Serine protease inhibition and modulatory-antibiotic activity of the proteic extract and fractions from Amburana cearensis.

This study investigated the inhibitory activity of serine protease, as well as antibacterial and antibiotic modifying activities of the crude extract and fractions of A. cearensis seeds. Microdilution assay was used to evaluate the antibacterial activity and the antibiotic resistance-modulating effects of samples against multiresistant bacteria Staphylococcus aureus (SA10) and Escherichia coli (EC06). In the inhibition test for serine protease, all the samples showed inhibition of enzymatic activity. Crude extract and fractions of A. cearensis seeds showed a Minimum Inhibitory Concentration ≥1024 µg/mL for all microorganisms tested. However, the samples acted as resistance modifying agent, presenting synergism when associated with gentamicin, norfloxacin and penicillin. The present study provides data indicating a possible use of the seeds extract of A. cearensis in association with antibiotics in the fight against bacterial infections.

Modulation of the antibiotic activity against multidrug resistant strains of 4-(phenylsulfonyl) morpholine.

The compound 4-(Phenylsulfonyl) morpholine belongs to the class of sulfonamides, which are widely used in the treatment of a large number of diseases caused by microorganisms. This compound has a morpholine group, which is also known for its antimicrobial properties. The aim of the present study was to investigate the antimicrobial and modulating activity of 4-(Phenylsulfonyl) morpholine against standard and multi-resistant strains of Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and strains of the fungi Candida albicans, C. tropicalis and C. krusei. Antimicrobial activity was assessed based on the minimum inhibitory concentration (MIC) using the microdilution method. MIC was ⩾1024 µg/mL for all microorganisms. Regarding modulating activity, the most representative effect occurred with the combination of 4-(Phenylsulfonyl) morpholine at a concentration of 128 µg/mL (MIC 1/8) and amikacin against P. aeruginosa 03, with a reduction in MIC from 312.5 to 39.06 µg/mL.

Avaliação comparativa da modulação de antibióticos, frente às cepas bacterianas de Escherichia coli, Staphylococcus aureus / Evaluación comparativa de la modulación de antibióticos frente a cepas bacterianas de Escherichia Coli, Staphylococcus / Comparative Evaluation of the Modulation of Antibiotic-Activity against Strains of Escherichia coli and Staphylococcus aureus

Introdução: Combinações múltiplas de drogas estão sendo utilizadas no combate à disseminação de bactérias patogênicas resistentes a antibióticos. No entanto, a utilização incorreta desses antibióticos fez com que algumas bactérias sejam selecionadas, deixando apenas as resistentes aos agentes antimicrobianos, com o consequente surgimento de resistência aos antibióticos. Objetivos: Nesse contexto, avaliaram-se as atividades microbiológicas dos antibióticos claritromicina, gentamicina, ciprofloxacino e imipenem, além de comparar as atividades da associação entre esses fármacos, frente às cepas bacterianas de Escherichia coli e Staphylococcus aureus. Materiais e Métodos: A Concentração Inibitória Mínima (CIM) foi realizada pelo método de microdiluição em caldo para cada uma das amostras selecionadas. Posteriormente, com base nos valores das cims, foi avaliado o efeito antimicrobiano da combinação das drogas pelo método de modulação. Resultados: A associação demonstrou efeitos sinérgicos frente às linhagens testadas, sugerindo-se que a associação dos antibióticos testados aumenta o seu potencial antimicrobiano. Conclusão: Nesse sentido, o uso de antibióticos em combinação pode ser realizado mediante investigações posteriores que comprovem a segurança de seu uso.

Introducción: Actualmente, se está utilizando la combinación de múltiples drogas en la lucha contra la propagación de bacterias patógenas resistentes a los antibióticos. Sin embargo, el uso inadecuado de estos antibióticos ha causado que algunas bacterias se seleccionen, con la consiguiente aparición de resistencia a los antibióticos. Objetivo: Se evaluó la actividad microbiológica de los antibióticos claritromicina, gentamicina, ciprofloxacino e imipenem, y se comparó la actividad sinérgica de estos fármacos, frente a las cepas bacterianas de Escherichia coli y Staphylococcus aureus. Materiales y Métodos: Se determinó la Concentración Mínima Inhibitoria (CMI) por el método de microdilución en caldo para cada una de las muestras seleccionadas y se evaluó el efecto antimicrobiano de la combinación de fármacos por el método de modulación. Resultados: La combinación mostró efectos sinérgicos frente a las cepas ensayadas, lo que sugiere que la asociación de los antibióticos ensayados aumenta su potencial antimicrobiano. Conclusión: Se puede utilizar antibióticos en combinación; sin embargo, se requiere realizar investigaciones adicionales que demuestren ser seguros para su utilización.

Introduction: Combining multiple drugs is an strategy used to combat the dissemination of pathogenic and drug resistant bacteria. However, the misuse of these drugs against bacteria have caused the selection of more resistant specimens called multidrug-resistant bacteria. Objective: In this work we evaluated the antibiotic activity of claritromicin, gentamicin, ciprofloxacin and imipenen, alone or associating one by one, against strains of Escherichia coli and Staphylococcus aureus. Material and methods: The minimal inhibitory concentration (mic) was performed using the microdilution assay. Based in the mic values, the antibiotic effect of the drugs alone and in association were determined. Results: The association between the drugs demonstrated the synergism against the bacterial strains. Conclusion: The use of the combined antibiotic-therapy can be positively performed, but additional studies have to be conducted first for proving that its use is safe.

Identification and modulatory activity assessment of 2-hydroxy-3,4,6-trimethoxyacetophenone isolated from croton anisodontus müll. Arg.(euphorbiaceae).

The n-hexane extract of the stem bark of Croton anisodontus yielded 2-hydroxy-3,4,6-trimethoxyacetophenone, a well-known substance, but isolated from this species for the first time. The antimicrobial and modulatory activities of the compound towards Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans, C. krusei and C. tropicalis strains were assessed. Antibiotics such as amikacin, gentamicin and neomycin were used in a sub-inhibitory concentration. Significant activity was observed towards P. aeruginosa and S. aureus 358, with p < 0.001 in association with amikacin. The present results place C anisodontus as an alternative source of 2-hydroxy-3,4,6-trimethoxyacetophenone with antibacterial potential.