Acquisition of yersinia murine toxin enabled Yersinia pestis to expand the range of mammalian hosts that sustain flea-borne plague
Fig 5
Rodent fleas can transmit Ymt mutant Y. pestis for at least 3 weeks when infected using brown rat blood.
Y. pestis transmission dynamics were monitored for 3 to 4 weeks for groups of 150–267 X. cheopis (A) or O. montana fleas infected using 3.4 x 108−1.9 x109 CFU/ml KIM6+ or KIM6+ymtH188N Y. pestis (B) in either mouse (blue) or brown rat (red) blood and subsequently maintained on sterile blood of the same type. Numbers in parentheses indicate the total number of fleas that fed followed by the number of fleas with evidence of foregut obstruction (partially or fully blocked). Roughly equivalent numbers of male and female fleas were used for transmission assays. Infection rate was determined for groups of 10–20 female C) X. cheopis or D) O. montana at various times following infection.