FAMILY V. BRUCELLACEAE 



413 



Habitat: Occurs in large numbers in 

 preputial secretions of dogs. 



14. Haemophilus citreus Diernhofer, 

 1949. (Wiener tierarztl. Monatsschr., 36, 

 1949, 582.) 



cit're.us. L. adj. citreus of the citron; 

 M.L. adj. citreus lemon-colored. 



Rods, 0.5 by 1.0 to 2.0 microns, occurring 

 singly and in short chains; frequently' 

 pleomorphic with long threads. Non-motile. 

 Stain poorly and unevenly, showing bi- 

 polar bodies. Gram-negative. 



Gelatin plus blood: No liquefaction. 



Plain agar: No growth. 



Blood agar containing 20 to 30 per cent 

 blood and 1.0 per cent glucose is optimum 

 for isolation. Colonies are 1 to 2 mm in 

 diameter, flat, moist and entire. Some 

 strains produce a narrow zone of hemolysis 

 around the colonies. Become slightly yel- 

 low; lemon-yellow when massed by loop. 



V and X agar colonies: Very small, trans- 

 parent, colorless. 



Serum, pus, fresh milk, potato extract 

 and yeast extract added to chocolate agar 

 stimulate luxuriant growth. 



Indole is produced. 



Weak acid from glucose. 



Nitrites produced from nitrates. 



Non-pathogenic for mice, guinea pigs and 

 calves. Does not induce disease in the 

 genital tracts of cattle. 



Aerobic. 



Grows at 37° C. Killed in 30 minutes at 

 50° C. 



Source: Isolated from genital secretions 

 from acute and chronic cases of vesicular 

 exanthema (exanthema coitale) in cattle. 



15. Haemophilus pisciuin Snieszko et 

 al., 1950. (Snieszko, Griffin and Friddle, 

 Jour. Bact., 59, 1950, 699.) 



pis'ci.um. L. noun piscis fish; M.L. 

 gen. pi. noun piscium of fishes. 



Rods, in lesions measuring 0.5 to 0.7 by 

 2.0 microns, in cultures measuring 0.8 to 

 1.0 by 1.0 to 3.0 microns, occurring singly, 

 in pairs, in irregular groups and occasionally 

 as filaments up to 12.0 microns in length. 

 Non-motile. May show bipolar staining. 

 Gram-negative. 



Requires diphosphothiamine or adenosine 

 triphosphate for growth (Griffin, Arch. 

 Biochem., 30, 1951, 100). Supplied by peptic 

 digest of fish tissue or 5 per cent sterile, 

 unheated potato extract; V and X factors 

 are not required. X in presence of diphos- 

 phothiamine increases growth response 

 (Griffin, Yale Jour. Biol, and Med., 24, 

 1952,411). 



Fish e.xtract gelatin colonies : Same as on 

 agar. No liquefaction. 



Fish extract gelatin stab: Growth best 

 near surface, filiform. No liquefaction. 



Fish extract agar colonies: 1 to 3 mm in 

 diameter, circular, entire, convex, opaque, 

 smooth, cream-colored. S variants are 

 butyrous, R variants are compact and 

 tough. 



Blood agar: Beta hemolysis. 



Fish extract agar slant: In 2 to 3 days, 

 growth is filiform, slightly glistening, 

 cream-colored. S variants are butyrous, 

 R variants are brittle. 



Fish extract broth: R variants show 

 transient clouding, then granular; adherent 

 to walls; clearing of medium; scant pellicle 

 or ring within a week. S variants remain 

 uniformly clouded for several days. 



Fish extract litmus milk: No change. 



Potato: No visible growth. 



Indole not produced. 



Acid but no gas in 2 to 3 days in fish 

 extract broth with glucose, fructose or 

 sucrose; slowly with maltose, trehalose or 

 starch; weak and slowly with mannose, 

 galactose, cellobiose or dextrin. No acid 

 with arabinose, xylose, rhamnose, lactose, 

 melibiose, raffinose, melezitose, inulin or 

 alcohols. 



Methyl red test positive; Voges- 

 Proskauer test negative after one week. 

 Fish extract used in media. 



Nitrites produced from nitrates. 



Aerobic, facultatively anaerobic. 



Optimum temperature, between 20° and 

 25° C. No growth at 35° C., slow growth 

 at 7° C. 



Pathogenic for trout. 



Source: Isolated from trout with ulcer 

 disease. 



Habitat : Found in infected trout. A cause 

 of ulcer disease in trout. 



