Assessment of Bacterial Isolates Associated with Microplastics and their Resistance to Antibiotics from Rivers Ureje, Emirin, Ogbese, Odo-Ayo and Elemi in Ado- Ekiti, Ekiti- State, Nigeria

The presence of microplastics in water bodies is a threat to humans and aquatic animals, they serve as substrates for the attachment of microorganisms and also act as vectors for diseases in the environment. Hence, the objective of this paper is to assess bacterial isolates associated with microplastics and their resistance to antibiotics from Rivers Ureje, Emirin, Ogbese, Odo-Ayo and Elemi in Ado- Ekiti, Ekiti State, Nigeria using appropriate standard. Results revealed bacterial isolates such as Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Shigella dysenteriae, Bacillus subtilis, B. licheniformis, Pseudomonas aeruginosa, Proteus mirabilis, Micrococcus luteus, Enterobacter aerogenes, B. cereus, Citrobacter freundii, Aeromonas spp and Proteus vulgaris. River Emirin had the highest concentration of microplastics with the mean value of 6.15 particles/L while water samples from Elemi river had the least value of 4.65 particles/L. The Gram negative bacterial isolates (Pseudomonas aeruginosa, Proteus vulgaris, P. mirabilis and Citrobacter spp) showed high susceptibility to gentamycin and high resistance to the remaining antibiotics. The Gram positive bacterial isolates (Staphylococcus aureus, Staphylococcus epidemidis and B. licheniformis were highly susceptible to gentamycin and resistant to amplclox, rifampicin, amoxil, streptomycin, chloramphenicol and norfloxacin. The antibiotic susceptibility profile showed that both Gram negative and Gram positive bacterial isolates exhibited multiple antibiotic resistances. Of the 423 bacterial isolates, 341(80.7%) showed MAI index greater than 0.2. The water samples from the rivers must be treated before use, there should be public enlightenment on adequate method of plastics disposal and indiscriminate use of antibiotics in order to eradicate the incidence of antibiotic resistance.