Emergence of new virulent Neisseria meningitidis serogroup C sequence type 11 isolates in France.

In France, there have been variations in the incidence of invasive meningococcal infection due to serogroup C isolates. Infection peaks were observed in 1992 and 2003 that involved isolates of phenotypes C:2a:P1.5,2 and/or C:2a:P1.

Association of meningococcal phenotypes and genotypes with clinical characteristics and mortality of meningitis in children.

Background: Neisseria meningitidis meningitis represents approximately one-half of the meningococcal cases in French children. To explore the contribution of bacterial typing in improving the management of cases, we aimed to describe clinical characteristics and mortality of meningococcal meningitis in children reported to the multicenter survey system, GPIP/ACTIV, in association with phenotypes/genotypes of bacterial isolates.

Methods: From 2001 to 2005, 259 pediatric wards and 168 microbiology laboratories enrolled all children with bacterial meningitis.

Emerging drugs for acute bacterial meningitis.

The management of acute bacterial meningitis is based on early antibiotic treatment to prevent unfavorable outcome (death and permanent sequelae). beta-Lactam antibiotics, particularly third-generation cephalosporins, are effective against most agents of community-acquired acute bacterial meningitis. Resistance to beta-lactams evolves, particularly in Streptococcus pneumoniae, that may lead to treatment failure.

Influenza A virus neuraminidase enhances meningococcal adhesion to epithelial cells through interaction with sialic acid-containing meningococcal capsules.

The underlying mechanisms of the epidemiological association between influenza virus infections and Neisseria meningitidis invasive infections are not fully understood. Here we report that adhesion of N. meningitidis to human Hec-1-B epithelial cells is enhanced by influenza A virus (IAV) infection.

[Anti-meningococcal vaccines].

Current anti-meningococcal vaccines are prepared from capsular saccharides (plain or conjugate). They target four serogroups A, C, Y and W135. No vaccine is available against serogroup B saccharide.

Transgenic mice expressing human transferrin as a model for meningococcal infection.

The pathogenesis of meningococcal disease is poorly understood due to the lack of a relevant animal model. Moreover, the use of animal models is not optimal as most meningococcal virulence determinants recognize receptors that are specifically expressed in human tissues. One major element of the host specificity is the system of meningococcal iron uptake by transferrin-binding proteins that bind specifically human transferrin but not murine transferrin.

Meningococcal vaccines: to eradicate the disease, not the bacterium.

Neisseria meningitidis is exclusively a human-adapted bacterium, most frequently found in asymptomatic carriage that promotes natural immunity. However, it is also the causative agent of severe invasive infections, such as septicaemia and/or meningitis that may lead to life-threatening septic shock. Vaccination with capsular polysaccharidic antigens (either plain or conjugated) induces serogroup specific protective antibodies.

Workshop on vaccine pressure and Neisseria meningitidis, Annecy, France, 9-11 March 2005.

A 3-day workshop, "Vaccine pressure and Neisseria meningitidis", was held in Annecy, France, 9-11 March 2005, to summarize the current state of knowledge regarding N. meningitidis capsule switching and vaccine pressure from capsular polysaccharide-based N. meningitidis vaccines, including conjugates.

Susceptibility of Neisseria gonorrhoeae to antimicrobial peptides from amphibian skin, dermaseptin, and derivatives.

We evaluated the antimicrobial effect of antimicrobial peptides from frog skin belonging to the dermaseptin family against reference and clinical Neisseria gonorrhoeae strains, including penicillin-resistant strains. Dermaseptin S4 exhibited anti-N. gonorrhoeae activity against all strains with MICs ranging between 10 and 100 microg/mL.

Differential role of lipooligosaccharide of Neisseria meningitidis in virulence and inflammatory response during respiratory infection in mice.

Meningococcal lipooligosaccharide (LOS) induces a strong proinflammatory response in humans during meningococcal infection. We analyzed the role of LOS in the inflammatory response and virulence during the early infectious process in a mouse model of meningococcal respiratory challenge. An lpxA mutant strain (serogroup B) devoid of LOS (strain Z0204) could not persist in the lungs and did not invade the blood.

