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 relationships amongNeisseria gonorrhoeaeserovars analysed by multilocus enzyme electrophoresis

1992 ◽  
Vol 108 (1) ◽  
pp. 31-38 ◽  
Author(s):  
C. L. Poh ◽  
J. C. Ocampo ◽  
G. K. Loh
Keyword(s):  
Genetic Diversity ◽  
Neisseria Gonorrhoeae ◽  
Genetic Relatedness ◽  
Genetic Relationships ◽  
Electrophoretic Analysis ◽  
Enzyme Electrophoresis ◽  
Enzyme Locus ◽  
Multilocus Enzyme Electrophoresis ◽  
Enzyme Loci ◽  
The Mean

Multilocus enzyme electrophoretic analysis was employed to assess the genetic relatedness ofNeisseria gonorrhoeae. Based on the diversity of electromorphs at 9 enzyme loci, 16 electrophoretic types (ETs) were estabilished amongst the 65 isolates. The average number of alleles per enzyme locus was 1·7 and the mean genetic diversity per locus was 0·212. The majority of isolates belonged to either ET1 (32·3%) or ET2 (16·9%). No specific correlation of ETs was seen with serovars as the major types, ETs 1 and 2, were found distributed amongst the various serovars. Major serovars such as Bacjk (IB-1/2) and Bajk (IB-3/6) were each represented by 6 or 8 ETs respectively. Analysis of the genetic relationships of ETs to each other showed some clustering of subgroups that were more closely related than others.

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.

Prevalence and genetic diversity of two adhesion-related genes, pilE and nadA, in Neisseria meningitidis in China

2013 ◽  
Vol 141 (10) ◽  
pp. 2163-2172 ◽  
Author(s):  
X. SUN ◽  
H. ZHOU ◽  
L. XU ◽  
H. YANG ◽  
Y. GAO ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Neisseria Meningitidis ◽  
Adhesion Molecules ◽  
Meningococcal Disease ◽  
Class Ii ◽  
Type Iv Pili ◽  
Invasive Meningococcal Disease ◽  
Class I ◽  
Type Iv

SUMMARYThe main Neisseria meningitidis adhesion molecules, type IV pili (Tfp) and Neisseria adhesion A (NadA), play important roles in the pathogenesis of invasive meningococcal disease. PilE is the major Tfp subunit. In this study, the prevalence and genetic diversity of pilE and nadA were investigated in the prevalent serogroups and clonal complexes (CC) of N. meningitidis isolated in China. All serogroup A strains belonging to CC1 and CC5 and all CC11 serogroup W135 strains were clustered into class II PilE clades. All serogroup C and most of serogroup B isolates except CC8 and ST5642 were class I PilE clades. Class II pilE sequences were highly conserved. All isolates belonging to class I PilE isolates were nadA negative. However, nadA-positive strains were exclusively found in CC5 and CC11 isolates (class II PilE). This study showed that PilE and NadA may be related to epidemic or endemic meningococcal disease.

scholarly journals Meningococcal Group B Vaccine For The Prevention Of Invasive Meningococcal Disease Caused By Neisseria meningitidis Serogroup B

2019 ◽  
Vol Volume 12 ◽  
pp. 3169-3188 ◽  
Author(s):  
Irene Rivero-Calle ◽  
Peter Francis Raguindin ◽  
Jose Gómez-Rial ◽  
Carmen Rodriguez-Tenreiro ◽  
Federico Martinón-Torres
Keyword(s):  
Neisseria Meningitidis ◽  
Meningococcal Disease ◽  
Invasive Meningococcal Disease ◽  
Meningococcal Group ◽  
Group B

scholarly journals Pharyngeal carriage of Neisseria meningitidis and Neisseria lactamica in households with infants within areas with high and low incidences of meningococcal disease

1991 ◽  
Vol 106 (3) ◽  
pp. 445-457 ◽  
Author(s):  
S. F. Olsen ◽  
B. Djurhuus ◽  
K. Rasmussen ◽  
H. D. Joensen ◽  
S. O. Larsen ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Neisseria Meningitidis ◽  
Meningococcal Disease ◽  
Odds Ratio ◽  
Lower Risk ◽  
Household Survey ◽  
Faroe Islands ◽  
Odds Ratios ◽  
Neisseria Lactamica ◽  
Group B

