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Journal of Clinical Microbiology, April 2004, p. 1694-1702, Vol. 42, No. 4
0095-1137/04/$08.00+0 DOI: 10.1128/JCM.42.4.1694-1702.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.
Multilocus Short Sequence Repeat Sequencing Approach for Differentiating among Mycobacterium avium subsp. paratuberculosis Strains
Alongkorn Amonsin,1 Ling Ling Li,1 Qing Zhang,1 John P. Bannantine,2 Alifiya S. Motiwala,3 Srinand Sreevatsan,3 and Vivek Kapur1*
Department
of Microbiology and Biomedical Genomics Center, University of
Minnesota, St. Paul, Minnesota 55108,1
National Animal Disease
Center, U.S. Department of Agriculture, Ames, Iowa
50010,2
Food Animal Health Research
Program, Ohio Agricultural Research and Development Center,
and Department of Veterinary Preventive Medicine, The Ohio
State University, Wooster, Ohio
446913
Received 14 August 2003/
Returned for modification 23 October 2003/
Accepted 2 January 2004

ABSTRACT
We
describe a multilocus short sequence repeat (MLSSR) sequencing
approach
for the genotyping of
Mycobacterium avium subsp.
paratuberculosis (
M. paratuberculosis) strains.
Preliminary analysis identified
185 mono-, di-, and trinucleotide
repeat sequences dispersed
throughout the
M. paratuberculosis
genome, of which 78 were
perfect repeats. Comparative nucleotide
sequencing of the 78
loci of six
M. paratuberculosis isolates
from different host
species and geographic locations identified a
subset of 11 polymorphic
short sequence repeats (SSRs), with an average
of 3.2 alleles
per locus. Comparative sequencing of these 11 loci was
used
to genotype a collection of 33
M. paratuberculosis
isolates
representing different multiplex PCR for IS
900 loci
(MPIL) or
amplified fragment length polymorphism (AFLP) types. The
analysis
differentiated the 33
M. paratuberculosis isolates
into 20 distinct
MLSSR types, consistent with geographic and
epidemiologic correlates
and with an index of discrimination of 0.96.
MLSSR analysis
was also clearly able to distinguish between sheep and
cattle
isolates of
M. paratuberculosis and easily and
reproducibly
differentiated strains representing the predominant MPIL
genotype
(genotype A18) and AFLP genotypes (genotypes Z1 and Z2) of
M. paratuberculosis described previously. Taken together, the
results
of our studies suggest that MLSSR sequencing enables facile
and
reproducible high-resolution subtyping of
M. paratuberculosis
isolates
for molecular epidemiologic and population genetic
analyses.

INTRODUCTION
Mycobacterium avium subsp.
paratuberculosis
(
M. paratuberculosis)
is a slowly growing,
acid-fast, mycobactin J-dependent bacterium.
Infection with
this bacterium leads to a chronic granulomatous
enteritis, termed
Johne's disease, in cattle and other ruminants
and occurs
worldwide (
11). Clinical
signs of the disease include
diarrhea, weight loss, fatigue, decreased
milk production, and
mortality. Infection with this pathogen results in
considerable
economic losses in the dairy production industry, with
estimated
annual costs of $40 to $227 per year per cow, totaling
industry-wide
annual losses of $1.5 billion
(
20,
21). In addition to the
serious
health and economic impacts of the pathogen to the dairy
industry,
several reports suggest a possible link between
M.
paratuberculosis and Crohn's disease in humans
(
5,
7,
10,
30).
Methods for
differentiation or subtyping of bacterial strains provide important
information for molecular epidemiologic analysis and assist in
providing an understanding of the population genetics of the species.
DNA-based molecular subtyping techniques such as multiplex PCR for
IS900 integration loci (MPIL)
(4,
20), restriction fragment
length polymorphism (RFLP) analysis
(6,
8,
23), and amplified
fragment length polymorphism (AFLP) analysis
(20) have been previously
applied to investigate genetic variation in M.
paratuberculosis. However, the MPIL, AFLP, and RFLP techniques are
generally unable to resolve M. paratuberculosis isolates into
meaningful epidemiologic groups due to the apparently restricted
genetic diversity within the subspecies. Furthermore, the data
generated by these techniques are biallelic and, hence, are able to
provide only limited information regarding the overall genetic
diversity and evolutionary mechanisms within the species.
