FAMILY VII. MICROCOCCACEAE 



465 



1. Staphylococcus aureus Rosenbach, 

 1884. (Staphylococcus pyogenes aureus Rosen- 

 bach, Mikroorganismen bei den Wund- 

 infektionskrankheiten des Menschen, 1884, 

 19 ; Staphylococcus pyogenes albus Rosenbach, 

 ibid., 21; Staphylococcus aiireus Rosenbach, 

 ibid., 27; Staphylococcus albus Rosenbach, 

 loc. cit.; Staphylococcus pyogenes citreus 

 Passet, Aetiologie der eiterigen phlegmone 

 des Menschen, Berlin, 1885, 9; Micrococcus 

 aureus Zopf, Die Spaltpilze, 3 Aufl., 1885, 

 57; Micrococcus pyogenes Lehmann and Neu- 

 mann, Bakt. Diag., 1 Aufl., 2, 1896, 165; 

 Micrococcus citreus Migula, Syst. d. Bakt., 

 S, 1900, 147; Micrococcus albus Buchanan, 

 Veterinary Bact., 1911, 196; Staphylococcus 

 citreus Bergey et al.. Manual, 1st ed., 1923, 

 55.) 



au're.us. L. adj. aureus golden. 



Spheres, 0.8 to 1.0 micron in diameter, 

 occurring singly, in pairs, in short chains 

 and in irregular clumps. Non-motile. Gram- 

 positive. 



Chromogenesis : Typical Staphylococcus 

 aureus cultures rather readily develop 

 variants that grow as dirty white colonies. 

 Such colonies quite frequently develop 

 strains that again produce the tj'pical 

 orange chromogenesis. On the other hand 

 cultures occur which are white on original 

 isolation. Such colonies usually do not 

 develop orange variants although they are 

 identical in other cultural characters and 

 in their physiological characters with the 

 orange strains. Some designate these white 

 forms as Staphylococcus albus, as did Rosen- 

 bach, and regard them as belonging to a 

 separate species. 



Passet used the name Staphylococcus pyo- 

 genes citreus for the organisms that produce 

 the yellower (more lemon-colored) colonies. 

 He distinguished these from the darker 

 yellow (more orange-colored) colonies de- 

 scribed by Rosenbach under the name 

 Staphylococcus aureus. Passet secured his 

 Staphylococcus citreus cultures from asepti- 

 cally drawn pus. He reports that the yellow 

 organisms were identical with the orange 

 organisms except for the difference in chro- 

 mogenesis. Later investigators have some- 

 times reported other differences in charac- 

 ters without referring back to Passet's 



original description, in which no such differ- 

 ences in characters are noted. 



Gelatin stab: Saccate liquefaction with 

 white to j-ellowish pellicle and white or yel- 

 low to orange sediment. 



Agar colonies: Circular, smooth, orange 

 to white, glistening, butj^rous, entire. 



Agar slant: Abundant, opaque, smooth, 

 flat, moist, white to j'ellowish or orange 

 growth. 



Broth: Turbid, becoming clear; yellowish 

 ring and sediment. 



Litmus milk: Acid, coagulated. 



Acid from glucose, lactose, sucrose, man- 

 nitol and glycerol. No acid from raffinose, 

 salicin or inulin. 



Optically inactive or levo-rotatory lactic 

 acid is produced (Orla- Jensen, The Lactic 

 Acid Bacteria, 1919,81). 



Acetoin produced from glucose. 



Starch and esculin not hydrolyzed. 



Sodium hippurate usually hydrolyzed. 



Nitrites produced from nitrates. 



Amino acids are required as a source of 

 nitrogen. 



Thiamin and nicotinic acid are required 

 for growth. 



Does not utilize NH4H2PO4 as a source of 

 nitrogen. 



Ammonia produced from peptone and 

 arginine. 



Blood agar: Beta hemolysis normally pro- 

 duced. 



Catalase-positive. 



Aerobic, facultatively anaerobic. 



Optimum temperature, 37° C. Grows at 

 10° and 45° C., these temperatures being 

 very near the minimum and maximum tem- 

 peratures respectively. 



Very salt tolerant, growing vigorously in 

 media containing 10 per cent NaCl. 



Certain strains, under favorable condi- 

 tions, produce not only exotoxins (hema- 

 toxin, dermatoxin, lethal toxin, etc.) but 

 also a potent enterotoxin which is a sig- 

 nificant cause of food poisoning (Dolman 

 and Wilson, Jour. Immunology, 35, 1938, 

 13). 



Pathogenic. 



Distinctive characters: Normally coagu- 

 lase-positive (human or rabbit plasma). 

 Ferments both glucose and mannitol under 

 anaerobic conditions. 



