Characterization of the variable-number tandem repeats in vrrA from different Bacillus anthracis isolates.

Published

Journal Article

PCR analysis of 198 Bacillus anthracis isolates revealed a variable region of DNA sequence differing in length among the isolates. Five polymorphisms differed by the presence of two to six copies of the 12-bp tandem repeat 5'-CAATATCAACAA-3'. This variable-number tandem repeat (VNTR) region is located within a larger sequence containing one complete open reading frame that encodes a putative 30-kDa protein. Length variation did not change the reading frame of the encoded protein and only changed the copy number of a 4-amino-acid sequence (QYQQ) from 2 to 6. The structure of the VNTR region suggests that these multiple repeats are generated by recombination or polymerase slippage. Protein structures predicted from the reverse-translated DNA sequence suggest that any structural changes in the encoded protein are confined to the region encoded by the VNTR sequence. Copy number differences in the VNTR region were used to define five different B. anthracis alleles. Characterization of 198 isolates revealed allele frequencies of 6.1, 17.7, 59.6, 5.6, and 11.1% sequentially from shorter to longer alleles. The high degree of polymorphism in the VNTR region provides a criterion for assigning isolates to five allelic categories. There is a correlation between categories and geographic distribution. Such molecular markers can be used to monitor the epidemiology of anthrax outbreaks in domestic and native herbivore populations.

Full Text

Duke Authors

Cited Authors

  • Jackson, PJ; Walthers, EA; Kalif, AS; Richmond, KL; Adair, DM; Hill, KK; Kuske, CR; Andersen, GL; Wilson, KH; Hugh-Jones, M; Keim, P

Published Date

  • April 1997

Published In

Volume / Issue

  • 63 / 4

Start / End Page

  • 1400 - 1405

PubMed ID

  • 9097438

Pubmed Central ID

  • 9097438

International Standard Serial Number (ISSN)

  • 0099-2240

Language

  • eng

Conference Location

  • United States