Amplified fragment length polymorphism analysis of human clinical isolates of Mycobacterium haemophilum from different continents.

The role of the species Mycobacterium haemophilum as a pathogenic non-tuberculous microorganism is becoming better defined with the use of specific detection methods. However, epidemiological investigations of this species are still scarce. We analysed the genetic diversity of M. haemophilum by amplified fragment length polymorphism (AFLP) typing and compared isolates from different parts of the world. In total, 128 isolates, including 41 from the USA, 51 from Australia, 28 from Europe and eight from Israel were compared using AFLP methodology. Two restriction enzymes (MseI and EcoRI) and one selective primer were applied and provided a high discriminatory power. Clusters of isolates with identical AFLP patterns, which could indicate a possible common source, were observed from the Netherlands, New York and Australia. No clear clustering on the basis of continental origin was observed; however, types were restricted to geographical areas and not found on other continents. A high genetic stability within the species was demonstrated by the long-term existence of a single type.

Tuberculosis in Australia, 1989-1992. Bacteriologically confirmed cases and drug resistance.

OBJECTIVE: To collate statistics, including drug susceptibility, of patients with bacteriologically confirmed tuberculosis in Australia during 1989-1992. DESIGN: Collaborative project among the five Australian mycobacterial reference laboratories. STUDY POPULATION: 2509 Australian residents with bacteriologically confirmed tuberculosis. OUTCOME MEASURES: Patient and specimen data, and drug susceptibility results recorded for isolates of Mycobacterium tuberculosis and Mycobacterium bovis. RESULTS: The annual incidence during 1989-1992 was about 3.6 per 100,000. The male-to-female ratio was 1.4:1 and about half the patients were under 50. Older men had high rates of disease. Lymphatic disease was significantly more common in females; the converse was true for pulmonary and pleural disease. Resistance to at least one of the common antituberculosis drugs was detected in 14.4% of isolates, and usually involved streptomycin (7.6%) and isoniazid (8.4%). Fewer than 1% of isolates were resistant to isoniazid and rifampicin in combination. CONCLUSIONS: By international standards, Australia remains a "low-incidence" country for tuberculosis, with a static annual incidence. Multiple drug resistance is uncommon and most patients should respond to the standard four-drug regimen. Nevertheless, because clinical data confirm that the pool of infected persons is being supplemented through immigration, and that certain population subgroups have high rates of disease, it is essential that Australia maintain effective control programs.