CHAPTER V 



TYPES OF INFECTION 



Udder-infections may be divided primarily into two 

 groups, depending upon the types of infectious organisms : 

 (1) simple or single infection; (2) complex or mixed 

 infection. 



Simple Udder-infection. — The simple udder-infection 

 is caused by one kind of bacteria. 



There are, however, different kinds of simple infections 

 because the type of organism which causes one case of 

 simple infection may be of a different type in other cases 

 of the simple infection. 



These types of infection induced by the different types 

 of bacteria are divided into two classes : 



1. That type of infection which principally shows typi- 

 cal milk-infection and externally only stroma-infection of 

 an acute character. 



2. That type of infection which shows a typical stroma- 

 infection of a chronic character. 



Types of Infection Which Show Principally Milk- 

 infection or Externally Only Stroma-infection of an Acute 

 Character. — These infections may be caused by three dif- 

 ferent kinds of bacteria: {a) bacteria of the streptococcic 

 group, streptococci; (h) bacteria of the staphylococcic 

 group, staphylococci, and (c) bacteria of the colon group, 

 colon bacteria or colon bacilli. 



The disease is named after the type of organism : Strep- 

 tomycosis mammae, staphylomycosis mammae, and coliba- 

 cillosis mammae, or udder-streptomycosis, udder-staphylo- 

 mycosis and udder-colibacillosis. 



Types of Infection Which Show Typical Stroma-infec- 

 tion of a Chrome Character. — (a) Bacillus pyogenes; (h) 



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