tened where they are in contact. Gram-nega- tive. Grows best on media with the addition of body fluids (blood, ascites, etc.) or other specially prepared media. Colonies are small and transparent, even- tually (2 to 4 days) developing a lobate margin, grayish white with a pearly opal- escence by transmitted light. Larger colo- nies form on special media. Acid from glucose. No acid from fructose, maltose, sucrose, mannitol or other sugars. Optimum temperature, 37° C. No growth below 25° C. Aerobic to facultatively anaerobic. Many strains develop more readily with increased CO2 tension. Source: Originally found in purulent venereal discharges. Also found in blood, conjunctiva, joints and cerebrospinal fluid. Habitat: The cause of gonorrhea and other infections of man. Not found in other animals. 2. Neisseria ineningitidis* (Albrecht and Ghon, 1903) Holland, 1920. (Diplococcus intracellular is meningitidis Weichsel- baum, Fortschr. d. Med., 5, 1887, 583; Neisseria weichselbaumii Trevisan, I generi e le specie delle Batteriacee, 1889, 32; Micrococcus intracelhilaris Migula, Syst. d. Bakt., 2, 1900, 189; Micrococcus menin- gitidis Albrecht and Ghon, Cent. f. Bakt., I Abt., Orig., 33, 1903, 498; Holland, Jour. Bact., 5, 1920, 224.) me.nin.gi'ti.dis. Gr. fem.n. meninx, meningis the membrane enclosing the brain; M.L. fem.n. meningitis, meningitidis in- flammation of the meninges. Common name: Meningococcus. In 1898, Councilman, Mallory and Wright (Epidemic Cerebrospinal Meningitis and its Relation to other Forms of Meningitis, Boston, 1898) definitely established the Gram-negative coccus as the cause of epi- demic meningitis. Spheres, 0.6 to 1.0 micron in diameter, occasionally larger; occur singly, in pairs with adjacent sides flattened or occa- sionally in tetrads. Gram-negative. Good growth is obtained on media con- taining blood, blood serum and other en- richment fluids with added glucose. Best growth on special media. Blood agar plates are generally employed to isolate the organism. The colonies are small, slightly conve.x, transparent, glis- tening. Colonies are larger on special media. Older cultures may show growth on nu- trient agar or glucose agar properly pre- pared. Semi-solid media are especially favorable for growth and are often used for isolation. With recently isolated strains frequent transplantation is necessary to keep the organism alive; older strains sur- vive longer. Cultures should be kept at 35° to 37° C. Acid from glucose and maltose. No acid from other carbohydrates. Nitrites not produced from nitrates. Optimum temperature, between 36° and 37° C. No growth at 22° C. Aerobic. Source: Originally found in the cerebro- spinal fluid. Also found in the nasopharj'n.x, in the blood, in the conjunctiva, in pus from joints and in petechiae in the skin. Habitat: Nasopharynx of man; not found in other animals. Cause of epidemic cerebro- spinal fever (meningitis). Four main groups of Neisseria meningiti- dis have been differentiated on the basis of agglutination reactions with immune serum. The Subcommittee on Neisseria of the In- ternational Committee on Bacteriological Nomenclature of the International Asso- ciation of Microbiologists has suggested
- The binomial Neisseria intracelhilaris , used in the first five editions of the Manual,
proved confusing because the names Micrococcus intracellularis, Diplococcus intracelhilaris and Streptococcus intracellularis have been used loosely for unrelated organisms. Neisseria weichselbaumii has also been so rarely used and at the same time is so loosely used that any attempt to introduce it now is inadvisable despite rights or priority. The equally available name Neisseria meningitidis was therefore adopted for the 6th edition of the Manual and is hereby continued. It has the obvious advantage of association with the common name, meningococcus, which has been repeatedly used in the literature.
