Previous Article | Next Article 
Journal of Clinical Microbiology, December 1999, p. 3883-3887, Vol. 37, No. 12
0095-1137/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.
Multilocus Sequence Typing and Antigen Gene
Sequencing in the Investigation of a Meningococcal Disease
Outbreak
Ian M.
Feavers,1
Stephen J.
Gray,2
Rachel
Urwin,3
Joanne E.
Russell,1,3
Jane A.
Bygraves,1
Edward B.
Kaczmarski,2 and
Martin
C. J.
Maiden3,*
Division of Bacteriology, National Institute
for Biological Standards and Control, South Mimms, Potters Bar,
Hertfordshire EN6 3QG,1 Wellcome Trust
Centre for the Epidemiology of Infectious Disease, Department of
Zoology, University of Oxford, Oxford OX1 3PS,3
and Public Health Laboratory, Withington Hospital,
Manchester M20 2LR,2 United Kingdom
Received 17 March 1999/Returned for modification 22 April
1999/Accepted 26 August 1999
 |
ABSTRACT |
Multilocus sequence typing and antigen gene sequencing were used to
investigate an outbreak of meningococcal disease in a university in the
United Kingdom. The data obtained showed that five distinct
Neisseria meningitidis strains belonging to the ET-37
complex were present in the student population during the outbreak.
Three of these strains were not associated with invasive disease, and
two distinct strains caused invasive disease, including several
fatalities. The initial case of the disease cluster was caused by a
strain distinct from that responsible for at least two subsequent cases
and two cases remote from the university, which were epidemiologically
linked to the outbreak. These observations were consistent with
pulsed-field gel electrophoresis data, but the sequence data alone were
sufficient to resolve the strains involved in the disease cluster.
Interpretation of the nucleotide sequence data was more straightforward
than interpretation of the fingerprint patterns, and the sequence data
provided information on the genetic differences among the isolates.
 |
INTRODUCTION |
Management of meningococcal disease
outbreaks is complicated by their unpredictability, the rapidity and
severity of the disease, and the resulting public anxiety
(4). In Europe and North America, most pathological
infections with Neisseria meningitidis are sporadic, endemic
cases among infants. Disease clusters also occur, and these often
affect teenagers and young adults attending schools, universities, or
other institutions. Timely and accurate isolate characterization is
essential to distinguish genuine disease outbreaks, comprising related
cases with a common epidemiological source, from clusters of temporally
and geographically proximate but unrelated cases. Although
identification of the serogroup of the outbreak strain is essential,
given the availability of vaccines against some, but not all, capsular
polysaccharides, serogrouping alone is not sufficient for outbreak
identification. Serotyping and serosubtyping (9), based on
subcapsular protein antigens, are also inadequate for this purpose,
particularly for serogroup B and C meningococci, which are responsible
for the majority of infections: an increasing proportion of isolates
are reported as not typeable (NT) or not subtypeable (12, 14,
15).
Disease outbreaks in educational and military institutions are often
caused by meningococci belonging to the electrophoretic type 37 (ET-37) complex (25, 26). The ET-37 complex, in common with other hypervirulent lineages of meningococci, was first identified by multilocus enzyme electrophoresis (5, 17, 19), a
technique unsuited to rapid outbreak investigation. Multilocus sequence typing (MLST), which is similar in concept to multilocus enzyme electrophoresis but which uses nucleotide sequence determination to
identify alleles of housekeeping genes, can rapidly identify hypervirulent meningococci (13). This report describes the
use of MLST (10, 13) and antigen gene sequencing (8,
16) in the investigation of a meningococcal disease cluster at a
British university (27).
 |
MATERIALS AND METHODS |
Nucleotide sequence determination.
Chromosomal DNA was
extracted from meningococcal cells grown as described previously
(8) by the Isoquick DNA extraction procedure (Orca
Research). Amplification and sequencing of the MLST genes were as
described previously (13), with the addition of primers for
amplification (primer fumC-A1 [5'-CAC CGA ACA CGA CAC GAT
GG-3'] and primer fumC-A2 [5'-ACG ACC AGT TCG TCA AAC TC-3']) and sequencing (primer fumC-S1 [5'-TCG GCA CGG GTT
TGA ACA GC-3'] and primer fumC-S2 [5'-CAA CGG CGG TTT CGC
GCA AC-3']) of the fumC gene. Amplification and sequencing
of the porA and porB genes were as described
previously (21, 24). Sequencing of the tbpB gene
was as described previously (18). Sequencing reactions were
performed with Big Dye terminators (PE Biosystems), and the products
were separated and detected with an Applied Biosystems Prism 377 automated sequencer. The sequences were assembled with the sequence
analysis package of Staden (20).
