Characterization of Multi-Antibiotic Resistant Histamine Producing Escherichia Species Isolated from Palm Wine Tapped from Elaeis guineensis in Enugu Ezike, Nigeria

Palm wine, locally called nkwu ellu or ekpo, holds significant cultural and economic importance as it is consumed on a daily basis in many parts of Nigeria. The presence of histamine in palm wine at a level that causes foodborne illnesses and allergic reactions is caused by both native and contaminating bacteria such as members of Enterobacteriaceae. This research determined the prevalence of histamine producing, multidrug-resistant Escherichia species from palm wine during fermentation. Microbiological analysis and histamine production were evaluated on randomly sampled palm wine. Bacterial isolation and phenotypic characterization were done according to standard microbiological procedures. DNA sequencing was employed to verify the specific strain of bacteria isolated. Antibiotic sensitivity testing was performed on the bacteria isolated. Of all the 320 palm wine samples tested, 37 (11.56%) were contaminated with histamine-producing Escherichia species. The strains of Escherichia species cultured include Escherichia coli (E. coli) UFV 251, Escherichia fergusonii APO3, E. coli Z1322PEC0229, E. coli PL-AGW6, E. coli Saman5 and E. coli ZK-1. Antibiotic susceptibility profiles showed that all these strains were multidrug-resistant. In regard to the duration of fermentation, the average histamine content (mg/kg) of the test palm wine tapped from standing life oil palm tree (nkwu ellu) and felled palm tree (ekpo) ranged from 1.00121e-4 to 9.82127e-2 and 1.22120e-2 to 9.96332e-1, respectively. The ability of these multidrug-resistant Escherichia species to produce histamine poses serious public health menace. Therefore, extensive improvement in the hygienic practices during production and handling, and the control of fermentation conditions are necessary to prevent the product contamination and histamine production to ensure the safety of the drink.