Novel allelic variants of Mycobacteria isolated in Brazil as determined by PCR-restriction enzyme analysis of hsp65.

Human isolates of Mycobacterium collected in 16 different states of Brazil were submitted to PCR-restriction analysis (PRA) of a 439-bp fragment of the hsp65 gene with HaeIII and BstEII. Fourteen allelic variants not described in clinical isolates so far were observed among 36 (10%) of 356 Brazilian strains, including a new pattern for Mycobacterium scrofulaceum, M. intracellulare, and M. flavescens, two new patterns for M. fortuitum, three new patterns each for M. gordonae and M. terrae, and one new pattern for M. avium complex-like strains. Two unidentified strains each also presented a new pattern, strongly suggesting that Mycobacterium genotypes are distributed biogeographically. The PRA procedure was also performed with 43 reference isolates belonging to 34 species, adding a further six new patterns to the identification algorithm. A database containing the normalized restriction patterns of both enzymes was constructed. Patterns available on the Internet can be introduced into this database, which will make possible the comparison of genotypes from isolates from different parts of the world.

Survey of mycobacteriology laboratory practices in an urban area with hyperendemic pulmonary tuberculosis.

SETTING: Rio de Janeiro, Brazil, where 10210 cases of tuberculosis (TB) were reported in 1997, 86.2% of them with pulmonary TB. OBJECTIVE: To assess laboratory resources, practices, biosafety measures and training needs relative to the volume of work required for the TB control program and implementation of directly observed therapy, short course (DOTS). DESIGN: A cross-sectional survey of laboratories that receive funds from the public sector and work with mycobacteria, using a structured questionnaire and onsite visits to collect data. The main outcome measure of interest was processing > or = 20 specimens per week. RESULTS: More than half (56.5%) of the laboratories reported performing < 20 specimens per week, a level at which it is difficult to maintain proficiency in mycobacteriologic techniques. The demand for sputum smear microscopy was not met. Working conditions such as shared laboratory and air space, inadequate ventilation, accidents with biological specimens, and inadequate disposal of biological waste present risks of TB transmission to laboratory workers and other staff. CONCLUSION: Training and supervising laboratory workers in good technique and biosafety practices and providing the necessary organization, resources and working conditions will strengthen TB control and facilitate implementation of DOTS. Several simple interventions are proposed.

DNA fingerprinting of Mycobacterium tuberculosis from patients with and without AIDS in Rio de Janeiro.

Isolates of Mycobacterium tuberculosis derived from patients with AIDS from a single hospital in Rio de Janeiro were typed using a standardized RFLP technique detecting IS6110 polymorphism. Nineteen isolates were obtained from 15 different patients. Eleven distinct IS6110 patterns were found, with 4 banding patterns shared by 2 patients. The clustering value of 53% was much higher in comparison with clustering of M. tuberculosis strains from TB patients without clinical signs for HIV infection from randomly selected health centers. We present these results as preliminary data on M. tuberculosis strain polymorphism in Brazil and on the higher risk for recent transmission amongst patients with AIDS.

DNA fingerprinting of mycobacterium tuberculis from patients with and without AIDS in Rio de Janeiro

Isolates of Mycobacterium tuberculosis derived from patients with AIDS from a single hospital in Rio de Janeiro were typed using a standardized RFLP technique detecting IS6110 polymorphism. Nineteen isolates were obtained from 15 different patients. Eleven distinct IS6110 patterns were found, with 4 banding patterns shared by 2 patients. The clustering value of 53 percent was much higher in comparison with clustering of M. tuberculosis strains from TB patients without clinical signs for HIV infection from randomly selected health centers. We present these results as preliminary data on M. tuberculosis strain polymorphism in Brazil and on the higher risk for recent transmission amongst patients with AIDS.