Yersinia pestis,causative agent of plague,occurs throughout the western United States in rodent populations and periodically causes epizootics in susceptible species,including black-tailed prairie dogs(Cynomys ludovic...Yersinia pestis,causative agent of plague,occurs throughout the western United States in rodent populations and periodically causes epizootics in susceptible species,including black-tailed prairie dogs(Cynomys ludovicianus).How Y.pestis persists long-term in the environment between these epizootics is poorly understood but multiple mechanisms have been proposed,including,among others,a separate enzootic transmission cycle that maintains Y.pestis without involvement of epizootic hosts and persistence of Y.pestis within epizootic host populations without causing high mortality within those populations.We live-trapped and collected fleas from black-tailed prairie dogs and other mammal species from sites with and without black-tailed prairie dogs in 2004 and 2005 and tested all fleas for presence of Y.pestis.Y.pestis was not detected in 2126 fleas collected in 2004 but was detected in 294 fleas collected from multiple sites in 2005,before and during a widespread epizootic that drastically reduced black-tailed prairie dog populations in the affected colonies.Temporal and spatial patterns of Y.pestis occurrence in fleas and genotyping of Y.pestis present in some infected fleas suggest Y.pestis was introduced multiple times from sources outside the study area and once introduced,was dispersed between several sites.We conclude Y.pestis likely was not present in these black-tailed prairie dog colonies prior to epizootic activity in these colonies.Although we did not identify likely enzootic hosts,we found evidence that deer mice(Peromyscus maniculatus)may serve as bridging hosts for Y.pestis between unknown enzootic hosts and black-tailed prairie dogs.展开更多
基金This study was funded by the NSF/NIH joint program in Ecology of Infectious Diseases(DEB-0224328)the National Center for Environmental Research(NCER)STAR program of the US-EPA(R-82909101-0)+2 种基金the National Institutes of Health-National Institute of Allergy and Infectious Diseases(1R15AI070183)the Pacific-Southwest Regional Center of Excellence(AI065359)Achievement Rewards for College Scientists Foundation Inc.,and the Cowden Endowment at Northern Arizona University.
文摘Yersinia pestis,causative agent of plague,occurs throughout the western United States in rodent populations and periodically causes epizootics in susceptible species,including black-tailed prairie dogs(Cynomys ludovicianus).How Y.pestis persists long-term in the environment between these epizootics is poorly understood but multiple mechanisms have been proposed,including,among others,a separate enzootic transmission cycle that maintains Y.pestis without involvement of epizootic hosts and persistence of Y.pestis within epizootic host populations without causing high mortality within those populations.We live-trapped and collected fleas from black-tailed prairie dogs and other mammal species from sites with and without black-tailed prairie dogs in 2004 and 2005 and tested all fleas for presence of Y.pestis.Y.pestis was not detected in 2126 fleas collected in 2004 but was detected in 294 fleas collected from multiple sites in 2005,before and during a widespread epizootic that drastically reduced black-tailed prairie dog populations in the affected colonies.Temporal and spatial patterns of Y.pestis occurrence in fleas and genotyping of Y.pestis present in some infected fleas suggest Y.pestis was introduced multiple times from sources outside the study area and once introduced,was dispersed between several sites.We conclude Y.pestis likely was not present in these black-tailed prairie dog colonies prior to epizootic activity in these colonies.Although we did not identify likely enzootic hosts,we found evidence that deer mice(Peromyscus maniculatus)may serve as bridging hosts for Y.pestis between unknown enzootic hosts and black-tailed prairie dogs.