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1.
Microb Pathog ; 193: 106769, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38955237

RESUMO

The bacterium Escherichia coli is one of the main causes of urinary tract infections. The formation of bacterial biofilms, especially associated with the use of urinary catheters, contributes to the establishment of recurrent infections and the development of resistance to treatment. Strains of E. coli that produce extended-spectrum beta-lactamases (ESBL) have a greater ability to form biofilms. In addition, there is a lack of drugs available in the market with antibiofilm activity. Promethazine (PMZ) is an antihistamine known to have antimicrobial activity against different pathogens, including in the form of biofilms, but there are still few studies of its activity against ESBL E. coli biofilms. The aim of this study was to evaluate the antimicrobial activity of PMZ against ESBL E. coli biofilms, as well as to assess the application of this drug as a biofilm prevention agent in urinary catheters. To this end, the minimum inhibitory concentration and minimum bactericidal concentration of PMZ in ESBL E. coli strains were determined using the broth microdilution assay and tolerance level measurement. The activity of PMZ against the cell viability of the in vitro biofilm formation of ESBL E. coli was analyzed by the MTT colorimetric assay and its ability to prevent biofilm formation when impregnated in a urinary catheter was investigated by counting colony-forming units (CFU) and confirmed by scanning electron microscopy (SEM). PMZ showed bactericidal activity and significantly reduced (p < 0.05) the viability of the biofilm being formed by ESBL E. coli at concentrations of 256 and 512 µg/ml, as well as preventing the formation of biofilm on urinary catheters at concentrations starting at 512 µg/ml by reducing the number of CFUs, as also observed by SEM. Thus, PMZ is a promising candidate to prevent the formation of ESBL E. coli biofilms on abiotic surfaces.


Assuntos
Antibacterianos , Biofilmes , Escherichia coli , Testes de Sensibilidade Microbiana , Prometazina , Cateteres Urinários , beta-Lactamases , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Prometazina/farmacologia , Escherichia coli/efeitos dos fármacos , beta-Lactamases/metabolismo , Cateteres Urinários/microbiologia , Antibacterianos/farmacologia , Humanos , Infecções Urinárias/microbiologia , Viabilidade Microbiana/efeitos dos fármacos , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/tratamento farmacológico
2.
Microb Pathog ; 155: 104892, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33894289

RESUMO

Staphylococcus aureus is a commensal bacterium and opportunistic human pathogen that can cause a wide variety of clinical infections. It is recognized for its ability to acquire antimicrobial resistance, so methicillin-resistant Staphylococcus aureus (MRSA) infections are a global healthcare challenge. Therefore, the development of new therapeutic options and alternative therapies for treatment is necessary. Curcumin, a polyphenolic substance found in the rhizome of turmeric longa L, has been shown to have several therapeutic properties, including antimicrobial activity. The objective of the study was to evaluate the in vitro antibacterial activity of curcumin alone and associated with oxacillin against MRSA strains, to analyze the mechanism of cell death involved in the isolated action of curcumin by means of flow cytometry and molecular docking, and to verify its superbiofilm action. Curcumin showed antibacterial activity in the range of 125-500 µg/mL against the tested strains, since it caused an increase in membrane permeability and DNA fragmentation, as revealed by flow cytometry analysis. Moreover, it was possible to observe interactions of curcumin with wild-type S. aureus DHFR, S. aureus gyrase and S. aureus gyrase complex with DNA, DNA (5'-D(*CP*GP*AP*TP*GP*CP*G)-3') and Acyl-PBP2a from MRSA by molecular docking. Curcumin also had a synergistic and additive effect when associated with oxacillin, and significantly reduced the cell viability of the analyzed biofilms. Thus, curcumin is a possible candidate for pharmaceutical formulation development for the treatment of MRSA infections.


