PERITONITIS AND BACTEREMIA IN MICE 



after the induction of pneumococcal peritonitis. 



These observations were corroborated by experiments in which 

 bacterial counts from blood were done repeatedly. In other experi- 

 ments where the infection was less massive the slower course of 

 disease was found to manifest itself in two different ways. First 

 the invasion of pneumococci from the peritoneal cavity to the blood 

 stream was more often delayed inhypothermic animals. If the fairly 

 similar experiments of the Figures 11 and 12 are taken together, 7 

 out of 15 hypothermic mice were bacteremic 40 hours after the inoc- 

 ulation as against 20 out of 22 controls (Chi- square with Yates' 

 correction 6.9; 0.01 > P > 0.001). Second, when bacteremia was once 

 established, the increase of the number of bacteria in the blood was 

 slower in hypothermic mice. Our results thus tally with those of 

 Watkyns et al. (1958). 



But one other significant observation was made; warming up of 

 hypothermic mice was deletarious. Bacteremic mice died during or 

 soon after this procedure and in mice which still had sterile blood, 

 bacteremia was often established and followed by death within a 

 short time. In others, death occurred without being preceded by 

 bacteremia. It is not possible to decide whether this effect was 

 caused by a weakening of the resistance by hypothermia against 

 bacterial assault as a whole or, more specifically, to an increased 

 sensitivity to bacterial toxins during the rewarming process which 

 in itself is traumatic and may involve an abnormal acceleration of 

 cell metabolism. 



SUMMARY AND CONCLUSION 



I. Experiments with h3^othermic mice maintained at 22° C to 

 23° C for more than 40 hours, almost invariably resulted in the 

 emergence of bacteria in peritoneal fluid and blood. These bacteria 

 belonged to species present in the intestine. When peritoneal and 

 blood findings were not identical, the demonstration of a species in 

 peritoneal fluid only was more frequent than in blood only. No major 



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