Phytobiotics Effects of Pawpaw (Carica papaya) Leaves and Fluted Pumpkin (Telferia ocidentalis) Leaves Extracts against Certain Aquatic Pathogens

Abstract

Due to an increase in the rate at which microorganism are resistant to antibiotics, there is need to assess the antimicrobial effect of some medicinal plant extracts in the treatment of fish pathogens: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus pyogenes, Bacillus substilis, Staphylococcus epidermidis, Salmonella typhi and Aeromonas hydrophila. The antimicrobial activity and inhibition diameter of methanolic and ethanolic extracts of pawpaw and fluted pumpkin leaves were evaluated against eight (8) clinical strains of bacteria isolated from Clarias gariepinus using agar well diffusion method. Minimum inhibitory concentration and phytochemical screening of these plants were determined using standard methods. Data were analyzed using descriptive statistics. The results of the present study showed that the zone of inhibition varies with the bacteria and the type of extracts. Ethanolic extract has better diameter of zone of inhibition than the methanolic extracts with highest zone of inhibition recorded in Pseudomonas aeruginosa (16.00 ± 0.02 mm) for fluted pumpkin leaves extracts and the lowest in Staphylococcus epidermidis (8.00 ± 0.01 mm) and Aeromonas hydrophilia (8.00 ± 0.00 mm) for fluted pumpkin leaves extracts respectively. Minimum inhibitory concentration of methanolic and ethanolic extract of pawpaw and fluted pumpkin leaves on the pathogenic bacteria tested were 425 µg/mL, and 850 µg/mL respectively. Phytochemical screening of these plants revealed the presence of saponins, flavonoids, tannins, cyanogenic glucosides and amino acid and proteins. The result have shown that methanolic and ethanolic extracts of pawpaw and fluted pumpkin leaves extracts possess antimicrobial functions and serve as a source of antimicrobial agents against fish pathogens.