BMC Microbiology
BioMed Central
Open Access
Research article
Identification of DNA sequence variation in Campylobacter jejuni
strains associated with the Guillain-Barré syndrome by
high-throughput AFLP analysis
Peggy CR Godschalk*1, Mathijs P Bergman1, Raymond FJ Gorkink2,
Guus Simons2,3, Nicole van den Braak1, Albert J Lastovica4, Hubert P Endtz1,
Henri A Verbrugh1 and Alex van Belkum1
Address: 1Department of Medical Microbiology & Infectious Diseases, Erasmus MC – University Medical Center Rotterdam, Dr. Molewaterplein
40, 3015 GD Rotterdam, The Netherlands, 2Department of Microbial Genomics, Keygene NV, Agro Businesspark 90, 6708 PW Wageningen, The
Netherlands, 3Pathofinder BV, Canisius Wilhelmina Hospital, Weg door Jonkerbos 100, 6532 SZ, Nijmegen, The Netherlands and 4Department
of Clinical Laboratory Sciences, Division of Microbiology, and IIDMM, University of Cape Town, Anzio Road, Observatory 7925, Cape Town,
South Africa
Email: Peggy CR Godschalk* - p.godschalk@erasmusmc.nl; Mathijs P Bergman - m.bergman@erasmusmc.nl;
Raymond FJ Gorkink - roy.gorkink@keygene.com; Guus Simons - g.simons@inter.nl.net; Nicole van den Braak - vandenbraak.npwcj@avans.nl;
Albert J Lastovica - lastoaj@mweb.co.za; Hubert P Endtz - h.p.endtz@erasmusmc.nl; Henri A Verbrugh - h.a.verbrugh@erasmusmc.nl; Alex van
Belkum - a.vanbelkum@erasmusmc.nl
* Corresponding author
Published: 04 April 2006
BMC Microbiology 2006, 6:32
doi:10.1186/1471-2180-6-32
Received: 19 October 2005
Accepted: 04 April 2006
This article is available from: http://www.biomedcentral.com/1471-2180/6/32
© 2006 Godschalk et al; licensee BioMed Central Ltd.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0),
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Background: Campylobacter jejuni is the predominant cause of antecedent infection in post-infectious
neuropathies such as the Guillain-Barré (GBS) and Miller Fisher syndromes (MFS). GBS and MFS are
probably induced by molecular mimicry between human gangliosides and bacterial lipo-oligosaccharides
(LOS). This study describes a new C. jejuni-specific high-throughput AFLP (htAFLP) approach for detection
and identification of DNA polymorphism, in general, and of putative GBS/MFS-markers, in particular.
Results: We compared 6 different isolates of the "genome strain" NCTC 11168 obtained from different
laboratories. HtAFLP analysis generated approximately 3000 markers per stain, 19 of which were
polymorphic. The DNA polymorphisms could not be confirmed by PCR-RFLP analysis, suggesting a
baseline level of 0.6% AFLP artefacts. Comparison of NCTC 11168 with 4 GBS-associated strains revealed
23 potentially GBS-specific markers, 17 of which were identified by DNA sequencing. A collection of 27
GBS/MFS-associated and 17 enteritis control strains was analyzed with PCR-RFLP tests based on 11 of
these markers. We identified 3 markers, located in the LOS biosynthesis genes cj1136, cj1138 and cj1139c,
that were significantly associated with GBS (P = 0.024, P = 0.047 and P < 0.001, respectively). HtAFLP
analysis of 13 highly clonal South African GBS/MFS-associated and enteritis control strains did not reveal
GBS-specific markers.
Conclusion: This study shows that bacterial GBS markers are limited in number and located in the LOS
biosynthesis genes, which corroborates the current consensus that LOS mimicry may be the prime
etiologic determinant of GBS. Furthermore, our results demonstrate that htAFLP, with its high
reproducibility and resolution, is an effective technique for the detection and subsequent identification of
putative bacterial disease markers.
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Background
The Guillain-Barré syndrome (GBS) is the most frequent
form of acute immune-mediated neuropathy. The Miller
Fisher syndrome (MFS) is a variant of GBS, affecting
mainly the eye muscles [1]. A respiratory or gastro-intestinal infection preceding the neurological symptoms is
reported by nearly two-thirds of all patients [2]. The most
frequently identified infectious agent is Campylobacter
jejuni, which is also the predominant cause of bacterial
diarrhoea worldwide [3,4]. The neuropathy is probably
induced by molecular mimicry between gangliosides in
nerve tissue and lipo-oligosaccharides (LOS) on the
Campylobacter cell surface [5]. This structural resemblance
leads to a cross-reactive immune response causing neurological damage. Biochemical and serological studies have
revealed that many C. jejuni strains express gangliosidelike structures in their LOS [6]. However, not all strains
expressing ganglioside mimics induce GBS. It is estimated
that only 1 in every 1000–3000 C. jejuni infections is followed by GBS [7,8], which suggests that additional bacterial determinants and/or host-related factors are
important as well.
Many researchers have studied collections of GBS-associated and control "enteritis-only" strains in search of GBSspecific microbial features. Several reports describe an
overrepresentation of specific Penner (heat stable, HS)
serotypes among GBS-associated strains from certain geographical areas [9,10]. The HS:19 and HS:41 serotypes are
the predominant serotypes preceding GBS in Japan and
South Africa, respectively [9,10]. Because HS:19 and
HS:41 strains represent a clonal population [11,12], the
observed overrepresentation of these serotypes does not
imply that the determinant of the Penner serotyping system, the capsular polysaccharide, is involved in the pathogenesis of GBS [13]. In addition, this phenomenon is not
seen in other regions, where GBS-associated strains are
genetically heterogeneous [14]. Various molecular typing
techniques have been used in search of GBS-specific features in C. jejuni, such as flaA-PCR-restriction fragment
length polymorphism (RFLP), pulsed field gel electrophoresis (PFGE), randomly amplified polymorphic DNA
(RAPD) analysis, ribotyping, amplified fragment length
polymorphism (AFLP) analysis and multi locus sequence
typing (MLST), but none of these have identified GBS-specific markers [14-17]. Very recently, Leonard et al. also
failed to detect GBS-specific features by the use of an open
reading frame (ORF)-specific C. jejuni DNA microarray
[18]. However, this array was based on the genome
sequence of strain NCTC 11168 and ORFs that are not
present in this strain will not be detected. In addition, possible GBS-factors other than those relating to presence or
absence of certain genes will not be detected using this
approach. Based on the molecular mimicry hypothesis,
other researchers focused on genes involved in LOS bio-
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synthesis and found significant associations with GBS
[19-22]. However, these associations are not absolute and
the question remains whether other GBS-specific microbial factors, either LOS-related or not, may exist.
