Anatural approach tocombating antibiotic-resistant pathogens inlivestock: Hibiscus sabdariffa-derived hibiscus acid asapromising solution.

Abstract

Weexamined the antibacterial efficacy ofstreptomycin, hibiscus acid, and their combination against multidrug-resistant Shiga-toxin-producing Escherichia coli (STEC) and Salmonella Typhimurium inmice. Wedetermined the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for streptomycin, hibiscus acid, and their combination against STEC and Salmonella. Fifteen sets ofsix mice ineach set were utilised: six groups were orally exposed to4log10 colony forming units (CFUs) ofS.Typhimurium and another six toSTEC, and three acted asthe controls. Six hours post-inoculation, specific groups ofmice received either oral solutions containing hibiscus acid at5 and 7mg/ml; streptomycin at50 and 450μg/ml; hibiscus acid/streptomycin (5mg/ml hibiscus acid and 50μg/ml streptomycin); orisotonic saline. The study determined the MIC and MBC of7mg/ml ofhibiscus acid; 300 and 450μg/ml ofstreptomycin; and two concentrations ofhibiscus/streptomycin (3mg/ml/ 20μg/ml and 5mg/ml/ 50μg/ml). Interestingly, the mice that were infected and subsequently treated with hibiscus acid at7mg/ml alone orin conjunction with streptomycin did not have either STEC orSalmonella intheir faecal samples, and none ofthe mice died. Incontrast, the untreated mice and those exclusively treated with streptomycin had the pathogens present intheir stool, leading tothe mortality ofall the subjects.