PFGE fingerprinting.
Approximately 10 N. meningitidis colonies, grown overnight on Columbia agar (Oxoid
Ltd.) supplemented with 5% horse blood in a atmosphere of 5%
CO2, were suspended in 150 µl of cell suspension buffer
(20 mM sodium chloride, 50 mM EDTA, 10 mM Tris-Cl [pH 7.2]). The
suspension was mixed with 150 µl of 2.0% agarose for pulsed-field gel electrophoresis (PFGE) plugs (Sigma) at 50°C, and the mixture was
immediately dispensed in two PFGE plug molds (Bio-Rad). Once set, the
plugs were expelled into 1 ml of lysis buffer (1 mg of lysozyme per ml,
50 mM sodium chloride, 0.2% sodium deoxycholate, 0.5% sodium lauryl
sarcosine, 10 mM Tris-Cl [pH 7.2]) and were incubated at 37°C
overnight. The plugs were washed three times for 30 min each time with
2 ml of TE buffer (50 mM EDTA, 20 mM Tris-Cl [pH 8.0]) at room
temperature and were then digested overnight at 55°C in 1 ml of
proteinase K reaction buffer (1 mg of proteinase K per ml, 0.2% sodium
deoxycholate, 1% sodium lauryl sarcosine, 100 mM EDTA [pH 8.0]).
Finally, the plugs were washed three times with TE buffer.
The plugs were cut into pieces that were washed once in 0.1 × TE
buffer for 1 h and were equilibrated for
3 h in 300 µl of the
appropriate enzyme-specific restriction buffer (New England Biolabs).
The buffer was replaced, and approximately 10 U of the appropriate
restriction endonuclease (SpeI, NheI, or
SfiI) (New England Biolabs) plus 0.1% acetylated bovine
serum albumin (New England Biolabs) was added. After overnight
incubation at the temperature recommended for the enzyme by the
manufacturer, restriction digestion was stopped by replacing the
reaction buffer with TE buffer. The digestion products were separated
with a Genepath System (Bio-Rad) operated in accordance with the
manufacturer's instructions. Program 13, for the separation of
fragments of 25 to 400 kb, was used for all endonuclease digestion
products. The gels were stained with 0.5 mg of ethidium bromide (Sigma)
per ml, visualized with UV illumination, and photographed with a
digital camera. Experiments with several replicate gels were performed for each restriction endonuclease.
Nucleotide sequence accession numbers.
The sequences of the
tbpB alleles from the ET-37 complex isolate, strain 1, and
strain 2 and from strains 3, 4, and 5 have been given GenBank accession
no. AJ250244 and AJ250243, respectively.
 |
RESULTS |
Epidemiology.
During 19 days there were six
university-associated cases of meningococcal disease with three deaths.
Case 1 occurred 2 weeks before cases 2 to 6, which were diagnosed over
5 days, and cases 1 to 5 involved students from the same accommodation
complex. Serogroup C meningococci were isolated from cases 1, 3, and 6; cases 2 and 5 were confirmed as having serogroup C meningococcal infections by PCR (2); and case 4 was diagnosed solely on
clinical grounds. Two patients from other towns (remote cases 1 and 2) were epidemiologically suspected as being part of the outbreak. During
outbreak investigation and control, 587 students were examined for
meningococcal carriage: 147 meningococci were isolated, and 6 of these
were serogroup C.
MLST.
All of the isolates from cases and five of the six
isolates from carriers were shown by MLST analysis to belong to the
ET-37 complex, but the isolates were not identical. Those from case 1, carrier 1, and carrier 2 were sequence type (ST)-11, which had
previously been reported to be characteristic of ET-37 complex isolates
(13). The other isolates from cases, including those from
the remote cases, were ST-50 (differentiated from ST-11 by the
aroE locus), two isolates from carriers (carriers 4 and 5) were ST-51 (which differed from ST-11 at the fumC and
pdhC loci), and the isolate from carrier 3 was ST-52 (which
varied from ST-11 at the abcZ locus) (Table
1 and Table
2).
Antigen gene sequences.
Further discrimination among the
isolates was apparent from the nucleotide sequences of the entire
porB gene, which encodes the serotyping antigen, and the
variable regions (VRs) of the porA gene, which determine
meningococcal serosubtype (Table 2). This confirmed that the isolate
from case 1 was distinct from the isolates from the other cases and
showed that while it was identical to the isolate from carrier 1 (strain 1), it was distinct from the isolate from carrier 2 (strain 3).