Comparative genomics technology facilitates genetic
marker identification but not all methods may be equally
suited for high-throughput marker searches. Molecular
typing techniques for Campylobacter strains differ in sensitivity and the overall coverage of genome regions
screened. For the detection of specific disease markers it is
desirable to use a technique that screens diversity in the
overall genome with a very high resolution. MLST and
flaA PCR-RFLP analyze restricted parts of the genome and
are not suitable for the detection of additional GBS-markers [23,24]. PFGE is based on digestion of genomic DNA
with a rare cutting restriction enzyme and only large insertions or deletions and mutations in the restriction sites
will be detected [14]. PFGE patterns normally display
between 10 and 20 fragments, which covers 120 nucleotides when a six nucleotide restriction enzyme recognition sequence is involved. AFLP analysis is considerably
more sensitive than PFGE for the detection of DNA
sequence polymorphism. In a conventional AFLP analysis, the use of two restriction enzymes and a primer pair
with 1 or 2 selective nucleotides leads to a DNA fingerprint pattern consisting of approximately 50–80 fragments per strain. This approach physically covers in the
order of 600–1000 nucleotides of the total genome for
sequence polymorphism [25]. Even the use of two restriction enzymes in PFGE will not make up for the difference
observed under a single AFLP reaction. As indicated
above, DNA microarrays cover the full genome but will
only detect differences in the presence of known genes.
Recently, we described a new high throughput AFLP
(htAFLP) approach for the identification of DNA polymorphism in Mycobacterium tuberculosis [26]. This method
has the capacity to detect mutations in more than 30,000
nucleotides scattered throughout the genome, depending
on the number of restriction enzymes and primer pairs
used. The choice of primers and restriction enzymes is crucial and selection of these requires close attention. A
wrong choice may lead to crowding of amplified fragments, caused by limiting (limited?) resolution of the gelsystem. Correct, computer-mediated comparison of AFLP
fingerprints may then be compromised. However, especially the enhanced resolution makes htAFLP an excellent
candidate technique for the detection of potential diseaseassociated markers.
The main objective of the current study was to search an
elaborate collection of C. jejuni stains isolated from GBS
patients for genetic markers associated with bacterial neuropathogenicity. To this aim, we developed htAFLP for C.
jejuni. We analyzed six isolates of strain NCTC 11168, the
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"genome" strain, obtained from different laboratories,
with the aim to detect base-level polymorphism introduced by sub-culturing or storage. In search of potential
GBS-specific markers, we compared the NCTC 11168
AFLP patterns with those of four GBS-associated strains.
In addition, we analyzed a collection of highly clonal
GBS-associated and control strains from South Africa.
Potential GBS-specific htAFLP markers were further identified by DNA sequencing and PCR-RFLP tests were developed. These PCR-RFLP tests were used to screen a larger
collection of GBS-associated and control strains for confirmation of the potential GBS markers.
http://www.biomedcentral.com/1471-2180/6/32
sequence. An AFLP polymorphism can also be the result
of a mutation in the nucleotides complementary to the
selective primer nucleotides. Because all 64 possible combinations of the +1/+2 primer pairs were used in this
htAFLP, such a mutation would be expected to result in an
additional polymorphism, with the same fragment length
and localization on the genome, in the AFLP pattern generated with a different primer pair. We did not detect such
complementary polymorphisms in the NCTC 11168
comparison. In conclusion, the polymorphic AFLP bands
observed in the NCTC 11168 comparison, representing
approximately 0.6% of all bands, probably represent the
low "background noise" of the htAFLP technique.
Results
Detection and identification of DNA sequence
polymorphism in NCTC 11168 strains of diverse origin
HtAFLP analysis of C. jejuni was performed with one
enzyme combination. Genomic DNA was digested with
MboI and DdeI and the restricted DNA was amplified by
using all 64 possible combinations of +1/+2 selective
primer pairs. This resulted in the generation of approximately 3000 fragments per strain. The average fragment
size was 243 basepairs (bp), ranging from 46 to 613 bp.
Comparative htAFLP analysis of the six NCTC 11168 isolates revealed 19 polymorphic fragments. After excision
from the gel, these fragments were amplified and the DNA
sequences were determined. BLAST analysis of the DNA
sequences resulted in the identification of 13/19 polymorphisms, which were spread throughout the genome
(Table 1). For the other polymorphic fragments, repeated
amplification and sequencing failed to generate DNA
sequences of sufficient quality for BLAST analysis.
Validation of NCTC 11168 polymorphism with a PCRRFLP approach
To verify whether the htAFLP-polymorphic fragments represent true DNA sequence polymorphism, we analyzed
the six NCTC 11168 isolates by PCR-RFLP analysis. An
AFLP polymorphism that is based on mutations in the
restriction site will result in a polymorphic RFLP pattern,
whereas insertions or deletions in the AFLP fragment will
result in size differences between the PCR products. Based
on the BLAST hit sequences (Table 1), PCR tests for amplifying twelve marker fragments and their flanking regions
were developed. Fragments of correct size were produced
with all primer sets and for all isolates (results not
shown). Next, PCR products of the six NCTC 11168
strains were digested in separate reactions with the AFLP
restriction enzymes (results not shown). None of the
digests showed polymorphic RFLP patterns. Thus, restriction site polymorphism or insertions/deletions could not
be confirmed as cause of the observed AFLP polymorphisms. Nine out of twelve (75%) digests with DdeI and
six of twelve (50%) digests with MboI resulted in RFLP
patterns as expected based on the NCTC 11168 DNA
Comparison of NCTC 11168 with GBS-associated strains
for the detection and identification of potential markers
for GBS
For the detection of putative markers for the GuillainBarré syndrome, we compared the NCTC 11168 isolates
with strain GB11, which was isolated from a GBS patient.
Strain NCTC 11168 was originally isolated from a patient
with gastroenteritis without neurological symptoms. It
had previously been shown that GB11 and NCTC 11168
are genetically closely related [14,15,27]. Because of this
relatedness, these strains are very suitable for the detection
of potential GBS-specific markers. HtAFLP analysis of
NCTC 11168 and GB11 generated 241 putative GBS
markers. Overall, 156 of 241 markers could be successfully identified with DNA sequencing and BLAST analysis.
A proportion of the marker fragments that were excised
from the gel could not be reliably reamplified and were
excluded from the analysis. Although BLAST searches
were conducted against all DNA sequences in the Pubmed
database, the most significant homology for all AFLP
DNA sequences was with C. jejuni DNA sequences. To further reduce this excessive number of putative GBS markers, we analyzed three additional GBS-associated strains,
not related to the NCTC 11168 and GB11 strains (Cura7,
Cura276 and 260.94; See Additional file 1). This reduced
the number of successfully sequenced putative GBS markers to 17 (Table 2). Three of these markers were located in
the LOS biosynthesis gene locus. Other genes encoded a
putative periplasmic protein and proteins involved in signal transduction, metabolism, transport, binding, amino
acid biosynthesis, fatty acid biosynthesis and DNA replication. Three genes were of unknown function. Markers 5
and 6 displayed distinct restriction site polymorphism
concordant with the AFLP polymorphism. These markers
contained largely overlapping DNA sequences and
showed a complementary pattern of presence and absence
in the GBS-associated and control strains (Table 2). Comparison of the DNA sequences revealed that these markers
were based on one DNA polymorphism: the presence of
an additional restriction site in the GBS strains due to a
point mutation (Figure 1).
