924 THE SPIROCHETES 



Leptospira, Andaman A and B types. — Organisms belonging to these two tjrpes were 

 isolated by Taylor and Goyle (1931) from patients suffering from a febrile disease in the 

 Andaman islands. Illness was confined mainly to adults working in mud or in marshy 

 districts in the autumn. The A type is antigenically distinct, and is of only moderate 

 virulence for the guinea-pig. The B type appears to be identical with Lepto. gn'ppotyphosa 

 (Walch-Sorgdrager 1939). 



Leptospira sejroe. — Isolated by Petersen and Christensen (1939) from the blood of a 

 fisherman in the small Danish island of Sejro. It is antigenically related to Lepto. hebdo- 

 madis, but absorption experiments show it to be distinct. Its virulence for guinea-pigs 

 is low. Its natural host appears to be a mouse, Mus spicilegus. 



Leptospira oryzeti. — This organism was isolated from rice-field workers in Italy (Babu- 

 dicri 1938, 1939). It appears to be antigenically related to Lepto. hatavice, but as it has 

 not yet been properly studied its claim to specific rank is still in doubt. 



Leptospira canicola. — -This is a natural parasite of dogs, in which it gives rise to a 

 disease more often associated with uraemia than with jaundice (see Chapter 82). It was 

 first distinguished from Lepto. icterohcBmorrJuigia} by Klarenbeek and Schiiffner (1933). 

 It differs from Lepto. icferohcemorrhagicB in its antigenic structure and its lower virulence 

 for guinea-pigs on first isolation. After passage through guinea-pigs, its virulence may 

 increase. No jaundice is produced, but in animals that survive leptospirje may be excreted 

 in the urine for months. Occasionally it infects human beings, but it is not a normal 

 parasite of rats (see Walch-Sorgdrager and Schiiffner 1938). Gardner (194.36) thinks that 

 there may be a type of leptospira infecting dogs and man in Great Britain differing from 

 Lepto. canicola, but the evidence on this point is not yet conclusive. 



Leptospira javanica. — Found in field-rats and cats in the Dutch East Indies (see Walch- 

 Sorgdrager 1939). Has not so far been isolated from human beings. 



Leptospira biflexa.— Usually referred to by German workers as Spirochceta pseudoictero- 

 genes. Widespread saprophyte found mainly in water. Described originally by Wolbach 

 and Binger (1914). Often attached to other spirochajtes and 

 protozoa (Zuelzer 1928). Especially prevalent in the slime of 

 ponds, lakes, and - rivers, in the slime that collects on the ends 

 of water taps and pipes, and in the roof slime of mines. Mor- 

 phologically indistinguishable from Lepto. icterohcemorrhagioe 

 (Fig. 219). Is very easy to cultivate. Can thrive in tap or 

 distilled water to which 0-1 per cent, potassium nitrate has 

 been added, provided that the reaction is not acid (Zuelzer 

 1928). Grows readily in the media used for Lepto. icterohcemor- 



p^Q 219 Lepto rhagice ; but Ringer's solution must be replaced by tap or dis- 



biflexa. tilled water, since biflexa is very susceptible to even low con- 



Dark-ground illumina- centrations of sodium chloride (Uhlenhuth and Zuelzer 1921). 

 tion ( X 1500 ca.). The simplest and most effective medium is 10 per cent, rabbit 



serum in distilled water. Isolation in pure culture is often 

 difficult. Hindle (1925) found that if 20 ml. of water were added to a Petri dish con- 

 taining a portion of human faeces about the size of a pea, and incubated at 25°-30° C. in 

 the dark, Lepto. biflexa was generally observable microscopically in 10 days, and was 

 abundant in 20 days. The leptospirse were able to pass through an L5 candle. These 

 observations formed the basis of several methods of isolation (Bauer 1927, Mochtar 1928, 

 von Vagedes 1935). The general principle is to filter the water through a suitable candle 

 and cultivate the filtrate. Is antigenically distinct from Lepto. icteroh(Bmorrhagice. A 

 specific precipitating siibstance of carbohydrate nature has been extracted from it by 

 Hindle and White (1934). Is non-pathogenic for animals. Is believed by certain workers 

 to be an avirulent form of Lepto. icterohcp.morrhagice, which can be rendered virulent by 

 suitable animal passage. Balance of evidence is against this view. 