The strain isolated from the two remaining university-associated cases
(cases 3 and 6) and the two remote patients (strain 2), which was
ST-50, was also characterized by distinct porA and
porB genes. While this strain possessed the same
porA VRs as a previously characterized ET-37 complex isolate
from the United Kingdom (Table 1), it was distinguishable by its ST and
porB allele. The remaining isolates from carriers (strain 4 and strain 5), which were indistinguishable from each other, were also
distinct on the basis of their antigen genes (Table 2). The ET-37
complex isolate and the strain 1 and strain 2 isolates possessed
identical tbpB alleles (numbered 2 in Table 2; GenBank
accession no. AJ250244), which was distinct from the tbpB
allele (numbered 1 in Table 2; GenBank accession no. AJ250243) shared
by the remaining isolates (strains 3, 4, and 5).
PFGE fingerprinting.
The 11 isolates examined gave related
fingerprint patterns with each of the three endonucleases that were
used in the present study and that have previously been shown to
identify relationships among meningococci (3). The isolates
from case 1 and carrier 1 (Strain 1) were indistinguishable from each
other. Their NheI fingerprint patterns were also observed
for the other ST-11 isolate (strain 3 from carrier 2; Fig.
1A), which was distinguished from them by
distinct SpeI and SfiI fingerprints (Fig. 1B and
C). They also had SpeI fingerprint patterns identical to
those of three of the strain 2 isolates (from case 6, remote case 1, and remote case 2; Fig. 1C) but were distinguished from these isolates
by their NheI and SfiI fingerprints. These three
strain 2 isolates had identical fingerprint patterns, but the remaining
strain 2 isolate (from patient 3) differed from them by two bands for
each fingerprint. All three fingerprints for the strain 4 isolate (from carrier 3) were unique. For all endonuclease fingerprints, the isolates
from carrier 4 and carrier 5 (strain 5) were identical and unique to
these two isolates.

View larger version (56K):
[in this window]
[in a new window]
|
FIG. 1.
PFGE fingerprint analysis of the isolates. Isolates are
identified by the same labelling as in Table 1 (except for "R.
Case," which stands for "remote case"). Standards were phage
lambda concatamers. (A) Fingerprints generated with restriction
endonuclease NheI; (B) fingerprints generated with
restriction endonuclease SfiI; (C) fingerprints generated
with restriction endonuclease SpeI. The results shown in
each panel are from the same gel, and the lanes appear in the same
order as on the original gel with the exception of those for remote
case 2 (R. Case 2), which were moved from a position adjacent to the
right-hand standard track for ease of comparison. To account for higher
sample loading, the photographic contrast of the first two sample lanes
of panel C (ET-37 isolate and Case 1) was adjusted independently of
that for the rest of the gel in the preparation of this figure.
|
|
 |
DISCUSSION |
The data obtained in the present study indicated that an ET-37
complex variant, strain 1 (Table 2), was responsible for at least four
cases of meningococcal disease suspected as being part of an outbreak.
Although samples from the three cases for which no meningococci were
isolated (cases 2, 4, and 5) were not available for MLST in this
particular outbreak investigation, two of these cases were shown to be
serogroup C by a PCR assay (2). Given their temporal and
geographic proximity to cases 3 and 6, it is likely, although not
proven, that strain 2 was the causative organism of these cases. As
MLST and antigen gene sequencing are PCR-based techniques, they can
potentially be applied directly to culture-negative clinical specimens
in future studies. The sequence data further demonstrated that while
the disease in case 1 was also caused by an ET-37 complex variant, it
was not part of the outbreak and that, with the exception of carrier 1, a close contact of case 1, neither of the disease-causing strains was
recovered from carriers. Finally, these sequence data showed that three
distinct ET-37 complex strains (strains 3 to 5) were circulating among
the student population during the outbreak without causing disease.
The sequence data provided resolution similar to that observed by PFGE
fingerprinting, but the data were more readily interpreted and were
easily compared with data obtained in other studies. The single anomaly
between the sequence data and the PFGE fingerprints was the different
patterns observed with one of the strain 2 isolates (from case 3) and
the remaining isolates. The two band differences seen in each PFGE
fingerprint might have been the result of a chromosome rearrangement,
which would have the effect of changing several fingerprint patterns
while the strain retained its ST and antigen genes. Chromosome
rearrangements are known within the pathogenic Neisseria
(6) and have been observed among ET-37 complex variants
(11); such rearrangements have a potentially confusing
effect on the interpretation of PFGE fingerprint data.
