Genetic diversity of Mycobacterium leprae in the state of São Paulo, an area of low-leprosy incidence in Brazil

ABSTRACT Background: Brazil has the second largest number of leprosy cases worldwide, and the state of São Paulo has been considered non-endemic since 2006. Methods: We analyzed 16 variable number tandem repeats loci and three single nucleotide polymorphisms loci of Mycobacterium leprae (M. leprae) in 125 clinical isolates from patients in different municipalities in the state. Results: The clustering pattern of M. leprae indicated that the transmission of leprosy persisted in the state and included scenarios of intra-extra-familial transmission in areas with low endemicity. Conclusions: A significantly active circulation of M. leprae was observed. Therefore, surveillance and control measures must be implemented.

Tuberculosis associated factors caused by Mycobacterium tuberculosis of the RDRio genotype

BACKGROUND Tuberculosis (TB) continues to be a disease that affects many countries around the world, including Brazil. Recently, a subtype of Latin American-Mediterranean family strain was identified and characterised by RDRio. The strain has been associated with different characteristics of the disease. OBJECTIVES In the present study we investigated the association of epidemiological, clinical, radiological and bacteriological variables with pulmonary tuberculosis caused by RDRioMycobacterium tuberculosis strain in large regions of São Paulo. METHODS We conducted a cross-sectional study in 530 patients with pulmonary tuberculosis, diagnosed using sputum culture, from two regions of the São Paulo state in Brazil. The samples were brought to São Paulo reference laboratories for epidemiological, clinical, radiological and bacteriological analyses, and the data were obtained from a TB notification system. RDRio genotyping and Spoligotyping of the samples were performed. For the analysis of the categorical variables we used the chi-square test or the Fisher’s exact test, and for the continuous variables, the Mann-Whitney test. In addition, a logistic regression was used for multivariate analysis. Differences with p < 0.05 were considered significant. FINDINGS The RDRio deletion was identified in 152 (28.7%) samples. In the univariate analysis, both the age groups above 25 years and alcohol consumption were associated with the RDRio deletion. The multivariate analysis confirmed the association of the RDRio deletion with the age groups: 25-35 years old [OR: 2.28 (1.02-5.07; p = 0.04)] and 36-60 years old (OR: 2.36 (1.11-5.05); p = 0.03], and also with alcohol consumption [OR: 1.63 (1.05-2.54); p = 0,03]. MAIN CONCLUSIONS In this study, we identified new factors associated with the M. tuberculosis of the RDRio deletion strains infection.

Clinical and epidemiological profiles of individuals with drug-resistant tuberculosis

Drug-resistant tuberculosis (TB) is a growing global threat. Approximately 450,000 people developed multidrug-resistant TB worldwide in 2012 and an estimated 170,000 people died from the disease. This paper describes the sociodemographic, clinical-epidemiological and bacteriological aspects of TB and correlates these features with the distribution of anti-TB drug resistance. Mycobacterium tuberculosis (MT) cultures and drug susceptibility testing were performed according to the BACTEC MGIT 960 method. The results demonstrated that MT strains from individuals who received treatment for TB and people who were infected with human immunodeficiency virus were more resistant to TB drugs compared to other individuals (p < 0.05). Approximately half of the individuals received supervised treatment, but most drug-resistant cases were positive for pulmonary TB and exhibited positive acid-fast bacilli smears, which are complicating factors for TB control programs. Primary healthcare is the ideal level for early disease detection, but tertiary healthcare is the most common entry point for patients into the system. These factors require special attention from healthcare managers and professionals to effectively control and monitor the spread of TB drug-resistant cases.

Cenário atual da tuberculose / Current scenario of tuberculosis

Mesmo após 133 anos desde a descoberta do Mycobacterium tuberculosis, a tuberculose continua ser uma das principais causas de morte por doenças infecciosas no mundo, principalmente em países em desenvolvimento.O objetivo deste estudo foi mostrar aspectos relevantes da doença visando uma atualização literária e a busca de um olhar mais atento à problemática da tuberculose no contexto atual. Foram utilizados 130 artigos advindos das bases LILACS, MEDLINE/PUBMED, SCielo, Paho, Biblioteca Cochrane, WHOLIS, IBECS e Scopus, com as principais palavras-chaves selecionadas em terminologia em saúde encontradas no DECS. As espécies pertencentes ao Complexo M. tuberculosis compartilham cerca de 99% de identidade do DNA,com sequências altamente conservadas, mas diferem na distribuição geográfica, patogenicidade e hospedeiros. O mecanismo de resistência clinicamente significativo para rifampicina é uma mutação do gene rpoB, que codifica o alvo desse antibiótico. Há grandes avanços no diagnóstico da TB, com novos instrumentos de biologia molecular e testes rápidos, mas ainda não substituem os métodos clássicos bacteriológicos, apesar de suas conhecidas limitações. Atualmente, a associação de métodos moleculares, principalmente aqueles baseados em reações da PCR tem proporcionado grande impulso nos estudos da epidemiologia molecular do MT. Embora haja uma diminuição do número de casos no mundo, dentre os desafios da doença estão a necessidade de pesquisas na área, envolvimento político para solucionar as questões sociais atribuídas à TB, treinamento permanente dos profissionais e monitoramento de vigilância dos casos para eliminar a doença no cenário mundial.

Even 133 years after the discovery of Mycobacterium tuberculosis, tuberculosis continues to be one of the main causes of death due to infectious diseases worldwide, especially in developing countries. The objective of this study was, after a survey of recent publications, to show issues relevant to the disease and to takea closer look at the tuberculosis problem in the current context. A total of 130 articles were found in the LILACS, MEDLINE/PubMed, SciELO, Paho, Cochrane Library, WHOLIS, IBECS and Scopus databases using the main keywords selected from health terminology of MeSH. Species belonging to the M. tuberculosis complex have highly conserved sequences and share about 99% DNA identity, but differ in their geographic distribution, pathogenicityand host. The clinically significant mechanismof rifampicin resistance is due to a mutation of the rpoB gene which encodes the target of the antibiotic. Great advances in the diagnosis of tuberculosis have occurred, with new molecular biology tools and rapid tests, but without replacing classical bacteriological methods, despite their known limitations. Recently, the association of molecular methods, especially based on PCR, has provided great impetus in molecular epidemiology studies of M. tuberculosis. Although the number of cases in the world has decreased, among the challenges are the need for further research, political involvement to solve social issues linked to tuberculosis, permanent training and the surveillance of cases in order to eliminate the disease on the world stage.