PEREZ'S BACILLUS, OR COCCO-BAVlLLVS F(ETIDVS OZ^NM 495 



TABLE 33 



Differentiation of H. bronchisepticus from Perez's Bacillus. 



motile, Gram-negative bacillus, which they call B. ozogenes. It coagulates milk, 

 ferments glucose, maltose, mannitol, lactose, and sucrose with the production of acid and 

 gas, gives a variable indole reaction, and forms HjS. 



Cocco-bacillus foetidus-ozaense Perez 



Synonym. — Perez's bacillus. 



Isolation. — By Perez in 1899 from nose of ozsena patients. 



Habitat. — Nose of ozaena patients ; sahva and nasal mucus of normal dogs. Probably 

 strict parasite. 



Morphology. — Small cocco-bacillus, 1-2 fi long by 0-5 fi broad ; some strains are coccoid, 

 some are bacillary. Parallel or bulging sides, rounded ends ; axis straight ; 

 arranged singly, in bundles of two or three members, and occasionally in pairs 

 end-to-end. Long sinuous filaments and long straight or curved bacilli may be 

 seen, especially in old cultures. Staining is fairly even. Non-motile or sluggishly 

 motile. Non-capsulated. Gram-negative. 



Agar Plate. — 24 hours at 37° C. Round, amorphous, low convex, greyish-white, trans- 

 lucent colonies, up to 1 mm. in diameter ; smooth glistening surface and entire 

 edge ; consistency butyrous or viscous ; emulsifiability easy. 7 days, colonies 

 are larger, 1-2 mm. in diameter, but owing to autolysis are flattened, almost colour- 

 less, transparent, and adherent to the medium ; surface is dull and very finely 

 granular. 



Agar Slope. — 24 hours at 37° C. Moderate, confluent, slightly raised, greyish-yellow, 

 sUghtly translucent growth, with glistening beaten-copper surface and entire edge ; 

 condensation water consists of grejnsh-white mucoid material. 7 days, whole 

 growth is flattened, and withered ; surface dry and covered with secondary 

 colonies. 



Gelatin Stab. — 7 days at 22° C. Moderate, mostly confluent, filiform growth, greyish-white 

 in colour, extending to bottom of tube. Surface growth 2-4 mm. in diameter, 

 slightly raised or flattened. No liquefaction, even after 3 weeks. After 2 to 3 

 weeks delicate feathery outgrowths from the stab appear in the upper half of the 

 medium. 



Broth. — 24 hours at 37° C. Moderate growth with moderate, uniform turbidity and a 

 sUght powdery deposit, disintegrating completely ; heavy, unpleasant, sweetish 

 odour. No surface growth. 



Horse Blood Agar Plate. — 24 hours at 37° C. Abundant grejdsh-white growth. No 

 haemolysis, but plate is browned. 



Potato. — 7 days at 37° C. Poor, confluent, shghtly raised, creamy white growth with 

 smooth surface ; potato browned. 



MacConkey's Agar. — 24 hours at 37° C. Good growth of small, round, low convex, yellow- 

 ish colonies, not unlike those of Salm. typhi. 



