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At least 127 records · Page 7Linked to original sources
PubMed1984

Serotype distribution of meningococci isolated in South Australia 1971 through 1980.

The serotypes of meningococci isolated from 76 sporadic cases of meningococcal disease in South Australia during the years 1971 through 1980 were determined. Thirty-four (56%) of the 61 group B strains were nontypable; the remainder were of five serotypes namely 8 (16%), 1 (13%), 2 (2a and 2b) (9%), 12 (3%), and 15 (3%). Four of the five group B type 2 strains were serotype 2b. Serotype 2a accounted for four of seven group C strains and four of five group W135 strains. Overall serotypes 2 (2a and 2b) (17%), 8 (13%), and 1 (10%) occurred most frequently amongst the typable strains, whereas 40 (53%) of the 76 strains were nontypable. The results indicate that several serotypes and many nontypable strains were responsible for the sporadic disease occurring during a 10-year period in Australia.

Australia↗
PubMed1976

An epidemic due to sulphonamide-resistant group A meningococci in the Helsinki area (Finland). Epidemiological and clinical observations.

An epidemic due to sulphonamide-resistant group A meningococci started in Finland in January 1973. By the end of 1974 the number of cases exceeded 1300. This report describes epidemiological and clinical observations in 370 patients treated in Helsinki 1973-1974. The incidence was about 65 per 100 000 per year in children under 7 years of age and about 10 per 100 000 in adults. More than one case occurred in 3.8% of the families and in 36% of the lodging-houses of the lowest social group. The fatality rate of patients treated in hospital was 4.1%. Persistent neurological damage was noticed in 4.6%.

Adolescent↗
PubMedDate not supplied

Clonal expansion of sequence type (ST-)5 and emergence of ST-7 in serogroup A meningococci, Africa.

One hundred four serogroup A meningococci in our collection, isolated in Africa from 1988 to 1999, were characterized by multilocus sequence typing (MLST). Our results and data from the Internet indicate that sequence type 5 (ST-5) strains were responsible for most of African outbreaks and sporadic cases during this period. In 1995, a new clone, characterized by ST-7 sequence, emerged and was responsible for severe outbreaks in Chad (1998) and Sudan (1999). MLST and epidemiologic data indicate that ST-5 and ST-7 represent two virulent clones. These two STs, which belong to subgroup III, differ only in the pgm locus: allele pgm3 is characteristic for ST-5 and allele pgm19 for ST-7. Subgroup III strains were responsible for two pandemics in the 1960s and 1980s. Our data show that the third subgroup III pandemic has now reached Africa.

Africa↗
PubMedDate not supplied

Genosubtyping by sequencing group A, B and C meningococci; a tool for epidemiological studies of epidemics, clusters and sporadic cases.

Genosubtyping, by sequencing variable regions (VRs) 1, 2 and 3 of the porA gene, was evaluated as a tool to detect clonality of isolates in meningococcal epidemics in Africa and clusters of disease in Sweden. All 63 examined meningococcal isolates were successfully genosubtyped. The isolates belonging to group A type 4 with genosubtype P1.20,9,35a showed little heterogeneity in African epidemics in 1988 and onwards. In Sweden, two meningococcal clones of group B type 15, with genosubtypes P1.7,16,35 and P1.7,16f,35, dominated during two clusters of meningococcal disease in 1995-96 and in sporadic cases thereafter. The characterisation of group C meningococci isolated during 1992 in Sweden indicated a cluster (type 2a with genosubtype P1.5a,10d,36b) connected with a discotheque visit. Two variants of VR2 (10p and 25b), not previously described, were found among the examined isolates. Nucleotide sequence analysis of VRs in the porA gene proved a valuable epidemiological tool since almost all isolates could be genosubtyped, in contrast to the phenotypic methods presently used.

Africa↗
PubMed2001

Automated non-culture-based sequence typing of meningococci from body fluids.

In recent years, the polymerase chain reaction has been used for the non-culture diagnosis of meningococcal disease, and sequence-based typing takes this further by providing the full characterisation normally only available by culture. In this study, porA gene sequencing was used to perform non-culture-based sequence typing of Neisseria meningitidis strains direct from body fluids. Non-culture porA gene sequencing provided the serosubtype of the infecting organism, and proved to be a useful method as N. meningitidis was not isolated from any of the patients in this study. In conclusion, porA gene sequencing is a very useful tool for the non-culture characterisation of meningococci and provides important information for public health management of cases and contacts.