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Table 1: Polymorphic htAFLP markers for NCTC11168 strains of diverse origin
NCTC11168 strainsb
11168 hit
sequenced
1
2
3
4
5
6
lengthc
Begin
end
1
2
+
-
+
-
+
+
+
-
-
+
+
469
252
28753
67665
28317
67858
3
-
-
+
-
-
-
110
122004 122083
4
5
-
-
+
+
+
+
+
+
+
+
118
86
153984 154075
212438 212383
6
+
+
+
+
+
-
420
573124 572971
7
-
-
+
+
+
+
49
589048 589393
8
-
-
+
+
+
+
382
788562 788468
9
-
-
+
-
-
-
463
10
-
-
-
+
+
-
228
11
+
-
-
+
-
-
226
12
+
+
-
+
+
+
191
13
-
-
+
-
+
+
126
104789
1
122729
6
122729
6
127029
1
151028
6
marker
gene and function
a
104832
2
122712
5
122711
7
127013
1
151038
1
Cj0023, purB, probable adenylosuccinate lyase
Cj0046, probable transmembrane transport
protein pseudogene
Cj0117, pfs, probable 5'-methylthioadenosine\Sadenosylhomocysteine nucleosidase
Cj0150c, probable aminotransferase
Cj0227, argD, probable acetylornithine
aminotransferase
Cj0612c, cft, probable ferritin; Cj0613, pstS,
possible periplasmic phosphate binding protein
Cj0629, possible lipoprotein; Highly similar to
Cj1678; Cj1678, possible lipoprotein
Cj0840c, fbp, probable fructose-1,6bisphosphatase
Cj1116c, ftsH, probable membrane bound zinc
metallopeptidase
Cj1295, unknown
Cj1295, unknown
Cj1339c, flaA, flagellin A
Cj1580c, probable peptide ABC-transport
system ATP-binding protein
aThe individual markers have been given a numerical code. bThe strains are numbered according to Additional file 1. The plusses and minuses
indicate the presence and absence, respectively, of the AFLP fragments. cThe fragment lengths, based on fragment position in the AFLP gels. dThe
begin and the end positions in the NCTC 11168 genome are given for all BLAST hits, as well as the corresponding genes and their function.
Screening of a large strain collection for potential GBS
markers by PCR-RFLP analysis
After htAFLP analysis of five strains to identify potential
GBS markers, we developed PCR-RFLP tests to screen a
large collection of 27 GBS/MFS-associated and 17 control
enteritis strains for the presence of these markers (for a
survey of these strains see Additional file 1). The strains
used in the htAFLP analysis were also included in the PCRRFLP analysis. One randomly selected NCTC 11168 isolate was included. Based on the BLAST hit sequences
(Table 2), PCR tests for amplifying 11/17 marker fragments and their flanking regions were developed (See
Additional file 2). Because markers 5 and 6 represented
the same DNA polymorphism, they were included in one
PCR test. Fragments of correct, expected size were produced with all primer sets. For 5/11 markers a PCR product was absent in a variable proportion of strains (Table
3), probably due to primer site sequence heterogeneity.
For example, we have observed previously that gene
cj1136, part of the LOS biosynthesis gene locus and containing marker 7, shows a large degree of DNA sequence
heterogeneity between strains (P. Godschalk, unpublished results). This leads to primer mismatches and
absence of PCR products in a proportion of strains. In 2/
10 PCR tests (markers 7 and 8), the htAFLP GBS-associated strains could be distinguished from strain NCTC
11168 through the pattern of presence and absence of
PCR products. PCR products for marker 7 were absent in
the GBS-associated strains used in the htAFLP and present
in NCTC 11168, which seemed to be in contrast with the
observation that the original AFLP fragment of marker 7
was present in the GBS strains and absent in NCTC 11168.
However, this apparent inconsistency can be explained by
the fact that the primer sequences of the PCR test were
based on the NCTC 11168 DNA sequence. For marker 7,
a PCR product was seen significantly more frequently in
control enteritis strains (5/27 (18.5%) GBS/MFS strains
versus 9/17 (52.9%) control enteritis strains, P = 0.024).
Next, we subjected the PCR products to a combined digestion with the AFLP restriction enzymes (Table 3). In 4/10
PCR tests (markers 3, 5/6, 9 and 13), the RFLP types were
concordant with the AFLP analysis i.e. the htAFLP GBSassociated strains shared the same RFLP type whereas
NCTC 11168 displayed a different RFLP type. In 3/10 PCR
tests (markers 11, 12 and 14), the htAFLP GBS-associated
strains did not have identical RFLP types (and for marker
14 there was no PCR product in two GBS strains), but
these RFLP types were also different from that of NCTC
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1
1
1
http://www.biomedcentral.com/1471-2180/6/32
10
20
30
40
------------------+-------------------+-------------------+-------------------+T A A A T T A T T A T G C T A A G A G T T C T A A A C A A T A T A T T A A C A A cj0615_genomeseq
A G A G T T C T A A A C A A T A T A T T A A C A A cj0615_11168_AFLP
T A A G A G T T C T A A A C A A G A T A T T A A C A A cj0615_GB11_AFLP
DdeI
41
26
28
50
60
70
80
------------------+-------------------+-------------------+-------------------+T A T T A C T T T A A T A T A T A A C A A T C C T A A A C C A A A T A T T A C A cj0615_genomeseq
T A T T A C T T T A A T A T A T A A C A A T C C T A A A C C A A A T A T T A C A cj0615_11168_AFLP
T A T T A C T T T A A T A T A T A A C A A T C C T A A A C C A A A T A T T A C A cj0615_GB11_AFLP
81
66
68
90
100
110
120
------------------+-------------------+-------------------+-------------------+A A T A T A A A C G A T T T A A A T T T T A A A C A T T A T T T A C T T A C T C cj0615_genomeseq
A A T A T A A A C G A T T T A A A T T T T A A A C A T T A T T T A C T T A C T C cj0615_11168_AFLP
A A T A T A A A C G A T T T A A A T T T T A A A C A T T A T T T A C T T A C T C cj0615_GB11_AFLP
121
106
108
130
140
150
160
------------------+-------------------+-------------------+-------------------+C T G A T A T G A G A G A A G A T G A A G T T C T T T C T T T T A A A G C A A G cj0615_genomeseq
C T G A T A T G A G A G A A G A T G A A G T T C T T T C T T T T A A A G C A A G cj0615_11168_AFLP
C T G A T A T G A G A G A A G A T G A A G T T C T T T C T T T T A A A G C A A G cj0615_GB11_AFLP
161
146
148
201
186
170
180
190
200
------------------+-------------------+-------------------+-------------------+G C A T G G T G T T A A T A C A G C C G G T C A T A G T A T A A A A A C A G T T cj0615_genomeseq
G C A T G G T G T T A A T A C A G C C G G T C A T A G T A T A A A A A C A G T T cj0615_11168_AFLP
G C A T G G T G T T A A T A C A G C C G A T C
cj0615_GB11_AFLP
MboI
210
220
230
240
------------------+-------------------+-------------------+-------------------+A G A G T G C T T C C T T T T T T A A T C A C A G C A A A A A C C G A T C A T G cj0615_genomeseq
A G A G T G C T T C C T T T T T T A A T C A C A G C A A A A A C C G A T C
cj0615_11168_AFLP
MboI
Figure
The
basis
1 of the AFLP polymorphism in the complementary markers 5 and 6
The basis of the AFLP polymorphism in the complementary markers 5 and 6 Marker 5 represents a fragment with
a length of 198 bp that was present in the ht AFLP GBS strains, whereas marker 6, a fragment of 253 bp, was only present in
the NCTC 11168 isolates. DNA sequence analysis of the GB11 and NCTC 11168 AFLP fragments and subsequent BLAST
searches showed that both markers were located in gene cj0615, encoding a possible periplasmic protein. Furthermore, DNA
sequence analysis revealed that a point mutation in the GBS strains had resulted in an additional MboI restriction site, resulting
the amplification of a shorter AFLP fragment in the GBS strains. Because the selective nucleotide flanking the MboI restriction
site was identical for the GB11 and NCTC 11168 fragment, the GBS fragments were amplified with the same primerpair as the
NCTC 11168 fragments. DNA sequences of markers 5 (cj0615_GB11_AFLP) and 6 (cj0615_NCTC 11168_AFLP) are given, as
well as the NCTC 11168 genome sequence of the same area (cj0615_genomeseq). The AFLP restriction sites are indicated
with boxes, the selective nucleotides are underscored and the point mutation is indicated in bold.
