Biochemical Identification and Antibiotics Susceptibility Pattern of Bacteria Isolated from Fomites in Dominion University Ibadan, Oyo State – Nigeria

Fomites surfaces (doorknobs) that can harbor and transmit microorganisms have been recognized as potential sources of infectious agents. Hence, understanding the bacterial diversity of fomites is essential to assess the risk of transmission and implement effective control measures. Nutrient, Mannitol Salt and MacConkey agar were used for the isolation of bacteria from fomites using the swab-rinse technique. Biochemical identification of bacterial isolates using catalase, coagulase, oxidase, indole, urea hydrolysis, and sugar fermentation were carried following standard microbiological protocols. Antibiotic susceptibility of the isolates to ten antibiotics was also carried out following the Kirby-Bauer disk diffusion method. A total of twenty (20) bacterial isolates were obtained from forty-five (45) fomites across five (5) locations. The peak microbial count was observed in the afternoon across all surfaces and the total heterotrophic count (THC) during this time ranged from 1.6 x 102 -1.9 x 105, 1.9 x 103 - 1.8 x 106 and 1.7 x 105 – 3.1 x 106 CFU/mL in week 1, 2 and 3, respectively. The Gram’s reaction revealed that 9 (45%) of the bacterial isolates were Gram positive while the remaining 11 (65%) were Gram negative. The biochemical characteristics revealed that all the bacterial isolates (100%) were catalase positive, 6 (30%) were coagulase positive, 4 (20%) were indole positive, 13 (65%) were urease positive, and 3 (15%) were oxidase positive. The sugar fermentation pattern showed that glucose and sucrose were the most preferred carbon sources across. The bacterial isolates belonged to five genera viz; Staphylococcus (45%), Proteus (10%), Escherichia (20%), Klebsiella (10%), and Pseudomonas (15%). Pefloxacin (10µg) and Ciprofloxacin (10µg) had the highest antagonistic effect while Zinnacef (20µg), Amoxicillin (30µg), and Erythromycin (10µg) had the least inhibitory effect against the test microorganisms, respectively. This research provides valuable insights into the bacterial composition of fomites within Dominion University, Ibadan. The knowledge gained from this study can serve as a foundation for developing targeted control strategies to ensure a safe and healthy campus environment.