Catalase Activity and Hydrophobicity Test of Bacteria Susceptible to Extracts of Cleistopholis Patens and Piliostigma Reticulatum

Antibacterial effect of the ethanol, methanol and ethyl acetate extracts of Piliostigma reticulatum and Cleistopholis patens on ten pathogenic bacteria including Pseudomonas aeruginosa, Salmonella typhi, Escherichia coli, Proteus vulgaris, Streptococcus pyogenes, Klebsiella aerogenes, Staphylococcus aureus, Serratia marscences, Yersinia enterocolitica and Shigella dysenteriae was investigated. Survival rate after treatment was investigated. Cell surface hydrophobicity after treatment was tested and the catalase activities of the plant extracts were determined. The results revealed that at 100mg/ml of extracts, the ethanol extracts of C. patens showed antibacterial activities against S. typhi, P. vulgaris, Str. pyogenes, K. aerogenes, Saureus and Yersinia enterocolitica with zones of inhibition of 18mm, 14mm, 18mm, 24mm, 14mm and 18mm respectively and the ethyl acetate extract was active against Sal. typhi, P. vulgaris, Str. pyogenes, K. aerogenes, S. aureus Ser. marscences and Y. enterocolitica with zones of inhibition of 14mm, 22mm, 18mm, 18mm, 14mm, 16mm and 16mm respectively while ethanol extract of P. reticulatum showed activity against P. aeruginosa, Sal. typhi, E.coli, Str. pyogenes, K. aerogenes, S. aureus, and Sh. dysenteriae with zones of inhibition of 13mm, 12mm, 10mm, 10mm, 8mm, 10mm and 14mm respectively. The ethyl acetate was active against E.coli, Str. pyogenes, K. aerogenes, S. aureus and Sh. dysenteriae respectively. The methanol extract had no activity against the test organisms. The kill- time curve showed that susceptible cells die after 10 and 20minutes after contact with the extracts of C. patens for most of the test bacteria while cell death occurred at 10, 20, 40, 50 and 60 min after contact. The hydrophobicity test showed that test organisms had hydrophobicity of between 47% and 99% in the extracts. Catalase production reduced considerably in some bacteria after treatment with plant extracts. The results obtained presupposes that the plant extracts are effective against some of the test organisms and their mode of activity are is that they interfere with the ability of bacteria to produce catalase, inducing cell death by the production of hydroxyl radical and also by to the enhancement of non-opsonic phagocytosis of bacteria by macrophages.