11168. This is not necessarily in contrast with the htAFLP
results, because different RFLP types among the htAFLP
GBS-associated strains may be due to heterogeneity in the
flanking regions of the AFLP fragment. For marker 2, the
RFLP types of the htAFLP strains were not concordant with
the htAFLP polymorphism: the NCTC 11168 and GB11
RFLP types were the same. RFLP types 3 and 4 of marker
9, located in gene cj1139c, were only detected in GBS/
MFS-associated strains (RFLP type 3 or 4 present in 15/27
(55.6 %) GBS/MFS-associated strains versus 0/17 (0%)
enteritis strains, P <0.0001). Although a PCR product for
marker 8, located in gene cj1138, was absent in the majority of strains, RFLP type 1 was more frequently found in
enteritis strains (5/15 enteritis strains versus 1/27 GBSassociated strains, P = 0.047).
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Analysis of South-African GBS-associated and control
HS:41 strains by htAFLP
In South Africa, serotype HS:41 is over-represented
among GBS-associated strains [10]. Previous studies have
shown that HS:41 strains, both GBS-associated and controls, are highly clonal [12]. As expected, htAFLP of six
GBS-associated, one MFS-associated and six control
HS:41 strains generated very homogeneous banding patterns (results not shown). A total of forty-five AFLP polymorphisms were detected, but there were no GBS-specific
markers. Interestingly, 28 AFLP polymorphisms displayed
a similar pattern: fragments were present in the MFS-associated strain and two or three control enteritis strains but
absent in the other strains (Figure 2). These fragments
were excised and DNA sequences were determined. BLAST
analysis of five DNA sequences revealed homologies with
various bacterial plasmidal DNA sequences (results not
shown).
Discussion
This study describes a high-throughput AFLP approach for
the detection and identification of DNA polymorphism
and putative GBS-markers in C. jejuni. Previously, we
showed that htAFLP is an excellent tool for assessing the
population structure and the expansion of pathogenic
clones in Staphylococcus aureus and for identification of
genetic polymorphism in the clonal microorganism Mycobacterium tuberculosis [26,28]. The optimal enzyme and
selective primer pair combinations are determined by in
silico calculations using the whole genome DNA sequence
of the target microorganism. The optimal number of AFLP
fragments to be generated depends on the aim of the
study. For the detection and identification of potential
disease markers, such as GBS-specific markers in C. jejuni
in the current study, it is desirable to screen the genome
with high resolution. For this, the generation of a large
number of AFLP fragments per strain is needed. Such high
resolution AFLP approach limits the number of strains
that can be analyzed, but this can be overcome by the subsequent analysis of a large number of strains by PCR-RFLP
tests, translated from the potential markers as detected by
the preceding htAFLP analysis. It is, of course, possible
that a disease-specific marker is not detected by htAFLP
because this approach does not result in 100% genome
coverage, which can only be reached with whole genome
sequencing. For C. jejuni, one enzyme combination (MboI
and DdeI) and 64 different +1/+2 selective primer pair
combinations physically covered approximately 30,000
nucleotides per strain, which represents approximately
2% of the genome.
To find out whether subculturing or storage of C. jejuni
strains leads to the emergence of DNA polymorphism, we
compared 6 isolates of the "genome" strain NCTC 11168
obtained from different laboratories worldwide by
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htAFLP analysis. The observed AFLP polymorphisms,
approximately 0.6% of the fragments per strain, could not
be confirmed by PCR-RFLP analysis. This indicates that
the AFLP polymorphisms probably represent the low
background noise of the htAFLP technique and that true
DNA polymorphism could not be detected in the six
NCTC 11168 isolates. The observed background noise
equals a reproducibility of approximately 99.6%, which is
still very high when compared to other genotyping techniques [29].
Recently, two groups described differences in virulence
properties, i.e. the ability to colonise chickens, between
different NCTC 11168 isolates that were not included in
the current study [30,31]. Full transcriptional profiling
revealed expression differences for several gene families in
the NCTC 11168 strains. HtAFLP analysis of the two
NCTC 11168 isolates that were studied by Carrillo et al.
[30,31] failed to identify polymorphisms responsible for
the difference in virulence properties (P. Godschalk and
C. Szymanski, unpublished data). It has to be emphasized
that by htAFLP still only a random proportion of the
genome is screened. DNA sequence variation (such as single-nucleotide polymorphisms, SNPs) leading to biological differences may therefore not be detected.
In search of GBS-specific markers, we first compared the
NCTC 11168 patterns with the AFLP patterns of the genetically related GBS-associated strain GB11. However,
although NCTC 11168 was originally isolated from the
faeces of a patient with gastroenteritis, we cannot exclude
that NCTC 11168 can induce GBS if a patient with the
right host susceptibility factors becomes infected with this
strain. The only substantial but probably very important
difference between NCTC 11168 and GB11 that has been
found so far, is that the LOS biosynthesis gene locus
strongly diverges between these strains, probably as result
of a horizontal exchange event [32]. Comparison of
NCTC 11168 with GB11 led to the detection of more than
two hundred possible GBS markers, which was substantially higher than the expected background noise of 0.6%,
underscoring the phylogenetic relevance of the polymorphisms. The number of possible GBS markers was reduced
to 23 after adding three additional GBS-associated strains.
For 17 markers, the location on the genome could be
identified after DNA sequence analysis. A relatively large
proportion of potential GBS markers (3/17;18%) was
located in the LOS biosynthesis gene locus, whereas this
locus only comprises 1% of the C. jejuni genome (1.64
Mbp). Although this may represent a true pathogenic
association with GBS, it is also possible that htAFLP preferentially picked up the LOS locus because it is a highly
polymorphic region. However, analysis of a larger C. jejuni
strain collection by PCR-RFLP analysis showed that the
three LOS-specific markers were indeed associated with
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1
2
3
4
5
260.94
233.94
233.95
308.95
367.95
6
7
370.95 242.98
8
9
378.96 386.96
10
11
12
13
199.97
250.97
242.97
21.97
Figureof2the htAFLP pattern of the HS:41 strains
Detail
Detail of the htAFLP pattern of the HS:41 strains A fragment of the banding patterns of the South African HS:41 strains
is shown. Lane 1–6 GBS-associated strains, lane 7 MFS-associated strain, lane 8–13 enteritis strains. Polymorphic bands representing plasmidal DNA sequences are indicated with arrows.
