Abstract

This study investigated the bactericidal efficacy of the ethanolic extract of Carica papaya seed on snail gastrointestinal tract (GIT) microbiota and associated histological changes. The bacterial isolates were characterized based on colony morphology, culture characteristics and biochemical tests. Each portion of the gut was further subjected to histological examination to ascertain the effect of this extract on the various regions of the snail gut. Three bacterial species (Salmonella, Klebsiella and Escherichia coli) were isolated from the GIT. Salmonella was the major isolate from all the sections of the GIT in the control. Klebsiella was the major isolate from all the GIT sections after administering 50 mg/kg body weight (b. wt) of the extract while Salmonella was absent. Klebsiella was the main isolate after administering 50 mg/kg, 100 mg/kg and 150 mg/kg of extract. E. coli and Salmonella and Klebsiella were isolated after administration of 150 mg/kg b. wt of extract. The histological changes included vacuolation of the crop, and reduction in sub-mucosal fat in the intestinal wall. The extract altered the microbiota of A. marginata GIT in a concentration dependent manner.

Key words: Archachatina marginata, Salmonella, Klebsiella, Escherichia coli, antibacterial.