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 / Identificação de micobactérias isoladas no Hospital Universitário de Santa Maria, Rio Grande do Sul, Brasil

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.

Foi avaliada a prevalência de micobactérias não tuberculosas (MNT) em relação ao total de casos de micobacterioses identificadas em pacientes do Hospital Universitário de Santa Maria, entre os anos de 2008 e 2010. Entre as amostras positivas para o gênero Mycobacterium, 67% eram do complexo Mycobacterium tuberculosis (CMTB) e 33% foram classificadas como MNT. Este estudo procura contribuir com a epidemiologia das micobacterioses, uma vez que os pacientes infectados por MNT necessitam de tratamento e acompanhamento diferenciado dos infectados pelo CMTB.