Restriction fragment length polymorphism study of nationwide samples of Mycobacterium tuberculosis in Thailand, 1997-1998

• Published in: The international journal of tuberculosis and lung disease Vol. 9; no. 5; pp. 576 - 581
• Main Authors: RIENTHONG, D, AJAWATANAWONG, P, RIENTHONG, S, SMITHTIKARN, S, AKARASEWI, P, CHAIPRASERT, A, PALITTAPONGARNPIM, P
• Format: Journal Article
• Language: English
• Published: Paris, France IUATLD 01.05.2005; Union internationale contre la tuberculose et les maladies respiratoires
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Bacterial diseases; Biological and medical sciences; Cluster Analysis; DNA, Bacterial - genetics; Drug Resistance; Female; Human bacterial diseases; Humans; Infectious diseases; Male; Medical sciences; Middle Aged; Molecular Epidemiology; Mycobacterium tuberculosis; Mycobacterium tuberculosis - classification; Mycobacterium tuberculosis - genetics; Mycobacterium tuberculosis - isolation & purification; Polymorphism, Restriction Fragment Length; RFLP; Thailand; Thailand - epidemiology; Tuberculosis; Tuberculosis and atypical mycobacterial infections; Thailand; Asia; Human; Sanitary program; Treatment resistance; Respiratory disease; Mycobacterial infection; Thailand; Infection; Restriction fragment length polymorphism; Tuberculosis; Mycobacterium tuberculosis; Mycobacteriales; Bacteriosis; Mycobacteriaceae; Molecular epidemiology; Bacteria; Genetics; Actinomycetes; drug resistance; Molecular biology; RFLP
• ISSN: 1027-3719; 1815-7920

SETTING: During 1997-1998, a national anti-tuberculosis drug resistance survey was conducted in Thailand as a part of a global project.OBJECTIVE: To evaluate the IS6110 hybridisation patterns and the level of clustering, which was expected to be low due to the short duration of the sample collection.DESIGN: Eight hundred and twenty-eight bacterial isolates were available for fingerprinting by standard IS6110 hybridisation.RESULTS: The restriction fragment length polymorphism patterns varied with geographic locations, ages of the patients, and resistance to rifampicin and streptomycin. The Beijing strain was more common among younger patients, and their prevalence appeared to decrease with the distance from Bangkok, while the opposite was true for the single-banded isolates. Excluding isolates containing five or less copies of IS6110, 26.4% were clustered. Clustering was more common among females. The clustered isolates were sometimes from different provinces and, if resistant to drugs, usually possessed different resistance profiles.CONCLUSIONS: The results question the validity of inferring recent transmission from the clustering of IS6110 hybridisation patterns in some settings in Thailand. The level of recent transmission in a nationwide study in a country with a high incidence of tuberculosis should be evaluated with caution.