Assuntos
Curcumina , Staphylococcus aureus Resistente à Meticilina , Antibacterianos/farmacologia , Biofilmes , Curcumina/farmacologia , Humanos , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Plâncton , Staphylococcus aureus
3.
Can J Microbiol ; 67(12): 885-893, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34314621

RESUMO

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the main human pathogens and is responsible for many diseases, ranging from skin infections to more invasive infections. These infections are dangerous and expensive to treat because these strains are resistant to a large number of conventional antibiotics. Thus, the antibacterial effect of ketamine against MRSA strains, its mechanism of action, and in silico interaction with sortase A were evaluated. The antibacterial effect of ketamine was assessed using the broth microdilution method. Subsequently, the mechanism of action was assessed using flow cytometry and molecular docking assays with sortase A. Our results showed that ketamine has a significant antibacterial activity against MRSA strains in the range of 2.49-3.73 mM. Their mechanism of action involves alterations in membrane integrity and DNA damage, reducing cell viability, and inducing apoptosis. In addition, ketamine had an affinity for S. aureus sortase A. These results indicate that this compound can be used as an alternative to develop new strategies to combat infections caused by MRSA.


Assuntos
Ketamina , Staphylococcus aureus Resistente à Meticilina , Aminoaciltransferases , Antibacterianos/farmacologia , Proteínas de Bactérias , Cisteína Endopeptidases , Humanos , Ketamina/farmacologia , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Staphylococcus aureus
4.
J Toxicol Environ Health A ; 84(4): 137-151, 2021 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-33103637

RESUMO

Troxerutin is a natural flavonoid present abundantly in tea, coffee, olives, wheat, and a variety of fruits and vegetables. Due to its diverse pharmacological properties, this flavonoid has aroused interest for treatment of various diseases, and consequently prompted investigation into its toxicological characteristics. The aim of this study was to evaluate the genotoxic and mutagenic effects and chemoprotective activity attributed to troxerutin using human peripheral blood leukocytes (PBLs) through several well-established experimental protocols based upon different parameters. Data demonstrated that troxerutin (100 to 1000 µM) induced no marked cytotoxic effect on PBLs after 24 hr, and did not produce strand breaks and mutagenicity. Regarding chemoprevention, this flavonoid attenuated cytotoxicity, genotoxicity, and mutagenicity initiated by hydrogen peroxide (H2O2) in human PBLs. Further, troxerutin demonstrated no marked cytotoxic effect on PBLs and exerted a protective effect against oxidative stress induced by H2O2 through modulation of GSH-dependent enzymes.


Assuntos
Glutationa/metabolismo , Peróxido de Hidrogênio/farmacologia , Hidroxietilrutosídeo/análogos & derivados , Leucócitos/fisiologia , Oxidantes/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Anticoagulantes/farmacologia , Humanos , Hidroxietilrutosídeo/farmacologia , Leucócitos/efeitos dos fármacos , Leucócitos/enzimologia
5.
Microb Pathog ; 148: 104365, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32619669

RESUMO

Coronavirus (COVID-19) is an enveloped RNA virus that is diversely found in humans and that has now been declared a global pandemic by the World Health Organization. Thus, there is an urgent need to develop effective therapies and vaccines against this disease. In this context, this study aimed to evaluate in silico the molecular interactions of drugs with therapeutic indications for treatment of COVID-19 (Azithromycin, Baricitinib and Hydroxychloroquine) and drugs with similar structures (Chloroquine, Quinacrine and Ruxolitinib) in docking models from the SARS-CoV-2 main protease (M-pro) protein. The results showed that all inhibitors bound to the same enzyme site, more specifically in domain III of the SARS-CoV-2 main protease. Therefore, this study allows proposing the use of baricitinib and quinacrine, in combination with azithromycin; however, these computer simulations are just an initial step for conceiving new projects for the development of antiviral molecules.


