SPECIFIC INFECTIOUS DISEASES PRODUCED BY COCCI 213 



finally the chronic stage sets in, and may persist indefinitely or 

 gradually disappear. The organism may be isolated from the 

 pus in the acute stage, or from the deeper layers of the mucosa 

 in the later stages. In the bull the glans penis may show gran- 

 ules similar to those of the vagina, or there may be a purulent 

 catarrh of the prepuce. In the cow the disease may involve the 

 uterus and possibly produce abortion and even sterility. 



Immunity. Recovery from the disease presumably results 

 from the development of an active immunity, probably opsonic 

 in nature. No means of artificial immunization have been 

 employed. 



Bacteriologic Diagnosis. The presence of a gram-negative 

 Streptococcus in the depths of the mucous membranes should be 

 diagnostic of the disease. Identification in the discharges would 

 necessitate cultures. 



Transmission. The disease is probably most commonly trans- 

 mitted by coition or by immediate contact with soiled litter and 

 fodder. 



Streptococcus Sp. 



Disease Produced. Contagious abortion in mares. Ostertag 

 in 1900 described a Streptococcus as the cause of abortion in mares. 



Distribution. Recorded only from Europe. 



Morphology. This organism somewhat resembles the preced- 

 ing morphologically. It is a coccus, occurring in short chains, 

 stains easily with anilin dyes, but is gram-negative. 



Isolation and Culture. Ostertag succeeded in isolating the 

 organism upon blood-serum in pure cultures from the uterine 

 mucous membranes and from the blood and internal organs of an 

 aborted fetus. This Streptococcus does not grow readily upon 

 most artificial media, but shows much better development upon the 

 addition of blood-serum. Serum bouillon shows initial clouding, 

 with subsequent sedimentation. Upon the solid serum media the 

 growth is poor, being scarcely visible to the naked eye. Milk 

 is not changed. It will be noted that both this organism and the 

 preceding may be differentiated, both morphologically and cul- 

 turally from the Str. pyogenes. 



Physiology. The organism quickly dies on artificial media, 



