scholarly journals Genetic and Antigenic Analysis of Invasive Serogroup CNeisseria meningitidisin Canada: A Decrease in the Electrophoretic Type (Et)-15 Clonal Type and an Increase in the Proportion of Isolates Belonging to the Et-37 (But Not Et-15) Clonal Type During the Period from 2002 to 2009

2012 ◽  
Vol 23 (3) ◽  
pp. e55-e59 ◽  
Author(s):  
Jianwei Zhou ◽  
Frances Jamieson ◽  
Sharon Dolman ◽  
Linda MN Hoang ◽  
Prasad Rawte ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Neisseria Meningitidis ◽  
Meningococcal Disease ◽  
Multilocus Sequence Typing ◽  
Enzyme Electrophoresis ◽  
Microbiology Laboratory ◽  
Antigenic Analysis ◽  
Multilocus Enzyme Electrophoresis ◽  
The Past ◽  
Clonal Type

BACKGROUND: Serogroup C meningococcal disease has been endemic in Canada since the early 1990s, with periods of hyperendemic disease documented in the past two decades. The present study characterized invasive serogroup C meningococci in Canada during the period from 2002 to 2009.METHODS: Serogroup C meningococci were serotyped using monoclonal antibodies. Their clonal types were identified by either multilocus enzyme electrophoresis or multilocus sequence typing.RESULTS: The number of invasive serogroup CNeisseria meningitidisisolates received at the National Microbiology Laboratory (Winnipeg, Manitoba) for characterization has dropped from a high of 173 isolates in 2001 to just 17 in 2009, possibly related to the introduction of the serogroup C meningococcal conjugate vaccine. Before 2006, 80% to 95% of all invasive serogroup C meningococci belonged to the electrophoreic type (ET)-15 clonal type, and the ET-37 (but not ET-15) type only accounted for up to 5% of all isolates. However, beginning in 2006, the percentage of the ET-15 clonal type decreased while the ET-37 (but not ET-15) type increased from 27% in 2006 to 52% in 2009. The percentage of invasive serogroup C isolates not belonging to either ET-15 or ET-37 also increased. Most ET-15 isolates expressed the antigenic formula of C:2a:P1.7,1 or C:2a:P1.5. In contrast, the ET-37 (but not ET-15) isolates mostly expressed the antigens of C:2a:P1.5,2 or C:2a:P1.2.CONCLUSION: A shift in the antigenic and clonal type of invasive serogroup C meningococi was noted. This finding suggests vigilance in the surveillance of meningoccocal disease is warranted.

scholarly journals Genealogical typing of Neisseria meningitidis

Microbiology ◽  
2009 ◽  
Vol 155 (10) ◽  
pp. 3176-3186 ◽  
Author(s):  
Xavier Didelot ◽  
Rachel Urwin ◽  
Martin C. J. Maiden ◽  
Daniel Falush
Keyword(s):  
Neisseria Meningitidis ◽  
Multilocus Sequence Typing ◽  
Sequence Data ◽  
Bacterial Pathogen ◽  
Evolutionary Relationships ◽  
Enzyme Electrophoresis ◽  
Substantial Variation ◽  
Statistical Tools ◽  
Confounding Effect ◽  
Multilocus Enzyme Electrophoresis

Despite the increasing popularity of multilocus sequence typing (MLST), the most appropriate method for characterizing bacterial variation and facilitating epidemiological investigations remains a matter of debate. Here, we propose that different typing schemes should be compared on the basis of their power to infer clonal relationships and investigate the utility of sequence data for genealogical reconstruction by exploiting new statistical tools and data from 20 housekeeping loci for 93 isolates of the bacterial pathogen Neisseria meningitidis. Our analysis demonstrated that all but one of the hyperinvasive isolates established by multilocus enzyme electrophoresis and MLST were grouped into one of six genealogical lineages, each of which contained substantial variation. Due to the confounding effect of recombination, evolutionary relationships among these lineages remained unclear, even using 20 loci. Analyses of the seven loci in the standard MLST scheme using the same methods reproduced this classification, but were unable to support finer inferences concerning the relationships between the members within each complex.

