ABSTRACT
Aim: The present study investigated the antimicrobial effectiveness of a rhamnolipid complexed with arginine (RLMIX_Arg) against planktonic cells and biofilms of methicillin-resistant Staphylococcus aureus (MRSA). Methodology: Susceptibility testing was performed using the Clinical & Laboratory Standards Institute protocol: M07-A10, checkerboard test, biofilm in plates and catheters and flow cytometry were used. Result: RLMIX_Arg has bactericidal and synergistic activity with oxacillin. RLMIX_Arg inhibits the formation of MRSA biofilms on plates at sub-inhibitory concentrations and has antibiofilm action against MRSA in peripheral venous catheters. Catheters impregnated with RLMIX_Arg reduce the formation of MRSA biofilms. Conclusion: RLMIX_Arg exhibits potential for application in preventing infections related to methicillin-resistant S. aureus biofilms.
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Subject(s)
Anti-Bacterial Agents , Arginine , Biofilms , Methicillin-Resistant Staphylococcus aureus , Microbial Sensitivity Tests , Surface-Active Agents , Biofilms/drug effects , Biofilms/growth & development , Methicillin-Resistant Staphylococcus aureus/drug effects , Arginine/pharmacology , Arginine/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Humans , Surface-Active Agents/pharmacology , Surface-Active Agents/chemistry , Glycolipids/pharmacology , Glycolipids/chemistry , Staphylococcal Infections/microbiology , Staphylococcal Infections/prevention & control , Staphylococcal Infections/drug therapy , Oxacillin/pharmacology , Drug SynergismABSTRACT
Aim: To evaluate the antifungal activity of amlodipine against strains of Candida spp. and to its possible mechanism of action.Methods: Broth microdilution tests were used to determine the minimum inhibitory concentration, while the synergistic activity was evaluated by calculating the fractional inhibitory concentration index. The action of amlodipine against biofilms was determined using the MTT assay and its possible mechanism of action was investigated through flow cytometry tests.Results: Amlodipine showed MICs ranging from 62.5 to 250 µg/ml, in addition to action against pre-formed and forming biofilms, with reductions between 50 and 90%. Amlodipine increases the externalization of phosphatidylserine and reduces the cell viability of fungal cells, suggesting apoptosis.Conclusion: Amlodipine had good antifungal activity against planktonic cells and biofilms of Candida spp., by leading the cells to apoptosis.
Candida is a type of fungus that can cause diseases. This fungus became stronger over time and drugs can no longer kill them easily, so it is important to find new drugs. We decided to study whether amlodipine, a drug used for heart disease, has action against Candida. We discovered that amlodipine make fungi weaker. We still need to do more studies to find out if amlodipine can help prevent Candida diseases.
ABSTRACT
The emergence of Candida spp. with resistance to antifungal molecules, mainly the azole class, is an increasing complication in hospitals around the globe. Aim: In the present research, we evaluated the synergistic effects of ketamine with two azole derivatives, itraconazole and fluconazole, on strains of Candida spp. to fluconazole. Materials & methods: The drug synergy was evaluated by quantifying the fractional inhibitory concentration index and by fluorescence microscopy and flow cytometry techniques. Results: Our achievements showed a synergistic effect between ketamine in addition to the two antifungal agents (fluconazole and itraconazole) against planktonic cells and biofilms of Candida spp. Conclusion: This combination promoted alteration of membrane integrity, generation of reactive oxygen species, damage to and DNA and externalization of phosphatidylserine.