An advantage of sequence-based isolate characterization is the
identification of genetic variation among isolates, which is not
possible in PFGE fingerprint analyses, from which the genetic reasons
for pattern changes cannot be easily deduced without additional data.
Three of the housekeeping gene changes among the STs, those in
abcZ, aroE, and pdhC, were likely to
have resulted from horizontal genetic exchange (Fig.
2). A single nucleotide change in the
fumC allele that distinguished ST-51 from the other STs
could have been a point mutational change; however, as this
polymorphism is present in other fumC alleles, it is
possible that this change was also due to a genetic exchange event.

View larger version (21K):
[in this window]
[in a new window]
|
FIG. 2.
Polymorphic sites present in the genes analyzed. For
each of the sequence types, the variant bases of the variant MLST loci
compared to the sequence of the allele present in ST-11 are shown. The
vertical numbers represent the base position within the MLST allele.
For the porA genes, the entire sequence for VR1 and VR2 are
given and their sequences are compared to the sequences defining
serotype P1.5,2. The variant nucleotides of the five porB
alleles compared with the sequence of porB2-2 are given, and
the vertical numbers indicate the base position in an alignment of all
known porB alleles. Allele porB2-39 was
distinguished from allele porB2 by a four-codon deletion
(data not shown) at base positions 604 to 615 inclusive. In all cases a
base identical to that of the first sequence is shown with a period, a
polymorphism is shown with the appropriate letter, and an alignment gap
is shown with a hyphen.
|
|
Two of the porB polymorphisms, those distinguishing
porB2-36 and porB2-38 from porB2-2,
were unlikely to have changed the immunogenicity of the encoded
proteins, and strains 1 and 5 serotyped as 2a. The porB2-39
allele in the NT isolate from carrier 2 (strain 3) was identical to the
porB2-2 allele except for a 12-bp deletion in predicted loop
V of the protein (7). The other porB variant from
an NT isolate, porB2-37, was a distinct allele that had
probably been introduced by horizontal genetic exchange. Among the
strains that were not subtypeable, the porA gene of strain 1 had been inactivated by an IS1301 insertion (1),
and no porA gene could be amplified from strain 4, indicating that porA may have been deleted in this
meningococcus. The porA allele conferring the P1.19d,15
subtype on strain 5 was probably the result of a horizontal genetic
exchange event, and the differences between the P1.5a,10- and
P1.5,2-encoding alleles may have been the result of the accumulation of
point mutations within the ET-37 complex over time. The tbpB alleles were sufficiently diverse that it is probable that this also
represented a horizontal genetic exchange event.
These results demonstrated that MLST and antigen gene sequencing can
provide high-resolution data applicable to epidemiological investigations of meningococcal disease outbreaks. In addition to
identifying strains belonging to the hypervirulent ET-37 complex, these
approaches distinguished strains identical by serological means or
antigen gene sequencing (Table 2), and the data obtained by these
approaches were more easily analyzed than PFGE fingerprint patterns
(Fig. 1). Furthermore, it is not necessary that sequence analyses be
performed simultaneously, and the sequence analyses of the housekeeping
and antigen genes can be performed sequentially as clinical specimens
become available. A final advantage is that the PCR sequencing-based
approaches have potential application when no isolate is available,
which is not possible for many approaches including PFGE fingerprint analysis.
 |
FOOTNOTES |
*
Corresponding author. Mailing address: Wellcome Trust
Centre for the Epidemiology of Infectious Disease, Department of
Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, United Kingdom. Phone and fax: 44 1865 271284. E-mail:
martin.maiden{at}zoo.ox.ac.uk.
 |
REFERENCES |
| 1.
|
Arhin, F. F.,
F. Moreau,
J. W. Coulton, and E. L. Mills.
1998.
Sequencing of porA from clinical isolates of Neisseria meningitidis defines a subtyping scheme and its genetic regulation.
Can. J. Microbiol.
44:56-63[Medline].
|
| 2.
|
Borrow, R.,
H. Claus,
M. Guiver,
L. Smart,
D. M. Jones,
E. B. Kaczmarski,
M. Frosch, and A. J. Fox.
1997.
Non-culture diagnosis and serogroup determination of meningococcal B and C infection by a sialyltransferase (siaD) PCR ELISA.
Epidemiol. Infect.
118:111-117[Medline].
|
| 3.
|
Bygraves, J. A., and M. C. J. Maiden.
1992.
Analysis of the clonal relationships between strains of Neisseria meningitidis by pulsed field gel electrophoresis.
J. Gen. Microbiol.
138:523-531[Abstract/Free Full Text].
|
| 4.
|
Cartwright, K. A. V. (ed.).