The panmictic nature ofNeisseria meningitidisserogroup B during a period of endemic disease in Canada

2001 ◽  
Vol 47 (4) ◽  
pp. 283-289 ◽  
Author(s):  
Fraser E Ashton ◽  
Dominique A Caugant
Keyword(s):  
Genetic Diversity ◽  
Cluster Analysis ◽  
Neisseria Meningitidis ◽  
Meningococcal Disease ◽  
Enzyme Electrophoresis ◽  
Endemic Disease ◽  
Multilocus Enzyme Electrophoresis ◽  
Common Serotypes ◽  
The Mean ◽  
Group B

Three hundred and one (301) strains of Neisseria meningitidis serogroup B, isolated from patients with meningococcal disease during the years 1994–1996, were subjected to multilocus enzyme electrophoresis, serotyping, and serosubtyping. Based on the analyses of 14 enzyme loci, 177 electrophoretic types (ETs) were identified. Of these, 136 were represented by single isolates and 41 were represented by multiple isolates (range 2–31). The mean genetic diversity for isolates was 0.444 and for ETs was 0.440. The index of association (IA) between loci was 0.530 ± 0.08 for isolates and 0.256 ± 0.10 for ETs. Cluster analysis revealed the presence of 39 lineages each represented by a single ET or clusters of ETs. The most common serotypes were 4, 15, and 14 and accounted for 84 (28.0%), 53 (17.6%), and 32 (10.6%) of the isolates, respectively, and were dispersed amongst 46 ETs (1–122), 35 ETs (3–165), and 26 ETs (18–76), respectively. The 109 (36.6%) nontypable (NT) isolates were amongst 74 ETs (6–177). The mean genetic diversity for serotypes 4, 15, and 14 and NT isolates was 0.368, 0.371, 0.343, and 0.442, respectively, and for ETs was 0.363, 0.354, 0.397, and 0.440, respectively. Combinations of serotypes and serosubtypes (number of isolates) that occurred most frequently were 4:P1.14 (17), 14:P1.16 (16), NT:P1.16 (16), 15:P1.16 (13), and NT:P1.13 (13). The majority of group B disease in Canada during 1994–1996 was caused by meningococci of considerable genetic diversity, and reflects a situation of endemic disease. However, the results also indicate that organisms belonging to the ET-5 complex, which has been responsible for outbreaks of group B disease globally for several decades, have been introduced into the country.Key words: meningococcal, genotypes, serotypes, serosubtypes, Neisseria meningitidis.

scholarly journals Genetic structure of Neisseria meningitidis serogroup C epidemic strains in South Brazil

1995 ◽  
Vol 37 (4) ◽  
pp. 281-289 ◽  
Author(s):  
Claudio Tavares Sacchi ◽  
Maria Lúcia Cecconi Tondella ◽  
Maria Cecília Outeiro Gorla ◽  
Ana Paula Silva de Lemos ◽  
Carmo Elias A. Melles ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Genetic Structure ◽  
Restriction Enzyme ◽  
Meningococcal Disease ◽  
Genetic Similarity ◽  
Rio Grande ◽  
Enzyme Electrophoresis ◽  
Rio Grande Do Sul ◽  
Multilocus Enzyme Electrophoresis ◽  
South Brazil

