[Isolation of L-form of Yersinia pestis from wild rodents in an epizootic focus].

Four Y. pestis cultures with unbalanced growth and 15 Y. pestis cultures in unstable L-forms were isolated from wild rodents Rhombomys opimus in the vicinity of lake Balkhash.

[Effect of the prolonged contact of a flea population with plague bacteria on the infective activity of vetors].

Results of the experimental infection of fleas (X. cheopis) with the plague agent after their long (2.5 years, 19 generations) feeding on infected white mice showed no difference in the infection activity of these insects as compared to control ones.