FAMILY MICROCOCCACEAE 



243 



Habitat : Skin and mucous membranes 

 of vertebrates. 



11. Micrococcus aurantiacus (Schroe- 

 ter) Cohn. (Bacteridium aurantiacuin 

 Schroeter, Beitr. z. Biol., 1, Heft 2, 1872, 

 126; Colin, Beitr. z. Biol., 7, Heft 2, 1872, 

 154; Pediococcus aurantiacus De Toni and 

 Trevisan, in Saccardo, Sylloge Fungorum, 

 8, 1889, 1051; Micrococcus aurantiacus- 

 sorghi Bruyning, Arch. Neer. Sci. E.xaet. 

 et Nat., 1, 1898, 297; Streptococcus 

 aurantiacus Chester, Man. Determ. 

 Bact., 1901, 69; Aurococcus aurantiacus 

 Winslow and Winslow, Systematic Rela- 

 tionships of the Coccaceae, 1908, 186; 

 Sarcina aurantiaca Holland, Jour. Bact., 

 5, 1920, 225 (not Sarcina aurantiaca 

 Flijgge, Die Mikroorganismen, 2 Aufl., 

 1886, 180); Staphylococcus aurantiacus 

 Holland, ibid.) From Latin, aurum, 

 gold;M. L., aurantium , the orange ;M.L., 

 aurantiacus, orange-colored. 



Spheres: Slightly ellipsoidal, 1.3 to 1.5 

 microns, occurring singly, in short chains 

 and in small clumps. Xon-motile. 

 Gram-positive. 



Gelatin colonies: Circular to oval, 

 smooth, glistening with yellow to orange 

 center. 



Gelatin stab : Yellow surface growth . 

 No liquefaction. 



Agar colonies: Circular, smooth, glis- 

 tening, yellow to orange, entire. 



Agar slant : Buff to scant orange-j^ellow, 

 beaded growth, raised, glistening. 



Broth : Turbid, with pellicle. 



Litmus milk: Faintly acid, no coagu- 

 lation. 



Potato : Slimy, yellow growth. Pig- 

 ment is insoluble in alcohol and ether. 



Indole not produced. 



Nitrites generally produced from ni- 

 trates. 



Slight acidity from glucose, fructose, 

 sucrose, lactose and mannitol. Xo acid 

 from raffinose, salicin, inulin. 



Starch not hydrolyzed. 



Ammonia produced from peptone. 



No growth in ammonium media. 



May be pathogenic. 



Optimum temperature 25°C. 



Aerobic. 



Source : First isolated from colonies 

 that grew on boiled egg exposed to dust 

 contamination. 



Habitat : Usually isolated from infec- 

 tions but also found in milk, cheese and 

 dust. 



Note: Albococcus cpidermidis (var. 

 A) Kligler (Jour. Infect. Dis., 12, 1913, 

 444) which was based on a white culture 

 received from Krai under the name 

 Micrococcus aurantiacus was apparently 

 a white strain of this organism as it grew 

 luxurianth^ on ordinary agar. 



12. Micrococcus epidermidis (Winslow 

 and Winslow) Hucker. [Staphylococcus 

 epidermidis albus Welch, Amer. Jour, of 

 Med. Sci., Phila., X. S., 102, 1891, 441; 

 Micrococcus epidermidis albus Randolph, 

 Jour. Amer. Med. Assoc, 31, 1898, 706; 

 Albococcus epidermidis Winslow and Win- 

 slow, Syst. Relationships Coccaceae, 

 New York, 1908, 201; Staphylococcus 

 epidermidis Evans, Jour. Inf. Dis., 15, 

 1916, 449; Hucker, X. Y. Agr. Exp. Sta. 

 Tech. Bull. 102, 1924, 21.) From Greek, 

 epidermis, the outer skin. 



Spheres: 0.5 to 0.6 micron, occurring 

 singly, in pairs and in irregular groups. 

 Xon-motile. Gram-positive. 



Gelatin stab : White surface growth 

 with slow saccate liquefaction. 



Agar colonies: Rather scant, white, 

 translucent. 



Broth: Turbid, with white ring and 

 sediment. 



Litmus milk: Acid. 



Potato : Limited growth, white. 



Indole not formed. 



Xitrites are produced from nitrates. 



Usually does not utilize XH4H2PO4 

 as a source of nitrogen. 



Acid formed from glucose, fructose, 

 maltose, lactose and sucrose, but not 

 from mannitol, raffinose, salicin or 

 inulin. 



Usually fails to hemolyze blood. Xo 

 coagulase produced. 



Parasitic rather than pathogenic. 



Aerobic, facultative. 



