334 



PATHOGENIC MICROORGANISMS 



Milk is coagulated and litmus milk indicates acid formation. 



Pathogenicity. — Micrococcus tetragenus is especially pathogenic 

 for Japanese mice, which succumb within three or four days to subcuta- 

 neous inoculation.^ Gray mice, rats, guinea-pigs, and rabbits are less 

 susceptible, showing only a localized reaction at the point of inoculation. 



Fig. 71. — Micrococcus Tetragenus. (In spleen of infected mouse.) 



The organism has occasionally been isolated from spontaneous abscesses 

 observed in domestic animals. 



In man, this microorganism is usually found without any particular 

 pathogenic significance, in sputum or saliva. In isolated cases, how- 

 ever, it has been described as the sole incitant of abscesses. 



Bezan9on ^ has isolated Micrococcus tetragenus from a case of menin- 

 gitis. A single case of tetragenus septicemia is on record, reported in 

 1905 by Forneaca.^ 



In America, this microorganism has not been frequently observed in 

 connection with disease. It is often found, however, in considerable 

 numbers, in smears of sputum which are being examined for pneumo- 

 cocci or tubercle bacilli. 



1 Mvller, Wien. klin. Woch., 17, 1904. 

 '^ Bezangon, Semaine med., 1898. 

 ' FomeoM, Rif. med., 1903. 



