Antibacterial Activity of Sorghum “Ogi” on Diarrhoeagenic Escherichia coli

Abstract

Aims: To investigate and compare the antibacterial activity of sorghum “ogi” slurry, liquor and that of conventional antibiotics against diarrhoeagenic Escherichia coli. Place and Duration of Study: This research work was carried out at the Department of Microbiology Laboratory, Federal University of Technology, Akure. Ondo state, Nigeria between June and September, 2017. Methodology: The pH and Titratable acidity (TTA) of ‘ogi' slurry and liquor were determined at the 0, 24, 48, 72 and 96 hours of fermentation. Microorganisms were isolated from both the slurry and liquor via a pour plate method. Identification and characterisation of various bacterial isolates including the stock culture (Escherichia coli) were based on Gram-staining technique and biochemical tests. The fungal isolates were identified by their morphological features and lactophenol cotton blue staining procedure. Antibacterial activity of 0.1 ml of 72 hours fermented liquor and slurry of Sorghum “ogi” including organisms isolated from the liquor and slurry were tested against Escherichia coli and were separately determined via agar well diffusion method. Antibacterial activity of conventional antibiotics such as Tetracycline, Amoxycylin and Ciprofloxacin were also determined. SPSS was used to analyse all the data in this research work. Results: Bacteria isolated from the slurry and liquor of sorghum ‘ogi’ include: Bacillus species, Corynebacterium species, Lactobacillus plantarum, Staphylococcus aureus, Staphylococcus epidermidis and Streptococcus species. Fungi isolated include: Mucor mucedo, Penicillium notatum, Rhizopus species and Saccharomyces cerevisiae. Corynebacterium sp, Staphylococcus epidermidis and Lactobacillus plantarum exerted growth inhibitory activity on the diarrhoeagenic E. coli used. Staphylococcus epidermidis exerted the highest growth inhibitory effect. Aspergillus niger exerted higher growth inhibitory effect on most of the E. coli used than Penicillium notatum. Conclusion: This study has shown that Sorghum “ogi” can be used as an alternative therapy to antibiotics to treat people who are suffering from diarrhoea caused by Escherichia coli.