Chemical composition and modulation of bacterial drug resistance of the essential oil from leaves of Croton grewioides.

The essential oil from leaves of Croton grewioides Baill was obtained by hydrodistillation using Clevenger apparatus, and its chemical composition was analyzed by GC-MS, where 18 compounds were identified, mostly as monoterpenes (55.56%) and sesquiterpenes (44.44%), in which the major constituent was the α-pinene (47.43%). The essential oil of Croton grewioides (EOCg) and its major compound (α-pinene) were evaluated as modulators of antibiotic resistance in strain SA-1199B and IS-58 of Staphylococcus aureus that overexpresses efflux protein. The minimum inhibitory concentrations (MICs) of the antibiotics were determined by the microdilution assay in the absence and in the presence of sub-inhibitory concentration of EOCg and α-pinene. Although the EOCg and α-pinene did not indicate relevant antibacterial activity in vitro, they acted as antibiotic resistance modulators, i.e., EOCg in combination with norfloxacin, reducted its MIC, by 64× whereas in combination with tetracycline it was observed a reduction of 4×. Additionally, it was observed a MIC reduction of tetracycline by 32×, when combined with α-pinene. The results suggest that EOCg and α-pinene modulate or even reverse bacterial resistance as a putative efflux pump inhibitor.

Gravidez na adolescência ­ ações lúdicas no ensino médio: relato de experiência do projeto de extensão / Pregnancy in adolescence - ludic actions in middle school: report of experience of extension project / Embarazo en la adolescencia ­ acciones lúdicas en la enseñanza secundaria: relato deexperienciadelproyecto deextensión

A extensão universitária trabalha com as diversas problemáticas que envolvem a comunidade, auxiliando-a de forma que haja uma troca de conhecimentos. Atualmente, uma das adversidades que envolvem a sociedade é a gravidez na adolescência, considerada um dos problemas de saúde reprodutiva. Diante desse impasse, é imprescindível que haja ações educativas que busquem orientar e ampliar os conhecimentos dos adolescentes para evitar uma gravidez não planejada. Esse trabalho objetiva relatar a experiência dos graduandos em um projeto de extensão universitária, desenvolvido em uma escola pública do município de Cuité-Paraíba. Foram realizados quatro encontros semanais sequenciais, por meio de oficinas pedagógicas. Essa proposta metodológica enfatizou a importância de uma gravidez planejada, os métodos contraceptivos, e caso ocorra a gravidez, os cuidados necessários para a saúde materna e fetal. As estratégias utilizadas foram atividades lúdicas, as quais facilitaram a interação com os alunos, bem como o aprendizado e envolvimento deles. Vivenciou-se a evolução dos estudantes a cada encontro, de acordo com seus questionamentos, atenção, participação e assiduidade efetiva. Ações estas que associadas aos comentários positivos dos estudantes e da direção, demonstram que os objetivos foram alcançados. Desta forma, evidenciou-se a importância da extensão universitária para a socialização e compartilhamento de saberes junto à comunidade.

The university extension works with as diverse problems that involve community, helping it in a way that there is an exchange of knowledge. One of the adversities which involve society is teenage pregnancy, one of the problems of reproductive health. Faced with this impasse, it is essential educational actions that seek to guide and to expand the knowledge of adolescents to avoid an unplanned pregnancy. This paper aims to report an experience of undergraduates in a university extension project, developed in a public school in the city of Cuité-Paraíba. Four weekly sequential meetings were held, through pedagogical workshops. This methodological proposal emphasized the importance of a planned pregnancy, contraceptive methods, and in case of pregnancy, the necessary care for maternal and fetal health. The strategy used was ludic activities, such as facilitating interaction with students, as well as learning and involvement. The evolution of the students in each meeting was studied, according to their questions, attention, participation and effective attendance. Actions that are associated with positive feedback from students and management demonstrate that the goals have been achieved. In this way, the importance of university extension for socialization and sharing of flavors with the community was evidenced.

La extensión universitaria trabaja con diversas problemáticas que involucran la comunidad, auxiliándola de modo que haya un intercambio de conocimientos. Actualmente una de las adversidades que afectan la sociedad es el embarazo en la adolescencia, considerado uno de los problemas de salud reproductivo. Ante este escenario, son imprescindibles acciones educativas que busquen orientar y ampliar los conocimientos de los adolescentes para evitar un embarazo no planeado. Este trabajo tiene el objetivo de relatar la experiencia de los graduandos en un proyecto de extensión universitario, desarrollado en una escuela pública de la ciudad de Cuité-Paraíba-Brasil. Fueron realizadas cuatro citas semanales secuenciales, por medio de talleres pedagógicos. Esta propuesta metodológica enfatizó la importancia de un embarazo planeado, los métodos anticonceptivos, y caso ocurra el embarazo, los cuidados necesarios para la salud materna y fetal. Las estrategias utilizadas fueron actividades lúdicas, que facilitaron la interacción con los alumnos, así como su aprendizaje y participación. Se percibió la evolución de los estudiantes a cada cita, de acuerdo con sus cuestionamientos, atención, participación y asiduidad efectiva. Estas acciones, asociadas a los comentarios positivos de los estudiantes y dirigentes, demuestran que los objetivos fueron logrados. De esta forma, se evidenció la importancia de la extensión universitaria para la socialización y el intercambio de saberes junto a la comunidad.