Assuntos
Antivirais/química , Antivirais/farmacologia , COVID-19/virologia , Proteases 3C de Coronavírus/antagonistas & inibidores , Proteases 3C de Coronavírus/química , SARS-CoV-2/efeitos dos fármacos , Sítios de Ligação/efeitos dos fármacos , Cisteína Endopeptidases/química , Inibidores de Cisteína Proteinase/química , Inibidores de Cisteína Proteinase/farmacologia , Descoberta de Drogas/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Humanos , Simulação de Acoplamento Molecular , Inibidores de Proteases/química , Inibidores de Proteases/farmacologia , SARS-CoV-2/enzimologia , Tratamento Farmacológico da COVID-19
6.
Microb Pathog ; 127: 335-340, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30529514

RESUMO

Emergence of methicilin resistant Staphylococcus aureus (MRSA) strains is a major cause of infirmity worldwide and has limited our therapeutic options against these pathogens. In this regard, the search for candidates with an antimicrobial activity, with a greater efficacy and a lower toxicity, is necessary. As a result, there is greater need to search for resistance modifying agents which, in combination with existing drugs, will restore the efficacy of these drugs. The antibacterial effect of fluoxetine was determined by a broth microdilution method (the M07-A9 method of the Clinical and Laboratory Standard Institute) and flow cytometry techniques in which the probable mechanism of action of the compound was also assessed. The isolates used in the study belonged to the Laboratory of Bioprospecting of Antimicrobial Molecules (LABIMAN) of the Federal University of Ceará. After 24 h, Methicillin-resistant Sthaphylococcus aureus (MRSA) strains showed fluoxetine MICs equal to 64 µg/mL and 128 µg/mL, respectively. Cytometric analysis showed that treatment with fluoxetine caused alterations to the integrity of the plasma membranes and DNA damage, which led to cell death, probably by apoptosis.


Assuntos
Antibacterianos/farmacologia , Fluoxetina/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Dano ao DNA , Citometria de Fluxo , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos
7.
Microb Pathog ; 107: 341-348, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28411060

RESUMO

Recent research has shown broad antifungal activity of the classic antidepressants selective serotonin reuptake inhibitors (SSRIs). This fact, combined with the increased cross-resistance frequency of the genre Candida regarding the main treatment today, fluconazole, requires the development of novel therapeutic strategies. In that context, this study aimed to assess the antifungal potential of fluoxetine, sertraline, and paroxetine against fluconazole-resistant Candida spp. planktonic cells, as well as to assess the mechanism of action and the viability of biofilms treated with fluoxetine. After 24 h, the fluconazole-resistant Candida spp. strains showed minimum inhibitory concentration (MIC) in the ranges of 20-160 µg/mL for fluoxetine, 10-20 µg/mL for sertraline, and 10-100.8 µg/mL for paroxetine by the broth microdilution method (M27-A3). According to our data by flow cytometry, each of the SSRIs cause fungal death after damaging the plasma and mitochondrial membrane, which activates apoptotic signaling pathways and leads to dose-dependant cell viability loss. Regarding biofilm-forming isolates, the fluoxetine reduce mature biofilm of all the species tested. Therefore, it is concluded that SSRIs are capable of inhibit the growth in vitro of Candida spp., both in planktonic form, as biofilm, inducing cellular death by apoptosis.


Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Farmacorresistência Fúngica/efeitos dos fármacos , Fluconazol/farmacologia , Inibidores Seletivos de Recaptação de Serotonina/farmacologia , Animais , Apoptose/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Candida/citologia , Candida/genética , Candida/crescimento & desenvolvimento , Contagem de Células , Morte Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , DNA Fúngico/efeitos dos fármacos , Fibroblastos/microbiologia , Citometria de Fluxo , Técnicas In Vitro , Potenciais da Membrana , Camundongos , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Membranas Mitocondriais/efeitos dos fármacos , Paroxetina/farmacologia , Plasma/efeitos dos fármacos , Inibidores Seletivos de Recaptação de Serotonina/administração & dosagem , Sertralina/farmacologia
8.
Antimicrob Agents Chemother ; 60(6): 3551-7, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27021328

