618 THE PYOGENIC STAPHYLOCOCCI 



Staphylococci are found in a very large number of the suppurative conditions 

 occurring in the mammalia and birds. The Staphylococcus aureus is the infecting 

 agent of an osteo- myelitis occurring in young geese (Lucet). The organism can 

 even develop in fish and was the cause of an epizootic which broke out among the 

 gudgeon in the Rhone (Charrin). 



SECTION I. THE EXPERIMENTAL DISEASE. 



Among the very numerous staphylococci which can be readily isolated 

 from the circumambient media as well as from the various suppurations 

 occurring in the human body it is but rarely that a very virulent organism 

 is found ; in the great majority of cases staphylococci isolated from these 

 sources are either very slightly virulent or totally avirulent. 



In the human subject. Garre produced boils by rubbing the skin energeti- 

 cally with a piece of wool soaked in a culture of Staphylococcus aureus. 



Rabbits. The rabbit is the best animal for purposes of experimental 

 inoculation. 



Sub-cutaneous inoculation. The sub-cutaneous inoculation of a few drops 

 of a virulent culture produces an abscess and at the same time a rise of tem- 

 perature : then the abscess points and discharges and the animal is well 

 again, but on rare occasions the organism may infect the blood stream with 

 fatal results. 



Muscatello and Ottaviano using a virulent culture of the Staphylococcus on serum- 

 broth produced a rapidly fatal result in rabbits with general dissemination of the 

 micro-organism after sub-cutaneous inoculation. No metastatic abscesses were 

 formed but the internal organs and especially the spleen showed lesions of necrosis. 



According to these observers, if a culture of a very virulent strain be inoculated 

 death takes place from toxaemia before the organism has had time to become general- 

 ized through the tissues. 



Intra-peritoneal inoculation. Intra-peritoneal inoculation is more severe 

 than sub-cutaneous inoculation : it leads to a rapidly fatal septic peri- 

 tonitis. Passage through rabbits increases the virulence of strains of staphy- 

 lococci, and the organism can be found in the blood and internal organs of 

 animals that die. 



Intra-pleural and intra-articular inoculation. Inoculation into the pleural 

 cavity or into a joint leads to a purulent effusion into the cavity, and the 

 animal succumbs in a few days. If the strain be very virulent it rapidly 

 produces septicaemia followed by death in 2148 hours. 



Intra-venous inoculation. Inoculation of a Staphylococcus into the veins 

 is as a rule followed by grave complications. In severe cases the organism 

 rapidly invades the tissues and sets up a condition of pyaemia with septic 

 foci in the internal organs and especially in the kidneys. Death takes place 

 in 48 hours or more. With a culture of increased virulence, death supervenes 

 more quickly ; no metastatic abscesses are formed but the internal organs 

 show areas of necrosis. Staphylococci are found in masses in the lumens of 

 the uriniferous tubules of the kidney : after the second day no micro-organisms 

 can be found in the blood (Muscatello and Ottaviano). 



In some cases, especially if lesions be artificially produced in the heart 

 beforehand, inoculation determines fatal ulcerative or vegetative endocarditis 

 (Wyssoko witch, Bibbert, Bonome). 



Rodet and Lannelongue reproduced the lesions of osteo-myelitis by intra- 

 venous inoculation. This can very easily be done if a bone be traumatized 

 before inoculation. In the rabbit it is possible to produce an inflammation at 

 the junction of the bone and epiphysis similar to that occurring in the human 

 subject* 



