FAMILY V. BRUCELLACEAE, Nom. Nov. (Parvobacteriaceae Rahn, Zent. f. Bakt., II Abt., 96, 1937, 281.) Bru.cel.la'ce.ae. M.L. fem.n. Brucella type genus of the family; -aceae ending to denote a family; M.L. fem.pl.n. Brucellaceae the Brucella famil3^ Small, coccoid to rod-shaped cells which occur singly, in pairs, in short chains or in groups; filamentous and pleomorphic forms are occasionally found. Motile and non-motile species occur, the motile species possessing from one to eight peritrichous fiagella; with certain of the motile species, motility can be demonstrated only at lower temperatures (18° to 26° C). May or may not be encapsulated. May or may not show bipolar staining. Gram- negative. V (phosphopyridene nucleotide) and/or X (hemin) factors are sometimes required for growth; blood serum and similar enrichment materials maybe required or may enhance growth. Increased CO2 tension may also favor growth, especially on primary isolation. Gelatin usuallj' not liquefied. Carbohydrates may or may not be attacked with the produc- tion of acid but no gas. Nitrites may or may not be produced from nitrates. Aerobic, facul- tatively anaerobic. Some invade living tissues; infection in some cases may take place by penetration of the organism through mucous membranes or through the unbroken skin. Parasites and pathogens which affect warm-blooded animals, including man, rarely cold- blooded animals. Key to the genera of family Brucellaceae. I. Non-motile at 37° C., but may be motile at lower temperatures. A. Predominantly occur singly or in masses. 1. Cells predominantly occur singly and do not occur in masses. a. Grow on peptone media but may require blood serum or similar enrichment materials for growth. b. Show, or tend to show, bipolar staining, c. Attacks carbohydrates. Genus I. Pasteurella, p. 395. cc. Does not attack carbohydrates. Genus II. Bordetella, p. 402. bb. Does not show bipolar staining. Genus III. Brucella, p. 404. aa. Requires V (phosphopyridene nucleotide) and/or X (hemin) factors for growth. Genus IV. Haemophilus, p. 406. 2. Cells predominantly occur singly and show pleomorphism and/or occur in masses. a. Growth occurs on ordinary media; increased CO2 tension enhances growth, especially on primary isolation. Genus V. Actinobacillus, p. 414. aa. Growth occurs on infusion media only after growth in chick embryo. Genus VI. Calymmatohacterium, p. 418. B. Predominant!}^ occur as diplobacilli. Genus VII. Moraxella, p. 419. II. Motile at 37° C. A. Optimum temperature for growth, 37° C. Litmus milk becomes strongly alkaline. Genus II. Bordetella, p. 402. B. Optimum temperature for growth, between 28° and 30° C. Litmus milk unchanged. Genus VIII. Noguchia, p. 421.