RESUMO

The incidence of fungal infections and, in particular, the incidence of fungal antibiotic resistance, which is associated with biofilm formation, have significantly increased, contributing to morbidity and mortality. Thus, new therapeutic strategies need to be developed. In this context, natural products have emerged as a major source of possible antifungal agents. Berberine is a protoberberine-type isoquinoline alkaloid isolated from the roots, rhizomes, and stem bark of natural herbs, such as Berberis aquifolium, Berberis vulgaris, Berberis aristata, and Hydrastis canadensis, and of Phellodendron amurense Berberine has been proven to have broad antibacterial and antifungal activity. In the present study, the potential antifungal effect of berberine against fluconazole-resistant Candida and Cryptococcus neoformans strains, as well as against the biofilm form of Candida spp., was assessed. The antifungal effect of berberine was determined by a broth microdilution method (the M27-A3 method of the Clinical and Laboratory Standards Institute) and flow cytometry techniques, in which the probable mechanism of action of the compound was also assessed. For biofilm assessment, a colorimetric 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was used to determine the susceptibility of sessile cells. The isolates used in the study belonged to the Laboratory of Bioprospection and Experiments in Yeast (LABEL) of the Federal University of Ceará. After 24 and 72 h, fluconazole-resistant Candida and Cryptococcus neoformans strains showed berberine MICs equal to 8 µg/ml and 16 µg/ml, respectively. Cytometric analysis showed that treatment with berberine caused alterations to the integrity of the plasma and mitochondrial membranes and DNA damage, which led to cell death, probably by apoptosis. Assessment of biofilm-forming isolates after treatment showed statistically significant reductions in biofilm cell activity (P < 0.001).


Assuntos
Antifúngicos/farmacologia , Berberina/farmacologia , Candida/efeitos dos fármacos , Candidíase/tratamento farmacológico , Criptococose/tratamento farmacológico , Cryptococcus neoformans/efeitos dos fármacos , Fluconazol/farmacologia , Animais , Berberina/efeitos adversos , Biofilmes/crescimento & desenvolvimento , Candida/classificação , Candida/genética , Candidíase/microbiologia , Linhagem Celular , Proliferação de Células , Criptococose/microbiologia , Cryptococcus neoformans/classificação , Cryptococcus neoformans/genética , DNA Fúngico/genética , Farmacorresistência Fúngica , Fluconazol/efeitos adversos , Humanos , Células L , Camundongos , Testes de Sensibilidade Microbiana , Membranas Mitocondriais/efeitos dos fármacos , Tipagem Molecular , Técnicas de Tipagem Micológica
9.
Antimicrob Agents Chemother ; 58(3): 1468-78, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24366745

RESUMO

Flavonoids are a class of phenolic compounds commonly found in fruits, vegetables, grains, flowers, tea, and wine. They differ in their chemical structures and characteristics. Such compounds show various biological functions and have antioxidant, antimicrobial, anti-inflammatory, and antiapoptotic properties. The aim of this study was to evaluate the in vitro interactions of flavonoids with fluconazole against Candida tropicalis strains resistant to fluconazole, investigating the mechanism of synergism. Three combinations formed by the flavonoids (+)-catechin hydrated, hydrated quercetin, and (-)-epigallocatechin gallate at a fixed concentration with fluconazole were tested. Flavonoids alone had no antifungal activity within the concentration range tested, but when they were used as a cotreatment with fluconazole, there was significant synergistic activity. From this result, we set out to evaluate the possible mechanisms of cell death involved in this synergism. Isolated flavonoids did not induce morphological changes or changes in membrane integrity in the strains tested, but when they were used as a cotreatment with fluconazole, these changes were quite significant. When evaluating mitochondrial damage and the production of reactive oxygen species (ROS) only in the cotreatment, changes were observed. Flavonoids combined with fluconazole were shown to cause a significant increase in the rate of damage and the frequency of DNA damage in the tested strains. The cotreatment also induced an increase in the externalization of phosphatidylserine, an important marker of early apoptosis. It is concluded that flavonoids, when combined with fluconazole, show activity against strains of C. tropicalis resistant to fluconazole, promoting apoptosis by exposure of phosphatidylserine in the plasma membrane and morphological changes, mitochondrial depolarization, intracellular accumulation of ROS, condensation, and DNA fragmentation.