1995.
Meningococcal disease.
John Wiley & Sons, Chichester, United Kingdom.
|
| 5.
|
Caugant, D. A.,
L. F. Mocca,
C. E. Frasch,
L. O. Froholm,
W. D. Zollinger, and R. K. Selander.
1987.
Genetic structure of Neisseria meningitidis populations in relation to serogroup, serotype, and outer membrane protein pattern.
J. Bacteriol.
169:2781-2792[Abstract/Free Full Text].
|
| 5a.
| Chan, M.-S. 1998, posting date. MLST Website.
[Online.] http://mlst.zoo.ox.ac.uk [6 October 1999, last date
accessed.]
|
| 6.
|
Dempsey, J. A.,
A. B. Wallace, and J. G. Cannon.
1995.
The physical map of the chromosome of a serogroup A strain of Neisseria meningitidis shows complex rearrangements relative to the chromosome of the two mapped strains of the closely related species N. gonorrhoeae.
J. Bacteriol.
177:6390-6400[Abstract/Free Full Text].
|
| 7.
|
Derrick, J. P.,
R. Urwin,
J. Suker,
I. M. Feavers, and M. C. J. Maiden.
1999.
Structural and evolutionary inference from molecular variation in Neisseria porins.
Infect. Immun.
67:2406-2413[Abstract/Free Full Text].
|
| 8.
|
Feavers, I. M.,
J. Suker,
A. J. McKenna,
A. B. Heath, and M. C. J. Maiden.
1992.
Molecular analysis of the serotyping antigens of Neisseria meningitidis.
Infect. Immun.
60:3620-3629[Abstract/Free Full Text].
|
| 9.
|
Frasch, C. E.,
W. D. Zollinger, and J. T. Poolman.
1985.
Serotype antigens of Neisseria meningitidis and a proposed scheme for designation of serotypes.
Rev. Infect. Dis.
7:504-510[Medline].
|
| 10.
|
Holmes, E. C.,
R. Urwin, and M. C. J. Maiden.
1999.
The influence of recombination on the population structure and evolution of the human pathogen Neisseria meningitidis.
Mol. Biol. Evol.
16:741-749[Abstract].
|
| 11.
|
Jelfs, J.,
R. Munro,
F. Ashton,
W. Rawlinson, and D. A. Caugant.
1998.
Global study of variation in a new variant of the ET-37 complex of Neisseria meningitidis, p. 5.
In
Proceedings of the Eleventh Pathogenic Neisseria Conference. Editions E.D.K., Paris, France.
|
| 12.
|
Maiden, M. C. J.
1998.
The impact of molecular techniques on the study of meningococcal disease, p. 265-291.
In
N. Woodford, and A. P. Johnson (ed.), Molecular bacteriology: protocols and clinical applications. Humana Press, Totowa, N.J.
|
| 13.
|
Maiden, M. C. J.,
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].
|
| 14.
|
Maiden, M. C. J., and I. M. Feavers.
1994.
Meningococcal typing.
J. Med. Microbiol.
40:157-158[Free Full Text].
|
| 15.
|
Maiden, M. C. J., and I. M. Feavers.
1995.
Population genetics and global epidemiology of the human pathogen Neisseria meningitidis, p. 269-293.
In
S. Baumberg, J. P. W. Young, E. M. H. Wellington, and J. R. Saunders (ed.), Population genetics of bacteria. Cambridge University Press, Cambridge, United Kingdom.
|
| 16.
|
Maiden, M. C. J.,
J. Suker,
A. J. McKenna,
J. A. Bygraves, and I. M. Feavers.
1991.
Comparison of the class 1 outer membrane proteins of eight serological reference strains of Neisseria meningitidis.
Mol. Microbiol.
5:727-736[Medline].
|
| 17.
|
Olyhoek, T.,
B. A. Crowe, and M. Achtman.
1987.
Clonal population structure of Neisseria meningitidis serogroup A isolated from epidemics and pandemics between 1915 and 1983.
Rev. Infect. Dis.
9:665-682[Medline].
|
| 18.
|
Rokbi, B.,
M. Mignon,
D. A. Caugant, and M. J. Quentin-Millet.
1997.
Heterogeneity of tbpB, the transferrin-binding protein B gene, among serogroup B Neisseria meningitidis strains of the ET-5 complex.
Clin. Diagn. Lab. Immunol.
4:522-529[Abstract].
|
| 19.
|
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.
51:837-884.
|
| 20.
|
Staden, R.
1996.
The Staden sequence analysis package.
Mol. Biotechnol.
