RESUMO
INTRODUCTION: In the last years the rapid expansion of multidrug-resistant A. baumannii strains have become a major health problem. Efflux pumps are a group of transport proteins that contribute to the development of antibiotic resistance. The aim of this study was to evaluate the effect of the efflux pump inhibitor carbonyl cyanide 3-chlorophenylhydrazone (CCCP) on the antimicrobial action of imipenem and cefepime on clinical strains of A. baumannii. MATERIALS AND METHODS: A total of 49 non-duplicate clinical samples were collected during January through December of 2018 from patients hospitalized in the Hospital Regional Docente de Cajamarca. Of the 49 samples obtained, the confirmatory identification of A. baumannii was performed on 47 samples by molecular methods. The amplification of the blaOXA-51-like gene was carried out by polymerase chain reaction (PCR). The determination of the minimum inhibitory concentration (MIC) was calculated using the microdilution method in culture broth. The susceptibility to both antibiotics (cefepime and imipenem) was evaluated in the presence and absence of the inhibitor carbonyl cyanide 3-chlorophenylhydrazone (CCCP). RESULTS: A total of 47 strains of A. baumannii were isolated: 97.87% (46/47) were resistant to Imipenem, 2.13% (1/47) of them were classified as intermediate and none of these strains were susceptible. On the other hand, 51.06% (24/47) of isolates were resistant to cefepime; 19.15% (9/47) intermediate and 29.79% (14/47) susceptible. We considered a significant difference in antibiotic susceptibility if the MIC changed at least 4 dilutions, after the addition of the inhibitor. In the case of CCCP in addition to imipenem, 2.1% (1/47) had a significant change of 4 or more reductions in MIC, 59.6% (28/47) achieved a change equal or less than 3 dilutions and 17.0% (8/47) did not have any change. In the case of CCCP with cefepime the percentage of strains with the significant change of MIC was 8.5% (4/47). On the other hand, 53.2% (24/47) presented a reduction equal or less than 3 dilutions and 12.8% (6/47) did not show changes. CONCLUSION: In conclusion, our results demonstrate that the use of CCCP may improve the antibiotic effect of imipenem and cefepime on clinical strains of A. baumannii. The relevance of this study is that it provides evidence that this efflux pump inhibitor may be an alternative treatment against multidrug-resistant A. baumannii.
Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Antibacterianos/farmacologia , Carbonil Cianeto m-Clorofenil Hidrazona/farmacologia , Cefepima/farmacologia , Imipenem/farmacologia , Ionóforos de Próton/farmacologia , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/genética , Acinetobacter baumannii/isolamento & purificação , Acinetobacter baumannii/metabolismo , Combinação de Medicamentos , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/genética , Sinergismo Farmacológico , Expressão Gênica , Genes MDR/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , beta-Lactamases/genética , beta-Lactamases/metabolismoRESUMO
Fungal resistance is the major problem related to fluconazole treatments. This study aims to develop innovative lipid core nanocapsules and nanostructured lipid carriers containing fluconazole, to study in vitro antifungal activity and to assess the possibility of resistance reversion in Candida albicans, C. glabrata, C. krusei, and C. tropicalis isolates. The action mechanism of nanoparticles was investigated through efflux pumps and scanning electron microscopy studies. The lipid core nanocapsules and nanostructured lipid carriers were prepared by interfacial deposition of preformed polymer and high-pressure homogenization methods, respectively. Both nanostructures presented sizes below 250 nm, SPAN < 1.6, negative zeta potential, pH slightly acid, high drug content and controlled drug release. The nanostructured lipid carriers were unable to reverse the fungal resistance. Lipid core nanoparticles displayed advantages such as a reduction in the effective dose of fluconazole and resistance reversion in all isolates tested - with multiple mechanisms of resistance. The main role of the supramolecular structure and the composition of the nanoparticles on antifungal mechanisms of action were discussed. The results achieved through this study have an impact on clinical therapy, with a potential application in the treatment of fungal infections caused by resistant isolates of Candida spp.
