[A case of Mycobacterium shimoïdei lung infection in Madagascar]. / Un cas d'infection pulmonaire à Mycobacterium shimoïdei à Madagascar.

In 1980, a 32 years-old Madagascan female developed a pulmonary tuberculosis, bacteriologically confirmed. She cured with right apical cavitary sequellae. In 1989, she presented haemoptysis again. Antituberculous treatment was adopted without bacteriological confirmation and did not improve clinical symptoms. In 1991 and 1992 cultures from sputa and bronchi aspiration yielded acid-fast bacilli identified as Mycobacterium shimoïdei. M. tuberculosis could not be detected. The patient died during treatment. This case is the fourth one in the literature. Whereas previous cases have been reported in Europe, Australia, Asia, this new case shows M. shimoïdei is also present in Africa.

Pulsed field gel electrophoresis of representatives of Mycobacterium tuberculosis and Mycobacterium bovis BCG strains.

Using field inversion gel electrophoresis (FIGE), different Mycobacterium tuberculosis strains, such as phage prototypes, exhibit different DNA restriction patterns which are easy to compare. Virulent and avirulent variants of M. tuberculosis H37, as well as daughter strains of M. bovis BCG, display characteristic DNA profiles. BCG strains isolated from suppurative adenitis following vaccination of French patients showed patterns identical to the BCG Pasteur strain used for vaccination. These results demonstrate that FIGE of DNA restriction fragments generated by DraI represents a suitable technique for the analysis of mycobacteria at a genomic level. The DraI profiles allow the differentiation and precise identification of the BCG Pasteur, Glaxo, Russian and Japanese strains.

Evaluation of nonradioactive DNA probes for identification of mycobacteria.

Commercial chemiluminescent DNA probes (Accuprobe; Gen-Probe, San Diego, Calif.) for the identification of Mycobacterium tuberculosis (MTB) complex, M. avium complex (MAC), M. gordonae, and M. kansasii were evaluated with 134 clinical isolates. These included 36 MTB complex, 40 MAC, 27 M. gordonae, 9 M. kansasii, and 22 Mycobacterium spp. The specificity was 100% for the four probes. The sensitivity was 100% for the MTB complex and M. gordonae probes and 95.2% for the MAC probe. Five of the nine M. kansasii isolates tested were not detected with the probe.

The genes coding for the antigen 85 complexes of Mycobacterium tuberculosis and Mycobacterium bovis BCG are members of a gene family: cloning, sequence determination, and genomic organization of the gene coding for antigen 85-C of M. tuberculosis.

A gene encoding the 33-kDa secreted protein of Mycobacterium tuberculosis (antigen 85-C) was isolated and sequenced. The corresponding DNA sequence contains a 1,020-bp coding region. The deduced amino acid sequence corresponds to a 340-residue protein consisting of a 46-amino-acid signal peptide and a 294-amino-acid mature protein. Comparison with previously described genes for the 30-kDa antigen (the alpha antigen of M. bovis BCG, also called antigen 85-B) and the 32-kDa antigens from M. bovis BCG and M. tuberculosis (antigens 85-A) indicates that the three genes share considerable sequence homology (70.8 to 77.5%) but may also code for distinctive epitopes. Strong differences among the three sequences are clearly visible upstream and downstream from the region coding for the mature proteins. The three genes have been detected in the genome of M. bovis BCG by Southern blot hybridization with three type-specific probes. Furthermore, hybridization of large DNA fragments (100 to 1,000 kbp) from M. tuberculosis separated by pulsed-field gel electrophoresis showed that the three genes coding for the antigen 85 complex are not clustered within the bacterial genome.

Restriction fragment length polymorphism analysis using IS6110 as an epidemiological marker in tuberculosis.

The mycobacterial insertion sequence IS6110 has been shown to be present in multiple copies in the chromosome of Mycobacterium tuberculosis. IS6110 restriction fragment length polymorphism analysis of strains isolated from patients who developed tuberculosis showed identical patterns over a 2- to 3-year period. In contrast, a high degree of polymorphism was observed between strains of the M. tuberculosis complex isolated from different patients. This study demonstrates that the presence of IS6110 does not induce in vivo major genomic rearrangements over a 2- to 3-year period and confirms its use as a valuable epidemiological marker in tuberculosis.

Characterization of a Mycobacterium tuberculosis insertion sequence, IS6110, and its application in diagnosis.

An insertion sequence-like element, IS6110, was isolated from a Mycobacterium tuberculosis cosmid library as a repetitive sequence. IS6110 shows similarities with elements of the IS3 family. This insertion sequence was found to be specific to mycobacteria belonging to the M. tuberculosis complex. For detection and identification of M. tuberculosis bacilli in uncultured specimens, oligonucleotides derived from the IS6110 sequence were used as primers and probes in polymerase chain reaction studies. The results obtained were consistent with results of classical identification procedures, bacteriological data, and clinical criteria.