5:233-241[Medline].
|
| 21.
|
Suker, J.,
I. M. Feavers,
M. Achtman,
G. Morelli,
J.-F. Wang, and M. C. J. Maiden.
1994.
The porA gene in serogroup A meningococci: evolutionary stability and mechanism of genetic variation.
Mol. Microbiol.
12:253-265[Medline].
|
| 22.
|
Suker, J.,
I. M. Feavers, and M. C. J. Maiden.
1996.
Monoclonal antibody recognition of members of the P1.10 variable region family: implications for serological typing and vaccine design.
Microbiology
142:63-69[Abstract/Free Full Text].
|
| 23.
|
Urwin, R.
1998.
Ph.D. thesis.
University of Staffordshire, Stoke-on-Trent, United Kingdom.
|
| 24.
|
Urwin, R.,
I. M. Feavers,
D. M. Jones,
M. C. J. Maiden, and A. J. Fox.
1998.
Molecular variation of meningococcal serotype 4 antigen genes.
Epidemiol. Infect.
121:95-101[Medline].
|
| 25.
|
Vogel, U.,
G. Morelli,
K. Zurth,
H. Claus,
E. Kriener,
M. Achtman, and M. Frosch.
1998.
Necessity of molecular techniques to distinguish between Neisseria meningitidis strains isolated from patients with meningococcal disease and from their healthy contacts.
J. Clin. Microbiol.
36:2465-2470[Abstract/Free Full Text].
|
| 26.
|
Wang, J.-F.,
D. A. Caugant,
G. Morelli,
B. Koumaré, and M. Achtman.
1993.
Antigenic and epidemiological properties of the ET-37 complex of Neisseria meningitidis.
J. Infect. Dis.
167:1320-1329[Medline].
|
| 27.
|
Williams, J. N.,
G. R. Jones,
M. Christodoulides,
K. Jolley, and J. E. Heckels.
1998.
Investigation into an outbreak of meningococcal infection at Southampton University, p. 254.
In
Proceedings of the Eleventh International Pathogenic Neisseria Conference Editions E.D.K., Paris, France.
|
Journal of Clinical Microbiology, December 1999, p. 3883-3887, Vol. 37, No. 12
0095-1137/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.
This article has been cited by other articles:
-
Didelot, X., Urwin, R., Maiden, M. C. J., Falush, D.
(2009). Genealogical typing of Neisseria meningitidis. Microbiology
155: 3176-3186
[Abstract]
[Full Text]
-
Russell, J. E., Urwin, R., Gray, S. J., Fox, A. J., Feavers, I. M., Maiden, M. C. J.
(2008). Molecular epidemiology of meningococcal disease in England and Wales 1975-1995, before the introduction of serogroup C conjugate vaccines. Microbiology
154: 1170-1177
[Abstract]
[Full Text]
-
Lau, S. H., Reddy, S., Cheesbrough, J., Bolton, F. J., Willshaw, G., Cheasty, T., Fox, A. J., Upton, M.
(2008). Major Uropathogenic Escherichia coli Strain Isolated in the Northwest of England Identified by Multilocus Sequence Typing. J. Clin. Microbiol.
46: 1076-1080
[Abstract]
[Full Text]
-
Honisch, C., Chen, Y., Mortimer, C., Arnold, C., Schmidt, O., van den Boom, D., Cantor, C. R., Shah, H. N., Gharbia, S. E.
(2007). Automated comparative sequence analysis by base-specific cleavage and mass spectrometry for nucleic acid-based microbial typing. Proc. Natl. Acad. Sci. USA
104: 10649-10654
[Abstract]
[Full Text]
-
Chen, Y., Zhang, W., Knabel, S. J.
(2007). Multi-Virulence-Locus Sequence Typing Identifies Single Nucleotide Polymorphisms Which Differentiate Epidemic Clones and Outbreak Strains of Listeria monocytogenes. J. Clin. Microbiol.
45: 835-846
[Abstract]
[Full Text]
-
Srinivasan, U., Zhang, L., France, A. M., Ghosh, D., Shalaby, W., Xie, J., Marrs, C. F., Foxman, B.
(2007). Probe Hybridization Array Typing: a Binary Typing Method for Escherichia coli. J. Clin. Microbiol.
45: 206-214
[Abstract]
[Full Text]
-
Elias, J., Vogel, U.
(2007). IS1301 Fingerprint Analysis of Neisseria meningitidis Strains Belonging to the ET-15 Clone. J. Clin. Microbiol.
45: 159-167
[Abstract]
[Full Text]
-
Olvera, A., Cerda-Cuellar, M., Aragon, V.
