Backgroud- Recent upsurge in bacterial resistance has led to search for alternative to antibiotics in treatment of infectious diseases including diarrhea. One of the common causative agent of diarrhea is Shigella sp. Lactic acid bacteria has been used in probiotic formulation for prevention of various form of diarrhea. This study investigates possible antagonistic effects of lactic and acetic bacteria on Shigella sp in co culture.
Method- Antibiotic susceptibility of Shigella spp. SS10 to ofloxacin, gentamycin, cefuroxime, ceftazidine, lincomycin, oxacillin, cloxacillin, cefotaxime, ciprofloxacin and nitrofurantoin was tested by disc diffusion method. Shigella spp. SS10 was co-incubated in two different experiments with 3 Lactobacillus species (Lactobacillus plantarum QN01, Lactobacillus parabuchneri SM03 and Lactobacillus fermetum SH01) and 1 Acetobacter pasteurianus RV04 which has been previously isolated from Nigeria-produced yogurts. An 8h old Shigella spp. SS10 was introduced into an overnight culture of LAB and a fresh Shigella spp. SS10 was inoculated into overnight culture of LAB. Viable counts of pathogens at 0h and after 24h co-incubation at 37oC were observed.
Results -Shigella spp. SS10 was resistant to 50% of the tested antibiotics. The co culture of tested LAB revealed an average of 4 log reduction in viable counts of the Shigella strain. The Acetobacter strain displayed very good inhibitory activity with a 4 log reduction in microbial load of Shigella spp SS10.
Conclusion - Lactic and Acetic acid bacteria isolated from Nigerian yoghurt has considerable activity against Shigella sp. in co culture experiment.
: Shigella, Nigeria produced Yogurts, Co-culture, Acetic acid bacteria, Lactic acid bacteria