Assuntos
Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Preparações de Ação Retardada/química , Farmacorresistência Fúngica/efeitos dos fármacos , Fluconazol/farmacologia , Proteínas Fúngicas/antagonistas & inibidores , Nanopartículas/química , Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Candida/genética , Candida/crescimento & desenvolvimento , Candida/metabolismo , Candida albicans/efeitos dos fármacos , Candida albicans/genética , Candida albicans/crescimento & desenvolvimento , Candida albicans/metabolismo , Candida glabrata/efeitos dos fármacos , Candida glabrata/genética , Candida glabrata/crescimento & desenvolvimento , Candida glabrata/metabolismo , Candida tropicalis/efeitos dos fármacos , Candida tropicalis/genética , Candida tropicalis/crescimento & desenvolvimento , Candida tropicalis/metabolismo , Caprilatos/química , Composição de Medicamentos/métodos , Farmacorresistência Fúngica/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Expressão Gênica , Genes MDR/efeitos dos fármacos , Hexoses/química , Concentração de Íons de Hidrogênio , Testes de Sensibilidade Microbiana , Nanopartículas/ultraestrutura , Palmitatos/química , Tamanho da Partícula , Triglicerídeos/química , Verapamil/farmacologiaRESUMO
La resistencia a las polimixinas mediada por plásmidos (gen mcr-1) representa una amenaza para la salud pública, puesto que colistina es utilizada en la práctica médica como una de las últimas alternativas para el tratamiento de gérmenes multiresistentes. Este estudio describe la circulaciónde cepas de Enterobacterias que portan este gen de resistencia, aisladas de pacientes hospitalizados, así como también de la comunidad. Los hallazgos de la Red de Vigilancia de la Resistencia a los Antimicrobianos-Paraguay fueron de casi el 5 % (4,7) en cepas remitidas con criterio de sospecha, siendo las especies involucradas Escherichiacoli, Klebsiella pneumoniae y Salmonella Schwarzengrund. Además, por métodos moleculares se confirmaron en todas ellas la portación de otros genes de resistencia (KPC, CTX-M, Qnr B, Qnr S, aac (6`)-Ib-cr) asociados al mcr-1. Palabras claves: Enterobacterias, resistencia, colistina, mcr-1.
Resistance to polymyxins mediated by plasmids (mcr-1 gene) represents a threat to public health, since colistin is used in medical practice, as one of the last alternatives, for the treatment of multi-resistant germs. This study describes the circulation of strains of Enterobacteria that carry this resistance gene, isolated from hospitalized patients, as well as from the community. The findings of the Red de Vigilancia de la Resistencia a los AntimicrobianosParaguay were almost 5% (4.7) in strains submitted with suspicion criteria; the species involved being Escherichia coli, Klebsiella pneumoniae and Salmonella Schwarzengrund. In addition, molecular methods confirmed in all of them the carrying of other resistance genes (KPC, CTX-M, Qnr B, Qnr S, aac (6`)-Ib-cr) associated with mcr-1. Key words: Enterobacteria, resistance, colistin, mcr-1.
Assuntos
Humanos , Masculino , Feminino , Resistência a Medicamentos/genética , Genes MDR/efeitos dos fármacos , Plasmídeos/farmacocinética , Colistina/farmacologia , Polimixinas/farmacocinética , Salmonella enterica/efeitos dos fármacos , Enterobacteriaceae/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacosRESUMO
Aerosolized amikacin reaches high concentrations in lung fluids, which are well above the minimum inhibitory concentrations (MICs) of resistant strains of Pseudomonas aeruginosa. However, P. aeruginosa can gain resistance to amikacin through different cumulative mechanisms; amikacin MICs are seldom reported beyond values of 1,000 µg/ml, as tested in clinical microbiology assays. To assess how high amikacin MICs can be reached by graded exposure, four amikacin-resistant P. aeruginosa isolates were grown in a 4-step increased exposure to amikacin; derivative strains were further characterized by measuring their comparative growth rate, biofilm-forming ability, and susceptibility to other antibiotics. In addition, the mechanism underlying the MIC increase was assessed phenotypically, using a set of 12 aminoglycoside disks, and measuring the effect of Phe-Arg-ß-naphthylamide, an efflux pump inhibitor. Graded exposure to amikacin increased MICs of resistant strains up to 10,000-20,000 µg/ml, without apparent fitness cost, and having variable consequences on their biofilm-forming ability, and on their susceptibility to other antibiotics. Decreased permeability may have contributed to hyper-resistance, although evidence was inconclusive and variable between strains. Amikacin-resistant P. aeruginosa is able to gain in vitro hyper-resistance with minimal changes in the specific phenotypes that were tested; the ability to achieve high-level amikacin (AMK) resistance may confound the clinical utility of this aerosolized AMK, but clinical data would be required to assess this.
