Objective:To investigate the efficacy of 17 ethnomedicinal plants belonging to Apocynaceae family used in combination with 16 conventional antibiotics against non-multidrug resistant-,multidrug resistant(MDR)-.and ext...Objective:To investigate the efficacy of 17 ethnomedicinal plants belonging to Apocynaceae family used in combination with 16 conventional antibiotics against non-multidrug resistant-,multidrug resistant(MDR)-.and extensive drug resistant(XDR) Acinetobacter baumannii(A.haumannii).Methods:Antibacterial activity and resistance modifying ability of 272combinations were determined by growth inhibition assays and further confirmed by time-kill assay.Results:Among the combinations of the antibiotics with Apocynaceae ethanol extracts on this pathogen,15(5%) had synergistic effects,23(8%) had partial synergistic effects and 234(86%) had no effects.Synergistic activity was observed mostly when the Apocynaceae extracts were combined with rifampicin or cefazolin.Interestingly.10 out of 17 combinations between the extracts and rifampicin displayed synergistic or partial synergistic behaviors.Holarrhena antidysenterica extract was additionally tested to restore rifampicin activity against clinical isolates of MDR and XDR A.haumannii.With respect to total or partial synergy,70%was XDR A.haumannii isolates and 66%was MDR A.haumannii isolates.Conclusions:Holarrhena antidysenterica extract clearly demonstrated the ability to restore rifampicin activity against both A.haumannii ATCC19606 and clinically isolated A.haumannii.Additional studies examining its active principles as well as nieclianisms of actions such as the effects on efflux pumps and outer membrane permeability alterations are recommended.展开更多
Multi-drug resistant microbial infections caused by Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi represent a critical public health issue worldwide. Plant-derived agents are cre...Multi-drug resistant microbial infections caused by Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi represent a critical public health issue worldwide. Plant-derived agents are credible sources for search and development of alternative antimicrobials to fight these infections. This study describes the in-vitro antibacterial activity of plants extracts from 15 medicinal plants of the Cameroonian pharmacopeia against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi. Plants selected based on their ethnopharmacological uses were extracted by either maceration or decoction using distilled water, ethanol, methanol and ethylacetate. The afforded extracts were phytochemically screened for bioactive secondary metabolites. The microdilution method was used to assess the antibacterial activity. The two promising extracts were tested in combination using the cbeckboard technique. Eighty one extracts showed antibacterial activity with eight having minimum inhibitory concentrations below 2.5 mg/mL. Results from combination assays with extracts from Terminalia catappa and Gnidia glauca leaves showed synergistic effect against Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi and additive effect against Staphylococcus aureus. These extracts mainly contained saponins, tannins, glucosides, phenols, triterpenes and anthraquinones. These results support the ethnobotanical claims and indicate further directions for the investigation of plants extracts to develop alternative drugs against multi-resistant bacteria.展开更多
基金supported by the Thailand Research Fund(BRG 5580015.Fiscal year 2012-2014)Miss Pinanong Na-Phatthalung and Miss Thanyaluck Siriyong are funded by Natural Product Research Center of Excellence Postgraduate Scholarship
文摘Objective:To investigate the efficacy of 17 ethnomedicinal plants belonging to Apocynaceae family used in combination with 16 conventional antibiotics against non-multidrug resistant-,multidrug resistant(MDR)-.and extensive drug resistant(XDR) Acinetobacter baumannii(A.haumannii).Methods:Antibacterial activity and resistance modifying ability of 272combinations were determined by growth inhibition assays and further confirmed by time-kill assay.Results:Among the combinations of the antibiotics with Apocynaceae ethanol extracts on this pathogen,15(5%) had synergistic effects,23(8%) had partial synergistic effects and 234(86%) had no effects.Synergistic activity was observed mostly when the Apocynaceae extracts were combined with rifampicin or cefazolin.Interestingly.10 out of 17 combinations between the extracts and rifampicin displayed synergistic or partial synergistic behaviors.Holarrhena antidysenterica extract was additionally tested to restore rifampicin activity against clinical isolates of MDR and XDR A.haumannii.With respect to total or partial synergy,70%was XDR A.haumannii isolates and 66%was MDR A.haumannii isolates.Conclusions:Holarrhena antidysenterica extract clearly demonstrated the ability to restore rifampicin activity against both A.haumannii ATCC19606 and clinically isolated A.haumannii.Additional studies examining its active principles as well as nieclianisms of actions such as the effects on efflux pumps and outer membrane permeability alterations are recommended.
文摘Multi-drug resistant microbial infections caused by Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi represent a critical public health issue worldwide. Plant-derived agents are credible sources for search and development of alternative antimicrobials to fight these infections. This study describes the in-vitro antibacterial activity of plants extracts from 15 medicinal plants of the Cameroonian pharmacopeia against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi. Plants selected based on their ethnopharmacological uses were extracted by either maceration or decoction using distilled water, ethanol, methanol and ethylacetate. The afforded extracts were phytochemically screened for bioactive secondary metabolites. The microdilution method was used to assess the antibacterial activity. The two promising extracts were tested in combination using the cbeckboard technique. Eighty one extracts showed antibacterial activity with eight having minimum inhibitory concentrations below 2.5 mg/mL. Results from combination assays with extracts from Terminalia catappa and Gnidia glauca leaves showed synergistic effect against Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi and additive effect against Staphylococcus aureus. These extracts mainly contained saponins, tannins, glucosides, phenols, triterpenes and anthraquinones. These results support the ethnobotanical claims and indicate further directions for the investigation of plants extracts to develop alternative drugs against multi-resistant bacteria.
