Daniela Fernandes Ramos

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Mutations related to streptomycin resistance in the rpsL and rrs genes are well known and can explain about 70% of this phenotypic resistance. Recently, the gidB gene was found to be associated with low-level streptomycin resistance in Mycobacterium tuberculosis. Mutations in gidB have been reported with high frequency, and this gene appears to be very(More)
Duroia macrophylla popularly known as "cabeça-de-urubú," "apuruí," or "puruí-grande-da-mata" occurs in the Amazon Forest. Its leaves and branches were collected twice and extracted with dichloromethane and methanol. All extracts were subjected to phytochemical investigation and terpenes and flavonoids were found in all dichloromethane and methanol extracts,(More)
Thirty-six plant extracts from the brazilian Atlantic Forest were tested for their antimycobacterial activity against Mycobacterium tuberculosis H37Rv and M. kansasii, using the method REMA in seriate concentrations of 100 to 0.20 μg/mL. Among the thirty six extracts tested, five were active against M. tuberculosis, and three of these extracts also showed(More)
When bacteria develop drug-resistant mutations, there is often an associated biological cost; however, some strains can exhibit low- or no-cost mutations. In the present study, a quantitative resazurin reduction assay was used to measure the biological cost of Mycobacterium tuberculosis isolates that contained different mutations in the rpsL, rrs, rpoB, and(More)
Tuberculosis is still a major health problem worldwide. Although treatment regimens currently available can cure almost all tuberculosis drug susceptible cases, problems such as the length of treatment, the need for multidrug therapy, the emergence of drug resistance, HIV co-infection and persistent Mycobacterium tuberculosis bacilli, stress the need for(More)
This paper reports the susceptibility profile to rifabutin (RFB) 1 and six recently synthesized RFB analogs 3-8, of either rifampicin (RFP) susceptible Mycobacterium tuberculosis and resistant clinical isolates from two sources: Mexico and Brazil. Taking into account that about 95% of M. tuberculosis strains resistant to RFP present mutations in the rpoB(More)
Three crude extracts of Aplysina caissara, a marine sponge endemic to Brazil, were tested against a hepatoma cell line and Mycobacterium tuberculosis. The results demonstrate that all extracts are toxic and capable of inhibiting cellular growth. Additionally, the extracts produced morphological aberrations and inhibited cell attachment to culture(More)
Drug resistant tuberculosis continues to increase and new approaches for its treatment are necessary. The identification of M. tuberculosis clinical isolates presenting efflux as part of their resistant phenotype has a major impact in tuberculosis treatment. In this work, we used a checkerboard procedure combined with the tetrazolium microplate-based assay(More)
Mycobacterium bovis is the main causative agent of animal tuberculosis (TB) and it may cause TB in humans. Molecular typing of M. bovis isolates provides precise epidemiological data on issues of inter- or intra-herd transmission and wildlife reservoirs. Techniques used for typing M. bovis have evolved over the last 2 decades, and PCR-based methods such as(More)
A series of 3-substituted 5-hydroxy-5-trifluoro[chloro]methyl-1H-1-isonicotinoyl-4,5-dihydropyrazoles (2a-i) were synthesised by the cyclocondensation reaction of 4-methoxy-1,1,1-trifluoro[chloro]-4-(substituted)-alk-3-en-2-ones (1a-i) and isoniazid (INH). Their in vitro antimicrobial activity was tested against INH-susceptible Mycobacterium tuberculosis(More)