Abstract

Varied but multiple antibiotic resistance rates were exhibited by all the foodborne indicator bacterial species, Citrobacter, Escherichia coli, Enterobacter, Klebsiella,Morganella morganii, Salmonella, Shigella, Pseudomonas isolated from four most-popular Nigerian indigenous fermented plant food condiments ogiri, iru, okpehe andugba. The generally most-resisted antibiotics (discs) were tetracycline (44.0 - 63.0%), cotrimoxazole (56.0 - 70.3%), nalidixic acid (28.0 - 74.1%), amoxicillin (28.0 - 88.9%) and augmentin (16.0 - 94.4%), while the least resisted antibiotics were ofloxacillin (0.0% - 1.85%) and gentamicin (4.0 - 16.7%). Antibacterial activities of crude extracts of local spices and essential oils of plant origin, as well as carvone, lactic and acetic acids on the multiple antibiotic resistant Gram-negative foodborne bacterial species were determined using modified agar well-diffusion assay. Crude extracts of Eugeniaaromatica (92.0%) and Allium sativum (72.0%) were maximally inhibitory; lactic (44.4%) and acetic (46.3%) acids were moderately inhibitory but essential oils of Eugeniauniflora (24.0%), Ageratum conyzoides (16.7%) and Chrsophylum albidium juice (13.0%) were minimally inhibitory in vitro, indicating that crude extracts of E. aromaticaand A. sativum can serve as easily prepared, non-chemical, plant-based, adjunct preservatives of fermented condiments both domestically and industrially, even by the traditional producers of the indigenous and similar condiments.

Key words: Cottage food production, essential oils, food safety, food processing, multiple antibiotic resistance, Nigerian indigenous fermented foods, plant foods.