(2006). Study of the population structure of Haemophilus parasuis by multilocus sequence typing. Microbiology
152: 3683-3690
[Abstract]
[Full Text]
-
Schouls, L. M., van der Ende, A., Damen, M., van de Pol, I.
(2006). Multiple-Locus Variable-Number Tandem Repeat Analysis of Neisseria meningitidis Yields Groupings Similar to Those Obtained by Multilocus Sequence Typing. J. Clin. Microbiol.
44: 1509-1518
[Abstract]
[Full Text]
-
Harrison, L. H.
(2006). Prospects for Vaccine Prevention of Meningococcal Infection. Clin. Microbiol. Rev.
19: 142-164
[Abstract]
[Full Text]
-
van Bergen, M. A. P., Dingle, K. E., Maiden, M. C. J., Newell, D. G., van der Graaf-Van Bloois, L., van Putten, J. P. M., Wagenaar, J. A.
(2005). Clonal Nature of Campylobacter fetus as Defined by Multilocus Sequence Typing. J. Clin. Microbiol.
43: 5888-5898
[Abstract]
[Full Text]
-
Birtles, A., Hardy, K., Gray, S. J., Handford, S., Kaczmarski, E. B., Edwards-Jones, V., Fox, A. J.
(2005). Multilocus Sequence Typing of Neisseria meningitidis Directly from Clinical Samples and Application of the Method to the Investigation of Meningococcal Disease Case Clusters. J. Clin. Microbiol.
43: 6007-6014
[Abstract]
[Full Text]
-
Perez-Losada, M., Viscidi, R. P., Demma, J. C., Zenilman, J., Crandall, K. A.
(2005). Population Genetics of Neisseria gonorrhoeae in a High-Prevalence Community Using a Hypervariable Outer Membrane porB and 13 Slowly Evolving Housekeeping Genes. Mol Biol Evol
22: 1887-1902
[Abstract]
[Full Text]
-
Koreen, L., Ramaswamy, S. V., Naidich, S., Koreen, I. V., Graff, G. R., Graviss, E. A., Kreiswirth, B. N.
(2005). Comparative Sequencing of the Serine-Aspartate Repeat-Encoding Region of the Clumping Factor B Gene (clfB) for Resolution within Clonal Groups of Staphylococcus aureus. J. Clin. Microbiol.
43: 3985-3994
[Abstract]
[Full Text]
-
Bennett, J. S., Griffiths, D. T., McCarthy, N. D., Sleeman, K. L., Jolley, K. A., Crook, D. W., Maiden, M. C. J.
(2005). Genetic Diversity and Carriage Dynamics of Neisseria lactamica in Infants. Infect. Immun.
73: 2424-2432
[Abstract]
[Full Text]
-
Nemoy, L. L., Kotetishvili, M., Tigno, J., Keefer-Norris, A., Harris, A. D., Perencevich, E. N., Johnson, J. A., Torpey, D., Sulakvelidze, A., Morris, J. G. Jr., Stine, O. C.
(2005). Multilocus Sequence Typing versus Pulsed-Field Gel Electrophoresis for Characterization of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli Isolates. J. Clin. Microbiol.
43: 1776-1781
[Abstract]
[Full Text]
-
Jolley, K. A., Wilson, D. J., Kriz, P., Mcvean, G., Maiden, M. C. J.
(2005). The Influence of Mutation, Recombination, Population History, and Selection on Patterns of Genetic Diversity in Neisseria meningitidis. Mol Biol Evol
22: 562-569
[Abstract]
[Full Text]
-
Yazdankhah, S. P., Kriz, P., Tzanakaki, G., Kremastinou, J., Kalmusova, J., Musilek, M., Alvestad, T., Jolley, K. A., Wilson, D. J., McCarthy, N. D., Caugant, D. A., Maiden, M. C. J.
(2004). Distribution of Serogroups and Genotypes among Disease-Associated and Carried Isolates of Neisseria meningitidis from the Czech Republic, Greece, and Norway. J. Clin. Microbiol.
42: 5146-5153
[Abstract]
[Full Text]
-
Bunikis, J., Garpmo, U., Tsao, J., Berglund, J., Fish, D., Barbour, A. G.
(2004). Sequence typing reveals extensive strain diversity of the Lyme borreliosis agents Borrelia burgdorferi in North America and Borrelia afzelii in Europe. Microbiology
150: 1741-1755
[Abstract]
[Full Text]
-
Sails, A. D., Swaminathan, B., Fields, P. I.
