Effects of Oyster Mushroom (Pleurotus ostreatus) on Body Weight and Pathology of Vital Organs in Pathogenic Staph Infection

Aims: Oyster mushroom is rich in secondary metabolites of pharmacological importance. This study evaluates the effect of ethanolic extract of Oyster mushroom on the vital organs of Staphylococcus aureus infected Wistar rats after seven days of administration. Study Design: Completely randomized design was used in the study. Place and Duration of Study: This study was carried out at the Microbiology, Parasitology and Ethnoveterinary medicine Unit of the Department of Animal Production and Health, Federal University of Technology, Akure, Nigeria, between March and December 2022. Methodology: The mushroom was processed using a cold extraction technique. A bacterial suspension of Staphylococcus aureus was inoculated via oral route into the experimental animals, which were randomly distributed into six groups of five. Group 1: normal control; group 2: positive control; group 3: negative control, inoculated but received no antimicrobial; and group 4 to 6 were inoculated, and administered with 625, 1250 and 2500 mg dose of the extract respectively. The treatment was administered for seven days, after which blood samples were cultured for the bacterial count and vital organs were analysed for pathological changes. Results: The colony count was significantly raised at 625 mg dose while the dose ranging from 1250 to 2500 mg yielded insignificant bacterial growth (P<0.01). The percentage weight gain was significantly lower (P<0.01) in 1250 mg extract in comparison with the negative control after 7 days complete treatment but there was no statistical variation in the 7 days post-treatment percentage weight gain and the relative organ weight (P<0.01).The histological sections showed no variation from normal controls except 625 mg liver that showed some vacuolations within the hepatocytes. Conclusion: The organ-body mean weight was proportionate, and the histological sections of the liver, kidney, skin, lungs, heart and spleen were indicative of no anatomical variations as compared with the normal control tissues. The beneficial effect of P. ostreatus on the vital organs was further established by the active clearing of S. aureus infection at 1250 to 2500 mg dose with no observable pathological change in the tissues. The bioactive agents inherent in P. ostreatus were effective against S. aureus infection. The vacuolations observed in the low dose liver sections unveiled the ill effect of under-dose treatment and its consequence on the liver cells. The histopathological investigations were suggestive of the safety and tolerance of P. ostreatus to the body system. Nevertheless, further studies should be carried out on its toxicological profiles.