60 STUDY AND IDENTIFICATION OF BACTERIA 



make transfers every one or two days. The meningococcus has been isolated from 

 the nasal secretions of patients. The possibility of these organisms being the M. 

 catarrhalis must be considered. 



Flexner has shown that in monkeys, which are susceptible to the disease, in- 

 jections of cultures of M. intracellularis into the spinal canal is followed by migra- 

 tion of the cocci to the nasal cavity both free and in phagocytic leukocytes. 



The meningococcus has a very slight resistance to sun or drying so 

 that its aerial transmission seems doubtful. It is supposed to effect 

 an entrance by the nares, thence reaching the cerebral meninges. Inf ec- 



FIG. 15. Diplococcus intracellularis meningitidis and pus cells. (Xiooo.) 



(Williams.} 



tion is probably by direct contagion. Several cases have been re- 

 ported where with a high leukocytosis the cocci have been found in the 

 polymorphonuclears of blood smears and in cultures from the blood. 

 (In about 25% of blood cultures where from 5 to 10 c.c. are employed.) 



By the use of initial injections into horses of killed cultures followed by alternate 

 injections into horses of living diplococci, then seven days later of an autolysate 

 made from different strains; seven days later again injecting living diplococci; thus 

 alternating material every week, an antiserum of value has been obtained by Flexner. 

 The immunization requires about one year. In using, withdraw about 20 c.c. of 

 patient's cerebrospinal fluid with a syringe, and then inject, through the same needle, 

 an equal quantity of the serum. The injection is repeated every day for three or 

 four days. 



For diagnosis, make smears and cultures from cerebrospinal fluid. 

 The sediment from the centrifuged material gives better results. In 

 tuberculosis the lymphocytes preponderate; in cerebrospinal meningitis 

 the polymorphonuclears. 