Short
sequence repeats (SSRs) or variable-number tandem repeats (VNTRs) in
bacterial DNA have been used as markers for the differentiation and
subtyping strains of several bacterial species, including
Mycobacterium tuberculosis
(9,
16), Yersinia
pestis (1),
Salmonella enterica subsp. enterica serovar
Typhimurium (17), and
Bacillus anthracis
(15). SSRs consist of
simple homopolymeric tracts of a single nucleotide (mononucleotide
repeats) or multimeric tracts (homogeneous or heterogeneous repeats),
such as di- or trinucleotide repeats, which can be identified as VNTRs
in the genome of the organism
(35). The variability of
the repeats is believed to be caused by slipped-strand mispairing
(31); the genetic
instability of polynucleotide tracts, especially poly(G-T)
(12); and DNA
recombination between homologous repeat sequences
(32).
The complete
genome sequence of M. paratuberculosis strain K10 (GenBank
accession number
AE016958)
has recently been characterized in the Department of Microbiology and
Biomedical Genomics Center, University of Minnesota(L. L. Li et al., unpublished data). Preliminary
bioinformatic analyses led to the identification of numerous SSRs in
the M. paratuberculosis genome. We evaluated the utility of a
multilocus SSR (MLSSR)-based typing approach for differentiating among
isolates of M. paratuberculosis. The results of our studies
suggest that MLSSR is a useful approach for strain differentiation and
enables the rapid and facile discrimination of epidemiologically and
geographically distinct strains of M.
paratuberculosis.

MATERIALS AND METHODS
Bacterial isolates and DNA isolation.
A total of 33
M. paratuberculosis isolates from different host
species and
geographic locations were used in this study, as
shown in Table
1.
M. paratuberculosis isolates were grown on
Middlebrook 7H9
broth or 7H11 agar (Difco Laboratories, Detroit,
Mich.) with oleic
acid-albumin-dextrose-catalase supplement
(Becton Dickinson, Sparks,
Md.) and mycobactin J (2 mg/100 ml).
In some instances the bacterial
cultures were incubated at 37°C
for 4 to 6 months until
colonies were observed. DNA was isolated
from the bacterial culture by
use of the QIAamp DNA Mini kit
(Qiagen Inc., Valencia, Calif.), as
described previously
(
20).
Database search for SSRs and primer design.
The whole-genome sequence of
M.
paratuberculosis strain K10
was analyzed for SSRs with Tandem
Repeat Finder (version 2.02)
software
(
3). The coordinates of
the SSRs were then matched
for the regions upstream and downstream to
locate the repeats
and open reading frame (ORF) flanking the repeat by
use of the
DNA sequence viewer and annotation software Artemis
(
28). Primers
specific
for sequences flanking these repeat sequences were
designed with Primer
3 software (
27) to yield
an average amplification
product of

250 bp for each sequence
(Table
2).
MLSSR.
A total of 78 loci were amplified by
PCR with specific primers,
and the amplification products were
sequenced to identify sequence
polymorphisms in each locus among six
strains of
M. paratuberculosis (reference strain MAP-K-10 and
isolates from cattle [isolates
MAP-08 and MAP-09], sheep
[isolates MAP-06 and MAP-11], and
a human [isolate
MAP-14]) (Table
1).
These six
M. paratuberculosis isolates were selected because
they represent the extent of
genetic diversity in the species, as
previously identified by
MPIL and AFLP analyses
(
20).
The
25-µl PCR amplification reaction mixture for each SSR comprised
1x PCR buffer II (Perkin-Elmer, Applied Biosystems Division,
Foster City, Calif.), 2.0 mM MgCl2 (Perkin-Elmer), 200
µM each deoxynucleoside triphosphate (Roche Diagnostic Co.,
Indianapolis, Ind.), 0.6 µmol of each primer (Integrated DNA
Technologies, Coralville, Iowa), 0.5 U of AmpliTaq Gold
(Perkin-Elmer), 5% dimethyl sulfoxide (Sigma Chemical Co, St.
