MICROBIOLOGY OF HIBERNATION IN GROUND SQUIRRELS 



cated that monkey kidney cells were susceptible to ECHO- 6 virus 

 and that Coxsackie B-3 virus could be isolated and propagated in 

 monolayers of HeLa cells. In addition, both viruses could be suc- 

 cessfully recovered from the fecal material of animals which had 

 been fed a suspension of the specific agents. 



Accordingly, 9 squirrels were given a suspension of 1 x 10^ ECHO- 

 6 virus particles and 8 others were fed 1 x lo''' particles of Cox- 

 sackie B-3 virus, using the method of administration described 

 above. Approximately half of the animals in each group were hiber- 

 nating and half were in the active state; all had been in the cold 

 room for the same period of time. Thereafter, fresh fecal samples 

 were collected at appropriate intervals and tested for the presence 

 of virus using monolayers of monkey kidney and HeLa cells. Serial 

 10-fold dilutions (10~^ to 10"^) of the fecal material were prepared 

 in Earles BSS and a duplicate series of tubes was inoculated with 

 0.1 ml of the proper dilutions. Incubation was carried out at 37° C, 

 and the cultures were examined daily for evidence of a cytopatho- 

 genic effect. 



RESULTS AND DISCUSSION 



The data indicated a significant increase in the number of psych- 

 rophiles and a simultaneous decrease in the number of coliform 

 bacilli following periods of hibernation. On the other hand, very 

 little fluctuation was observed in either the total counts at 37° C 

 or the numbers of fecal streptococci, and these did not appear to 

 be influenced in any way by hibernation. The values shown repre- 

 sent the averages obtained with the 15 ground squirrels studies. Al- 

 though there was some variation in the hibernating habits, activity, 

 food consumption, and normal intestinal flora of the individual ani- 

 mals, each of the squirrels tested demonstrated these character- 

 istic trends. 



A representative number of the coliform bacilli and psychro- 

 philes were isolated and their temperature-growth relations deter- 



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