In the present study we report the results of an analysis, based on serotyping, multilocus enzyme electrophoresis (MEE), and ribotyping of N. meningitidis serogroup C strains isolated from patients with meningococcal disease (MD) in Rio Grande do Sul (RS) and Santa Catarina (SC) States, Brazil, as the Center of Epidemiology Control of Ministry of Health detected an increasing of MD cases due to this serogroup in the last two years (1992-1993). We have demonstrated that the MD due to N.meningitidis serogroup C strains in RS and SC States occurring in the last 4 years were caused mainly by one clone of strains (ET 40), with isolates indistinguishable by serogroup, serotype, subtype and even by ribotyping. One small number of cases that were not due to an ET 40 strains, represent closely related clones that probably are new lineages generated from the ET 40 clone referred as ET 11A complex. We have also analyzed N.meningitidis serogroup C strains isolated in the greater São Paulo in 1976 as representative of the first post epidemic year in that region. The ribotyping method, as well as MEE, could provide useful information about the clonal characteristics of those isolates and also of strains isolated in south Brazil. The strains from 1976 have more similarity with the actual endemic than epidemic strains, by the ribotyping, sulfonamide sensitivity, and MEE results. In conclusion, serotyping with monoclonal antibodies (C:2b:P1.3), MEE (ET 11 and ET 11A complex), and ribotyping by using ClaI restriction enzyme (Rb2), were useful to characterize these epidemic strains of N.meningitidis related to the increased incidence of MD in different States of south Brazil. It is mostly probable that these N.meningitidis serogroup C strains have poor or no genetic corelation with 1971-1975 epidemic serogroup C strains. The genetic similarity of members of the ET 11 and ET 11A complex were confirmed by the ribotyping method by using three restriction endonucleases.

scholarly journals Sequencing of the porB Gene: a Step toward a True Characterization of Neisseria meningitidis

2006 ◽  
Vol 13 (10) ◽  
pp. 1087-1091 ◽  
Author(s):  
R. Abad ◽  
B. Alcalá ◽  
C. Salcedo ◽  
R. Enríquez ◽  
M. J. Uría ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Neisseria Meningitidis ◽  
Meningococcal Disease ◽  
Nucleotide Sequences ◽  
Epidemiological Surveillance ◽  
Allelic Variants ◽  
Potential Vaccine

ABSTRACT Variations in class 2/3 (PorB) proteins form the basis for meningococcal serotyping. Antibodies against these proteins are bactericidal, making serotyping results useful not only for epidemiological surveillance of meningococcal disease but also for identifying potential vaccine components. A total of 20 to 60% of meningococcal B and C isolates from any given population are nontypeable (NT) using a panel of monoclonal antibodies. To analyze the mechanisms responsible for the nonserotypeability characteristic in Neisseria meningitidis, we (i) established the nucleotide sequences of porB gene in 146 meningococcal strains (95 not recognized by the serotyping panel), (ii) identified 18 new allelic variants of the porB gene, (iii) correlated allelic variants with serotypes, (iv) suggest the nontypeability characteristic in those 95 NT strains, and (v) reject the possibility of variation in the levels of PorB expression.

scholarly journals Potential Capsule Switching from Serogroup Y to B: The Characterization of Three suchNeisseria meningitidisIsolates Causing Invasive Meningococcal Disease in Canada

2005 ◽  
Vol 16 (3) ◽  
pp. 171-174 ◽  
Author(s):  
Raymond SW Tsang ◽  
Dennis KS Law ◽  
Shaun D Tyler ◽  
Gwen S Stephens ◽  
Mark Bigham ◽  
...  
Keyword(s):  
Neisseria Meningitidis ◽  
Meningococcal Disease ◽  
Multilocus Sequence Typing ◽  
Housekeeping Gene ◽  
Sequence Type ◽  
Invasive Meningococcal Disease ◽  
Group B

Three group BNeisseria meningitidisisolates, recovered from meningococcal disease cases in Canada and typed as B:2c:P1.5, were characterized. Multilocus sequence typing showed that all three isolates were related because of an identical sequence type (ST) 573. Isolates typed as 2c:P1.5 are common in serogroup Y meningococci but rare in isolates from serogroups B or C. Although no serogroup Y isolates have been typed as ST-573, eight isolates showed five to six housekeeping gene alleles that were identical to that of ST-573. This suggested that the B:2c:P1.5 isolates may have originated from serogroup Y organisms, possibly by capsule switching.

scholarly journals The 1998 Senegal Epidemic of Meningitis Was Due to the Clonal Expansion of A:4:P1.9, Clone III-1, Sequence Type 5 Neisseria meningitidis Strains