Assuntos
Amicacina/farmacologia , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Seleção Genética , Aerossóis , Arginina/análogos & derivados , Arginina/farmacologia , Biofilmes/crescimento & desenvolvimento , Transporte Biológico/efeitos dos fármacos , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Expressão Gênica , Genes MDR/efeitos dos fármacos , Genes MDR/genética , Humanos , Testes de Sensibilidade Microbiana , Fenótipo , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/crescimento & desenvolvimento , Pseudomonas aeruginosa/isolamento & purificaçãoRESUMO
Excretion of lipophilic cationic toxic compounds from the interior of the hepatocyte to the bile is mediated by P-Glycoprotein. It is an integral protein located in the bile canaliculi. The present work study the hepatic expression of P-Glycoprotein in different models of experimental liver disease: Acute paracetamol intoxication, extrahepatic cholestasis and cholestasis followed by acute paracetamol intoxication. mRNA was isolated from liver tissue, and the expression of Pg-p was assessed by Northern blot. It is concluded that the hepatic expression of mdr1b is increased in the experimental liver diseases when compared to controls. On the other hand, mdr2 expression was similar between the different groups (AU)
Assuntos
Animais , Masculino , Ratos , Acetaminofen/toxicidade , Analgésicos não Narcóticos/toxicidade , Colestase Extra-Hepática/induzido quimicamente , Regulação da Expressão Gênica , Genes MDR/genética , Hepatopatias/induzido quimicamente , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Acetaminofen/metabolismo , Doença Aguda , Analgésicos não Narcóticos/metabolismo , Bile/metabolismo , Colestase Extra-Hepática/metabolismo , Northern Blotting , Proteínas de Transporte/metabolismo , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Genes MDR/efeitos dos fármacos , Hepatócitos , Hepatopatias/metabolismo , Overdose de Drogas , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/efeitos dos fármacos , RNA Mensageiro/metabolismo , Ratos WistarRESUMO
Excretion of lipophilic cationic toxic compounds from the interior of the hepatocyte to the bile is mediated by P-Glycoprotein. It is an integral protein located in the bile canaliculi. The present work study the hepatic expression of P-Glycoprotein in different models of experimental liver disease: Acute paracetamol intoxication, extrahepatic cholestasis and cholestasis followed by acute paracetamol intoxication. mRNA was isolated from liver tissue, and the expression of Pg-p was assessed by Northern blot. It is concluded that the hepatic expression of mdr1b is increased in the experimental liver diseases when compared to controls. On the other hand, mdr2 expression was similar between the different groups.
Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Acetaminofen/toxicidade , Analgésicos não Narcóticos/toxicidade , Doença Hepática Induzida por Substâncias e Drogas , Colestase Extra-Hepática/induzido quimicamente , Regulação da Expressão Gênica , Genes MDR/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/efeitos dos fármacos , Acetaminofen/metabolismo , Doença Aguda , Analgésicos não Narcóticos/metabolismo , Animais , Bile/metabolismo , Northern Blotting , Proteínas de Transporte/metabolismo , Colestase Extra-Hepática/metabolismo , Modelos Animais de Doenças , Overdose de Drogas , Regulação da Expressão Gênica/efeitos dos fármacos , Genes MDR/efeitos dos fármacos , Hepatócitos , Hepatopatias/metabolismo , Masculino , RNA Mensageiro/metabolismo , Ratos , Ratos WistarRESUMO
El tratamiento y control de la malaria ha sido obstaculizado por la capacidad del parásito para desarrollar resistencia a agentes antimaláricos. La cloroquina, que ha sido el principal agente antimalárico debido a su eficiencia, baja toxicidad y costo, ahora frecuentemente fracasa en el control de la enfermedad. El mecanismo por el cual los parásitos desarrollan resistencia a cloroquina no se ha establecido hasta el momento, aunque inicialmente la amplificación, sobre-expresión y mutaciones puntuales en un gen denominado pfmdr1 (Plasmodium falciparum multidrug resistant gene) fueron asociadas con el fenotipo cloroquinorresistente (CQR); estudios posteriores suscitaron controversia acerca de esta asociación. En el trabajo se estudió la expresión del gen pfmdr1 en las cepas colombianas de P. falciparum y en dos cepas de referencia, una sensible (Haití 135) y una resistente (Palo Alto), mediante un ensayo de slot-blot. Los resultados obtenidos permiten sugerir que la expresión del gen pfmdr1 no está directamente relacionada con el fenotipo resistente