[Beijing family and other genotypes of Mycobacterium tuberculosis isolates in Okayama district].
OBJECTIVE
The purpose of this study is to investigate the distribution of Mycobacterium tuberculosis genotypes, such as Beijing family and other genotypes in Okayama district, and to examine the relation between these genotype strains and prevalent strains.


METHODS
The 142 M. tuberculosis strains isolated in Okayama City from January 2000 to December 2002 were subjected to IS6110-RFLP and spoligotyping for the population-based study. In addition, 13 strains having 1 to 5 IS6110 copies isolated in Okayama Prefecture excluding Okayama City were also subjected to spoligotyping.


RESULTS
A total of 103 (72.5%) of 142 strains belonged to Beijing family. Furthermore, 3 of 4 groups of prevalent strains belonged to the family. Twenty one strains out of 39 rest strains could be classified into 10 shared types (STs) of 259 STs in the worldwide spoligotype database. In addition, 15 out of 26 strains from inside and outside of Okayama City having 1 to 5 IS6110 copies showed common unique spoligotype. Moreover, the age of majority patients who were infected with M. tuberculosis of the Beijing family or other genotypes were older than 60 years.


CONCLUSIONS
It was suggested that Beijing family had been the main infection source, and the spread of strains of Beijing family and other genotypes occurred considerably in old times, and the unique genotype strains remained for a long time as peculiar strains.
Ohata
Ritsuko
R
Department of Microbiology, Okayama Prefectural Institute for Environmental Science and Public Health, 739-1, Uchio, Okayama-shi, Okayama 701-0298, Japan. ritsuko_oohata@pref.okayama.jp
Tada
Atsuhiko
A
D015373:Bacterial Typing Techniques; D005838:Genotype; D006801:Humans; D007564:Japan; D008875:Middle Aged; D017720:Molecular Epidemiology; D009169:Mycobacterium tuberculosis / Q000235:genetics* / Q000302:isolation & purification