Iranian Biomedical Journal

en Molecular Characterization of Multi-Drug Resistant Histamine-Producing Gram-Negative Bacteria Isolated from Fermented Prosopis africana Seeds (okpee) in Nigeria Molecular Microbiology Molecular Microbiology مقاله کامل Full Length/Original Article Background: Fermented Prosopis africana seeds (okpee) are naturally protein-rich but exude odors that attract houseflies. These flies can carry contaminants, including pathogens and histamine-producing bacteria. Bacterial histamine in food can cause illnesses and pseudo-hypersensitivity reactions. This study investigated multidrug-resistant, histamine-producing Gram-negative bacteria (GNB) isolated from okpee sold in Enugu Ezike, Nigeria. Methods: Histamine content of the mesquite seed samples was determined using high-performance liquid chromatography. Bacteriological isolates from randomly sampled okpee were identified by 16S rRNA gene sequencing. Antibiotic susceptibility of the isolated bacteria was assessed using the Kirby-Bauer disk agar diffusion method. The isolates were also screened for resistant plasmids and virulence genes (Stx2 and toxA). Results: Histamine levels of the fermented samples averaged 1.0 × 10-4-6.2 × 10-1 mg/kg. Of 240 samples of okpee screened, 25 (10.5%) were contaminated with histamine-producing GNB, including Pseudomonas spp., Escherichia coli, E. fergusonii, and Shigella flexneri. All the isolated histamine-producing bacteria were resistant to amoxicillin, erythromycin, ampicillin, and cefuroxime, with more than 50% exhibiting resistance to the other antibiotics tested. The test isolates were found to harbor multiple resistant plasmids (size: 0.5 kbp-10 kbp) and virulence factor genes Stx2 and toxA. Conclusion: This study observed a high prevalence of bacterial contaminants capable of producing histamine in okpee sold in Enugu Ezike, Nigeria. The isolates were multidrug-resistant and harbored virulent genes, posing a serious public health risk. Therefore, strengthening hygiene practices during the production and handling of okpee is necessary to prevent contamination and ensure product safety.   Fermentation, Gram-negative bacteria, Histamine, Virulence factors 153 164 http://ibj.pasteur.ac.ir/browse.php?a_code=A-10-6497-1&slc_lang=en&sid=1 Cyril Adonu adonucyril@gmail.com 0000-0002-3486-8137 Yes Department of Pharmaceutical Microbiology and Biotechnology, Faculty of Pharmaceutical Sciences, Enugu State University of Science and Technology, Enugu State, Nigeria Sunday Urama uramasundayemmanuel@gmail.com 0009-0002-3691-5897 No Department of Pharmaceutical Microbiology and Biotechnology, Faculty of Pharmaceutical Sciences, Enugu State University of Science and Technology, Enugu State, Nigeria Abugu Felix abugufelix1632@gmail.com 0009-0000-3593-6667 No Department of Pharmaceutical Microbiology and Biotechnology, Faculty of Pharmaceutical Sciences, Enugu State University of Science and Technology, Enugu State, Nigeria Eze Victor urchpharm@yahoo.com 0009-0002-6866-8931 No Department of Pharmaceutical Microbiology and Biotechnology, Faculty of Pharmaceutical Sciences, Enugu State University of Science and Technology, Enugu State, Nigeria Treasure Ujam treasure.ujam@esut.edu.ng 0000-0002-8523-3086 No Department of Pharmaceutical Microbiology and Biotechnology, Faculty of Pharmaceutical Sciences, Enugu State University of Science and Technology, Enugu State, Nigeria Gospel OKpara udochukwugospel@gmail.com 0009-0007-8987-2428 No Department of Pharmaceutical Microbiology and Biotechnology, Faculty of Pharmaceutical Sciences, Enugu State University of Science and Technology, Enugu State, Nigeria Hannah Okorie hannah.okorie@esut.edu.ng 0000-0003-4477-3972 No Department of Pharmaceutical Chemistry, Faculty of Pharmaceutical Sciences, Enugu State University of Science and Technology, Enugu State, Nigeria Eucharia Imanyika eucharia.imanyika@esut.edu.ng 0000-0002-8611-8952 No Department of Medical Microbiology, College of Medicine, Enugu State University of Science and Technology, Enugu State, Nigeria