Antagonistic effects of three lactic acid bacterial strains isolated from Nigerian indigenous fermented Ogi on E. coli EKT004 in co-culture

Abstract

E. coli is one of the major pathogenic bacteria that cause diarrhoea in human. Traditional fermented foods, e.g. Ogi, has been used indigenously to treat diarrhoea. This study was aimed at investigating the antagonistic activity of selected lactic acid bacteria (LAB) isolated from three varieties of ogi against multidrug resistant E. coli EKT004. Antibiotic susceptibility of the tested E. coli EKT004 strain to ofloxacin, gentamycin, cefuroxime, ceftazidine, lincomycin, oxacillin, cloxacillin, cefotaxime, ciprofloxacin, and nitrofurantoin was tested by disc diffusion method. E. coli EKT004 was co-incubated in two different experiments with Weissella paramesenteroides, Lactobacillus plantarum, and L. fermentum that have been previously isolated from Ogi. An 8 h old E. coli was introduced into an overnight culture of LAB and a fresh E. coli was inoculated into overnight culture of LAB. Viable count of pathogen at 0 h and after 24 h co-incubation at 37 °C was observed. The tested E. coli EKT004 was resistant to cefuroxime, ceftazidime, lincomycin, oxacillin, cloxacillin, and cefotaxime. The tested LAB isolates have a broad spectrum of activity against E. coli EKT004 used for the study with a decrease of 6–8 log of E. coli as compared with the control. These results indicate a direct effect of lactic acid bacterial strains on multidrug resistant E. coli strain.