Effect of the Association and Evaluation of the Induction to Adaptation of the (+)-α-pinene with Commercial Antimicrobials against Strains of Escherichia coli.

BACKGROUND: The increasing and inappropriate use of antibiotics has increased the number of multidrug-resistant microorganisms to these drugs, causing the emergence of infections that are difficult to control and manage by health professionals. As an alternative to combat these pathogens, some monoterpenes have harmful effects on the bacterial cell membrane, showing themselves as an alternative in combating microorganisms. Therefore, the positive enantiomer α -pinene becomes an alternative to fight bacteria, since it was able to inhibit the growth of the species Escherichia coli ATCC 25922, demonstrating the possibility of its use as an isolated antimicrobial or associated with other drugs. AIMS: The aim of this study is to evaluate the sensitivity profile of E. coli ATCC 25922 strain against clinical antimicrobials associated with (+) -α-pinene and how it behaves after successive exposures to subinhibitory concentrations of the phytochemicals. METHODS: The minimum inhibitory concentration (MIC) was determined using the microdilution method. The study of the modulating effect of (+) -α-pinene on the activity of antibiotics for clinical use in strains of E. coli and the analysis of the strain's adaptation to the monoterpene were tested using the adapted disk-diffusion method. RESULTS: The results demonstrate that the association of monoterpene with the antimicrobials ceftazidime, amoxicillin, cefepime, cefoxitin and amikacin is positive since it leads to the potentiation of the antibiotic effect of these compounds. It was observed that the monoterpene was able to induce crossresistance only for antimicrobials: cefuroxime, ceftazidime, cefepime and chloramphenicol. CONCLUSION: It is necessary to obtain more concrete data for the safe use of these combinations, paying attention to the existence of some type of existing toxicity reaction related to the herbal medicine and to understand the resistance mechanisms acquired by the microorganism.

In Silico and In Vitro Investigation of the Antifungal Activity of Isoeugenol against Penicillium citrinum.

INTRODUCTION: This increase in the prevalence of drug-resistant pathogens occurs at a time when the discovery and development of new antimicrobial agents occur slowly. In this context, the objective of this study was to investigate the antifungal activity of isoeugenol, a phenylpropanoid, by in vitro and in silico assays against Penicillium citrinum strains. MATERIAL AND METHOD: For in silico analysis, the software PASS online, Molinspiration and Osíris were used. For the determination of Minimum Inhibitory Concentration (MIC) and Minimal Fungicide Concentration (MFC) of isoeugenol and voriconazole were carried out using the broth microdilution technique. PASS online has shown that isoeugenol has the opportunity to present antiseptic, antifungal, antibacterial, antimycobacterial activities. Molinspiration showed that the phytoconstituent has good potential for oral bioavailability. CONCLUSION: In the analysis with the Osiris program, it was demonstrated that isoeugenol has low irritant and tumorigenic risk. The MIC of isoeugenol varied between 256 and 32 µg/mL, MIC50 of 64 µg/mL and MIC90 was 128 µg/mL. The MFC50, MFC90 and MFC of the isoeugenol for P. citrinum species were 64, 256 and 518 µg/mL, respectively. After analysis, it was verified that the isoeugenol have bactericidal effect against the strains of P. citrinum. After these results, it is important to discover the mechanism of action involved in the antifungal action of the compound, as well as in vitro and in vivo toxicity tests.

Antibacterial Activity and Time-kill Kinetics of Positive Enantiomer of α-pinene Against Strains of Staphylococcus aureus and Escherichia coli.

Research on new antimicrobial agents is needed, as more and more microorganisms that cause antibiotic-resistant diseases are emerging commercially. In this group, we can find strains of Staphylococcus aureus and Escherichia coli, which are highly opportunistic species. Faced with this perspective, research using essential oils present in plants is emerging as a therapeutic alternative for the treatment of antimicrobial infections. Many of these oils have, in their composition, monoterpene α-pinene, that shows to have antibacterial activity. The purpose of this research is to evaluate the antimicrobial activity of the positive enantiomer of α-pinene against strains of Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922. The methodologies used were: Disc-diffusion test, broth microdilution and bacterial death kinetics, all of which were standardized by CLSI. As a result, inhibition halos of 11 mm was obtained for the gram-positive strain and 12 mm for the gram-negative strain, both at the same concentration, 160 µl / ml. In addition, it was possible to observe with the death curve that the concentrations (1.25 µl/mL and 2.5 µl/mL of the (+)-α-pinene were able to eliminate the formation of bacterial colonies at one time of exposure of 2 hours for the E. coli strain. However, the death curve of the S. aureus strain was characterized by non-elimination of bacterial colonies at a 24 hours exposure time used for the experiment. Only amikacin evidenced its bacterial killing rate of all colonies within two hours of exposure. At the end, it was possible to verify the activity of the phytoconstituent against Escherichia coli strains ATCC 25922 and Staphylococcus aureus ATCC 25923, recommending the continuity of the studies with the use of different methodologies so that (+) - α-pinene in the future can be a compound used in antimicrobial therapy.

