Mycobacterium tuberculosis strains of the Beijing genotype are rarely observed in tuberculosis patients in South America

The frequency of the Beijing genotype of Mycobacterium tuberculosis as a cause of tuberculosis (TB) in South America was determined by analyzing genotypes of strains isolated from patients that had been diagnosed with the disease between 1997 and 2003 in seven countries of the subcontinent. In total, 19 of the 1,202 (1.6 percent) TB cases carried Beijing isolates, including 11 of the 185 patients from Peru (5.9 percent), five of the 512 patients from Argentina (1.0 percent), two of the 252 Brazilian cases (0.8 percent), one of the 166 patients from Paraguay (0.6 percent) and none of the samples obtained from Chile (35), Colombia (36) and Ecuador (16). Except for two patients that were East Asian immigrants, all cases with Beijing strains were native South Americans. No association was found between carrying a strain with the Beijing genotype and having drug or multi-drug resistant disease. Our data show that presently transmission of M. tuberculosis strains of the Beijing genotype is not frequent in Latin America. In addition, the lack of association of drug resistant TB and infection with M. tuberculosis of the Beijing genotype observed presently demands efforts to define better the contribution of the virulence and lack of response to treatment to the growing spread of Beijing strains observed in other parts of the world.

Linfadenites tuberculóides em suínos abatidos no Estado de Säo Paulo, Brasil: aspectos macroscópicos histopatológicos em pesquisa de micobactérias / Tuberculosis lymphadenitis in slaughtered swine from Säo Paulo State (Brazil): gross lesions, histopathology and demonstration of mycobacteria

Como a ocorrência de linfadenites tuberculóides nos suínos oferece risco à saúde pública, sobretudo em indivíduos imunocomprometidos, foi estudada a distribuiçäo das lesöes tuberculóides e a presença de micobactérias em linfonodos, tecido hepático e muscular de suínos de abate, no Estado de Säo Paulo, SP (Brasil), no período de 1993-1994. Foram estudadas 60 carcaças de suínos abatidos, sendo que, trinta apresentavam lesöes tuberculóides macroscópicas (grupo A) e trinta estavam livres de tais lesöes (grupo B ou controle). Foram analisadas seis localizaçöes: linfonodos (retrofaríngeos, jejunais e mediastínicos), tecido hepático e tecido muscular (masséter e diafragma). Os exames executados foram: histopatologia e o cultivo para micobactérias. No grupo A, 14 em 30 carcaças apresentaram granuloma na histopatologia e, em 14, houve o isolamento de representantes do Complexo MAC (Mycobacterium avium-intracellulare). No grupo B, näo foram observadas lesöes na histopatologia, e de quatro carcaças houve o isolamento de micobactérias de rápido crescimento. As lesöes macroscópicas foram encontradas predominantemente nos linfonodos mesentéricos. O Complexo MAC foi isolado apenas em linfonodos do grupo com lesäo, näo sendo isolado em tecido hepático e muscular. Näo foi possível o estabelecimento de relaçäo entre o tipo de micobactéria isolada e as características macroscópicas das lesöes.