Mycobacterium tuberculosis isolates from Rio de Janeiro reveal unusually low correlation between pyrazinamide resistance and mutations in the pncA gene.

It has been widely accepted, that pyrazinamide (PZA) resistance in Mycobacterium tuberculosis is correlated with mutations in the pncA gene. But since years researchers have been puzzled by the fact that up to 30% of PZA resistant strains do not show any correlation between PZA resistance and mutations in the pncA gene, and thus may vary with geographic area. The objective of the study was to investigate the correlation between PZA susceptibility and mutations in pncA gene in M. tuberculosis isolates from individuals living in a highly endemic area. Therefore we analyzed drug resistant and multidrug resistant (MDR) isolates from patients in Rio de Janeiro, Brazil. From a total of 97 clinical isolates of M. tuberculosis 35 were identified as PZA resistant, 24/35 strains did not show PZase activity and 15/24 (62.5%) strains possess mutation in the pncA gene. This is a low correlation between PZA resistance and PZase activity (68.6%) and even lower correlation between PZA resistance and the presence of mutation in pncA gene (45.7%). Most of the mutations found were conserved near the active site or metal binding site of PZase. The 146A>C mutation was found both in PZA resistant and susceptible isolates, suggesting that this mutation may not fully associated with PZA resistance. Of the mutations found, three have not been previously described. The insertions 192-193 TCCTCGTC and 388-389 AGGTCGATG, although found before, here was found to be a short tandem repeat and in one strain, insertion of the IS6110 was observed 55nt upstream of the gene. All PZA resistant isolates had no mutation in the gene coding ribosomal protein S1 (rpsA), which has recently been proposed as alternate target for pyrazinoic acid (POA). The results show a low association of PZA resistance and pncA gene mutations in a selected patient group from an highly endemic area. Our findings point out that the phenotypic susceptibility testing remains important for the detection of PZA-resistant M. tuberculosis

Genotyping did not evidence any contribution of Mycobacterium bovis to human tuberculosis in Brazil

Submitted by Sandra Infurna ([email protected]) on 2016-10-11T15:30:42Z No. of bitstreams: 1 alexandre_santos_etal_IOC_2011.pdf: 239001 bytes, checksum: 50d5454a5f61743435cbeee1d8103caf (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2016-10-11T15:46:25Z (GMT) No. of bitstreams: 1 alexandre_santos_etal_IOC_2011.pdf: 239001 bytes, checksum: 50d5454a5f61743435cbeee1d8103caf (MD5)Made available in DSpace on 2016-10-11T15:46:25Z (GMT). No. of bitstreams: 1 alexandre_santos_etal_IOC_2011.pdf: 239001 bytes, checksum: 50d5454a5f61743435cbeee1d8103caf (MD5) Previous issue date: 2011Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular Aplicada a Micobactérias. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular Aplicada a Micobactérias. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Instituto de Doenças Torácicas. Laboratório de Micobacteriologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular Aplicada a Micobactérias. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular Aplicada a Micobactérias. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Instituto de Doenças Torácicas. Laboratório de Micobacteriologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Hanseníase. Rio de Janeiro, RJ, Brasil.Ministério da Saúde. Fundação Oswaldo Cruz. Centro de Referência Nacional em Tuberculose Prof. Hélio Fraga. Rio de Janeiro, RJ, Brasil.Clínica de Tuberculose Augusto Guimarães, Centro de Referencia Regional em Tuberculose. Program de Controle de Tuberculose. Campos, RJ, Brasil;.EMBRAPA. Divisão de Saúde Animal. Juiz de Fora, MG, Brasil.Universidade Federal do Rio de Janeiro. Instituto de Doenças Torácicas. Laboratório de Micobacteriologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular Aplicada a Micobactérias. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Faculdade de Medicina. Departamento de Medicina Interna. Rio de Janeiro, RJ, Brasil / Universidade Federal do Rio de Janeiro. Hospital Universitário Clementino Fraga Filho. Laboratório de Pesquisa Multidisciplinar. Rio de Janeiro, RJ, Brasil.The contribution of Mycobacterium bovis to the global burden of tuberculosis (TB) in man is likely to be underestimated due to its dysgonic growth characteristics and because of the absence of pyruvate in most used media is disadvantageous for its primary isolation. In Brazil Mycobacterium culture, identification and susceptibility tests are performed only in TB reference centers, usually for selected cases. Moreover, solid, egg-based, glycerol-containing (without pyruvate supplementation) Löwenstein-Jensen (L-J) or Ogawa media are routinely used, unfavouring M. bovis isolation. To determine the importance of M. bovis as a public health threat in Brazil we investigated 3046 suspected TB patients inoculating their clinical samples onto routine L-J and L-J pyruvate enriched media. A total of 1796 specimens were culture positive for Mycobacterium spp. and 702 TB cases were confirmed. Surprisingly we did not detect one single case of M. bovis in the resulting collection of 1674 isolates recovered from M. bovis favourable medium analyzed by conventional and molecular speciation methods. Also, bacillary DNA present on 454 sputum smears from 223 TB patients were OxyR genotyped and none was recognized as M. bovis. Our data indicate that M. bovis importance on the burden of human TB in Brazil is marginal

Implementation of a Brazilian Cardioprotective Nutritional (BALANCE) Program for improvement on quality of diet and secondary prevention of cardiovascular events: A randomized, multicenter trial

Background: Appropriate dietary recommendations represent a key part of secondary prevention in cardiovascular disease (CVD). We evaluated the effectiveness of the implementation of a nutritional program on quality of diet, cardiovascular events, and death in patients with established CVD. Methods: In this open-label, multicenter trial conducted in 35 sites in Brazil, we randomly assigned (1:1) patients aged 45 years or older to receive either the BALANCE Program (experimental group) or conventional nutrition advice (control group). The BALANCE Program included a unique nutritional education strategy to implement recommendations from guidelines, adapted to the use of affordable and regional foods. Adherence to diet was evaluated by the modified Alternative Healthy Eating Index. The primary end point was a composite of all-cause mortality, cardiovascular death, cardiac arrest, myocardial infarction, stroke, myocardial revascularization, amputation, or hospitalization for unstable angina. Secondary end points included biochemical and anthropometric data, and blood pressure levels. Results: From March 5, 2013, to Abril 7, 2015, a total of 2534 eligible patients were randomly assigned to either the BALANCE Program group (n = 1,266) or the control group (n = 1,268) and were followed up for a median of 3.5 years. In total, 235 (9.3%) participants had been lost to follow-up. After 3 years of follow-up, mean modified Alternative Healthy Eating Index (scale 0-70) was only slightly higher in the BALANCE group versus the control group (26.2 ± 8.4 vs 24.7 ± 8.6, P <.01), mainly due to a 0.5-serving/d greater intake of fruits and of vegetables in the BALANCE group. Primary end point events occurred in 236 participants (18.8%) in the BALANCE group and in 207 participants (16.4%) in the control group (hazard ratio, 1.15; 95% CI 0.95-1.38; P =.15). Secondary end points did not differ between groups after follow-up. Conclusions: The BALANCE Program only slightly improved adherence to a healthy diet in patients with established CVD and had no significant effect on the incidence of cardiovascular events or death. © 2019 The Author