MIRAGLIA AND BERRY 



secondary infection with staphylococci in mice maintained in the 

 cold. 



The differences in host behavior at room temperature and at low 

 temperature in response to salmonella infection is more apparent at 

 infectious dosages below or at the approximate LD^q level. With 

 heavier inocula, homeostatic balance becomes erratic. This is 

 especially true in experiments in which attempts were made to cul- 

 ture organs for bacteria at the 14th post- infection day. In this regard, 

 data not included in this report indicate that while the per cent of 

 salmonella positive livers is greater in animals held at 5° C than in 

 those at room temperature, this difference becomes less pronounced 

 as heavier inocula are employed. The per cent of livers positive for 

 staphylococci, however, increase with increasing dosages of sal- 

 monellae, especially of strain RIA, 



There still remain to be answered several perplexing questions. 

 Not the least of these is the observation that while by their very na- 

 ture staphylococcal infections tend to localize and form well-defined 

 foci of infection, this has never been observed in the hundreds of 

 animals autopsied during the course of these investigations. Gross 

 examination of the nasal passages and sinuses failed to show a local- 

 ized pathology in 14 days, the usual term of these studies. The in- 

 vasion involves lung, heart, kidney, spleen and liver in an unpre- 

 dictable manner and without any apparent preference for any specific 

 tissues, this in face of the the usual course of events in which the 

 staphylococci frequently invade the kidneys with subsequent overt 

 signs. 



Paradoxical also has been the observation that while mice fed the 

 coagulase- positive Staphylococcus aureus, strain Giorgio, as a con- 

 taminant in their ration following acid treatment become intestinal 

 carriers of this strain, they alsobecome nasal carriers of the same 

 strain, perhaps by the manner in which they eat. This state rarely 

 lasts for more than 48 hours nor are more than 30 to 40 per cent of 

 the mice such transient carriers. Even so, these individuals never 

 yielded coagulase-positive isolates from deep tissue. 



It would appear, then, that while a correlation seems to exist be- 

 tween the flora ofthe nose and that of deep tissue, this can not, under 



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