Molecular Genotyping of Mycobacterium tuberculosis Isolates from Turkey

Abstract

To survey the circulating strains of Mycobacterium tuberculosis in Turkey, all clinical isolates (381 patients) recovered in laboratories in six cities during one-month periods were collected and typed by IS6110-DNA fingerprinting and spoligotyping. Drug susceptibilities were also determined. About 23% of the isolates were resistant to one or more drugs and about 4% were multidrug resistant (i.e., resistant to at least isoniazid and rifampin). IS6110-DNA fingerprints and spoligotypes were obtained from 368 and 374 strains, respectively. Of the 374 isolates spoligotyped, 87 (23%) displayed unique spoligotypes and 287 (77%) displayed one of 34 spoligotypes (2-77 isolates per pattern). The clustered spoligotypes included ones that matched spoligotypes of the T (37% of isolates), LAM (20%), Haarlem (8%) and Beijing (2%) families. Of the 368 isolates IS6110-typed, 232 (63%) displayed unique IS6110-fingerprint patterns and 136 (37%) displayed one of 35 patterns (2-34 isolates per pattern). When IS6110 fingerprinting and spoligotyping information were combined for the 381 isolates tested, 273 isolates (72%) displayed unique genotypes and 108 isolates (28%) displayed one of 34 genotypes (2-24 isolates per genotype). In summary, many different strains are circulating in Turkey with no single strain appearing to be dominant as has been observed in other areas of the world with high tuberculosis incidence.