Assessment of the antimicrobial activity of wonderful kola (Buchholzia coriacea) on Salmonella species isolated from seafoods

Abstract

The increasing failure of chemotherapeutic agents and the growing incidence of antibiotic resistance among pathogens have prompted the screening of medicinal plants for their antimicrobial potential. This study aimed to determine the efficacy of ethanol and aqueous seed extracts of Buchholzia coriacea (wonderful kola) against Salmonella species isolated from seafood (clam and prawn) using the agar well diffusion method. Wonderful kola seeds were purchased from Mile 3 Market, and pure cultures of Salmonella spp. were isolated from clam and prawn samples using standard microbiological techniques at the Microbiology Laboratory, Rivers State University. The results showed that ethanol yielded a higher quantity of extract (14.37 g) compared to the aqueous solvent (3.88 g). The percentage yields were 28.74% and 7.76% for the ethanol and aqueous extracts, respectively. The minimum inhibitory concentration (MIC) of both aqueous and ethanol extracts for the two isolates (ISO 1 and ISO 2) was 50%. The minimum bactericidal concentration (MBC) of the aqueous extract for both isolates was also 50%, whereas for the ethanol extract, the MBC was 25% for ISO 1 and 50% for ISO 2. Measurable zones of inhibition were observed for both extracts. The aqueous extract produced inhibition zones ranging from 11-15 mm for ISO 1 and 11-17 mm for ISO 2, while the ethanol extract produced zones ranging from 13-17 mm for ISO 1 and 11-14 mm for ISO 2. Although the extracts demonstrated antimicrobial activity against the isolates, the consumption or therapeutic use of plant extracts should be supported by comprehensive research evidence and professional medical advice.

Keywords: Antimicrobial activity, wonderful kola, Salmonella sp., seafoods.