The rise and fall of epidemic Neisseria meningitidis serogroup W135 meningitis in Burkina Faso, 2002-2005.

Background: During the period 2001-2002, Burkina Faso reported its first meningitis epidemic due to Neisseria meningitidis (Nm) serogroup W135, prompting concerns that this serogroup would persist as a cause of epidemic disease.

Methods: During the period 2002-2005, hospital- and population-based surveillances were conducted in 3 districts in Burkina Faso. Etiology was determined by culture, polymerase chain reaction (PCR), and latex agglutination.

Immunogenicity of meningococcal PBP2 during natural infection and protective activity of anti-PBP2 antibodies against meningococcal bacteraemia in mice.

Objective: To evaluate the immunogenicity of the meningococcal penicillin-binding protein 2 (PBP2) and its potential as a vaccine candidate.

Methods: The immunogenicity of meningococcal PBP2 was investigated using acute and convalescent sera from patients who recovered from meningococcal disease. Sera were tested against purified recombinant PBP2s corresponding to meningococcal isolates of different genetic lineages, of different serogroups and with various susceptibility levels to penicillin G.

Conserved virulence of C to B capsule switched Neisseria meningitidis clinical isolates belonging to ET-37/ST-11 clonal complex.

Capsule switching in Neisseria meningitidis is thought to occur by horizontal DNA exchange between meningococcal strains. Antigenic variants may be generated by allelic replacement of the siaD gene; the variants may then be selected by specific immunity against the capsular antigen. There were several vaccination campaigns against serogroup C in France in 2002, following an increase in the prevalence of invasive isolates of serogroup C of the phenotype C:2a:P1.

Bacterial meningitis in children: a French prospective study.

From January 2001 through December 2003, a total of 1084 children with bacterial meningitis were enrolled in a prospective French nationwide survey. The most frequent pathogens found in children older than 28 days were Neisseria meningitis (55.3%) and Streptococcus pneumoniae (33.

[Meningococcal vaccines: present status and perspectives].

Neisseria meningitidis can cause asymptomatic carriage, followed by acquired immunity, or septicaemia, meningitis, septic arthritis or pericarditis. Vaccination induces protective bactericidal antibodies to invasive diseases. Meningococcal capsular polysaccharides are immunoprotective antigens from which vaccines are produced against serogroups A, C, Y and W135, including conjugate vaccines against serogroup C.

Neisseria meningitidis pili induce type-IIA phospholipase A2 expression in alveolar macrophages.

Induction of type-IIA secreted phospholipase A2 (sPLA2-IIA) expression by bacterial components other than lipopolysaccharide has not been previously investigated. Here, we show that exposure of alveolar macrophages (AM) to Neisseria meningitidis or its lipooligosaccharide (LOS) induced sPLA2-IIA synthesis. However, N.

The establishment of Neisseria meningitidis serogroup W135 of the clonal complex ET-37/ST-11 as an epidemic clone and the persistence of serogroup A isolates in Burkina Faso.

We analyzed 48 invasive isolates of Neisseria meningitidis that were isolated from meningitis cases in Burkina Faso (April 2002 to April 2003). Thirty-nine of these isolates had the phenotype (serogroup:serotype:serosubtype) W135:2a:P1.5,2, eight isolates were A:4:P1.

The concept of "tailor-made", protein-based, outer membrane vesicle vaccines against meningococcal disease.

Protein-based, outer membrane vesicle (OMV) vaccines have previously proven to be efficacious against serogroup B meningococcal disease in Norway and Cuba. Currently, a public health intervention is going on in order to control a serogroup B epidemic in New Zealand. The scale-up and standardization of vaccine production required for controlling the New Zealand epidemic has allowed the establishment of large-scale GMP manufacturing for OMV vaccines.

Interlaboratory comparison of PCR-based identification and genogrouping of Neisseria meningitidis.

Twenty clinical samples (18 cerebrospinal fluid samples and 2 articular fluid samples) were sent to 11 meningococcus reference centers located in 11 different countries. Ten of these laboratories are participating in the EU-MenNet program (a European Union-funded program) and are members of the European Monitoring Group on Meningococci. The remaining laboratory was located in Burkina Faso.