Tannic Acid as a Potential Modulator of Norfloxacin Resistance in Staphylococcus Aureus Overexpressing norA.

BACKGROUND: Tannins have shown inhibitory effects against pathogenic bacteria, and these properties make tannins potential modifying agents in bacterial resistance. METHODS: The minimum inhibitory concentration (MIC) of tannic acid (TA), gallic acid (GA) and norfloxacin (Nor) against Staphylococcus aureus SA-1119 (NorA-effluxing strain) was determined using broth microdilution tests. To assess the modulation of antibiotic resistance, the MIC of Nor was determined in growth media with or without TA or GA at a subinhibitory concentration (1/4 MIC). The checkerboard method was performed to obtain the fractional inhibitory concentration index (FICI) for the combined application of TA and Nor. RESULTS: TA displayed a weak inhibitory effect (MIC 512 µg/ml) against S. aureus SA-1119, while no inhibitory effect was displayed by GA (MIC >512 µg/ml). However, when TA was tested at a subinhibitory concentration in combination with Nor, the MIC of Nor against S. aureus SA-1119 decreased from 128 to 4 µg/ml (32-fold); this effect was not observed for GA. In the checkerboard assay, the MIC of TA and Nor decreased from 512 to 128 µg/ml (4-fold) and from 128 to 8 µg/ml (16-fold), respectively. The combination of TA and Nor presented an FICI as low as 0.31, which indicates a synergistic interaction. CONCLUSIONS: TA is a potential agent for increasing the clinical efficacy of Nor to control resistant S. aureus.

Modulation of Drug Resistance in Staphylococcus aureus with Coumarin Derivatives.

Semisynthetic and commercial coumarins were investigated for their antibacterial and adjuvant properties with antibiotic agents against norfloxacin, erythromycin, and tetracycline resistant Staphylococcus aureus as based on efflux mechanisms. The coumarins and certain commercial antibiotics had their Minimum Inhibitory Concentrations determined by broth microdilution assay against resistant S. aureus strains which overexpress efflux pump proteins. For evaluation of the modulatory activity, the antibiotics MICs were determined in the presence of the coumarin derivatives at subinhibitory concentration. Although the coumarins did not display relevant antibacterial activity (MIC ≥ 128 µg/mL), they did modulate the antibiotics activities. Various coumarins, especially the alkylated derivatives in combination with antibiotics at subinhibitory concentrations, modulated antibiotic activity, reducing the MIC for tetracycline and norfloxacin by 2 to 8 times. Polar Surface Area (PSA) studies were performed and the fact that the presence of apolar groups is an important factor for the modulatory activity of coumarins was corroborated. Docking on the Penicillin-Binding Protein from MRSA identified that 18 is a potential ligand presenting low E binding. The results indicate that coumarin derivatives modulated antibiotic resistance and may be used as potential antibiotic adjuvants, acting by bacterial efflux pump inhibition in S. aureus.

Flavonoids from Praxelis clematidea R.M. King and Robinson modulate bacterial drug resistance.

Chemical studies of Praxelis clematidea R.M. King & Robinson resulted in the isolation of six flavones: Apigenine, genkwanine, 7,4'-dimethylapigenin, trimethylapigenin, cirsimaritin and tetramethylscutellarein, which were tested for their toxicity against Staphylococcus aureus SA-1199B, a strain possessing the NorA efflux pump. Efflux pumps are integral proteins of the bacterial membrane and are recognized as one of the main causes of bacterial drug resistance, since they expel antibiotics from the cell. The inhibition of this transporter is one form of modulating bacterial resistance to antimicrobial drugs. The flavones tested did not show any significant antibacterial activity against the Staphylococcus aureus strain used, but were able to modulate bacterial drug resistance. This property might be related to the degree of lipophilicity of the flavones conferred by the methoxyl groups, since 4',5,6,7 tetramethoxyflavone the most methoxylated compound, reduced the minimal inhibitory concentration of the drug 16-fold.

Drug resistance modulation in Staphylococcus aureus, a new biological activity for mesoionic hydrochloride compounds.

Two salts of the mesoionic compounds 1,4-diphenyl-5-(5-nitro-2-furanyl)-1,3,4-thiadiazolium-2-thiol chloride (MC-1) and 4-phenyl-5-(5-nitro-2-furanyl)-1,3,4-thiadiazolium-2-phenylamine chloride (MC-2) were synthesized utilizing 1,4-diphenyl-thiosemicarbazide and 5-nitro-2-furoyl chloride as starting materials. Their structures were characterized by IR, ¹H-NMR, ¹³C-NMR and elemental analysis. These compounds were analyzed for their influence on the effectiveness of norfloxacin, tetracycline, and erythromycin (standard antibiotics) against resistant strains of Staphylococcus aureus. MC-1 and MC-2, at sub-inhibitory concentrations of 16 µg/mL, favourably modulated the antibiotic activity of tetracycline by 16- and 32-fold, respectively (MIC), and that of erythromycin by 4-fold.