Abstract
The present study aimed to evaluate the antimicrobial activity of aqueous extracts of the mixture of spices used as accompanying soup of braised fish against multidrug resistant (MDR) bacteria isolated from raw and braised fish collected in the city of Bangangté, Cameroon. A survey was conducted in the city of Bangangté to diagnose the braising fish processes. Pathogens were isolated from raw and braised fish samples collected in fish farms and selling points, and their susceptibility to 16 commonly used antibiotics was tested using the Kirby-Bauer disk diffusion method. The aqueous extracts of spices' formulations used as accompanying soup of braised fish were tested against MDR isolates using the well diffusion method. The results revealed that 13 spices are used in the preparation of accompanying soups of braised fish. Three formulations were identified with mbongo, clove and prekeses as the main differential spices. These formulations were either heated at 100 °C/30 min (process 1) or not (process 2) before being served to consumers'. Fifty-five strains belonging to six species (Salmonella Typhi, Salmonella Paratyphi, Escherichia coli, Escherichia vulneralis, Staphylococcus aureus and Staphylococcus spp.) were isolated from the different samples. Forty-four isolates were resistant to several antibiotics with Multiple Antibiotic Resistance indexes ranging from 0.18 to 0.81. The aqueous extracts of all the formulations were active against the MDR isolates independent of the formulation and preparation process, with inhibition diameters varying significantly (p < 0.05) from one isolate to another. Heated extracts were less active than the unheated ones and the most active extract was from the formulation including clove. The strains E. coli and E. vulneralis were most resistant to the different extracts whereas S. Typhi, S. aureus, Staphylococcus spp. and S. Paratyphi A, were more sensitive. This study evidenced that fish products from Bangangté city contain MDR pathogens and demonstrated that the formulations of spices used as accompanying soup for braised fish are active against these MDR pathogens. It suggests their potential use as strategy to combat the antimicrobial resistance phenomena associated to foodborne gastroenteritis pathogens. It also suggests that more attention should be paid to the use of antibiotics in fish farming activities.