FAMILY XII. CORYNEBACTERIACEAE 



583 



deposit, and there is no reversal of pH in 

 broth. 



Ten years of observations in all parts of 

 the world have shown (McLeod, Bact. Rev., 

 7, 1943, 1) that a small percentage of strains 

 does not correspond closely to any of these 

 three types. Variant strains are found most 

 frequently' in regions where the diphtheria 

 is of mild or moderate severity. 



Aerobic, facultative. 



Optimum temperature, between 34° and 

 36° C. Grows well at 37° C. 



Relationship to other species: A compari- 

 son of cultures has shown Corynebacterium 

 ulcerans Gilbert and Stewart to be identical 

 with C. diphtheriae Lehmann and Neumann 

 (Henriksen and Grelland, Jour. Path, and 

 Bact., 64, 1952, 509). 



Source: Commonly from membranes in 

 the pharynx, larynx, trachea and nose in hu- 

 man diphtheria; from the seemingly healthy 

 pharynx and nose in carriers; occasionally 

 from the conjunctiva and infected super- 

 ficial wounds. Found occasionally infecting 

 the nasal passages and wounds in horses; 

 also reported from natural diseases in fowl. 



Habitat: The cause of diphtheria in man. 

 Pathogenic to guinea pigs, kittens and rab- 

 bits. For action on other animals see An- 

 drewes et al. (Diphtheria. London, 1923, 

 170 ff.). 



2. Corynebacterium enzymicum (IVIel- 

 lon, 1917) Eberson, 1918. (An unusual diph- 

 theroid bacillus, Mellon, Med. Record, New 

 York, 81, 1916, 240; Bacillus enzymicus Mel- 

 lon, Jour. Bact., 2, 1917, 297; Eberson, Jour. 

 Inf. Dis., 23, 1918, 29.) 



en.zy'mi.cum. Gr. noun zynie leaven; 

 M.L. noun enzymum enzyme; M.L. adj. 

 enzymicus relating to enzyme. 



Rods, beaded and club-shaped, definitely 

 pleomorphic, showing coccoid forms. Non- 

 motile. Gram-positive. 



Gelatin stab: Slight surface growth. No 

 liquefaction. 



Glucose agar: Bacillary form shows very 

 small colorless colonies. Coccoid form shows 

 heavy, yellowish white, moist growths. 



Blood agar: Same as on glucose agar. 



Loefiier's blood serum: Fine, moist, con- 

 fluent growth. 



Glucose broth: Bacillary form shows 



granular sediment. Coccoid form shows 

 diffuse, luxuriant growth. 



Litmus milk: Acid, coagulated. 



Potato: No growth. 



Indole production slight. 



Acid from glucose, maltose, sucrose, dex- 

 trin and glycerol. 



Slight production of nitrites from nitrates. 



Aerobic, facultative. 



Optimum temperature, 37° C. 



Pathogenic for rabbits, guinea pigs and 

 mice. 



Source: Isolated from lungs, blood and 

 joints. 



Habitat: From human sources so far as 

 known. 



3. Corynebacterium hoagii (Morse, 

 1912) Eberson, 1918. (Bacillus X, Hoag, 

 Boston Med. and Surg. Jour., 167, 1907, 10; 

 Bacillus hoagiiMoTse, Jour. Inf. Dis., 11, 

 1912, 284; Eberson, Jour. Inf. Dis., 23, 1918, 

 10.) 



hoa'gi.i. M.L. gen. noun hoagii of Hoag; 

 named for Dr. Louis Hoag, the bacteriolo- 

 gist who first isolated this species. 



Rods, 0.8 to 1.0 by 1.0 to 3.0 microns, oc- 

 curring singly. Show polar staining in the 

 shorter forms while the longer forms are 

 barred and slightly club-shaped. Non-mo- 

 tile. Gram-positive. 



Gelatin colonies: Small, dull, pale pink, 

 entire. 



Gelatin stab: Slight pink surface growth. 

 No liquefaction. 



Agar colonies: Small, pale pink, dull, 

 granular, entire. 



Agar slant: Filiform, dull, pink growth. 



Broth: Turbid, with slight pink sediment. 



Litmus milk: Slightly alkaline, with pink 

 sediment. 



Potato: Dull, filiform streak. 



Indole not produced. 



Acid from glucose and sucrose but not 

 maltose. 



Nitrites not produced from nitrates. 



Blood serum: Dull, filiform, pink streak. 



Aerobic. 



Optimum temperature, 30° C. 



Source: Isolated from the throat; also 

 from air contamination of cultures. 



Habitat: Unknown. 



