Rapid Variable-Number Tandem-Repeat Genotyping for Mycobacterium lepraeClinical Specimens

Autor: Kimura, Miyako, Sakamuri, Rama Murthy, Groathouse, Nathan A., Rivoire, Becky L., Gingrich, David, Krueger-Koplin, Susan, Cho, Sang-Nae, Brennan, Patrick J., Vissa, Varalakshmi
Zdroj: Journal of Clinical Microbiology; June 2009, Vol. 47 Issue: 6 p1757-1766, 10p
Abstrakt: ABSTRACTMycobacterium lepraeis the noncultivable pathogen of leprosy. Since the genome sequence of an isolate of M. lepraehas become available, multiple-locus variable-number tandem-repeat (VNTR) analysis (MLVA) has been explored as a tool for strain typing and identification of chains of transmission of leprosy. In order to discover VNTRs and develop methods transferable to clinical samples, MLVA was applied to a global collection of M. lepraeisolates derived from leprosy patients and propagated in armadillo hosts. PCR amplification, agarose gel electrophoresis, and sequencing methods were applied to DNA extracts from these infected armadillo tissues (n= 21). We identified polymorphisms in 15 out of 25 short-tandem-repeat (STR) loci previously selected by in silico analyses of the M. lepraegenome. We then developed multiplex PCR for amplification of these 15 loci in four separate PCRs suitable for fluorescent fragment length analysis and demonstrated STR profiles highly concordant with those from the sequencing methods. Subsequently, we extended this method to DNA extracts from human clinical specimens, such as skin biopsy specimens (n= 30). With these techniques, mapping of multiple loci and differentiation of genotypes have been possible using total DNA extracts from limited amounts of clinical samples at a reduced cost and with less time. These practical methods are therefore available and applicable to answer focused epidemiological questions and to allow monitoring of the transmission of M. lepraein different countries where leprosy is endemic.
Databáze: Supplemental Index