Avaliação da atividade antimicrobiana in vitro e determinação da concentração inibitória mínima (CIM) de extratos hidroalcoólico de angico sobre cepas de Staphylococcus aureus / Evaluation of the antimicrobial activity in vitro and determination of minimum the inhibitory concentration (MIC) of hidroalcoholic extracts of angico in strains Staphylococcus aureus

Plantas medicinais com propriedades antimicrobianas juntamente com a problemática da resistência microbiana são de grande relevância, principalmente em países de desenvolvimento,são uma ótima alternativa para investimentos em pesquisas, pois apontam para o uso de novos antibióticos que sejam eficazes diante dos patógenos emergentes. O objetivo desse estudo foi avaliar a atividade antimicrobiana in vitro do extrato hidroalcoólico da Anadenanthera macrocarpa (angico) e determinação da concentração inibitória mínima (CIM) sobre amostras de cepas de Staphylococcus aureus de origem humana. A atividade antimicrobiana e a CIM do extrato do angico frente a cepas de S. aureus foi determinada por difusão em placa com Ágar Mueller-Hinton usando o método de pour plate. Após solidificação do inóculo (1mL) adicionado ao ágar (25mL) foram feitas cavidades de 6mm, preenchidas com 50ul do extrato. Foram testadas 10 amostras de S. aureus e a atividade foi determinada pela presença de halo de inibição igual ou superior a 8mm. Todas as amostras monstraram-se sensiveis à ação do extrato de angico com halos de inibição variando de 19 a 25 mm. O extrato hidroalcoólico do angico apresentou atividade antimicrobiana e CIM de 3,12% (1:32) para todas as cepas de S. aureus testadas.

Avaliação da atividade antimicrobiana in vitro do extrato hidroalcóolico de Stryphnodendron adstringens(Mart) Coville sobre isolados ambulatoriais de Staphylococcus aureus / Evaluation of the antimicrobial activity in vitro of the hydroalcoholic extract Stryphnodendron adstringens against of Staphylococcus aureus

Staphylococcus aureus é um agente etiológico importante associado a infecções adquiridas, onde se destaca por frequencia elevada e sua patogenicidade, e que foi capaz de desenvolver rapidamente resistência aos antibióticos , constituindo uma séria ameaça à saúde´pública. As plantas tem sido uma fonte valiosa de produtos para manutenção da saúde humana e consideradas uma das melhores fontes para se obter uma variedade de drogas, entre elas, encontra-se o Stryphnodendron adstringens (basrbatimão) que apresenta uma entre outras ações, atividade antimicrobiana. A atividade antimicrobiana foi determinada pelo método de difusão em meio sólido, processo cavidade-placa e a concentração inibitória mínima foi calculada considerando a menor concentração do extrato capaz de inibir o crescimento bacteriano, após incubação a 37 graus Celsius durante 24 horas. O extrato hidroalcóolico de barbatimão foi testado frente ao extrato bruto (100%) e nas diluições referentes a concentrações 50%, 25%, 12,5%, 6,25%, 3,12%, 1,56% e 0,78%, onde foi observado que todas as cepas testadas foram sensíveis ao extrato, onde maior halo de inibição de crescimento bacteriano foi de 22mm, no extrato bruto (100%) e o menor de 8mm na diluição de 1:64 (1,56%)

Perfil de sensibilidade de Salmonella sp. de ambiente aquático a antimicrobianos comerciais e a extratos hidroalcoólicos de plantas medicinais / Profile of sensitivity of Salmonella sp. of water environment for commercial antimicrobials and the hydroalcoholic extracts of medical plants

Doenças de veiculação hídrica é a causa de grandes problemas de saúde pública no mundo, sendo a Salmonella sp. umrepresentante dessa classe de microrganismos patogênicos. A contaminação dos recursos hídricos vem acompanhada de outro fator agravante, o crescente aparecimento de cepas de Salmonella sp. resistentes aos antimicrobianos comerciais, demonstrando a importância de encontrar novas substâncias com atividade antimicrobiana. Este estudo objetivou verificar a sensibilidade de 28 cepas de Salmonella sp., isoladas de um rio impactado por esgotos em Campina Grande (PB), a antimicrobianos comerciais e analisar a atividadeantimicrobiana dos seguintes extratos hidroalcoólicos: Rosmarinus officinalis, Ximenia americana, Anadenanphera colubrina, Astronium uruncleura, Sprychnobendron abscringens e Anarcadium occidentale. As análises foram realizadas no Laboratório deMicrobiologia da Universidade Estadual da Paraíba (Campina Grande/PB). Na metodologia, foram usados métodos de difusão em placas com meio sólido Mueller-Hinton. Observou-se, diante dos antimicrobianos comercias, 6 (21,5) cepas resistentes à Tetraciclina,seguida por Cotrimoxazol com 1 (3,6) cepa resistente. Nenhuma resistência foi verificada à Amicacina, Amoxacilina, Aztreonam, Cefalotina, Cefoxitina, Cloranfenicol, Gentamicina, Imipenema e Lomefloxacina. Dos seis extratos hidroalcoólicos testados, todosapresentaram atividade antimicrobiana às cepas de Salmonella sp. testadas, apenas o Rosmarinus officinalis mostrou pouca atividade, sendo eficaz a 4 (14,3) das cepas testadas.