Louis, Mo.), and 1 µl of DNA. The amplification conditions
consisted of an initial denaturation at 94°C for 15 min,
followed by 35 cycles of denaturation at 94°C for 45
s, annealing at 60°C for 1 min, and extension at 72°C
for 2 min 30 s, with a final extension step at 72°C
for 7 min. A 2-µl volume of the PCR products was mixed with 2
µl of loading buffer (0.2% Orange G in 50%
glycerol), and the mixture was electrophoresed in 1% agarose
with 0.5 µg of ethidium bromide per ml. The gels were
photographed under UV light with an Eagle Eye II gel documentation
system (Stratagene, La Jolla, Calif.). The PCR amplicons were then
sequenced with an ABI 3100 automated fluorescent DNA sequencer
(Perkin-Elmer) at the University of Minnesota's Advanced Genetic
Analysis Center
(www.agac.umn.edu).
MLSSR data analysis.
The
sequences of each SSR locus of 33 isolates were aligned,
and the numbers of tandem repeats were identified by use of the
MegAlign program (DNASTAR Inc., Madison, Wis.). The nucleotide
sequences of 11 polymorphic SSR loci were analyzed for each isolate,
and allele numbers were assigned to reflect the number of copies or the
number of nucleotide substitutions represented in the SSR sequence for
each locus. Statistical analysis for genetic diversity and overall
relationships among the isolates was performed with the computer
programs ETDIV and ETCLUS, which were modified for use with the SSR
data (2). MLSSR types were
then assigned on the basis of the unique combination of alleles for
each locus. Genetic diversity (D) was calculated by using the
following equation: 1
(allele
frequency)2(22,
29). The unweighted pair
group method with arithmetic averages-based cluster analysis and
bootstrap analysis with 1,000 replications were performed with the
program PAUP (version 4.0; Sinauer Associates, Inc. Sunderland, Mass.),
and the index of discrimination (D) was determined as
described previously
(13).

RESULTS
SSRs in M. paratuberculosis genome.
Analysis of the whole-genome sequence
of
M. paratuberculosis strain K10 (4.83 Mbp) identified 185
SSRs consisting of three
or fewer nucleotides per repeat unit. Of
these, 78 mono-, di-,
and trinucleotide repeats with perfect matches
between adjacent
copies were identified and were included as candidate
polymorphic
loci for further analysis (Table
2). These 78 SSR loci were
also
selected for inclusion in our analysis because they were short
(1
to 3 bp), as is common in prokaryotes, and each locus had
at least five
copies. Dinucleotide repeats were the most frequently
identified SSRs
in the
M. paratuberculosis genome and were present
at 63
distinct loci, with the copy numbers varying between 5
and 5.5 per
repeat. Mono- and trinucleotide repeats were represented
at 2 and 13
loci, respectively.
MLSSR analysis revealed that 11 of the 78
loci were polymorphic in the six isolates examined. The ORFs or genes
flanking each locus were also identified (Table
3). For example, locus 2 is located within ORF 210_MAP.128, which
is unique to M. paratuberculosis. Locus 3 was
identified in an intergenic region between two ORFs: a 5' ORF
encoding 6-aminohexanoate-cyclic dimer and a 3' ORF encoding
alpha/beta-hydrolase (Table
3). The functional
consequences of the presence of the loci and the influence of the locus
copy number on the expression of the adjacent genes deserve further
investigation.
MLSSR.
The 11 polymorphic SSR loci identified
in the preliminary screening
were characterized in 27 additional
M.
paratuberculosis isolates
that were previously characterized by
MPIL and AFLP analyses
(
20).
The analysis
identified 20 MLSSR types among the 33
M. paratuberculosis
isolates
recovered from different host species and geographic areas
(Tables
1 and
4). The
D value for each SSR locus was calculated on the
basis of
the allele frequency and the number of alleles and
revealed an average
number of alleles per locus of 3.20, with
an average
D value
of 0.393 and a range of
D values of 0.100
to 0.700
(
21,
28) (Table
3). While the allelic
variation observed
in this study focused on the number of copies of the
SSRs (Fig.
1A),
it is noteworthy that some loci also revealed one or two base
substitutions
in some isolates (Fig.
1B). For instance, the
analysis revealed
a single polymorphic site each at SSR loci 4 and 10
and four
and five polymorphisms at loci 5 and 9, respectively (Fig.
2).