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Table 2: Putative GBS-markers detected by htAFLP
markera
11168
GB11
strainsb
cura 7
cura 276
O:41
lengthc
11168 hit sequenced
begin
end
gene and function
1
-
+
+
+
+
112
324441
324363
2
+
-
-
-
-
265
400499
400264
3
-
+
+
+
+
115
575807
575893
4
-
+
+
+
+
152
576061
576182
5
6
7
8
9
10
+
+
+
+
+
+
-
+
+
+
-
+
+
+
-
+
+
+
-
198
253
241
138
97
169
904760
904817
1070741
1073190
1074261
1090751
904594
904596
1070662
1073082
1074320
1090612
11
+
-
-
-
-
89
1092245
1092185
12
13
+
+
-
-
-
-
181
137
1236007
1236406
1236080
1236298
14
+
-
-
-
-
438
1264182
1264586
15
+
-
-
-
-
163
1328311
1328184
16
+
-
-
-
-
203
1334951
1334779
17
+
-
-
-
-
102
Cj0355c, probable two-component
regulator
Cj0432c, murD, probable UDP-Nacetylmuramoylalanine – D-glutamate ligase
Cj0615, pstA, probable phosphate transport
system permease protein
Cj0615, pstA, probable phosphate transport
system permease protein
Cj0967, possible periplasmic protein
Cj0967, possible periplasmic protein
Cj1136, probable galactosyltransferase
Cj1138, probable galactosyltransferase
Cj1139c, probable galactosyltransferase
Cj1157, dnaX, probable DNA polymerase III
subunit gamma
Cj1161c, probable cation-transporting
ATPase
Cj1306c, unknown
Cj1306c, unknown, similar to Cj1310c,
Cj1305c, Cj1342c, Cj0617/0618
Cj1336, unknown, identical to Cj1318
(except the C-term)
Cj1394, probable fumarate lyase; Cj1393,
metC', probable cystathionine beta-lyase
Cj1400c, fabI, probable enoyl- [acyl-carrierprotein] reductase [NADH]
Cj1101, probable ATP-dependent DNA
helicase
aThe
individual markers have been given a numerical code. bThe plusses and minuses indicate the presence and absence, respectively, of the AFLP
fragments. cThe estimated fragment lengths on the AFLP gels are given. dThe begin and the end positions in the NCTC 11168 genome are given for
all BLAST hits, as well as the corresponding genes and their function. Note that markers 5 and 6 are largely overlapping and have a complementary
pattern of presence and absence (see also Figure 1).
GBS (marker 7, P = 0.024; marker 8, P = 0.047; marker 9,
P <0.001). These findings are concordant with the proposed pathogenic mechanism of GBS and with previous
reports that certain genes involved in LOS biosynthesis or
specific nucleotide sequences within these genes occur
more frequently in GBS-associated C. jejuni strains [1922].
ond, a certain combination of multiple C. jejuni genes
may be required for the induction of GBS. Detection of
such combinations of markers ("polygenic markers") is
extremely labour-intensive and cannot be achieved with
the current approach. Finally, it is possible that htAFLP
failed to detect GBS-specific markers because htAFLP does
not accomplish 100% genome coverage.
There are several possible explanations for the fact that we
did not find molecular markers that are 100% specific for
the Guillain-Barré syndrome. First, it is possible that truly
GBS-specific features do not exist in C. jejuni. There is a
broad variability in the severity and spectrum of clinical
symptoms in GBS patients [33]. Different ganglioside
mimicking structures and anti-ganglioside antibody specificities have been associated with certain clinical presentations [34-36], and therefore, C. jejuni markers may be
associated with a subset of various disease entities.
Because of this heterogeneity and the presumed importance of host-related factors, the existence of features in C.
jejuni that are specific for GBS may be questionable. Sec-
One of the three additional GBS-associated strains mentioned above was from a collection of South-African
HS:41 strains. In South Africa, the HS:41 serotype is overrepresented among GBS-associated strains [10]. A certain
feature of these strains may be responsible for their capacity to trigger GBS. HS:41 strains were found to be indistinguishable by previous genotyping studies, indicating that
HS:41 strains form a genetically stable clone [12]. It is
important to note that the enteritis-only HS:41 strains
may have the same GBS-inducing capacity as the GBSassociated strains, because host-related factors are also
crucial for developing GBS. We analyzed both GBS-associated and control enteritis-only HS:41 strains, as well as an
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Table 3: Results of the PCR-RFLP analysis for 11 potential GBS markers identified by htAFLP analysis
marker nr (genomic localization)b
straina
disease
GB1
GB2
GB3
GB4
GB5
MF6
MF7
MF8
GB11
GB13
GB15
GB16
GB17
GB18
GB19
MF20
GB21
GB23
GB24
GB25
GB26
GB29
GB30
cura 7
cura 69
cura 276
260.94
E97-0737
E97-0747
E97-0796
E97-0873
E97-0903
E97-0921
E97-0974
E97-0980
E97-0998
E97-1013
E98-623
E98-624
E98-682
E98-706
E98-1033
E98-1087
NCTC
11168-1
GBS
GBS
GBS
GBS
GBS
MFS
MFS
MFS
GBS
GBS
GBS
GBS
GBS
GBS
GBS
MFS
GBS
GBS
GBS
GBS
GBS
GBS
GBS
GBS
GBS
GBS
GBS
enteritis
enteritis
enteritis
enteritis
enteritis
enteritis
enteritis
enteritis
enteritis
enteritis
enteritis
enteritis
enteritis
enteritis
enteritis
enteritis
enteritis
2 (cj0432) 3 (cj0615)
1
2
2
1
1
2
1
1
1
1
1
1
1
2
1
1
2
1
2
1
1
1
3
2
2
2
2
1
1
1
2
1
1
1
1
2
1
2
2
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
1
1
2
2
1
2
2
2
1
2
1
2
1
2
2
2
2
2
1
2
3
2
2
2
1
2
1
2
2
1
1
2
2
1
5,6
(cj0967)
1
2
2
2
1
2
1
2
2
1
3
1
1
2
1
3
2
1
2
1
1
3
2
2
2
2
1
1
1
2
1
3
1
1
2
3
2
2
1
3
3
1
1
7 (cj1136) 8 (cj1138)
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
nd
nd
1
1
1
1
9
(cj1139c)
11
(cj1161c)
12
(cj1306)
13
(cj1306)
14
(cj1336)
0
1
1
2
3
4
3
0
4
0
0
3
0
4
5
5
4
4
3
3
3
4
4
4
4
0
0
0
0
2
6
0
5
7
5
2
2
0
0
1
0
0
1
2
2
2
0
2
1
2
2
2
2
2
1
2
2
1
2
0
1
1
1
1
1
2
2
2
4
1
2
1
2
1
0
nd
1
2
1
2
2
1
2
1
1
1
2
4
3
1
5
6
5
6
7
5
5
1
5
4
3
5
0
1
1
5
5
10
1
8
3
8
9
2
5
5
5
11
11
5
5
11
5
5
2
2
1
1
1
5
2
3
3
1
4
0
4
1
5
1
4
1
4
6
7
8
5
1
4
8
1
10
1
5
9
5
5
1
10
4
nd
8
6
1
1
nd
10
nd
nd
10
4
1
4
1
1
2
3
4
3
5
3
3
5
6
4
4
4
7
4
aStrains that were used in the htAFLP are indicated in bold. bThe marker numbers correspond with the marker numbers displayed in Table 3. For
each marker, the different RFLP types are indicated with numbers. 0 = single band (no restriction), – = no PCR product, nd = not determined.