Bacterial Typing Techniques↗
PubMed2002

[Universal vaccination against group C meningococci and pneumococci; advice from the Health Council of the Netherlands].

A committee of the Health Council of the Netherlands recently advised the Minister of Health on nationwide vaccination against group-C meningococci and pneumococci. They recommended the introduction of both vaccines into the national vaccination programme. The meningococcal C vaccine should be introduced as soon as possible, and the pneumococcal vaccine should be introduced as soon as a combined vaccine against diphtheria, tetanus, pertussis and polio and H. influenzae type B is available. In the meantime, due to various clusters of meningococcal disease caused by Neisseria meningitidis C in the Netherlands, parents have started to have their children vaccinated by buying vaccines and asking their general practitioners to perform the vaccination. This unfavourable situation must be controlled by the government through clear publicity to parents and healthcare workers.

Health Policy↗
PubMed1992

[The type subtyping of meningococci by means of whole-cell immunoenzyme analysis].

In this work the method of the whole-cell enzyme immunoassay, used for the serotype-subtyping of meningococci by means of specific monoclonal antibodies, is described. High specificity of the method, the simplicity of the assay procedure and evaluation of its results, as well as the availability of this method for practical use, have been demonstrated. The results of this investigation confirm the importance of the evaluation of type-subtype appurtenance of reference and laboratory strains used in experiments. Study of 72 meningococcal strains obtained from patients has revealed their polyclonal character in respect of their type-subtype signs.

Antibodies, Monoclonal↗
PubMed1986

[Use of a coagglutination reaction based on a Soviet staphylococcal reagent for serogrouping Streptococcus group B and meningococci].

The coagglutination (COA) test is used for the serogrouping of streptococci, group B, and meningococci. The trial of a Soviet commercial preparation (staphylococcal reagent) has shown good prospects for its use in the COA test and high specificity of this test method. The availability of highly specific immune sera permits making standard kits for the identification of different infective agents in the COA test.

Agglutination Tests↗
PubMed1986

[Isolation and characteristics of a specific polysaccharide of group-B meningococci].

The optimum conditions for the isolation and purification of the specific polysaccharide of group B meningococci have been developed. The advantages of the use of synthetic culture media for growing the initial bacterial culture have been demonstrated. The purified polysaccharides have been found to contain about 70% of sialic acid and less than 1% of protein and nucleic acid admixtures. The molecular parameters of group B polysaccharide depended on the growth phase of the bacterial culture. The most valuable culture was obtained at the exponential phase of growth. High serological activity and specificity of the polysaccharide in the passive hemagglutination test recommend it for studies on the development of diagnostic and prophylactic preparations.

Animals↗
PubMed1985

[Antigenic affinity of meningococci and human A- and B-group erythrocytes].

The use of the modified method of isohemagglutinin adsorption by microbial antigens in experiments with the causative agent of meningococcal infection has led, for the first time, to the detection of meningococcal antigens affined to the antigens of human erythrocytes, groups A and B. The antigenic affinity of group A erythrocytes and meningococci has proved to be more pronounced in meningococcal strains isolated from the spinal fluid of patients than in cultures obtained from the nasopharynx of healthy persons. The detection of the affinity of these antigens makes it possible to explain the mechanism of differences in the susceptibility of persons with different blood groups to meningococcal infection by "antigenic mimicry".

ABO Blood-Group System↗
PubMed1983

[Electron microscopic study of meningococci in stab cultures].

The study of the ultrastructure of meningococci (strain C0638) in the process of submerged batch cultivation permitted the authors to follow changes in the fine structure of these microorganisms in different phases of the growth of the culture. Thus, the meningococcal populations retained their ultrastructure most intact during the exponential phase and the growth rate deceleration phase. During these growth phases a faintly pronounced reaction of the surface structures with ruthenium red was observed. In the stationary phase and in the atrophy phase this reaction was completely absent. The accumulation of exotoxin bubbles in the membrane was shown to achieve its maximum in the atrophy phase; besides, these structures regularly appeared at the death of the cells under the action of alkali. A hypothesis explaining the appearance of these bubbles is put forward.

