Antibacterial Properties of Crude Metabolic Extracts from Clostridium spp. Isolated from Cattle Yards Against Some Clinical Bacterial Isolates in Benin City

The soil is a reservoir for various clostridial pathogens, with agricultural soils representing a major source of contamination for overlying crops and grazing livestock. Indigenous bacteria in the soil environment can produce a wide range of solvents and metabolites more efficiently. This study therefore was aimed at determining the antibacterial potential of crude metabolic extracts from Clostridium spp. isolated from cattle yards in Benin City, Nigeria against clinically relevant bacterial isolates. Soil samples were collected in triplicates each at 0-5 cm depth using soil Auger from cattle farmlands in Eyaen, Aduwawa 1, Aduwawa 2 and Dumez in Benin City Nigeria. Clinical isolates were collected from Medical Microbiology Laboratory, University of Benin Teaching Hospital, Benin City Nigeria. The physicochemical parameters of the soil were analysed using standard methods. Minerals and heavy metals were determined using atomic absorption spectrophotometry. Bacteria were isolated using dilution technique and cultured on appropriate culture media followed by in-vitro screening for virulent factors. Isolated pathogens were subsequently assessed for antibiotic resistance to common antibiotics and resistance to crude metabolites using modified Kirby-Bauer disc diffusion method, while Clostridium species were further identified using molecular technique. The phosphorus, magnesium, iron, zinc and copper where above the Federal Ministry of Environment (FMEnv) acceptable limit while electrical conductivity was below and potassium within FMEnv acceptable limit. The total Clostridium counts of soil samples ranged from 5.13±0.02 × 103cfu/g - 5.53±0.10 × 103cfu/g. The Clostridium isolates identified from the soil samples were Clostridium sporogens, Clostridium butyricum, Clostridium bolteae, Clostridium septicum, and Clostridium perfringens. Staphylococcus aureus was found to exhibit positive characteristics for gelatinase, lipase, DNAse and hemolysin production. C. perfringenss and C. butyricum had the highest zone of inhibition against Escherichia coli (1.07±0.03 mm) and Staphylococcus aureus (1.07±0.03 mm), while C. perfringens had the least zone of inhibition against P. aeruginosa (0.10±0.00 mm). Enterobacter aerogenes had the highest percentage antibiotic resistance (50%) which was against amoxicillin, followed by Pseudomonas aeruginosa (42.1%) against sparfloxacin. Clostridium species exhibit varying degrees of antibacterial activity against specific bacterial isolates which prove its potential therapeutic applications. Therefore, Clostridium species can be used commercially for the production of antibiotics after purification and proper
standardization.