Winning the War against Multi-Drug Resistant Diarrhoeagenic Bacteria

Abstract

Drug-resistant-diarrhoeagenic bacteria are currently emerging healthcare challenge. This study investigated the effects of Vernonia amygdalina, Garcinia kola, tetracycline and metronidazole combinations on such bacteria. Agar well diffusion method was employed to determine the inhibitory effects of the herbal extracts on diarrhoeagenic bacteria while Time-Kill Assay was used to determine bactericidal effects of the extracts against test isolates. Interactions between plant extracts and antibiotics were investigated using Checkerboard assay. Minimum inhibitory concentrations of the extracts against the bacterial isolates ranged between 3.125–50 mg/mL, while those of tetracycline and metronidazole ranged from 30–50 μg/mL. Synergism was observed against B. cereus and S. aureus for metronidazole + aqueous G. kola at all ratios. Generally, the combinations aqueous G. kola + ethanolic G. kola and aqueous G. kola + ethanolic V. amygdalina showed more pronounced synergism against the Staphylococcus aureus than B. cereus isolates with the fractional inhibition concentration (FIC) indices ranging from 0.32–0.95. Synergism of tetracycline + crude extracts and metronidazole combinations were more pronounced on the test isolates and especially on the Gram-negative organisms with FIC indices ranging from 0.41–0.91. Conclusion: The herbal extracts combinations and extracts–antibiotics combinations are synergistic on diarrhoeagenic bacteria at defined combination ratios.

Combinations of Alchornea cordifolia, Cassytha filiformis and Pterocarpus santalinoides in diarrhoegenic bacterial infections

“…For instance, the triple antibiotic paste (containing equal amounts of minocycline, ciprofloxacin, and metronidazole) is very effective in eliminating wide range of bacteria causing teeth decay [35]. Combination of tetracycline and metronidazole was found to be effective against multi-drug resistant diarrhoegenic bacteria [36].…”

Anti-bacterial activity of Annona muricata Linnaeus extracts: a systematic review

“…In other natural matrixes, Enemchukwu et al (2019) studied Vernonia amygdalina, Garcinia kola, tetracycline and metronidazole and combinations and found that synergic activity exists against diarrheagenic bacteria. Mancarz et al ( 2019) studied a synergic interaction of two extracts from Liquidambar styraciflua with ciprofloxacin and tetracycline and a synergistic interaction was observed against the gram-positive bacterial Enterococcus faecalis (ATCC 29212) and S. aureus (ATCC 2592).…”

Preliminary study on the synergistic interaction of Garcinia kola and Vernonia amygdalina against Candida albicans

“…The search for plant based antifungal agents to tackle this menace has been on the increase probably due to their recorded improved effects over conventional antifungal agents [4,5]. Factors such as side effects, emergence of resistant strains, costs and availability have hindered wide utilization of some conventional antimicrobial drugs [6,7]. More so, bio-prospecting of medicinal plants as a reliable alternative for new drug candidates over the years has proven to be a reliable source of surplus biologically active molecules [8,9].…”