Epidemic cerebrospinal meningitis

Epidemic cerebrospinal meningitis (meningococcal epidemic meningitis), acute infectious disease, which afflicts meninges of the brain and spinal cord.


Fig. 2. Meningococci in the spinal fluid.

Etiology. The causative agent of epidemic cerebrospinal meningitis is the meningococcus Neisseria meningitidis. First isolated in pure culture Weichselbaumer (A. Weicliselbaum) in 1887 from the cerebrospinal fluid of patients (Fig. 2). The determinant of Berga meningococcal disease classified as Schizomycetes, order Eubacteriales, family Neisseriaceae. Meningococci are cells wrong spherical shape with a diameter of 0,6-1,0 MK. In a smear they often arranged in pairs, at least - singly or in a notebook. Meningococci gram, motionless, spores do not form, capsules does not have, even in the presence of typespecific immune sera marked swelling of the cell wall.
Meningococci well grow on nutrient mediums, which added glucose and blood, serum, ascitic or any other containing the native protein liquid. Some strains grow well on synthetic and semi-synthetic environments. On blood agar freshly isolated strains of Neisseria meningitides form S-colony without the zone of hemolysis.
In older cultures often the appearance R-colonies. With the growth in liquid media meningococci form a uniform clouding of the environment and sediment. Optimum growth meningokokkov at 2 degrees 37 degrees. Freshly isolated strains need to reseed almost daily, old crops require less frequent transfers. Keep strains should at 2 degrees 35-37°, better on egg medium Dorsey.
Meningococci - aerobes, although most strains requires high concentration (2-22%) of CO2 in the air. Meningococci not forming indol and H2S, do not restore the nitrate to nitrite, is decomposed with the formation of acid only glucose and maltose. Meningococci resistant to the influence of external factors, quickly perish under the influence of antiseptics, is very sensitive to antibiotics and chemotherapeutic drugs.
According to the adopted in 1950 scheme, meningococci are divided into four serologic groups: a, b, C, D, corresponding to the I, II, II and IV types accepted classification. Typespecific antigens are polysaccharides. Meningococci contain nonspecific lipo-polisaharida-protein antigen, having the properties of endotoxin, calling in rabbits phenomenon Shvartsman.
Protivoallergicheskoy immunity short and wears typespecific character. Material for the allocation of a pure culture is the cerebrospinal fluid of patients or nasal discharge bakterionositelej. Sowing material should be done as quickly as possible, without its cooling the lower temperature of 37 degrees. Allocated culture mikroskopiruyut (you can also explore the sediment cerebrospinal fluid) and then subjected to a serological identification with poly - and monovalent vaccines.