(2003). Utility of Multilocus Sequence Typing as an Epidemiological Tool for Investigation of Outbreaks of Gastroenteritis Caused by Campylobacter jejuni. J. Clin. Microbiol.
41: 4733-4739
[Abstract]
[Full Text]
-
Sails, A. D., Swaminathan, B., Fields, P. I.
(2003). Clonal Complexes of Campylobacter jejuni Identified by Multilocus Sequence Typing Correlate with Strain Associations Identified by Multilocus Enzyme Electrophoresis. J. Clin. Microbiol.
41: 4058-4067
[Abstract]
[Full Text]
-
Diggle, M. A., Bell, C. M., Clarke, S. C.
(2003). Nucleotide sequence-based typing of meningococci directly from clinical samples. J Med Microbiol
52: 505-508
[Abstract]
[Full Text]
-
Goulding, J. N., Stanley, J., Olver, W., Neal, K. R., Ala'Aldeen, D. A. A., Arnold, C.
(2003). Independent subsets of amplified fragments from the genome of Neisseria meningitidis identify the same invasive clones of ET37 and ET5. J Med Microbiol
52: 151-154
[Abstract]
[Full Text]
-
Diggle, M.A., Clarke, S.C.
(2003). Detection and genotyping of meningococci using a nested PCR approach. J Med Microbiol
52: 51-57
[Abstract]
[Full Text]
-
Urwin, R., Holmes, E. C., Fox, A. J., Derrick, J. P., Maiden, M. C. J.
(2002). Phylogenetic Evidence for Frequent Positive Selection and Recombination in the Meningococcal Surface Antigen PorB. Mol Biol Evol
19: 1686-1694
[Abstract]
[Full Text]
-
van Loo, I. H. M., Heuvelman, K. J., King, A. J., Mooi, F. R.
(2002). Multilocus Sequence Typing of Bordetella pertussis Based on Surface Protein Genes. J. Clin. Microbiol.
40: 1994-2001
[Abstract]
[Full Text]
-
Claus, H., Maiden, M. C. J., Maag, R., Frosch, M., Vogel, U.
(2002). Many carried meningococci lack the genes required for capsule synthesis and transport. Microbiology
148: 1813-1819
[Abstract]
[Full Text]
-
Kotetishvili, M., Stine, O. C., Kreger, A., Morris, J. G. Jr., Sulakvelidze, A.
(2002). Multilocus Sequence Typing for Characterization of Clinical and Environmental Salmonella Strains. J. Clin. Microbiol.
40: 1626-1635
[Abstract]
[Full Text]
-
Nallapareddy, S. R., Duh, R.-W., Singh, K. V., Murray, B. E.
(2002). Molecular Typing of Selected Enterococcus faecalis Isolates: Pilot Study Using Multilocus Sequence Typing and Pulsed-Field Gel Electrophoresis. J. Clin. Microbiol.
40: 868-876
[Abstract]
[Full Text]
-
HOOKEY, J.V., ARNOLD, C.
(2001). A comparison of multilocus sequence typing and fluorescent fragment-length polymorphism analysis genotyping of clone complex and other strains of Neisseria meningitidis. J Med Microbiol
50: 991-995
[Abstract]
[Full Text]
-
Clarke, S. C., Diggle, M. A., Edwards, G. F. S.
(2001). Semiautomation of Multilocus Sequence Typing for the Characterization of Clinical Isolates of Neisseria meningitidis. J. Clin. Microbiol.
39: 3066-3071
[Abstract]
[Full Text]
-
Dingle, K. E., Colles, F. M., Wareing, D. R. A., Ure, R., Fox, A. J., Bolton, F. E., Bootsma, H. J., Willems, R. J. L., Urwin, R., Maiden, M. C. J.
(2001). Multilocus Sequence Typing System for Campylobacter jejuni. J. Clin. Microbiol.
39: 14-23
[Abstract]
[Full Text]
-
Jolley, K. A., Kalmusova, J., Feil, E. J., Gupta, S., Musilek, M., Kriz, P., Maiden, M. C. J.
(2000). Carried Meningococci in the Czech Republic: a Diverse Recombining Population. J. Clin. Microbiol.
38: 4492-4498
[Abstract]
[Full Text]
-
Goulding, J. N., Hookey, J. V., Stanley, J., Olver, W., Neal, K. R., Ala'Aldeen, D. A. A., Arnold, C.
(2000). Fluorescent Amplified-Fragment Length Polymorphism Genotyping of Neisseria meningitidis Identifies Clones Associated with Invasive Disease. J. Clin. Microbiol.
38: 4580-4585
[Abstract]
[Full Text]