SULKIN AND ALLEN 



temperature. The apparent alteration in the bat rabies virus strain 

 which occurred as a result of a period of "incubation" in bats at 

 5° C further supports this concept. There is also indication that the 

 Japanese B encephalitis virus may be altered by passage through 

 bats at 10° C. The virus demonstrable inthe blood and other tissues 

 of these animals upon transfer to 24° C often produces a disease in 

 mice characterized by increased incubation time, bizarre paralytic 

 symptoms and frequently, recovery. In experiments now inprogress 

 we are studying strains of viruses following single and multiple 

 passages through bats held at low temperature. These in vivo studies 

 are being paralleled with in vitro experiments using monolayer and 

 explant cultures of bat brown fat, kidney and embryonic tissue, as 

 well as preparations of tissues from warm-blooded animals in an 

 effort to produce virus strains altered by passage at low tempera- 

 ture in different host systems. A study of virus strains altered by 

 the pressures of low temperature exerted inthe intact bat, cultures 

 of bat tissues, and cultures of tissues from warm-blooded animals 

 should provide devinitive information concerningthe mechanisms of 

 temperature-induced variations in animal viruses. 



LITERATURE CITED 



1. Bell, J. F., and G. J. Moore. 1960. Rabies virus isolated from 



brown fat of naturally infected bats. Proc. Soc. Exp. Biol. Med. 

 103: 140-142. 



2. Bellamy, R. E.,W. C.Reeves, and R. P. Scrivani. 19 58. Relation- 



ships of mosquito vectors to winter survival of encephalitis 

 viruses. II. Under experimental conditions. Am. J. Hyg. 67: 

 90-100. 



3, Chang, I-C. 1958. Studies on Japanese B encephalitis in cold- 



blooded animals. Pediatrics 4: 27-49. 



4, Corristan, E., L. LaMotte, Jr., and D. G. Smith. 1956, Suscep- 



tibility ofbats to certain encephalitis viruses. Fed.Proc. 15:584. 



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