Culture Media↗
PubMed1983

Serotyping of meningococci by coagglutination with monoclonal antibodies.

Treatment of agar-grown meningococci with dilute hydrochloric acid and suspension in saline after washing gave a preparation suitable for meningococcal serotyping by staphylococcal coagglutination with monoclonal antibodies. The monoclonal antibodies available for use and attached to protein A on the staphylococci were directed against the serotype protein antigens 2a, 2b (class 2), 15 (class 3) and the subtype protein antigens P1. 2 and P1. 16 (class 1). Ninety per cent of systemic strains and thirty-four per cent of a collection of carrier isolates, both from Norway late 1981/early 1982, were typable. The serotype antigen 15 alone or in combination with P1. 16 or P1. 16 alone were detected in about 85 per cent of the systemic strains. The quality of the whole-cell meningococcal antigen was important for the test to be easily read.

Agglutination Tests↗
PubMed1980

Virulence factors in meningococci.

It is well established that meningococcus strains vary in virulence from non-invasive to highly invasive. This review, based on the literature, presents some of the characteristics of the bacteria that may be of importance for their virulence. It is assumed that factors such as production of an IgA1-protease or the ability to attach to the nasopharyngeal epithelial cells contribute to the virulence of the bacteria. The true role of the lipopolysaccharide for the virulence is not clear, but this substance is obviously of great importance in the pathogenesis of the disease caused by virulent strains. Encapsulated meningococci possess antiphagocytic surface factors that may contribute to their virulence. Such characteristics, which provide the bacteria with the ability to resist the bactericidal action of humoral serum factors, are believed to be the major factors determining virulence. Capsular material together with the serotype protein, or a co-variant protein, are essential in endowing the bacteria with resistance to the killing effect of serum factors.

Adhesiveness↗
PubMed1994

[The new epidemiologic situation in the Czech Republic caused by the C:2a:P1.2 (P1.5) strain of meningococci].

A new epidemiological situation for invasive meningococcal disease developed in the Czech Republic in 1993. The investigation of meningococcal noncapsular antigens revealed that the new strain Neisseria meningitidis C:2a:P1.2 (P1.5) is the causative agent. This strain has never been found in the Czech Republic before, at least not since 1973 (Czech meningococci have been sero/subtyped since). The investigation of the relationships by ET-typing revealed that this Neisseria meningitidis C:2a:P1.2 (P1.5) belongs to the ET-37 clone. In spring 1993 this new meningococcal clone caused an unusual increase of morbidity in two districts in one region of the Czech Republic and during the next winter/spring season (1993/1994) it spread to all regions of the country. This new strain causes severe and frequently atypical clinical manifestations, with the highest morbidity and fatality rates in the age group of 15-19 years (20% fatality in 1993).

Adolescent↗
PubMed1975

[Possibility of increasing the sensitivity of the fluorescent antibody indirect method in detection of meningococci].

It was shown that different representatives of the Neisseria genus had common antigens of protein nature, detected by the immunofluorescent method. Common antigens can be destroyed during treatment of bacterial smears with proteolytic enzymes; with preservation of group-specific antigens this considerably increases the specificity of the fluorescent antibody method in detection of meningococci.

Fluorescent Antibody Technique↗
PubMed1975

[Nasopharyngeal microorganisms--antagonists of meningococci].

A study was made of the species composition of symbiotic microbial flora of the nasopharynx in healthy persons and meningococcus carriers, inhibiting in vitro the growth of the test strains of miningococci. Saprophytic streptococci and particularly Str. salivarius served as the principal and the most active antagonists of meningococci in both groups of the persons examined. Comparison of the inhibitory activity of antagonists in the groups examined revealed no significant differences. However, there were seen differences in the quantitative composition of the isolated antagonists: saprophytic streptococci, particularly Str. salivarius were isolated in great amounts, and more frequently from healthy individuals, and nondifferentiated Gram positive cocci of conditionally distinguished group--from carriers. Taking into consideration the high inhibitory activity of Str. salivarius it is supposed that it can be used as an indicator of the state of insensitiveness of the human organism to the meningococcus infection.

Antibiosis↗