It is interesting that the vast majority of the nucleotide
substitutions
were found in MAP-06, an isolate recovered
from a sheep.
Genetic relationships among M. paratuberculosis isolates based on MLSSR analysis.
The unweighted pair
group method with arithmetic averages-based
cluster analysis of
M.
paratuberculosis identified 20 distinct
MLSSR types among the
isolates that were grouped into two major
clusters, clusters M and N
(Fig.
3). Cluster M contained 87.88%
(29 of 33) of the isolates in the
sample, including isolates
recovered from bovine, caprine, murine,
deer, rabbit, and human
sources. The isolates in cluster M with the
most common MPIL
and AFLP fingerprints, A18 and Z1 and Z2,
respectively, were
further divided into three groups, clusters M1, M2,
and M3.
Cluster M1 contained one isolate (isolate MAP-06), which was
recovered
from a sheep and which had the A1 MPIL fingerprint. Three of
the
five isolates from caprine sources were assigned to cluster
M2. A
total of 13 unique genotypes, including a majority (10
of 15) of the
bovine isolates included in this study, were represented
in cluster M3.
In addition, the three isolates from human sources
included in the
sample used in this study were also found in
cluster M3. Interestingly,
two isolates recovered from humans
(isolates MAP-14 and 0003) were
clustered into the same clade
as an isolate of bovine origin (isolate
0180). Isolates that
were recovered from a mouse (isolate 0012),
rabbits (isolates
0237 and 0160 to 0162), a deer (isolate 0883), and
soil (isolate
0560) were also grouped along with the M3
genotype.
In contrast to cluster M, which consisted of isolates
recovered
from a variety of animal species, all four isolates that were
included
in cluster N were recovered from sheep. Strains of ovine
origin
(four of five) also showed a distinct allelic profile compared
with
the profiles of strains from cattle, goats, or
humans.
Discriminatory power of subtyping methods.
The discriminatory
power (D) of MLSSR in comparison with those of other subtyping
methods was determined as described previously
(13). MPIL analysis
differentiated the 27 M. paratuberculosis isolates for which
MPIL typing information was available into 6 subtypes with a D
value of 0.50, indicating only limited discriminatory power, while
MLSSR differentiated 27 M. paratuberculosis into 17 subtypes
with a D value of 0.96. In contrast, AFLP analysis
differentiated the 24 M. paratuberculosis isolates for which
AFLP typing information was available into 15 subtypes, with a
D value of 0.92
(20). In comparison,
MLSSR differentiated the 24 M. paratuberculosis isolates into
14 subtypes, with higher D value of 0.95. Overall, MLSSR
distinguished 20 subtypes among the 33 isolates in the sample with a
D value of 0.96, indicating that it has a relatively high
index of discrimination (Tables
3 and
4).

DISCUSSION
SSRs
have been used to type many bacterial pathogens associated
with human
and animal infections
(
32). Within the genus
Mycobacterium,
VNTR or mycobacterial interspersed repetitive
units have been
used for the subtype-specific differentiation of
several
Mycobacterium species
(
19,
26,
35). In the present study
we have identified
polymorphic SSRs by genomic analysis of
M.
paratuberculosis and used this information to develop a highly
discriminatory
method for the typing of
M. paratuberculosis
isolates.
The SSRs discovered during our preliminary screening of
the M. paratuberculosis genome were similar to the repeats
that have previously been described in other bacteria, including
Haemophilus, Mycoplasma, and Mycobacterium
spp. (24,
32,
33). It has previously
been recognized that regions of mono-, di-, and trinucleotide tandem
repeats are often the most diverse in a bacterial genome, while complex
longer repeats generally have lower levels of diversity
(14). This is thought to
result from slipped-strand mispairing (or replication slippage events)
of the DNA polymerase that occurs with greater frequency on the SSRs, a
hypothesis that remains to be tested for the SSRs that we have
identified in M. paratuberculosis
(32).