MFS-associated isolate by htAFLP. Although we did not
detect GBS-specific bands, we found that the MFS-associated isolate and half of the enteritis-only strains contained
several additional fragments that appeared to be linked.
DNA sequences of these fragments showed homologies
with plasmidal DNA sequences, indicating that a subset of
the HS:41 strains contained a plasmid. To our knowledge,
the South African HS:41 strains we used in this study have
never been analyzed for the presence of plasmids.
Whether the presence of a plasmid is of importance for
the virulence or neuropathogenic potential of HS:41
strains currently remains unknown, but seems unlikely
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based on the distribution of plasmidal DNA in the tested
strains.
Conclusion
Previous searches for C. jejuni markers for GBS-invoking
potential were unsuccessful when performed with general
genotyping techniques. Some studies that focussed at specific loci or sometimes even specific genes found potential, though not absolute, GBS markers within the LOS
biosynthesis genes [19-22]. We have used a method,
htAFLP, that detects sequence polymorphisms in a wide,
non-gene dependent scale. Theoretically approximately
2% of the total genome is covered by this approach. However, we still conclude that bacterial GBS markers are not
absolute, limited in number and located in the LOS biosynthesis gene locus. This corroborates the current consensus that LOS mimicry with human gangliosides may
be the prime etiologic determinant of GBS. In addition to
bacterial factors, host-related factors probably play an
important role in the pathogenesis of GBS as well.
Furthermore, our results demonstrate that htAFLP, with
its high reproducibility and resolution, is an adequate
technique for the detection and subsequent identification
of putative disease and epidemiological markers. Analysis
of a limited number of strains in great detail by htAFLP
and subsequent screening of a large collection of strains
with simple PCR-RFLP tests combines high sensitivity
with the possibility to screen large groups of strains. This
allows for the identification of regions of genomic instability or variability. Finally, htAFLP does not require complete genome sequences and it is not influenced by the
presence of sequences not present in the genome strain(s).
As such, htAFLP is the second best option, after complete
sequencing of the genome of multiple strains, for the
unbiased detection of genome polymorphisms associated
with pathogenicity or other features of bacterial isolates
from diverse clinical and environmental origin.
Methods
Bacterial strains, culture conditions and DNA isolation
The C. jejuni strains used for htAFLP analysis are described
in Additional file 1. We collected 6 isolates of the
"genome" strain NCTC 11168 strains from different labs
worldwide [37]. For the detection of potential GBS markers, we included four C. jejuni strains isolated from the
diarrhoeal stools of GBS patients from different geographical areas (The Netherlands, Curaçao, South Africa). In
addition, we analyzed a collection of 6 GBS-associated, 1
MFS-associated and 6 enteritis-only HS:41 strains isolated
from South African patients [12]. After identification of
potential GBS markers by htAFLP analysis of these strains,
we screened a larger collection of 27 GBS/MFS-associated
and 17 control strains isolated from enteritis patients with
PCR-RFLP tests for the presence of these markers (See
http://www.biomedcentral.com/1471-2180/6/32
Additional file 1). C. jejuni strains were cultured for 24–48
hours on blood agar plates in a micro-aerobic atmosphere
at 37°C. DNA was isolated using the Wizard Genomic
DNA Purification Kit (Promega, Madison, WI).
High-throughput AFLP
AFLP analysis was performed essentially as described by
Vos et al. [38]. The optimal enzyme and primer combinations for C. jejuni were determined using the predictive
software package REcomb [39]. Digestion with MboI and
DdeI (Boehringer-Mannheim, Mannheim, Germany) was
combined with the ligation of a specific linker oligonucleotide pair (MboI: 5'-CTCGTAGACTGCGTACC-3' and 5'GATCGGTACGCAGTCTAC-3'; DdeI: 5'-GACGATGAGTCCTGAG-3' and 5'-TNACTCAGGACTCAT-3'). Subsequently, a non-selective pre-amplification was performed
using the MboI primer (5'-GTAGACTGCGTACCGATC-3')
and DdeI primer (5'-GACGATGAGTCCTGAGTNAG-3').
The selective amplifications were performed using different linker-specific primer combinations. The 33P-labeled
MboI primer was extended with a single nucleotide (+1),
whereas the DdeI primer was equipped with a 3' terminal
dinucleotide (+2). These nucleotides probe sequence variation beyond that present in the restriction site itself. All
64 possible extension combinations were used. Radioactive labelling was used to enable isolation of DNA fragments from gels for post-AFLP sequencing analysis.
Amplified material was analyzed on 50x30 cm slabgels
and the amplimers were visualized using phosphor-imaging. Post-AFLP, gels were fixed, dried and stored at ambient temperature.
Marker selection and identification
Marker bands were scored using the automated interpretation software package AFLP QuantarPro (Keygene NV,
Wageningen, The Netherlands), resulting in a binary table
scoring marker fragment absence (0) or presence (1). Polymorphic marker fragments were validated by visual
inspection of the autoradiographs. Bands differing in signal intensity were not considered to be polymorphic. A
potential marker for GBS was defined as an AFLP polymorphism that discerns the GBS-associated strains from
the NCTC 11168 isolates. Potential GBS marker fragments
can either be present or absent in GBS-associated strains
as compared to NCTC 11168.
Relevant fragments were excised from the gels and reamplified using their matching AFLP consensus primer set
without restriction site-specific +1 and +2 extension
sequences attached. The amplimers were subjected to
DNA sequencing using a 96-well capillary sequencing
machine (MegaBACE; Amersham). For fragment identification, the DNA sequences were subjected to BLASTn and
BLASTx searches through the NCBI website [40]. BLAST
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results enable genomic localization and gene annotation
for the polymorphic marker fragments.
PCR-RFLP polymerase chain reaction – restriction fragment length polymorphism
Development of PCR-RFLP tests
PCR-RFLP tests were developed to confirm polymorphism
in the different NCTC 11168 isolates and to screen a collection of C. jejuni GBS/MFS-associated and control
strains. PCR-RFLP tests could only be developed for the
markers of which the localization on the C. jejuni genome
was identified. Forward and reverse primers were
designed (Primer Designer 4, Sci Ed Software, North Carolina) and synthesized, located approximately 50–200 bp
upstream or downstream of the homologous region,
respectively (Table 2). Because of the wide range of melting temperatures (Tm) of the primers and the sometimes
considerable differences in Tm between primers within
one PCR reaction, a touch-down PCR approach was
applied. The program consisted of 15 cycles of 1 min
94°C, 1 min 70°C minus 1°C for each following cycle
(lowest temperature 55°C), 1 min 72°C, followed by 25
cycles of 0.5 min 94°C, 1 min Tm – 5°C and 1 min at
72°C. Tm – 5°C represents the lowest melting temperature of the two primers used in the reaction minus 5°C.
