Analise do polimorfismo genetico de cepas de Mycobacterium tuberculosis isoladas de pacientes portadores de tuberculose pulmonar atendidos no Hospital das Clinicas da UNICAMP

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

Tuberculosis is a major concem in developing countries. The contribution of genotyping techniques to trace epidemiological chains is remarkable, IS 6110RFLP being the preferred typing method. AIDS epidemics has had a major impact on the incidence of tuberculosis. Not so many genotyping studies have been made in Brazil in order to check for the number of IS6110 present in local strains of M tuberculosis, as well as the distribution and clustering ofM tuberculosis strains. We performed DNA finger printing using Restriction-Fragment-Length-Polymorphism (RFLP) analysis of at least one isolate from every patient with positive AFB smear, confirmed pulmonary tuberculosis at a major hospital in Campinas, São Paulo, Brazil from January 1996 through July 1999. All fmgerprints were analyzed using proper software, and compared to an international database from the Institute for the Study of Human Bacterial Pathogenesis, Department of Pathology, Baylor College of Medicine. Medical records were reviewed for relevant clinical data. During the study period, 98 patients were included, yelding 76 fingerprints. All M tuberculosis strains had an adequate number of IS6110 (5-21) for the analysis. HIV infection was confirmed in nearly half the patients when it was available. 58 strains exhibited unique patterns whereas 17 others could be grouped in 7 clusters (2 to 6 strains in each cluster). When compared to the mentioned database, 6 strains matched the same genotype from strains originated from El Passo, Juarez, Houston, and New York. Some clustered strains could be recovered during almost all the study period. M tuberculosis strains recovered from patients in Brazil can be genotyped using IS6110 RFLP, since they harbor an adequate number of such sequences. Recently acquired infections could be documented in 19% of cases since the strains could be clustered. The transmission of infection is intense, since some of clustered strains could be recovered during all the study period. The global dissemination of M tuberculosis strains could be evidenced by demonstration of identical fingerprints occurring in a distant country

ASSUNTO(S)

biologia molecular micobacterias tuberculose

ACESSO AO ARTIGO

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