Assuntos
Antifúngicos/farmacologia , Apoptose/efeitos dos fármacos , Candida tropicalis/efeitos dos fármacos , Catequina/análogos & derivados , Catequina/farmacologia , Fluconazol/farmacologia , Quercetina/farmacologia , Antifúngicos/administração & dosagem , Interações Medicamentosas , Farmacorresistência Fúngica/efeitos dos fármacos , Sinergismo Farmacológico , Fluconazol/administração & dosagem , Testes de Sensibilidade Microbiana , Espécies Reativas de Oxigênio/metabolismo
10.
Future Microbiol ; 19(8): 667-679, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38864708

RESUMO

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.


[Box: see text].


Assuntos
Antibacterianos , Arginina , Biofilmes , Staphylococcus aureus Resistente à Meticilina , Testes de Sensibilidade Microbiana , Tensoativos , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Arginina/farmacologia , Arginina/química , Antibacterianos/farmacologia , Antibacterianos/química , Humanos , Tensoativos/farmacologia , Tensoativos/química , Glicolipídeos/farmacologia , Glicolipídeos/química , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/prevenção & controle , Infecções Estafilocócicas/tratamento farmacológico , Oxacilina/farmacologia , Sinergismo Farmacológico
11.
Future Microbiol ; 19(15): 1309-1320, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39101446

RESUMO

Aim: Evaluate the anticandidal effect of Croton heliotropiifolius Kunth essential oil and its interaction with azoles and N-acetylcysteine (NAC) against planktonic cells and biofilms.Materials & methods: Broth microdilution and checkerboard methods were used to evaluate the individual and combined activity with fluconazole and itraconazole (ITRA). The antibiofilm effect of the oil was assessed in 96-well plates alone and combined with ITRA and NAC, and cytotoxicity determined by MTT.Results: The oil inhibited all Candida species growth. The activity was enhanced when associated with ITRA and NAC for planktonic cells and biofilms in formation. The effective concentrations were lower than the toxic ones to V79 cells.Conclusion: C. heliotropiifolius Kunth essential oil is an anticandidal alternative, and can be associated with ITRA and NAC.


Candida is a type of fungus that can cause disease in people. In recent years, the number of available drugs to treat this disease have declined. It is important to search for new drugs. Plants are often used to improve health, so we tested the essential oil of a plant called Croton heliotropiifolius to see if it could kill the fungus. We found that the essential oil could kill the fungus, and could be used with other drugs to improve their effects.


Assuntos
Acetilcisteína , Antifúngicos , Biofilmes , Candida , Croton , Itraconazol , Testes de Sensibilidade Microbiana , Óleos Voláteis , Croton/química , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Itraconazol/farmacologia , Antifúngicos/farmacologia , Acetilcisteína/farmacologia , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Sinergismo Farmacológico , Animais , Linhagem Celular , Fluconazol/farmacologia , Cricetinae
12.
Future Microbiol ; 19(16): 1365-1375, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39235062

RESUMO

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.