Several
important attributes of a strain differentiation assay determine its
utility in a clinical or epidemiologic setting. Especially for
organisms such as M. paratuberculosis that have restricted
levels of genetic diversity, the discriminatory power of an assay is a
particularly important attribute. Assays such as MPIL and RFLP analysis
have been shown to have only moderate abilities to differentiate among
epidemiologically distinct isolates of M. paratuberculosis and
therefore have limited applicabilities in molecular epidemiologic
studies (4,
5,
33). The recently
described AFLP technique has been shown to have a greater resolving
power than the other two approaches but suffers from the limitation
that allelic variation is indexed at anonymous biallelic markers
(20). In contrast, the
MLSSR assay described herein is far more discriminatory, being able to
differentiate 33 M. paratuberculosis from distinct geographic
localities and host species into 20 subtypes on the basis of allelic
variation at the 11 SSR loci examined, with a notably high D
value of 0.96. Consistent with its high discriminatory power, MLSSR
enabled the differentiation of seemingly monomorphic M.
paratuberculosis strains that were indistinguishable by MPIL and
AFLP analyses (20). An
important advantage of the MLSSR approach is that it also indexes
variations at known genetic loci and has the ability to identify
multiple alleles per locus. Together, these attributes not only allow
an increase in the strain-resolving power of the assay but also enable
an understanding of the genetic mechanisms driving strain
diversification and evolution within the species.
Another key
attribute of a strain differentiation assay is its ability to identify
epidemiologically and genetically related strains of a bacterial
species. In this context, MLSSR analysis clearly showed that some
isolates that are of sheep origin (cluster N) are genetically distinct
from those of bovine, caprine, and human origin (cluster M), a finding
consistent with those of previous studies
(4,
6,
20). It is noteworthy,
however, that the five isolates of sheep origin examined during this
study were represented by three distinct MLSSR types (MLSSR types 1, 19
and 20), and four isolates clustered together in cluster N.
Interestingly, all four of these phylogenetically linked M.
paratuberculosis isolates were recovered from sheep in South
Dakota, suggesting that they are both genetically and epidemiologically
related and well distinguishable from the other isolates in the
collection. The same isolates were also grouped into four distinct MPIL
genotypes (A1, A8, A16, and A17) and three AFLP genotypes (Z7, Z8, and
Z18), suggesting that they are indeed genetically distinct from the
other isolates in the collection. However, by the MPIL and the AFLP
approaches, these isolates do not cluster together as closely as they
do by MLSSR analysis
(20). Hence, these
results suggest that MLSSR analysis may enable molecular epidemiologic
investigations that will lead to a better understanding of strain
transmission and the spread of M. paratuberculosis in natural
populations and across host species.
In contrast to the
relatively close clustering of the sheep M. paratuberculosis
strains in the samples examined, far greater diversity was observed in
isolates of bovine origin. The analysis showed that while a majority of
the M. paratuberculosis isolates of bovine origin clustered
together in the M3 subgroup, 60% (three of five) of the caprine
isolates were represented by the closely related cluster M2, suggesting
that caprine isolates bear greater genetic resemblance to cattle
strains than to isolates of ovine origin, a finding that is consistent
with the findings of previous studies
(34). Similarly, deer and
cattle strains also appeared to be more closely related to each other
by MLSSR analysis, suggesting a sharing of strains of M.
paratuberculosis in wildlife species that graze or that may
otherwise come into close contact with cattle, as hypothesized
previously
(25).
Our studies
demonstrate that MLSSR analysis offers several advantages over other
methods for differentiating among M. paratuberculosis
isolates. First, as described above, the technique has a high
discriminatory power for known multiallelic genetic loci, an essential
attribute for the effective differentiation of genetically distinct
isolates. Second, MLSSR results are based upon DNA sequencing and,
hence, are unambiguous and reproducible and can likely be obtained for
most loci of all M. paratuberculosis isolates, even those
recovered from sheep or wildlife species, as demonstrated by our
studies described herein. However, we note the formal possibility that
mutations or deletions at the primer sites may render some strains
untypeable at some loci, such as loci 10 and 11 in MAP-06. Third, MLSSR
analysis is based on the amplification of SSR loci by PCR and thus not
only is rapid but also may be performed directly with bacterial
colonies without DNA extraction. Fourth, due to the considerable
advances in automated DNA sequencing technologies and the falling
prices of DNA sequencing, the MLSSR method is amenable to adaptation
for high-throughput analysis and can be performed relatively
inexpensively as well. Finally, a key advantage of the approach is that
the data are sequence based and, hence, enable accurate interlaboratory
comparisons to be made and the information used in the development of
SSR databases for further molecular epidemiologic studies, which are
greatly required in this field
(18). While it must be
recognized that sequence errors due to strand slippage during either
PCR or sequencing reactions may result in an erroneous assignment of
genotype, the occurrence of such slippage errors is minimized by
increasing the amount of sequence coverage at the locus (by confirming
both the forward and the reverse sequences or testing duplicate
samples), as is routinely practiced in our laboratory.
