492 PFEIFFERELLA, AND CERTAIN ALLIED ORGANISMS 



together by a thick, purulent, yellowish exudate. The scrotal skin becomes adher- 

 ent, and ulcerates. Death in 14 days. P.M., besides the testicular lesions, there 

 may be submiliary nodules in the spleen projecting above the surface, greyish- 

 white nodules in the lungs and liver, and subcutaneous or periarticular abscesses. 

 Bacilli are present in the fresh lesions. 



Pfeifferella whitmori 



Isolation. — Isolated by Whitmore and Krishnaswami (1912) from human patients with 

 melioidosis. 



Synonyms. — B. pseudomallei, B. whitmori. 



Habitat. — Parasite of rodents and man. 



Morphology. — Small, slender rods, 1-2 n long and 0-4-0'5 fi broad ; sides parallel, ends 

 rounded, axis straight ; arranged singly, in pairs end-to-end, or sometimes in long 

 parallel bundles, the bacilli being embedded in an interstitial substance Varia 

 tions occur in depth of staining ; bipolar staining common, especially in films from 

 infected tissues. Motile ; Gram-negative ; acid-fast granules have been described 

 in freshly isolated strains (Finlayson 1944). The short, oval, bipolar-stained rods 

 are characteristic of the rough form ; the longer, narrower rods, arranged in paUsades 

 with irregular staining and shadow forms, are characteristic of the smooth variant . 



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

 yeUow colonies, 1-2 mm. in diameter ; smooth, ghstening surface and entire edge ; 

 consistency mucoid ; emulsifiabihty easy. 14 days, colonies are opaque, often 

 coloured yellow, brown, or pinkish, and may have a wrinkled centre. 



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

 spreading growth, with glistening, beaten-copper surface, and edge undulate or 

 made up of single colonies. Growth more profuse than that of Bact. coli. Cul- 

 tures have a mouldy, earthy smell. 



Gelatin Stab. — 10 days at 20° C. Abundant, fiUform growth, mostly of discrete colonies 

 extending to bottom of tube. Stratiform liquefaction ; between the liquefied and 

 unliquefied portions of the gelatin there is a thick nodular peUicle of growth. 



Broth. — 24 hours at 37° C. Good growth with moderate turbidity, and slight powdery 

 deposit disintegrating completely ; may be shght pelhcle formation. 10 days, 

 luxuriant growth with dense turbidity and a heavy viscous deposit disintegrating 

 with difficulty. The rough form gives rise to a slight turbidity and a wrinkled 

 surface peUicle. According to NichoUs (1930), the rough form produces about 0-2 

 per cent, oxalate (calculated as calcium oxalate) in 4 days ; the smooth form pro- 

 duces not more than about 0-01 per cent., but renders the medium alkaline — -pH 8-4. 



Glycerol Agar. — 3 days at 37° C. May be ( 1 ) profuse mucoid growth with smooth glistening 

 surface, or (2) profuse growth with dull, wrinkled, corrugated, or honeycombed 

 surface. 



Horse Blood Agar Plates. — 3 days at 37° C. Abundant growth of round, low convex, 

 greyish-green colonies, 1-2 mm. in diameter. No hsemolysis, except, perhaps, with 

 freshly isolated strains. 



Loeffler's Serum. — 3 days at 37° C. Good, confluent, sUghtly raised, creamy growth with 

 smooth surface and undulate edge. Liquefaction by freshly isolated strains after 

 a variable number of days. Sometimes the growth itself appears to become liquefied, 

 and runs down the slope. 



Potato. — 24 hours at 37° C. S. type : good growth of a creamy or lemon-yellow colour 

 not very easy to see ; later the colour deepens to cafe-au-lait or chocolate. R. 

 type : forms dry, dull, dirty-white growth. 



MacConkey's Agar.— 3 days at 37° C. Abundant growth of red, opaque, low convex or 

 umbonate colonies, 2-3 mm. in diameter. 



