bacterial contamination present indicates an immediate need for better hygiene practices, improved cleaning methods, and public education to limit the microbial hazards associated with public transportation. Reduced sensitivity to commonly prescribed antibiotics, such as erythromycin in Staphylococcus aureus, indicates emerging antimicrobial resistance, posing greater risks to public health through limited treatment options and the spread of resistant strainsin the community.