In
conclusion, we have described here the development of MLSSR-based
typing for the subtype-specific differentiation of M.
paratuberculosis isolates. Our preliminary analyses suggest that
this approach will be of considerable utility in enabling detailed
molecular epidemiologic and population genetic analyses of this
important animal pathogen.

ACKNOWLEDGMENTS
Research in the laboratory
of V. Kapur is funded by grants from
the U.S. Department of
Agriculture, the National Institutes
of Health, and the Minnesota
Agricultural Experimental Station.
Research in the laboratory of S.
Sreevatsan is funded through
a seed grant from the Ohio Agricultural
Research and Development
Center's research enhancement competitive
grants
program.

FOOTNOTES
* Corresponding
author. Mailing address: University of Minnesota, 1500 Gortner Ave.,
St. Paul, MN 55108. Phone: (612) 625-7712. Fax: (612) 624-6264. E-mail:
vkapur{at}umn.edu.


REFERENCES
1 - Adair,
D. M., P. L. Worsham, K. K. Hill,
A. M. Klevytska, P. J. Jackson, A. M.
Friedlander, and P. Keim. 2000. Diversity in a
variable-number tandem repeat from Yersinia pestis.J. Clin. Microbiol.
38:1516-1519.[Abstract/Free Full Text]
2 - Amonsin,
A., J. F. Wellehan, L. L. Li, P. Vandamme, C.
Lindeman, M. Edman, R. A. Robinson, and V. Kapur.1997
. Molecular epidemiology of Ornithobacterium
rhinotracheale. J. Clin. Microbiol.
35:2894-2898.[Abstract/Free Full Text]
3 - Benson,
G. 1999. Tandem repeats finder: a program to analyze
DNA sequences. Nucleic Acids Res.
27:573-580.[Abstract/Free Full Text]
4 - Bull,
T. J., J. Hermon-Taylor, I. Pavlik, F. El-Zaatari,
and M. Tizard. 2000. Characterization of IS900 loci in
Mycobacterium avium subsp. paratuberculosis and
development of multiplex PCR typing. Microbiology
146(Pt
9):2185-2197.[Abstract/Free Full Text]
5 - Bull,
T. J., E. J. McMinn, K. Sidi-Boumedine, A. Skull,
D. Durkin, P. Neild, G. Rhodes, R. Pickup, and J.
Hermon-Taylor. 2003. Detection and verification of
Mycobacterium avium subsp. paratuberculosis in fresh
ileocolonic mucosal biopsy specimens from individuals with and without
Crohn's disease. J. Clin. Microbiol.
41:2915-2923.[Abstract/Free Full Text]
6 - Cousins,
D. V., S. N. Williams, A. Hope, and G. J.
Eamens. 2000. DNA fingerprinting of Australian
isolates of Mycobacterium avium subsp.
paratuberculosis using IS900 RFLP. Aust. Vet.
J.
78:184-190.[Medline]
7 - El-Zaatari,
F. A., M. S. Osato, and D. Y. Graham.2001
. Etiology of Crohn's disease: the role of
Mycobacterium avium paratuberculosis. Trends Mol.
Med.
7:247-252.[CrossRef][Medline]
8 - Francois,
B., R. Krishnamoorthy, and J. Elion. 1997. Comparative
study of Mycobacterium paratuberculosis strains isolated from
Crohn's disease and Johne's disease using restriction
fragment length polymorphism and arbitrarily primed polymerase chain
reaction. Epidemiol. Infect.
118:227-233.[CrossRef][Medline]
9 - Gascoyne-Binzi,
D. M., R. E. Barlow, R. Frothingham, G. Robinson,
T. A. Collyns, R. Gelletlie, and P. M. Hawkey.2001
. Rapid identification of laboratory contamination
with Mycobacterium tuberculosis using variable number tandem
repeat analysis. J. Clin. Microbiol.
