INHIBITION OF SOME INTESTINAL PATHOGENS BY LACTOBACILLUS SPECIES ISOLATED FROM OGI

Twenty five strains of Lactobacillus species and yeast were isolated from ogi. They were identified as Lactobacillus plantarum (32.4%), L. delbrueckii (14.5%), L. casei (16.2%), L. fermentum (10.3%) L. acidophilus (16.4%), L. brevis (7.4%). The lactic acid strains were tested for bacteriocin and the strains that were tested positive were not used for further investigation while catalase was added to growth medium to eliminate hydrogen peroxide production. The organisms inhibited to varying degrees the growth of various intestinal pathogens of human, the typed strains collected from the University College hospital (UCH), Ibadan, Nigeria were used as indicator organisms. These are Salmonella typhii; Shigella dysenteriae; Escherichia coli; Salmonella typhimurium; and Staphylococcus aureus. Generally, gram positive bacteria were more inhibited than gram negative bacteria. Acidic pH supported inhibition while temperature (30- 35 o C) had negative effect on inhibitory activity of all the isolates except L. delbrueckii which tolerated temperature of 45 0 C. We detected that ogi may be useful in preventing gastroenteritis caused by the aforementioned intestinal pathogens.