Assuntos
Anlodipino , Antifúngicos , Biofilmes , Candida , Testes de Sensibilidade Microbiana , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Candida/fisiologia , Candida/crescimento & desenvolvimento , Anlodipino/farmacologia , Viabilidade Microbiana/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Humanos , Citometria de Fluxo , Plâncton/efeitos dos fármacos , Plâncton/crescimento & desenvolvimento
13.
Future Microbiol ; 19(13): 1157-1170, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39012219

RESUMO

Aim: To evaluate the antifungal activity of mangiferin against Candida spp. resistant to fluconazole.Materials & methods: The antifungal activity of mangiferin was assessed using broth microdilution and its interaction with azoles and amphotericin B was evaluated by checkerboard. The activity of mangiferin against Candida spp. biofilms was assessed using the MTT colorimetric assay and its possible mechanism of action was evaluated using flow cytometry.Results: Mangiferin showed activity against Candida albicans, Candida tropicalis and Candida parapsilosis resistant to fluconazole and showed synergism with azoles and amphotericin B. Mangiferin increased the activity of antifungals against Candida biofilms and caused depolarization of the mitochondrial membrane and externalization of phosphatidylserine, suggesting apoptosis.Conclusion: mangiferin combined with antifungals has potential against Candida spp.


Candida is a type of fungus that can make people ill. Over time, many species of Candida have found ways to resist the drugs used to kill them. It is important to find new drugs. We decided to see if a substance called mangiferin works against Candida. We found that mangiferin works against Candida and may help other drugs to work better. We still need to do more studies to find out whether mangiferin can help prevent diseases caused by Candida in the future.


Assuntos
Anfotericina B , Antifúngicos , Biofilmes , Candida , Farmacorresistência Fúngica , Sinergismo Farmacológico , Fluconazol , Testes de Sensibilidade Microbiana , Xantonas , Antifúngicos/farmacologia , Xantonas/farmacologia , Fluconazol/farmacologia , Biofilmes/efeitos dos fármacos , Farmacorresistência Fúngica/efeitos dos fármacos , Anfotericina B/farmacologia , Candida/efeitos dos fármacos , Humanos , Apoptose/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Azóis/farmacologia
14.
J Med Microbiol ; 73(2)2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38385528

RESUMO

Introduction. Candida albicans and Staphylococcus aureus are recognized for their development of resistance and biofilm formation. New therapeutic alternatives are necessary in this context.Hypothesis. Etomidate shows potential application in catheters against mixed biofilms of fluconazole-resistant C. albicans and methicillin-resistant S. aureus (MRSA).Aim. The present study aimed to evaluate the activity of etomidate against mixed biofilms of fluconazole-resistant C. albicans and MRSA.Methodology. The action of etomidate against mature biofilms was verified through the evaluation of biomass and cell viability, and its ability to prevent biofilm formation in peripheral venous catheters was determined based on counts of colony forming units (c.f.u.) and confirmed by morphological analysis through scanning electron microscopy (SEM).Results. Etomidate generated a reduction (P<0.05) in biomass and cell viability starting from a concentration of 250 µg ml-1. In addition, it showed significant ability to prevent the formation of mixed biofilms in a peripheral venous catheter, as shown by a reduction in c.f.u. SEM revealed that treatment with etomidate caused substantial damage to the fungal cells.Conclusion. The results showed the potential of etomidate against polymicrobial biofilms of fluconazole-resistant C. albicans and MRSA.


Assuntos
Etomidato , Staphylococcus aureus Resistente à Meticilina , Fluconazol/farmacologia , Candida albicans , Antifúngicos/farmacologia , Etomidato/farmacologia , Biofilmes , Testes de Sensibilidade Microbiana
15.
Antimicrob Agents Chemother ; 57(4): 1691-700, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23357774

