neous polyarthritis in mice, from the naso- doubtedly caused by ingestion of infected pharynx and infected middle-ears of milk, and the portal of entry was thought laboratory and wild rats, from cervical ab- to be intestinal. scesses in guinea pigs and from the blood Comment: Another type of rat-bite fever and joint fluids of humans suffering from rat (Soduku) is caused by Spirillum minus bite fever. Similar organisms, which many Carter. Clinically the two etiologically dis- regard as identical with Streptobacillus tinct diseases may be indistinguishable. moniliformis Levaditi et al., have been Mixed infections may occur, reported as the cause of Haverhill fever Habitat: Commonly found as an inhabi- (Erythema arthriticum epidemicum); the tant of the naso-pharynx of rats. Occurs as Haverhill epidemic in the United States the etiological agent of an epizootic septic (1926), which has given name to the disease polyarthritis in mice and of one type of rat- when not contracted by rat bite, was un- bite fever. FAMILY VII. MICROCOCCACEAE PRIBRAM, 1929.* (Jour. Bact., 18, 1929, 385.) Mi.cro.coc.ca'ce.ae. M.L. mas.n. Micrococcus type genus of the familj-; -aceac ending to denote a family; M.L. fem.pl.n. Micrococcaceae the Micrococcus family. Cells in their free condition spherical; during division, somewhat elliptical. Endospores not produced (except mSarcina ureae under special conditions). Division is primarily in two or three planes; some anaerobic cells divide only in a single plane, producing chains. If the cells remain in contact after division, they are frequently flattened in the plane of last division. They occur singly or in pairs, tetrads, packets, irregular masses or even in chains. Motility is rare. Gram-positive although the free-living and saprophytic species may de- colorize so readily that they are sometimes reported as Gram-variable or even as Gram- negative. Many species form a non-water-soluble, yellow, orange, pink or red pigment. The aerobic species produce abundant growth on ordinary culture media and are capable of slight anaerobic growth. Anaerobic to aerotolerant species also occur. Heterotrophic. No visible gas is produced by the aerobic species from carbohydrates, which are frequently fer- mented. The anaerobic species sometimes produce gas, such as methane, carbon dioxide and hydrogen. Gelatin is often slowly liquefied. Free-living, saprophytic to parasitic or even pathogenic. The typical aerobic micrococci frequently live on the skin, in skin glands or in the skin gland secretions of Vertebrata; however, sea-water and soil forms may occur. The anaerobic species live primarily in decomposing organic materials. Key to the genera of family Micrococcaceae. I. Aerobic to facultatively anaerobic species. Also includes some obligate anaerobes that occur in packets (Sarcina). A. Cells are generally found in irregular masses; occasionally they are single or in pairs. 1. Action on glucose, if any, is oxidative. Aerobic. Genus I. Micrococcus, p. 455. 2. Glucose fermented anaerobically with the production of acid. Facultatively anaerobic. Genus II. Staphylococcus, p. 464. B. Cells normally occur in tetrads or packets of eight cells. 1. Parasitic species occurring in tetrads. White to pale yellow chromogenesis. Non-motile. Genus III. Gaffkya, p. 446.
- Arranged by Prof. Robert S. Breed, Cornell University, Geneva, New York, October,
1955.