2000 ◽  
Vol 38 (1) ◽  
pp. 198-200
Author(s):  
Pierre Nicolas ◽  
Georges Raphenon ◽  
Martine Guibourdenche ◽  
Laurent Decousset ◽  
Richard Stor ◽  
...  
Keyword(s):  
Neisseria Meningitidis ◽  
Clonal Expansion ◽  
Pulsed Field Gel Electrophoresis ◽  
Sequence Type ◽  
Enzyme Electrophoresis ◽  
Multilocus Enzyme Electrophoresis ◽  
Meningitis Belt ◽  
Dna Restriction Fragments ◽  
Dna Restriction ◽  
First Time

ABSTRACT Between January and April 1998, a meningitis outbreak due to serogroup A meningococcus took place in Senegal. The outbreak began in Gandiaye, 165 km to the east of Dakar, and progressed towards the towns of Gossas, Niakkhar, Guinguineo, Fatik, Foundiougne, Dioffior, Sokone, Kaolack, and Nioro. At the same time, the outbreak reached regions of Kaffrine, Koungheul, and Tambacounda in the east of Senegal. A total of 1,350 cases and 200 deaths were reported. The WHO Collaborating Center in Marseilles received 24 strains for analysis. All were serogroup A Neisseria meningitidis , type 4 and subtype P1.9. Multilocus enzyme electrophoresis, performed by Institut Pasteur Paris, showed that the strains belonged to clone III-1. DNA restriction fragments generated by endonuclease Bgl II and analyzed by pulsed-field gel electrophoresis showed 24 indistinguishable fingerprint patterns similar to those of meningococcus strains isolated from African outbreaks since 1988. Three strains were studied by multilocus sequence typing (MLST) with seven loci. The comparison between sequences and existing alleles on the MLST website ( http://mlst.zoo.ox.ac.uk ) allowed us to assign these strains to sequence type 5 (ST5), as their sequences were identical to the consensus at seven loci. All 24 strains were susceptible to penicillin, amoxicillin, chloramphenicol, and rifampin. Subgroup III is finishing its spread towards west of the meningitis belt of Africa. To our knowledge, this is the first time subgroup III, and more precisely ST5, strains are reported as being responsible for a meningitis outbreak in Senegal.

scholarly journals Molecular Epidemiology of Recent Belgian Isolates of Neisseria meningitidis Serogroup B

1998 ◽  
Vol 36 (10) ◽  
pp. 2828-2834 ◽  
Author(s):  
M. Van Looveren ◽  
P. Vandamme ◽  
M. Hauchecorne ◽  
M. Wijdooghe ◽  
F. Carion ◽  
...  
Keyword(s):  
Neisseria Meningitidis ◽  
Gel Electrophoresis ◽  
Epidemiological Data ◽  
Pulsed Field Gel Electrophoresis ◽  
Enzyme Electrophoresis ◽  
Clin Microbiol Infect ◽  
Epidemic Clone ◽  
Multilocus Enzyme Electrophoresis ◽  
Repetitive Motif ◽  
Reference Strains

In Belgium an increase in the incidence of meningococcal disease has been noted since the early 1990s. Four hundred twenty clinical strains isolated during the period from 1990 to 1995, along with a set of 30 European reference strains, and 20 Dutch isolates were examined by random-primer and repetitive-motif-based PCR. A subset was investigated by multilocus enzyme electrophoresis and pulsed-field gel electrophoresis. The data were compared with results obtained by serotyping (M. Van Looveren, F. Carion, P. Vandamme, and H. Goossens, Clin. Microbiol. Infect. 4:224–228, 1998). Both phenotypic and molecular epidemiological data suggest that the lineage III ofNeisseria meningitidis, first encountered in The Netherlands in about 1980, has been introduced in Belgium. The epidemic clone, as defined by oligonucleotide D8635-primed PCR, encompasses mainly phenotypes B:4:P1.4 and B:nontypeable:P1.4, but strains with several other phenotypes were also encountered. Therefore, serotyping alone would underestimate the prevalence of the epidemic clone.

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