738 MICEOBIOLOGY OF DISEASES OF MAN AND DOMESTIC ANIMALS 



The temperature relations are of some importance in identifying 

 the coccus. It has a minimum temperature of about 25°, an opti- 

 mum of 37° and a maximum of 42°. Its atmospheric requirements are 

 those of an aerobe. 



Upon suitably enriched agar media the colonies are small, grayish 

 and glistening with a smooth outline and granular center. In broth 

 growth is slow and occurs at the surface. Only rarely is growth ob- 

 tained on gelatin media chiefly because of the unfavorable temperature 

 required. There is no change in litmus milk.. Acid is fornied from 

 dextrose and maltose. 



The toxins of the meningococcus are probably intracellular. 



The resistance of the organism to unfavorable conditions is very 

 slight, and it undergoes autolytic changes almost with the same rapidity 

 as does the gonococcus. 



Meningitis due to this coccus does not occur naturally in animals, 

 but it has been produced in moakeys artificially. Laboratory animals 

 inoculated subcutaneously, intraperitoneally or intravenously with a 

 sufficiently large dose will die without developing meningitis. 



Animals immunized by graded doses show specific agglutinins, 

 opsonins and lysins. Horses so treated yield a serum which in some 

 hands has given very favorable results. In recent epidemics in the 

 British and Canadian armies, however, the mortality has ranged from 

 about 40 to 50 per cent and the serum has been distinctly disappointing. 



As the germs leave the body in the discharges of the nose and mouth, 

 the prevention and control of the disease would appear at first thought 

 to be an easy matter, but the occurrence of carriers and ignorance of 

 the factors which govern the virulence of the infective agent and the 

 individual's susceptibility make epidemic meningitis a very difficult 

 problem from the standpoint of public health. 



Infectious Mastitis* 



Infectious mastitis or mammitis (inflammation of the udder) 

 appears in isolated outbreaks and is serious for the individual owner and 

 individual herd, but it never spreads widely. It may affect a large 

 portion of the herd and cause heavy financial losses. Infectious masti- 

 tis may have serious significance for children and others consuming 



* Prepared by M. H. Reynolds. 



