OBSERVATIONS ON THE VARIABILITY OF THE PLAGUE BACILLUS IN THE FLEAS. II. PASSAGE OF THE AVIRULENT SUBCULTURE 610-A THROUGH FLEAS AND PREGNANT GUINEA PIGS
ARMY BIOLOGICAL LABS FREDERICK MD
Pagination or Media Count:
Results showed that the avirulent properties of the 610-A subculture, which remained the same following its passage through the organism of normal susceptible animals, under other conditions passage through the organism of pregnant guinea pigs or as a result of prolonged residence in the gastro- intestinal tract of active plague carriers -- the fleas X. cheopis and X. minax may change to the side of a noticeable increase of virulence. The possibility of the transmission of the subculture under study from infected fleas during bloodsucking supplements the data obtained, which strongly sheds a certain light on the variability of the causative agent under natural conditions.