Infections with bacteria of the species NEISSERIA MENINGITIDIS.

A fulminant infection of the meninges and subarachnoid fluid by the bacterium NEISSERIA MENINGITIDIS, producing diffuse inflammation and peri-meningeal venous thromboses. Clinical manifestations include FEVER, nuchal rigidity, SEIZURES, severe HEADACHE, petechial rash, stupor, focal neurologic deficits, HYDROCEPHALUS, and COMA. The organism is usually transmitted via nasopharyngeal secretions and is a leading cause of meningitis in children and young adults. Organisms from Neisseria meningitidis serogroups A, B, C, Y, and W-135 have been reported to cause meningitis. (From Adams et al., Principles of Neurology, 6th ed, pp689-701; Curr Opin Pediatr 1998 Feb;10(1):13-8)

A species of gram-negative, aerobic BACTERIA. It is a commensal and pathogen only of humans, and can be carried asymptomatically in the NASOPHARYNX. When found in cerebrospinal fluid it is the causative agent of cerebrospinal meningitis (MENINGITIS, MENINGOCOCCAL). It is also found in venereal discharges and blood. There are at least 13 serogroups based on antigenic differences in the capsular polysaccharides; the ones causing most meningitis infections being A, B, C, Y, and W-135. Each serogroup can be further classified by serotype, serosubtype, and immunotype.

Vaccines or candidate vaccines used to prevent infection with NEISSERIA MENINGITIDIS.

One of the short-acting SULFONAMIDES used in combination with PYRIMETHAMINE to treat toxoplasmosis in patients with acquired immunodeficiency syndrome and in newborns with congenital infections.

Strains of Neisseria meningitidis found mostly in Africa.

A 93-kDa serum glycoprotein encoded by C7 gene. It is a polypeptide chain with 28 disulfide bridges. In the formation of MEMBRANE ATTACK COMPLEX; C7 is the next component to bind the C5b-6 complex forming a trimolecular complex C5b-7 which is lipophilic, resembles an integral membrane protein, and serves as an anchor for the late complement components, C8 and C9.

Strains of Neisseria meningitidis responsible for most sporadic cases in teenagers and almost all outbreaks of disease in this age group. These strains are less common in infants.

Purplish or brownish red discoloration, easily visible through the epidermis, caused by hemorrhage into the tissues. When the size of the discolorization is >2-3 cm it is generally called Ecchymoses (ECCHYMOSIS).

A 150-kDa serum glycoprotein composed of three subunits with each encoded by a different gene (C8A; C8B; and C8G). This heterotrimer contains a disulfide-linked C8alpha-C8gamma heterodimer and a noncovalently associated C8beta chain. C8 is the next component to bind the C5-7 complex forming C5b-8 that binds COMPLEMENT C9 and acts as a catalyst in the polymerization of C9.

A 53-kDa protein that is a positive regulator of the alternate pathway of complement activation (COMPLEMENT ACTIVATION PATHWAY, ALTERNATIVE). It stabilizes the ALTERNATIVE PATHWAY C3 CONVERTASE (C3bBb) and protects it from rapid inactivation, thus facilitating the cascade of COMPLEMENT ACTIVATION and the formation of MEMBRANE ATTACK COMPLEX. Individuals with mutation in the PFC gene exhibit properdin deficiency and have a high susceptibility to infections.

Suspensions of attenuated or killed bacteria administered for the prevention or treatment of infectious bacterial disease.

Process of determining and distinguishing species of bacteria or viruses based on antigens they share.

The natural bactericidal property of BLOOD due to normally occurring antibacterial substances such as beta lysin, leukin, etc. This activity needs to be distinguished from the bactericidal activity contained in a patient's serum as a result of antimicrobial therapy, which is measured by a SERUM BACTERICIDAL TEST.

A penicillin derivative commonly used in the form of its sodium or potassium salts in the treatment of a variety of infections. It is effective against most gram-positive bacteria and against gram-negative cocci. It has also been used as an experimental convulsant because of its actions on GAMMA-AMINOBUTYRIC ACID mediated synaptic transmission.

Polysaccharides found in bacteria and in capsules thereof.

Immunoglobulins produced in a response to BACTERIAL ANTIGENS.

Strains of Neisseria meningitidis which are the most common ones causing infections or disease in infants. Serogroup B strains are isolated most frequently in sporadic cases, and are less common in outbreaks and epidemics.

Administration of vaccines to stimulate the host's immune response. This includes any preparation intended for active immunological prophylaxis.

Systemic inflammatory response syndrome with a proven or suspected infectious etiology. When sepsis is associated with organ dysfunction distant from the site of infection, it is called severe sepsis. When sepsis is accompanied by HYPOTENSION despite adequate fluid infusion, it is called SEPTIC SHOCK.

Strains of Neisseria meningitidis responsible for most outbreaks of meningococcal disease in Western Europe and the United States in the first half of the 20th century. They continue to be a major cause of disease in Asia and Africa, and especially localized epidemics in Sub-Sahara Africa.

Semisynthetic vaccines consisting of polysaccharide antigens from microorganisms attached to protein carrier molecules. The carrier protein is recognized by macrophages and T-cells thus enhancing immunity. Conjugate vaccines induce antibody formation in people not responsive to polysaccharide alone, induce higher levels of antibody, and show a booster response on repeated injection.

Ongoing scrutiny of a population (general population, study population, target population, etc.), generally using methods distinguished by their practicability, uniformity, and frequently their rapidity, rather than by complete accuracy.

A species of gram-negative, aerobic BACTERIA commonly found in the NASOPHARYNX of infants and children, but rarely pathogenic. It is the only species to produce acid from LACTOSE.

Strains of Neisseria meningitidis which, in the United States, causes disease in mostly adults and the elderly. Serogroup Y strains are associated with PNEUMONIA.

Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)

The condition of harboring an infective organism without manifesting symptoms of infection. The organism must be readily transmissible to another susceptible host.

Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.

Porins are protein molecules that were originally found in the outer membrane of GRAM-NEGATIVE BACTERIA and that form multi-meric channels for the passive DIFFUSION of WATER; IONS; or other small molecules. Porins are present in bacterial CELL WALLS, as well as in plant, fungal, mammalian and other vertebrate CELL MEMBRANES and MITOCHONDRIAL MEMBRANES.

Proteins isolated from the outer membrane of Gram-negative bacteria.