This site needs JavaScript to work properly. Please enable it to take advantage of the complete set of features!
Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

NIH NLM Logo
Log in
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2000 May;182(10):2928-36.
doi: 10.1128/JB.182.10.2928-2936.2000.

Multiple-locus variable-number tandem repeat analysis reveals genetic relationships within Bacillus anthracis

Affiliations

Multiple-locus variable-number tandem repeat analysis reveals genetic relationships within Bacillus anthracis

P Keim et al. J Bacteriol. 2000 May.

Abstract

Bacillus anthracis is one of the most genetically homogeneous pathogens described, making strain discrimination particularly difficult. In this paper, we present a novel molecular typing system based on rapidly evolving variable-number tandem repeat (VNTR) loci. Multiple-locus VNTR analysis (MLVA) uses the combined power of multiple alleles at several marker loci. In our system, fluorescently labeled PCR primers are used to produce PCR amplification products from eight VNTR regions in the B. anthracis genome. These are detected and their sizes are determined using an ABI377 automated DNA sequencer. Five of these eight loci were discovered by sequence characterization of molecular markers (vrrC(1), vrrC(2), vrrB(1), vrrB(2), and CG3), two were discovered by searching complete plasmid nucleotide sequences (pXO1-aat and pXO2-at), and one was known previously (vrrA). MLVA characterization of 426 B. anthracis isolates identified 89 distinct genotypes. VNTR markers frequently identified multiple alleles (from two to nine), with Nei's diversity values between 0.3 and 0.8. Unweighted pair-group method arithmetic average cluster analysis identified six genetically distinct groups that appear to be derived from clones. Some of these clones show worldwide distribution, while others are restricted to particular geographic regions. Human commerce doubtlessly has contributed to the dispersal of particular clones in ancient and modern times.

PubMed Disclaimer

Figures

FIG. 1
FIG. 1
Electrophoretic analysis of MLVA fragments from different B. anthracis isolates. Fluorescent image of an ABI377 electrophoresis gel containing amplification products from 45 different B. anthracis isolates. All eight VNTR loci are present in each lane. Each marker allele is a unique size and color combination, allowing easy identification of similar-sized fragments from different alleles. The 48 isolates were chosen randomly from the worldwide diversity set shown in Table 1. Sizes are shown in bases.
FIG. 2
FIG. 2
MLVA-based dendrogram and genotype scores. The eight VNTR marker loci were used to calculate a simple matching coefficient among all 89 unique MLVA genotypes. UPGMA cluster analysis was performed to identify groups of similar genotypes from the worldwide collection. The genetic distance is presented as the absolute number of differences in marker alleles among genotypes. The amplicon sizes presented are based upon nucleotide sequence determinations using the primers listed in Table 2. Country abbreviations are defined in Table 1. The vaccine strains Sterne, STI-1, and V770-NP1 are lacking the pXO2 plasmid marker and were not included in the cluster analysis. However, we have annotated the data set (see Geographical [Geo.] Region column) to indicate where these important strains match other genotypes based on analysis using seven marker loci. STI-1 did not match any of the genotypes but is related to the cluster A1.a isolates (see text for details). In addition, we have labeled the genotypes of the well-known strains Ames and Vollum. Marker alleles are presented as their sizes in nucleotides. The vrrA allele 313 corresponds to VNTR4 described previously (7, 8). G, genotype number; N, no. of isolates.

References

    1. Andersen G L, Simchock J M, Wilson K H. Identification of a region of genetic variability among Bacillus anthracis strains and related species. J Bacteriol. 1996;178:377–384. - PMC - PubMed
    1. Boyd E F, Wang F S, Whittam T S, Selander R K. Molecular genetic relationships of the salmonellae. Appl Environ Microbiol. 1996;62:804–808. - PMC - PubMed
    1. Eitzen E M. Use of biological weapons. In: Sidell F R, Takafuji E T, Franz D R, editors. Medical aspects of chemical and biological warfare. Washington, D.C.: Office of the Surgeon General; 1997. pp. 437–450.
    1. Freidlander A M. Anthrax. In: Sidell F R, Takafuji E T, Franz D R, editors. Medical aspects of chemical and biological warfare. Washington, D.C.: Office of the Surgeon General; 1997. pp. 467–478.
    1. Frothingham R, Meeker-O'Connell W A. Genetic diversity in the Mycobacterium tuberculosis complex based on variable numbers of tandem DNA repeats. Microbiology. 1998;144:1189–1196. - PubMed

Publication types

Full text links
Atypon full text link Atypon Free PMC article
Cite

AltStyle によって変換されたページ (->オリジナル) /