RESUMO
Forty-five Haemophilus influenzae strains isolated from patients were characterized based on biochemical characteristics. Their capsular types were determined by polymerase chain reaction (PCR); they were compared, using two molecular methods [ribotyping with a specific DNA probe amplified from the 16S rDNA region from H. influenzae and through restriction fragment length polymorphism (RLFP) of an amplified 16S DNA region]. The strains were better discriminated by the ribotyping technique that used the 16S probe and by the combination of both techniques. Biotypes I and IV were the most common, followed by biotypes VI, VIII and III. Biotypes II and VII were not found. Most of the capsular samples were nontypable (89 percent), with capsular types a and b found in 2 and 9 percent of the samples, respectively. We concluded that there is a very close genetic identity among pathogenic and non-pathogenic strains.
Assuntos
Humanos , Técnicas de Tipagem Bacteriana/métodos , DNA Bacteriano/análise , DNA Ribossômico/análise , Haemophilus influenzae/classificação , /análise , Haemophilus influenzae/genética , Haemophilus influenzae/isolamento & purificação , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Ribotipagem , SorotipagemRESUMO
Forty-five Haemophilus influenzae strains isolated from patients were characterized based on biochemical characteristics. Their capsular types were determined by polymerase chain reaction (PCR); they were compared, using two molecular methods [ribotyping with a specific DNA probe amplified from the 16S rDNA region from H. influenzae and through restriction fragment length polymorphism (RLFP) of an amplified 16S DNA region]. The strains were better discriminated by the ribotyping technique that used the 16S probe and by the combination of both techniques. Biotypes I and IV were the most common, followed by biotypes VI, VIII and III. Biotypes II and VII were not found. Most of the capsular samples were nontypable (89%), with capsular types a and b found in 2 and 9% of the samples, respectively. We concluded that there is a very close genetic identity among pathogenic and non-pathogenic strains.
Assuntos
Técnicas de Tipagem Bacteriana/métodos , DNA Bacteriano/análise , DNA Ribossômico/análise , Haemophilus influenzae/classificação , RNA Ribossômico 16S/análise , Haemophilus influenzae/genética , Haemophilus influenzae/isolamento & purificação , Humanos , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Ribotipagem , SorotipagemRESUMO
Tuberculosis (TB) is a major concern in developing countries. In Brazil, few genotyping studies have been conducted to verify the number of IS6110 copies present in local prevalent strains of Mycobacterium tuberculosis, the distribution and clustering of strains. IS6110 DNA fingerprinting was performed on a sample of M. tuberculosis isolates from patients with AFB smear-positive pulmonary TB, at a hospital in Brazil. The IS6110 profiles were analyzed and compared to a M. tuberculosis database of the Houston Tuberculosis Initiative, Houston, US. Seventy-six fingerprints were obtained from 98 patients. All M. tuberculosis strains had an IS6110 copy number between 5-21 allowing for differentiation of the isolates. Human immunodeficiency virus infection was confirmed in nearly half the patients of whom data was available. Fifty-eight strains had unique patterns, while 17 strains were grouped in 7 clusters (2 to 6 strains). When compared to the HTI database, 6 strains matched isolates from El Paso, Ciudad de Juarez, Houston, and New York. Recently acquired infections were documented in 19% of cases. The community transmission of infection is intense, since some clustered strains were recovered during the four-year study period. The intercontinental dissemination of M. tuberculosis strains is suspected by demonstration of identical fingerprints in a distant country.
Assuntos
Mycobacterium tuberculosis/genética , Tuberculose Pulmonar/microbiologia , Técnicas de Tipagem Bacteriana , Brasil , Impressões Digitais de DNA , Bases de Dados Genéticas , Genótipo , Humanos , Mycobacterium tuberculosis/classificação , Polimorfismo de Fragmento de RestriçãoRESUMO
Tuberculosis (TB) is a major concern in developing countries. In Brazil, few genotyping studies have been conducted to verify the number of IS6110 copies present in local prevalent strains of Mycobacterium tuberculosis, the distribution and clustering of strains. IS6110 DNA fingerprinting was performed on a sample of M. tuberculosis isolates from patients with AFB smear-positive pulmonary TB, at a hospital in Brazil. The IS6110 profiles were analyzed and compared to a M. tuberculosis database of the Houston Tuberculosis Initiative, Houston, US. Seventy-six fingerprints were obtained from 98 patients. All M. tuberculosis strains had an IS6110 copy number between 5-21 allowing for differentiation of the isolates. Human immunodeficiency virus infection was confirmed in nearly half the patients of whom data was available. Fifty-eight strains had unique patterns, while 17 strains were grouped in 7 clusters (2 to 6 strains). When compared to the HTI database, 6 strains matched isolates from El Paso, Ciudad de Juarez, Houston, and New York. Recently acquired infections were documented in 19 percent of cases. The community transmission of infection is intense, since some clustered strains were recovered during the four-year study period. The intercontinental dissemination of M. tuberculosis strains is suspected by demonstration of identical fingerprints in a distant country