PERiroNrris and bacteremia in mice 



EXPERIMENTAL 



Method 



Pneumococcal infection was induced by intraperitoneal (i.p.) in- 

 jection of broth cultures in doses which were previously found to 

 cause infection of a desired course and massivity in normal mice. 



Results 



In preliminary experiments for stating optimal conditions for the 

 following study, hypothermia was found generally to prolong the 

 average survival time of mice after their inoculation (i.p.) with 

 pneumococci. The results of such an experiment are reported in 

 Figure 8. 



In all, 32 mice were inoculated (i.p.) ^\ith 20,000 pneumococci 

 Type in, while six mice were kept as controls. About three hours 

 later, 16 inoculated mice and the controls were made hypothermic. 

 The remaining 16 inoculated mice were kept normothermic. After 

 about 49 hours, surviving hypothermic mice were warmed up. 

 Cultures from heart blood were made from succumbed mice as 

 soon as we were sure they were dead. 



The average survival time in the hypothermic group was 36 

 hours as opposed to 16 hours in the normothermic group and 59 

 hours for five out of six h3T)othermic controls not inoculated; 

 the sixth animal in this group survived. In the inoculated hypo- 

 thermic group, three mice lived to be warmed up, but died during 

 or soon after this procedure. Pneumococci were found in peri- 

 toneal fluid of all inoculated mice. In heart blood they were abun- 

 dant in all normothermic mice, but only in six hypothermic ones, 

 whereas three had pneumococci in moderate numbers and seven 

 mice had even less. 



It should be added that among five inoculated hypothermic 

 mice and five not inoculated ones which sustained hypothermia 



255 



