Antibiotic Resistant and Plasmid Borne Bacteria Associated with Locally Produced Honey in Enugu State, Nigeria

Aim: The aim of this study is to isolate and identify bacteria contaminants present in the honey samples sold in Ogbete market and detect the presence of imipenem resistance genes in the isolates.

Place and Duration of Study: A total of four samples were collected from Ogbete market at Zenith bank, Peace mass, Wheelbarrow and Peace park stations between the early hours of the morning (8-9am) within the month of April, 2023.

Methodology: Microbiological analysis was carried out on the samples, including antimicrobial susceptibility test using disc diffusion method., after which Molecular analysis involving DNA extraction, PCR and Plasmid Profiling, were carried out.

Results: The total mean heterotrophic bacterial count ranged from 0.03±2.5×103cfu/ml to 22.1±25.5×103cfu/ml. The highest total mean heterotrophic bacterial count was recorded in Zenith bank while the lowest was in Peace mass. The bacteria isolated and characterized through morphological and biochemical tests include Escherichia coli (45%) Klebsiella spp. (41%), Staphylococcus spp. (9%) and Streptococcus spp. (5%). Escherichia coli had the highest frequency of occurrence at 45% while Streptococcus spp. had the lowest at 5%. The sensitivity test showed that the isolates with the highest frequency of occurrence, Escherichia coli and Klebsiella spp. posed a high resistance to Imipenem and Nalidixic at 80% while the least resistance was in Levofloxacin at 10% from these two isolates. The gene of interest, BlaIMP was found after PCR assay. Plasmid DNA was further carried out using the alkaline lysis method using the Zymo research kit. All isolates possessed a single plasmid with molecular weight of 23.1kbp.

Conclusion: These isolates may undergo horizontal gene transfer and confer resistance to other microorganisms. Thus, there is need for the development of proper measures to counter bacterial contamination of locally produced honey as this poses a threat to public health.