This resulted in the amplification of not only the AFLP
fragment itself, but also of their flanking sequences. Next,
15 µl of each PCR product was subjected to a separate or
combined digestion with the restriction enzymes (1 unit/
reaction) used for the AFLP (MboI and DdeI). After overnight incubation at 37°C, the digests were analyzed on
2% agarose gels. The PCR-RFLP analysis will reveal
whether or not the AFLP variability was due to variation
in the restriction sites (different RFLP patterns) or to insertions or deletions within the AFLP fragment (size differences in PCR products). AFLP variation due to differences
in the selective extension nucleotides of the AFLP primers
will not be detected using this approach.
PFGE pulsed field gel electrophoresis
Authors' contributions
PCRG analyzed and interpreted the data and drafted the
manuscript. MPB designed and carried out the PCR-RFLP
marker analysis. RFJG performed the htAFLP analysis and
DNA sequencing. GS participated in the design of the
study and htAFLP setup. NVDB collected the strains, performed DNA extractions and participated in the marker
identification. AJL provided the South African C. jejuni
strains and participated in the design of the study. HPE
participated in the design of the study and writing of the
manuscript. HAV participated in the design of the study.
AVB conceived and coordinated the study and participated in writing of the manuscript. All authors critically
read the manuscript and approved the final version.
Additional material
Additional file 1
C. jejuni strains used in this study Description of data: a summary of all
strains used in this study is given in this table, with strain numbers, associated disease, origin of the strain and technique(s) that were used to analyse the strains in this study.
Click here for file
[http://www.biomedcentral.com/content/supplementary/14712180-6-32-S1.doc]
Additional file 2
Primer sequences used in the PCR-RFLP analysis for the validation of
potential GBS markersDescription of data: (none, title sufficiently
describes data)
Click here for file
[http://www.biomedcentral.com/content/supplementary/14712180-6-32-S2.doc]
Abbreviations
AFLP amplified fragment length polymorphism
GBS Guillain-Barré syndrome
HS heat stable
htAFLP high-throughput AFLP
LOS lipo-oligosaccharide
MFS Miller Fisher syndrome
MLST multi locus sequence typing
ORF open reading frame
Acknowledgements
The research described in this communication has been supported by
grants provided by the Dutch Ministry of Economic Affairs (BTS 00145), the
Human Frontier Science Program (RPG 38/2003) to AVB and HPE and by
The Netherlands Organization for Scientific Research (920-03-225) to
P.C.R.G. A.J.L. is indebted to the South African Medical Research Council
and the University of Cape Town for financial support. AFLP is a registered
trademark of Keygene NV and the AFLP technology is covered by patents
(US006045994A, EP0534858B1) and patent applications owned by Keygene
NV.
References
1.
2.
3.
Fisher M: An unusual variant of acute idiopathic polyneuritis:
syndrome of ophthalmoplegia, ataxia and areflexia. N Engl J
Med 1956, 255:57-65.
Yuki N: Infectious origins of, and molecular mimicry in, Guillain-Barré and Fisher syndromes. Lancet Infect Dis 2001, 1:29-37.
Jacobs BC, Rothbarth PH, van der Meché FGA, Herbrink P, Schmitz
PIM, De Klerk MA, van Doorn PA: The spectrum of antecedent
Page 11 of 13
(page number not for citation purposes)
BMC Microbiology 2006, 6:32
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
infections in Guillain-Barré syndrome: a case-control study.
Neurology 1998, 51:1110-1115.
Winer JB, Hughes RAC, Anderson MJ, Jones DM, Kangro H, Watkins
RP: A prospective study of acute idiopathic neuropathy. II.
Antecedent events.
J Neurol Neurosurg Psychiatry 1988,
51:613-618.
Nachamkin I: Chronic effects of Campylobacter infection.
Microbes Infect 2002, 4:399-403.
Prendergast MM, Moran AP: Lipopolysaccharides in the development of the Guillain-Barré syndrome and Miller Fisher syndrome forms of acute inflammatory peripheral
neuropathies. J Endotoxin Res 2000, 6:341-359.
McCarthy N, Giesecke J: Incidence of Guillain-Barré syndrome
following infection with Campylobacter jejuni. Am J Epidemiol
2001, 153:610-614.
Mishu Allos B: Association between Campylobacter infection
and Guillain-Barré syndrome. J Infect Dis 1997, 176:S125-128.
Kuroki S, Saida T, Nukina M, Haruta T, Yoshioka M, Kobayashi Y,
Nakanishi H: Campylobacter jejuni strains from patients with
Guillain-Barré syndrome belong mostly to Penner serogroup 19 and contain beta-N-acetylglucosamine residues.
Ann Neurol 1993, 33:243-247.
Lastovica AJ, Goddard EA, Argent AC: Guillain-Barré syndrome
in South Africa associated with Campylobacter jejuni O:41
strains. J Infect Dis 1997, 176:S139-143.
Nachamkin I, Engberg J, Gutacker M, Meinersman RJ, Li CY, Arzate P,
Teeple E, Fussing V, Ho TW, Asbury AK, Griffin JW, McKhann GM,
Piffaretti JC: Molecular population genetic analysis of Campylobacter jejuni HS:19 associated with Guillain-Barre syndrome and gastroenteritis. J Infect Dis 2001, 184:221-226.
Wassenaar TM, Fry BN, Lastovica AJ, Wagenaar JA, Coloe PJ, Duim
B: Genetic characterization of Campylobacter jejuni O:41
isolates in relation with Guillain-Barré syndrome. J Clin Microbiol 2000, 38:874-876.
Karlyshev AV, Linton D, Gregson NA, Lastovica AJ, Wren BW:
Genetic and biochemical evidence of a Campylobacter jejuni
capsular polysaccharide that accounts for Penner serotype
specificity. Mol Microbiol 2000, 35:529-541.
Endtz HP, Ang CW, van den Braak N, Duim B, Rigter A, Price LJ,
Woodward DL, Rodgers FG, Johnson WM, Wagenaar JA, Jacobs BC,
Verbrugh HA, van Belkum A: Molecular characterization of
Campylobacter jejuni from patients with Guillain-Barré and
Miller Fisher syndromes. J Clin Microbiol 2000, 38:2297-2301.
Dingle KE, van den Braak N, Colles FM, Price LJ, Woodward DL,
Rodgers FG, Endtz HP, van Belkum A, Maiden MCJ: Sequence typing confirms that Campylobacter jejuni strains associated
with Guillain-Barré and Miller Fisher syndromes are of
diverse genetic lineage, serotype and flagella type. J Clin Microbiol 2001, 39:3346-3349.
Engberg J, Nachamkin I, Fussing V, McKhann GM, Griffin JW, Piffaretti
JC, Nielsen EM, Gerner-Smidt P: Absence of clonality of Campylobacter jejuni in serotypes other than HS:19 associated with
Guillain-Barré syndrome and gastroenteritis. J Infect Dis 2001,
184:215-220.
Fujimoto S, Allos BM, Misawa N, Patton CM, Blaser MJ: Restriction
fragment length polymorphism analysis and random amplified polymorphic DNA analysis of Campylobacter jejuni
strains isolated from patients with Guillain-Barré syndrome.
J Infect Dis 1997, 176:1105-1108.
