5 WOUND INFECTION 



with the disease with which one or both of its parents were 

 suffering. In these cases the specific bacteria were transmitted 

 either from the sire at the time of coition, or later to the 

 foetus in the uterus from the dam. It is important not to 

 confuse these rare cases with those in which the offspring are 

 born uninfected but subsequently contract the disease. Many 

 of the so-called hereditary diseases are the result of post natal 

 infection. 



§4. Wound infection. Wound infections are the direct 

 results of the entrance of certain microorganisms into trau- 

 matisms and operative incisions. They fall very naturally 

 into two classes namely, (i) those producing acute or more 

 chronic inflammatory processes usually leading to suppuration 

 and finally healing by granulation, and (2) iniections which 

 may in the beginning appear like the first or, cause so little 

 disturbance as to be unnoticed at the time, but sooner or later 

 result in a local or remotely situated lesion or lesions. Fre- 

 quently these are recognized as distinct diseases although 

 in some cases, such as scirrhous cord, the origin is easily 

 traced to an operation where infection was possible. In this 

 second group of wound infections there are in addition to the 

 scirrhous cord or botryomycosis, infectious cellulitis of cattle 

 and sheep and still other disorders which may not seem to be 

 dependent upon wound infection but which the results of re- 

 cent investigations suggest as their primary cause. These af- 

 fections will be treated separately in subsequent paragraphs 

 but their relation to wound infection renders them worthy of 

 note in this connection. 



A third class should be mentioned, namely, those specific 

 diseases such as tetanus and symptomatic anthrax where the 

 virus is supposed always to be introduced through a wound 

 either in the skin or mucous membranes. 



§ 5. Bacteria causing wound infection. A large num- 

 ber of species of bacteria and a few fungi are included among 

 the organisms which are known to produce wound infections 

 in animals. Usually, however, the forms encountered are 

 micrococci, especially those belonging to the staphylococcus 

 group, streptococci, a few bacilli, especially those belonging to 



