VIRULENCE FACTORS AND ANTIMICROBIAL RESISTANCE PATTERN OF BACTERIAL ISOLATES FROM READY-TO-EAT WATERMELONS AND PINEAPPLES IN OTA

Ready-to-eat (RTE) fruits are increasingly found in the markets as consumers demand fresh fruits on-the-go to meet up with a fast-paced lifestyle. Despite their advantages, the fruits are exposed to contamination due to the many processes they go through before they reach the consumer. This creates conditions for pathogens to establish themselves on the surface and within the pulp of fruits which may lead to illnesses on consumption. The aim of this study was to examine retailed RTE fruits in Ota for bacterial contaminants, highlight their antibiotic susceptibility patterns and detect selected virulence factors. RTE watermelons and pineapples were sampled from vendors along strategic locations in Ota, Ogun State. The fruits were analyzed using standard microbiological methods. Presumptive identification was by biochemical tests, Kirby-Bauer disc diffusion method was used to determine their resistance patterns against eight antibiotics. The isolates were screened for haemolytic activity, protease activity, and biofilm formation. Molecular characterization was carried out using polymerase chain reaction. The 16SrRNA gene of the isolates was amplified using the primer pair 27F- 5′- AGAGTTTGATCCTGGCT CAG -3’, and 1492R 5’- GGTTACCTTGTTACGACTT -3’. to confirm isolates. The isolates were tested against eight antibiotics for their susceptibility and screened for haemolytic activity, protease activity, and biofilm formation. The isolates identified via Gram-staining and biochemical tests were Bacillus, Listeria, Sarcina, Pseudomonas, Lactobacillus, Micrococcus, Staphylococcus, and Streptococcus species. Bacillus sp. was detected in both pineapples and watermelons. The most active antibiotics with their susceptibility rates were Ofloxacin (88%), Gentamicin (77%), and Erythromycin (33%). A 100% resistance to Ceftazidime, Cefuroxime, Cloxacillin, Nitrofurantoin, and Cefixime was observed. Staphylococcus was resistant to all the antibiotics. The isolates possessed at least one virulence factor. Of the isolates, 38.9% were negative for biofilm formation, 50% were proteolytic, and 61.1% showed either beta or alpha haemolysis. Bacteria with diverse pathogenic factors are present in RTE fruits. It is recommended that actions which will reduce the bacterial load on RTE fruits are enforced.