In vitro antimicrobial efficacy of a fixed-dose combination of RHZE against M. tuberculosis

The use of drugs in fixed-dose combination (FDC) is now recommended by the World Health Organization (WHO) due to the emergence of multidrug-resistant strains of Mycobacterium tuberculosis. FDC uses different drugs against tuberculosis (TB) in a single tablet for phase-intensive therapeutic intervention. This therapy aims to optimize treatment, to prevent inappropriate use of drugs, and to prevent the emergence of new resistant strains. This study aims to evaluate the susceptibility of clinical isolates of M. tuberculosis against rifampicin, isoniazid, ethambutol, and pyrazinamide. The antimicrobials were tested separately and in associations according to FDC. This was used for broth microdilution method, which was compared to the proportions method previously considered as the gold standard. In antimicrobials testing alone, several strains were resistant to one, two, or three drugs. However, when applied to association of drugs in FDC, there was no antimicrobial resistance. The results strengthen the FDC's concept, which aims to unite the four anti-TB drugs to combat bacterial resistance

Atividade Antibiofilme da Cumarina frente Pseudomonas Aeruginosa / Antibiofilm Activity of Cumarina front Pseudomonas Aeruginosa

A utilização inadequada de fármacos antimicrobianos desencadeou o aumento de cepas resistentes aos tratamentos. Este cenário se torna mais preocupante quando os microrganismos se apresentam na forma de biofilme. Os biofilmes são estruturas complexas de aglomerados microbianos, protegidos por uma camada de exopolissacarídeos (EPS) que impede a penetração  dos fármacos, dificultando ainda mais o tratamento das infeções. Com isso, o emprego de plantas medicinais como alternativa de tratamento antimicrobiano está crescendo no mercado farmacêutico, pois estas possuem metabólitos secundários, que são os principais responsáveis pelas atividades biológicas das plantas. Tendo em vista os metabólitos secundários como fonte de pesquisa, em nosso estudo, destacamos a classe das cumarinas, que são compostos fenólicos presentes em uma vasta diversidade de vegetais e possui relatos de atividades antimicrobiana, antioxidante e antiviral. Diante disso, este estudo tem por objetivo avaliar a atividade antibiofilme da cumarina frente a biofilme formado por P. aeruginosa (PA01). A atividade antibiofilme foi avaliada por técnica semi-quantitativa em placas de 96 poços. O biofilme foi revelado utilizando solução de cristal violeta e o biofilme solubilizado foi submetido à leitura em 570nm. Além disso, foi realizada a contagem de células sésseis. Os resultados observados demonstraram que a cumarina é capaz de inibir a formação do biofilme em até 78% e reduzir a contagem de colônias sésseis. Haja vista esses resultados, a cumarina apresenta significativamente atividade antibiofilme, com isso sugerimos que está substância pode ser utilizada como alternativa de tratamento para infecções que envolvem a formação de biofilmes. 

In vitro antimicrobial efficacy of a fixed-dose combination of RHZE against M. tuberculosis

ABSTRACT The use of drugs in fixed-dose combination (FDC) is now recommended by the World Health Organization (WHO) due to the emergence of multidrug-resistant strains of Mycobacterium tuberculosis. FDC uses different drugs against tuberculosis (TB) in a single tablet for phase-intensive therapeutic intervention. This therapy aims to optimize treatment, to prevent inappropriate use of drugs, and to prevent the emergence of new resistant strains. This study aims to evaluate the susceptibility of clinical isolates of M. tuberculosis against rifampicin, isoniazid, ethambutol, and pyrazinamide. The antimicrobials were tested separately and in associations according to FDC. This was used for broth microdilution method, which was compared to the proportions method previously considered as the gold standard. In antimicrobials testing alone, several strains were resistant to one, two, or three drugs. However, when applied to association of drugs in FDC, there was no antimicrobial resistance. The results strengthen the FDC's concept, which aims to unite the four anti-TB drugs to combat bacterial resistance

Identification of mycobacteria isolated at University Hospital of Santa Maria, Rio Grande do Sul, Brazil

This study evaluated the prevalence of nontuberculous mycobacterium (NTM) in relation to the total number of cases of mycobacterial infections detected in patients admitted at the University Hospital of Santa Maria from 2008 to 2010. From the positive samples for the genus Mycobacterium, 67% belonged to the Mycobacterium tuberculosis complex (MTBC) and 33% of them were classified as NTM. This investigation aims to contribute to the epidemiology of mycobacterioses, inasmuch as patients infected by NTM require distinctive treatment and monitoring in comparison with those infected by MTBC