SUMMARYIn a household survey in the Faroe Islands, an isolated community with hyperendemic occurrence of meningococcal disease due to serogroup B 15, 1604 persons were examined for pharyngeal carriage of Neisseria meningitidis and N. lactamica. Two areas were chosen having experienced high (HIA), and two having experienced low incidences (LIA) of disease. Living in HIA compared with LIA was associated with higher risk of N. meningitidis B 15 carriage and lower risk of N. lactamica carriage, with odds ratios of 2·7 (95% confidence interval (CI) 1·4–5·1, P = 0·003) and 0·41 (95% CI 0·31–0·53, P < 0·0001), respectively. In HIA the risk of N. meningitidis carriage was much lower in non-carriers than carriers of N. lactamica, with an odds ratio of 0·19 (95% CI 0·08–0·47, P = 0·0003); in LIA this association (odds ratio 0·51, P = 0·05) was much weaker. Children 0–14 years had substantially higher risk of being carriers of N. meningitidis group B 15 if the mothers were so, with an odds ratio of 11 (95% CI 4–29, P < 0·0001).

Molecular surveillance ofNeisseria meningitidiscapsular switching in Portugal, 2002–2006

2008 ◽  
Vol 137 (2) ◽  
pp. 161-165 ◽  
Author(s):  
M. J. SIMÕES ◽  
M. CUNHA ◽  
F. ALMEIDA ◽  
C. FURTADO ◽  
L. BRUM
Keyword(s):  
Neisseria Meningitidis ◽  
Genetic Relationship ◽  
Meningococcal Disease ◽  
Gel Electrophoresis ◽  
Vaccination Schedule ◽  
Pulsed Field Gel Electrophoresis ◽  
Allelic Profile ◽  
Molecular Surveillance ◽  
Laboratory Surveillance ◽  
Group B

SUMMARYNeisseria meningitidiscapsular switching has been reported in several countries. In order to establish the genetic relationship within group B and C strains expressing subtypes 2a or 2b, and to evaluate whether C to B capsular switching occurred in Portugal, 64 meningococci (56 serogroup C and 8 serogroup B) isolated from invasive meningococcal disease were typed using molecular methods. The studied phenotypes, 2b:P1.5,2 and 2a:P1.5-1,10-8, were the most frequent among serogroup C, but were uncommon among serogroup B strains. The multi-locus sequence typing (MLST) allelic profile and the pulsed-field gel electrophoresis (PFGE) fingerprints showed that seven serogroup B strains were genotypically identical to C strains, suggesting that capsular switching occurred. Active laboratory surveillance to find evidence of capsule switching is a now priority as MenC was introduced in the Portuguese vaccination schedule in January 2006.

scholarly journals Characterization of Urease-Positive Thermophilic Campylobacter Subspecies by Multilocus Enzyme Electrophoresis Typing

2003 ◽  
Vol 69 (6) ◽  
pp. 3308-3310 ◽  
Author(s):  
Motoo Matsuda ◽  
Aki Kaneko ◽  
Timothy Stanley ◽  
B. Cherie Millar ◽  
M. Miyajima ◽  
...  
Keyword(s):  
Allelic Variation ◽  
Enzyme Electrophoresis ◽  
Multilocus Enzyme Electrophoresis ◽  
Thermophilic Campylobacter ◽  
Variation Data ◽  
Quantitative Analyses ◽  
The Mean ◽  
Campylobacter Lari ◽  
Reference Strains

ABSTRACT Thirty-one urease-positive thermophilic Campylobacter (UPTC) isolates, including three reference strains (NCTC12892, NCTC12895 and NCTC12896), and three Campylobacter lari isolates, which were isolated from several countries and sources, were compared genotypically by using multilocus enzyme electrophoresis (MLEE). We examined allelic variation around seven enzyme loci, including the adenylate kinase, alkaline phosphatase, catalase, fumarase, malic enzyme, malate dehydrogenase, and l-phenylalanyl-l-leucine peptidase loci. MLEE typing revealed the presence of 23 different electrophoretic types (ETs) among the 31 UPTC isolates, and 14 isolates shared six electrophoretic profiles. Three different ETs were identified for the three C. lari isolates examined, and no ETs were shared by UPTC and C. lari isolates. Quantitative analyses were subsequently performed by using allelic variation data, and the results demonstrated that the mean genetic diversity was 0.655. In conclusion, MLEE demonstrated that the UPTC isolates examined are genetically hypervariable and form a cluster separate from the C. lari cluster.

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