39:69-74.[Abstract/Free Full Text]
10 - Grimes,
D. S. 2003. Mycobacterium avium
subspecies paratuberculosis as a cause of Crohn's
disease. Gut
52:155.[Free Full Text]
11 - Harris,
N. B., and R. G. Barletta. 2001.
Mycobacterium avium subsp. paratuberculosis in
veterinary medicine. Clin. Microbiol. Rev.
14:489-512.[Abstract/Free Full Text]
12 - Henderson,
S. T., and T. D. Petes. 1992.
Instability of simple sequence DNA in Saccharomyces
cerevisiae. Mol. Cell. Biol.
12:2749-2757.[Abstract/Free Full Text]
13 - Hunter,
P. R., and M. A. Gaston. 1988.
Numerical index of the discriminatory ability of typing systems: an
application of Simpson's index of diversity. J.
Clin. Microbiol.
26:2465-2466.[Abstract/Free Full Text]
14 - Keim,
P., L. B. Price, A. M. Klevytska, K. L.
Smith, J. M. Schupp, R. Okinaka, P. J. Jackson, and
M. E. Hugh-Jones. 2000. Multiple-locus
variable-number tandem repeat analysis reveals genetic relationships
within Bacillus anthracis. J. Bacteriol.
182:2928-2936.[Abstract/Free Full Text]
15 - Kim,
W., Y. P. Hong, J. H. Yoo, W. B. Lee,
C. S. Choi, and S. I. Chung. 2002.
Genetic relationships of Bacillus anthracis and closely
related species based on variable-number tandem repeat analysis and
BOX-PCR genomic fingerprinting. FEMS Microbiol. Lett.
207:21-27.[CrossRef][Medline]
16 - Kremer,
K., D. van Soolingen, R. Frothingham, W. H. Haas,
P. W. Hermans, C. Martin, P. Palittapongarnpim, B.
B. Plikaytis, L. W. Riley, M. A. Yakrus,
J. M. Musser, and J. D. van Embden.1999
. Comparison of methods based on different molecular
epidemiological markers for typing of Mycobacterium
tuberculosis complex strains: interlaboratory study of
discriminatory power and reproducibility. J. Clin.
Microbiol.
37:2607-2618.[Abstract/Free Full Text]
17 - Lindstedt,
B. A., E. Heir, E. Gjernes, and G. Kapperud.2003
. DNA fingerprinting of Salmonella enterica
subsp. enterica serovar Typhimurium with emphasis on phage
type DT104 based on variable number of tandem repeat loci.J. Clin. Microbiol.
41:1469-1479.[Abstract/Free Full Text]
18 - Maiden,
M. C., J. A. Bygraves, E. Feil, G. Morelli,
J. E. Russell, R. Urwin, Q. Zhang, J. Zhou, K. Zurth,
D. A. Caugant, I. M. Feavers, M. Achtman, and
B. G. Spratt. 1998. Multilocus sequence
typing: a portable approach to the identification of clones within
populations of pathogenic microorganisms. Proc. Natl. Acad. Sci.
USA
95:3140-3145.[Abstract/Free Full Text]
19 - Mazars,
E., S. Lesjean, A. L. Banuls, M. Gilbert, V. Vincent, B.
Gicquel, M. Tibayrenc, C. Locht, and P. Supply. 2001.
High-resolution minisatellite-based typing as a portable approach to
global analysis of Mycobacterium tuberculosis molecular
epidemiology. Proc. Natl. Acad. Sci. USA
98:1901-1906.[Abstract/Free Full Text]
20 - Motiwala,
A. S., M. Strother, A. Amonsin, B. Byrum, S. A.
Naser, J. R. Stabel, W. P. Shulaw, J. P.
Bannantine, V. Kapur, and S. Sreevatsan. 2003.
Molecular epidemiology of Mycobacterium avium subsp.
paratuberculosis: evidence for limited strain diversity,
strain sharing, and identification of unique targets for diagnosis.J. Clin. Microbiol.
41:2015-2026.[Abstract/Free Full Text]
21 - National
Animal Health Monitoring System. 1997. Johne's
disease on U. S. dairy operations. Report N245.1087. USDA,
APHIS, VS, CEAH, National Animal Health Monitoring System, Fort
Collins,
Colo.