Leonard EEII, Tompkins LS, Falkow S, Nachamkin I: Comparison of
Campylobacter jejuni isolates implicated in Guillain-Barré
syndrome and strains that cause enteritis by a DNA microarray. Infect Immun 2004, 72:1199-1203.
van Belkum A, van den Braak N, Godschalk P, Ang W, Jacobs B, Gilbert M, Wakarchuk W, Verbrugh H, Endtz H: A Campylobacter
jejuni gene associated with immune-mediated neuropathy.
Nat Med 2001, 7:752-753.
Nachamkin I, Liu J, Li M, Ung H, Moran AP, Prendergast MM, Sheikh
K: Campylobacter jejuni from patients with Guillain-Barré
syndrome preferentially expresses a GD1a-like epitope.
Infect Immun 2002, 70:5299-5303.
Godschalk PCR, Heikema AP, Gilbert M, Komagamine T, Ang CW,
Glerum J, Brochu D, Li J, Yuki N, Jacobs BC, van Belkum A, Endtz HP:
The crucial role of Campylobacter jejuni genes in anti-ganglioside antibody induction in Guillain-Barré syndrome. J Clin
Invest 2004, 114:1659-1665.
http://www.biomedcentral.com/1471-2180/6/32
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
Koga M, Takahashi M, Masuda M, Hirata K, Yuki N: Campylobacter
gene polymorphism as a determinant of clinical features of
Guillain-Barré syndrome. Neurology 2005, 65:1376-1381.
Dingle KE, Colles FM, Wareing DRA, Ure R, Fox AJ, Bolton FE,
Bootsma HJ, Willems RJL, Urwin R, Maiden MCJ: Multilocus
sequence typing system for Campylobacter jejuni. J Clin Microbiol 2001, 39:14-23.
Ayling RD, Woodward MJ, Evans S, Newell DG: Restriction fragment length polymorphism of polymerase chain reaction
products applied to the differentiation of poultry Campylobacters for epidemiological investigations. Res Vet Sci 1996,
60:168-172.
Duim B, Wassenaar TM, Rigter A, Wagenaar J: High-resolution
genotyping of Campylobacter strains isolated from poultry
and humans with amplified fragment length polymorphism
fingerprinting. Appl Environ Microbiol 1999, 65:2369-2375.
van den Braak N, Simons G, Gorkink R, Reijans M, Eadie K, Kremers
K, van Soolingen D, Savelkoul P, Verbrugh H, van Belkum A: A new
high-throughput AFLP approach for identification of new
genetic polymorphism in the genome of the clonal microorganism Mycobacterium tuberculosis. J Microbiol Methods 2004,
56:49-62.
Duim B, Ang CW, Van Belkum A, Rigter A, Van Leeuwen NW, Endtz
HP, Wagenaar JA: Amplified fragment length polymorphism
analysis of Campylobacter jejuni strains isolated from chickens and from patients with gastroenteritis or Guillain-Barré
or Miller Fisher syndrome.
Appl Environ Microbiol 2000,
66:3917-3923.
Melles DC, Gorkink RFJ, Boelens HAM, Snijders SV, Peeters JK,
Moorhouse MJ, van der Spek PJ, van Leeuwen WB, Simons G, Verbrugh HA, van Belkum A: Natural population dynamics and
expansion of pathogenic clones of Staphylococcus aureus. J
Clin Invest 2004, 114:1732-1740.
Patton CM, Wachsmuth IK, Evins GM, Kiehlbauch JA, Plikaytis BD,
Troup N, Tompkins L, Lior H: Evaluation of 10 methods to distinguish epidemic-associated Campylobacter strains. J Clin
Microbiol 1991, 29:680-688.
Carrillo CD, Taboada E, Nash JHE, Lanthier P, Kelly J, Lau PC, Verhulp
R, Mykytczuk O, Sy J, Findlay WA, Amoako K, Gomis S, Willson P,
Austin JW, Potter A, Babiuk L, Allan B, Szymanski CM: Genomewide expression analyses of Campylobacter jejuni
NCTC11168 reveals coordinate regulation of motility and
virulence by flhA. J Biol Chem 2004, 279:20327-20338.
Gaynor EC, Cawthraw S, Manning G, MacKichan JK, Falkow S, Newell
DG: The genome-sequenced variant of Campylobacter jejuni
NCTC 11168 and the original clonal clinical isolate differ
markedly in colonization, gene expression, and virulenceassociated phenotypes. J Bacteriol 2004, 186:503-517.
Gilbert M, Godschalk PCR, Karwaski MF, Ang CW, van Belkum A, Li
J, Wakarchuk WW, Endtz HP: Evidence for acquisition of the
lipooligosaccharide biosynthesis locus in Campylobacter
jejuni GB11, a strain isolated from a patient with GuillainBarré syndrome, by horizontal exchange. Infect Immun 2004,
72:1162-1165.
van der Meché FGA, Visser LH, Jacobs BC, Endtz HP, Meulstee J, Van
Doorn PA: Guillain-Barré syndrome: multifactorial mechanisms versus defined subgroups. J Infect Dis 1997, 176:S99-102.
Chiba A, Kusunoki S, Obata H, Machinami R, Kanazawa I: Serum
anti-GQ1b IgG antibody is associated with ophthalmoplegia
in Miller Fisher syndrome and Guillain-Barré syndrome: clinical and immunohistochemical studies.
Neurology 1993,
43:1911-1917.
Jacobs BC, Van Doorn PA, Schmitz PIM, Tio-Gillen AP, Herbrink P,
Visser LH, Hooijkaas H, Van der Meché FGA: Campylobacter
jejuni infections and anti-GM1 antibodies in Guillain-Barré
syndrome. Ann Neurol 1996, 40:181-187.
Ang CW, Laman JD, Willison HJ, Wagner ER, Endtz HP, de Klerk MA,
Tio-Gillen AP, van den Braak N, Jacobs BC, van Doorn PA: Structure of Campylobacter jejuni lipopolysaccharides determines antiganglioside specificity and clinical features of
Guillain-Barré and Miller Fisher patients. Infect Immun 2002,
70:1202-1208.
Parkhill J, Wren BW, Mungall K, Ketley JM, Churcher C, Basham D,
Chillingworth T, Davies RM, Feltwell T, Holroyd S, Jagels K, Karlyshev
AV, Moule S, Pallen MJ, Penn CW, Quail MA, Rajandream MA,
Rutherford KM, van Vliet AH, Whitehead S, Barrell BG: The
Page 12 of 13
(page number not for citation purposes)
BMC Microbiology 2006, 6:32
38.
39.
40.
http://www.biomedcentral.com/1471-2180/6/32
genome sequence of the food-borne pathogen Campylobacter jejuni reveals hypervariable sequences. Nature 2000,
403:665-668.
Vos P, Hogers R, Bleeker M, Reijans M, van de Lee T, Hornes M, Frijters A, Pot J, Peleman J, Kuiper M, et al.: AFLP: a new technique
for DNA fingerprinting. Nucleic Acids Res 1995, 23:4407-4414.
Reijans M, Lascaris R, Groeneger AO, Wittenberg A, Wesselink E,
van Oeveren J, Wit E, Boorsma A, Voetdijk B, van der Spek H: Quantitative comparison of cDNA-AFLP, microarrays, and genechip expression data in Saccharomyces cerevisiae. Genomics
2003, 82:606-618.
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