Japan International Research Center for Agricultural Sciences (JIRCAS)
2023
Ibaraki, Japan
Escherichia coli (E. coli) and other Enterobacteriaceae isolated from fermented products were evaluated for pH, salt tolerance, and multidrug resistance to nine antimicrobial categories, including acetamides, aminoglycosides, β-lactams, cephalosporins, fluoroquinolones, polymyxins, quinolones, sulfonamides, and tetracycline. E. coli was identified in 34% of total fermented samples, followed by Proteus spp. (18%), Providencia spp. (3%), and Citrobacter spp. (3%). Other minor Enterobacteriaceae species detected in 6% of the total samples were Enterobacter aerogenes, Enterobacter cloacae, Ewardsiella tarda, Klebsiella oxytoca, Kluyvera cryocrescens, Morganella moganii, Raoultella planticola, Raoultella terrigena, and Salmonella enterica. Most isolated bacteria can withstand 8% NaCl concentration. However, they were inhibited at 4 pH. Over 50% of the isolated E. coli, Proteus mirabilis, Proteus penneri, and Proteus vulgaris were multidrug-resistant to B-lactams, polypeptides cyclic, sulfonamides, and tetracyclines.