170 MEDICAL BACTERIOLOGY 



Dixon and Rucker also succeeded in isolating a similar but probably not 

 identical organism from the brain and cord of patients dead- of the disease. 

 At first they were inclined to believe it the causative organism but later rejected 

 it as the specific etiological factor. Recently Rosenow and others have obtained 

 cultures of an organism described as pleomorphic streptococcus from the nasal 

 mucosa, the pharynx and tonsils of poliomyelitis patients. They have isolated 

 the same organism from the ventricular fluid, brain and cord of fatal cases. 



The pleomorphic streptococcus is described as a coccus arranged in pairs 

 like pneumococci (but without a capsule) and in chains. Marked variations in 

 size are observed. In dextrose-ascitic broth growth occurs under aerobic and 

 anaerobic conditions but is more rapid in an aerobic atmosphere. 



Incubated at body temperature growth appears in from 3 to 5 days and con- 

 tinues for several weeks. Old cultures show large and club-shaped forms. 

 Young cultures are Gram positive and old cultures Gram negative. 



Growth occurs on blood-agar incubated at body temperature, aerobically. 

 Some describe the colonies on this medium as small, white, and dry, without 

 any change in the appearance of the underlying or surrounding medium; others 

 describe a slight clear zone or greenish zone surrounding each colony. 



Various observers have reported inoculation of rabbits by placing pleo- 

 morphic streptococcus upon the nasal mucosa, by injecting it subcutaneously, 

 by injecting it into a nerve or beneath the dura. In such cases symptoms and 

 pathological changes associated with the pleomorphic streptococcus and re- 

 covery of the organism have convinced Rosenow and others that it is the specific 

 cause of poliomyelitis but at present we must consider their case not proven. 



Netter has discovered that the blood serum of persons recovered from polio- 

 myelitis possesses distinct therapeutic value, practically undiminished through- 

 out their life. He recommends the intraspinal injection of such serum in the 

 treatment of the disease, from 5 to 13 cc. each day for i week. 



SPIROCHJSTA ICTEROHEMORRHAGA 



(Spirochaeta Nodosa) 



The discoveries recently reported by Ito, Matsuzaki, Uhlenhuth and Fromme 

 seem to indicate that Weil's disease is caused by infection and that the offending 

 organism is a small spirochete. 



Ito and Matsuzaki have described three closely allied strains of spirochaeta 

 icterohemorrhaga that apparently are the same as spirochaeta nodosa. 



This organism (or organisms) has been found constantly associated with 

 Weil's disease. Blood cultures, especially when made on the fourth or fifth 

 day of the disease are usually positive. The organism is occasionally present 

 in the sputum, urine, or feces of patients during the disease and sometimes 

 as long as 50 days after recovery. 



Inoculation of mice, rats and guinea-pigs with cultures obtained from 

 patients causes disease the same as in man and identical to the disturbance pro- 

 duced by inoculation of these animals with the urine of patients. 