RESUMO

There have recently been significant increases in the prevalence of systemic invasive fungal infections. However, the number of antifungal drugs on the market is limited in comparison to the number of available antibacterial drugs. This fact, coupled with the increased frequency of cross-resistance, makes it necessary to develop new therapeutic strategies. Combination drug therapies have become one of the most widely used and effective strategies to alleviate this problem. Amiodarone (AMD) is classically used for the treatment of atrial fibrillation and is the drug of choice for patients with arrhythmia. Recent studies have shown broad antifungal activity of the drug when administered in combination with fluconazole (FLC). In the present study, we induced resistance to fluconazole in six strains of Candida tropicalis and evaluated potential synergism between fluconazole and amiodarone. The evaluation of drug interaction was determined by calculating the fractional inhibitory concentration and by performing flow cytometry. We conclude that amiodarone, when administered in combination with fluconazole, exhibits activity against strains of C. tropicalis that are resistant to fluconazole, which most likely occurs via changes in the integrity of the yeast cell membrane and the generation of oxidative stress, mitochondrial dysfunction, and DNA damage that could lead to cell death by apoptosis.


Assuntos
Amiodarona/farmacologia , Antifúngicos/farmacologia , Candida tropicalis/efeitos dos fármacos , Candida tropicalis/patogenicidade , Fluconazol/farmacologia , Farmacorresistência Fúngica , Sinergismo Farmacológico , Testes de Sensibilidade Microbiana
16.
J Med Microbiol ; 72(10)2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37801011

RESUMO

Species of the genus Candida, characterized as commensals of the human microbiota, are opportunistic pathogens capable of generating various types of infections with high associated costs. Considering the limited pharmacological arsenal and the emergence of antifungal-resistant strains, the repositioning of drugs is a strategy used to search for new therapeutic alternatives, in which minocycline and doxycycline have been evaluated as potential candidates. Thus, the objective was to evaluate the in vitro antifungal activity of two tetracyclines, minocycline and doxycycline, and their possible mechanism of action against fluconazole-resistant strains of Candida spp. The sensitivity test for antimicrobials was performed using the broth microdilution technique, and the pharmacological interaction with fluconazole was also analysed using the checkerboard method. To analyse the possible mechanisms of action, flow cytometry assays were performed. The minimum inhibitory concentration obtained was 4-427 µg ml-1 for minocycline and 128-512 µg ml-1 for doxycycline, and mostly indifferent and additive interactions with fluconazole were observed. These tetracyclines were found to promote cellular alterations that generated death by apoptosis, with concentration-dependent reactive oxygen species production and reduced cell viability. Therefore, minocycline and doxycycline present themselves as promising study molecules against Candida spp.


Assuntos
Antifúngicos , Fluconazol , Humanos , Fluconazol/farmacologia , Antifúngicos/farmacologia , Candida , Minociclina/farmacologia , Doxiciclina/farmacologia , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Farmacorresistência Fúngica
17.
J Med Microbiol ; 72(2)2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36762524

RESUMO

Candida spp. infections are a serious health problem, especially in patients with risk factors. The acquisition of resistance, often associated with biofilm production, makes treatment more difficult due to the reduced effectiveness of available antifungals. Drug repurposing is a good alternative for the treatment of infections by Candida spp. biofilms. The present study evaluated the in vitro antibiofilm activity of sertraline in reducing the cell viability of forming and matured biofilms, in addition to elucidating whether effective concentrations are safe. Sertraline reduced biofilm cell viability by more than 80 % for all Candida species tested, acting at low and safe concentrations, both on mature biofilm and in preventing its formation, even the one with highest virulence. Its preventive mechanism seemed to be related to binding with ALS3. These data indicate that sertraline is a promising drug with anticandidal biofilm potential in safe doses. However, further studies are needed to elucidate the antibiofilm mechanism and possible application of pharmaceutical forms.


