In vitro antimicrobial and resistance-modifying activities of aqueous crude khat extracts against oral microorganisms.

摘要: Summary Objectives To assess antimicrobial activities of aqueous crude khat (Catha edulis) extracts against a panel oral microorganisms and to test their ability modify bacterial resistance tetracycline penicillin in vitro. Design Lyophilized were prepared from three cultivars. The agar dilution method the NCCLS was used extracts, at concentrations 20–1.25 mg/ml, 33 strains. MIC defined as lowest concentration which there no visible growth. Slight growth marked reduction (MGR). E-test determine MICs penicillin-G for resistant strains absence presence sub-MIC (5 mg/ml). Results Eighteen (55%) sensitive (MICs 5–20 mg/ml). Most these periodontal pathogens with Porphyromonas gingivalis Tannerella forsythensis being most susceptible (MIC 5–10 mg/ml). Veillonella parvula, Actinomyces israelii some streptococci not sensitive. Except Lactobacillus acidophilus that showed MGR 1 mg/ml, cariogenic species neither active Streptococcus pyogenes 10–20 mg/ml) but Candida albicans Staphylococcus aureus. resulted 2–4-fold potentiation tested antibiotics Conclusions Khat has water-soluble constituents possessing selective antibacterial activity bacteria. There is preliminary evidence an antibiotic resistance-modifying component. Further investigation needed identify components clinical relevance.