22 - Nei,
M. 1973. Analysis of gene diversity in subdivided
populations. Proc. Natl. Acad. Sci. USA
70:3321-3323.[Abstract/Free Full Text]
23 - Pavlik,
I., A. Horvathova, L. Dvorska, J. Bartl, P. Svastova, R. du Maine, and
I. Rychlik. 1999. Standardisation of restriction
fragment length polymorphism analysis for Mycobacterium avium
subspecies paratuberculosis. J. Microbiol.
Methods
38:155-167.[CrossRef][Medline]
24 - Peterson,
S. N., C. C. Bailey, J. S. Jensen,
M. B. Borre, E. S. King, K. F. Bott, and
C. A. Hutchison III. 1995. Characterization
of repetitive DNA in the Mycoplasma genitalium genome:
possible role in the generation of antigenic variation. Proc.
Natl. Acad. Sci. USA
92:11829-11833.[Abstract/Free Full Text]
25 - Riemann,
H., M. R. Zaman, R. Ruppanner, O. Aalund, J. B.
Jorgensen, H. Worsaae, and D. Behymer. 1979.
Paratuberculosis in cattle and free-living exotic deer.J. Am. Vet. Med. Assoc.
174:841-843.[Medline]
26 - Roring,
S., A. Scott, D. Brittain, I. Walker, G. Hewinson, S. Neill, and R.
Skuce. 2002. Development of variable-number tandem
repeat typing of Mycobacterium bovis: comparison of results
with those obtained by using existing exact tandem repeats and
spoligotyping. J. Clin. Microbiol.
40:2126-2133.[Abstract/Free Full Text]
27 - Rozen,
S., and H. Skaletsky. 2000. Primer 3 on the WWW for
general users and for biologist programmers. Methods Mol.
Biol.
132:365-386.[Medline]
28 - Rutherford,
K., J. Parkhill, J. Crook, T. Horsnell, P. Rice, M. A.
Rajandream, and B. Barrell. 2000. Artemis: sequence
visualization and annotation. Bioinformatics
16:944-945.[Abstract/Free Full Text]
29 - Selander,
R. K., D. A. Caugant, H. Ochman, J. M.
Musser, M. N. Gilmour, and T. S. Whittam.1986
. Methods of multilocus enzyme electrophoresis for
bacterial population genetics and systematics. Appl. Environ.
Microbiol.
51:873-884.[Free Full Text]
30 - Stabel,
J. R. 1998. Johne's disease: a hidden
threat. J. Dairy Sci.
81:283-288.[Abstract]
31 - Strand,
M., T. A. Prolla, R. M. Liskay, and T. D.
Petes. 1993. Destabilization of tracts of simple
repetitive DNA in yeast by mutations affecting DNA mismatch repair.Nature
365:274-276.[CrossRef][Medline]
32 - van
Belkum, A., S. Scherer, L. van Alphen, and H. Verbrugh.1998
. Short-sequence DNA repeats in prokaryotic genomes.Microbiol. Mol. Biol. Rev.
62:275-293.[Abstract/Free Full Text]
33 - van
Belkum, A., S. Scherer, W. van Leeuwen, D. Willemse, L. van Alphen, and
H. Verbrugh. 1997. Variable number of tandem repeats
in clinical strains of Haemophilus influenzae. Infect.
Immun.
65:5017-5027.[Abstract/Free Full Text]
34 - Whittington,
R. J., A. F. Hope, D. J. Marshall,
C. A. Taragel, and I. Marsh. 2000. Molecular
epidemiology of Mycobacterium avium subsp.
paratuberculosis: IS900 restriction fragment length
polymorphism and IS1311 polymorphism analyses of isolates from
animals and a human in Australia. J. Clin.
Microbiol.
38:3240-3248.[Abstract/Free Full Text]
35 - Wiid,
I. J., C. Werely, N. Beyers, P. Donald, and P. D.
van Helden. 1994. Oligonucleotide (GTG)5 as
a marker for Mycobacterium tuberculosis strain identification.J. Clin. Microbiol.
32:1318-1321.[Abstract/Free Full Text]
Journal of Clinical Microbiology, April 2004, p. 1694-1702, Vol. 42, No. 4
0095-1137/04/$08.00+0 DOI: 10.1128/JCM.42.4.1694-1702.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.
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