Assuntos
Candida , Candidíase , Humanos , Sertralina/farmacologia , Sertralina/uso terapêutico , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Candidíase/tratamento farmacológico , Biofilmes , Testes de Sensibilidade Microbiana , Candida albicans
18.
Colloids Surf B Biointerfaces ; 207: 112017, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34391169

RESUMO

In the past two decades, the increase in microbial resistance to conventional antimicrobials has spurred scientists around the world to search tirelessly for new treatments. Synthetic amino acid-based surfactants constitute a promising alternative to conventional antimicrobial compounds. In this work, two new cationic amino acid-based surfactants were synthesized and their physicochemical, antifungal and antibiofilm properties evaluated. The surfactants were based on phenylalanine-arginine (LPAM) and tryptophan-arginine (LTAM) and prepared from renewable raw materials using a simple chemical procedure. The critical micelle concentrations of the new surfactants were determined by conductivity and fluorescence. Micellization of LPAM and LTAM took place at 1.05 and 0.54 mM, respectively. Both exhibited good antifungal activity against fluconazole-resistant Candida spp. strains, with a low minimum inhibitory concentration (8.2 µg/mL). Their mechanism of action involves alterations in cell membrane permeability and mitochondrial damage, leading to death by apoptosis. Furthermore, when LPAM and LTAM were applied with Amphotericin B, a significant synergistic effect was observed against all the studied Candida strains. These new cationic surfactants are also able to disperse biofilms of Candida spp. at low concentrations. The results indicate that LPAM and LTAM have potential application to combat the advance of fungal resistance as well as microbial biofilms.


Assuntos
Antifúngicos , Fluconazol , Anfotericina B/farmacologia , Antifúngicos/farmacologia , Arginina , Biofilmes , Candida , Farmacorresistência Fúngica , Fluconazol/farmacologia , Testes de Sensibilidade Microbiana , Fenilalanina , Tensoativos/farmacologia , Triptofano
19.
Toxicol In Vitro ; 62: 104718, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31706955

RESUMO

Ketamine is a potent uncompetitive NMDA receptor antagonist that provides amnesia, analgesia, environmental dissociation and immobility, where it has its cytotoxic effect well described in the literature. However, the work on its genotoxic/mutagenic potentials are scarce and insufficient and does not allow a reasonable evaluation of its role. Thus, in the present work, we decided to evaluate the genotoxic and mutagenic effects of ketamine on human peripheral blood leukocytes (PBLs) and Salmonella typhimurium (TA98, TA97a, TA100, and TA102) through several well-established experimental protocols based on different parameters in the presence or not of exogenous metabolizing S9 fraction. Our data revealed that ketamine induces a weak cytotoxic effect on human PBLs after 24 h and is devoided of hemolytic effects. A small amount of DNA strand breaks levels were detected in the modified comet assay (employment of FPG enzyme) only at highest concentrations (500 and 700 µg/mL) of ketamine, highlighting our pro-oxidant data regarding ketamine. However, the oxidative DNA lesions were almost completely repaired which reflects in the lack of mutagenesis (micronuclei and chromosomal aberrations) on human PBLs and no increases in revertants numbers on S. typhimurium/microsome test (500 to 5000 µg/plate). In summary, ketamine is a weak oxidative DNA damaging agent and is devoid of mutagenic properties on eukaryotic and prokaryotic models.


Assuntos
Anestésicos Dissociativos/toxicidade , Ketamina/toxicidade , Leucócitos/efeitos dos fármacos , Mutagênicos/toxicidade , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Aberrações Cromossômicas/induzido quimicamente , Ensaio Cometa , Quebras de DNA , Dano ao DNA , Hemólise/efeitos dos fármacos , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Testes de Mutagenicidade , Estresse Oxidativo
20.
Future Microbiol ; 15: 177-188, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32077323

RESUMO

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.


Assuntos
Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Fluconazol/farmacologia , Itraconazol/farmacologia , Ketamina/farmacologia , Animais , Biofilmes/efeitos dos fármacos , Candida/fisiologia , Candida albicans/efeitos dos fármacos , Candida albicans/fisiologia , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA , Fragmentação do DNA , DNA Fúngico/efeitos dos fármacos , Farmacorresistência Fúngica , Sinergismo Farmacológico , Células L , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Testes de Sensibilidade Microbiana , Viabilidade Microbiana , Fosfatidilserinas/metabolismo , Espécies Reativas de Oxigênio/metabolismo
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