[Multiple infections of Mycobacterium tuberculosis in treated patients].
OBJECTIVE
To identify multiple infections of Mycobacterium tuberculosis in tuberculosis patients.


METHODS
From the clinical isolates of M. tuberculosis during 1999 to 2004 stored at Shanghai Municipal Center for Disease Control and Prevention, cases who had two isolates with different drug resistance patterns in the same treatment episode were selected. The first isolate from the selected patients was inoculated onto Middlebrook 7H11 agar plates, and 30 single colonies from each isolate were picked and genotyped by the 7 loci Variable Number Tandem Repeat (VNTR) method.


RESULTS
Two out of 22 isolates had two different genotypes among their 30 single colonies, and the proportions of the two genotype colonies were 24:6 and 29:1. The other 20 isolates showed identical genotype pattern among their 30 single colonies.


CONCLUSIONS
Multiple infections of M. tuberculosis occurred in tuberculosis patients in Shanghai.
Fang
Ren-Dong
RD
Department of Veterinary Medicine, College of Animal Science and Technology, Southwest University, Chongqing 400716, China.
Li
Xia
X
Li
Jing
J
Shen
Xin
X
Wu
Jie
J
Gui
Xiao-Hong
XH
Liu
Li
L
Gao
Qian
Q
Mei
Jian
J
D015373:Bacterial Typing Techniques; D004269:DNA, Bacterial; D005838:Genotype; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000302:isolation & purification*; D009181:Mycoses / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D015163:Superinfection / Q000382:microbiology*; D014376:Tuberculosis / Q000382:microbiology*
D004269:DNA, Bacterial