Abstract

A significant percentage of the population in Port Harcourt metropolis consumes olive oil for mostly cooking and religious reasons. The production of good quality olive oil free from pathogenic microorganism is essential to prevent diseases or illnesses associated with contamination of olive oil. This study was aimed at determining the microbial composition of different olive oil brands sold in Port Harcourt metropolis. Five (5) samples of different olive oil brands were used for the study. Isolation and enumeration of microorganisms was done on appropriate Agar medium using standard microbiological techniques. The results showed that the Total Heterotrophic Bacteria Count (THBC) ranged from 1.0 × 10⁵ to 7.6 ×10⁵CFU/ml and Total Heterotrophic Fungi Count (THFC) was zero. Twenty five (25) bacteria isolates belonging to 5 genera with their percentage of occurrence were; Pseudomonas sp. (16%), Bacillus sp. (16%), Micrococcus sp. (8%), Staphylococcus spp. (28%), Escherichia coli (28%) and Klebsiella sp. (4%). Percentage occurrence from bacterial isolates showed that Staphylococcus spp. and Escherichia coli were the most dominant bacterial species while Klebsiella sp. was the least occurring bacterial species. Antibiotic sensitivity results showed that Staphylococcus sp. were more susceptible to Ciprofloxacin, Erythromycin, and Levofloxacin but showed resistance to Gentamicin, Cefuroxime and Ceftazidime. Escherichia coli was more susceptible to Ofloxacin, Augmentin, Peflacine, Ciprofloxacin, and Ceporex, but resistant to Ceftriaxone and Gentamicin. Pseudomonas sp. was more susceptible to Ofloxacin, and Ciprofloxacin but resistant to Ceftriaxone. Bacillus sp. was susceptible (100%), to all antibiotics tested, except Levofloxacin (75%) and Cefuroxime (50%). Klebsiella sp was resistant to Ceftriaxone but susceptible to all other antibiotics tested. The presence of potential pathogens such as Pseudomonas sp., Bacillus sp., Micrococcus sp., Staphylococcus spp., Escherichia coli, and Klebsiella sp. which exhibited antibiotic resistance as shown in this study buttress the urgent need for actions to safeguard public health. Microbiological testing of olive oil brands for microbial contaminants is important, to ensure compliance with standards and prevention of public health outbreak.