Elevation and vegetation determine Cryptosporidium oocyst shedding by yellow-bellied marmots (Marmota flaviventris) in the Sierra Nevada Mountains

Diego Montecino-Latorre; Xunde Li; Chengling Xiao; Edward R Atwill

doi:10.1016/j.ijppaw.2015.02.004

Elevation and vegetation determine Cryptosporidium oocyst shedding by yellow-bellied marmots (Marmota flaviventris) in the Sierra Nevada Mountains

Int J Parasitol Parasites Wildl. 2015 Mar 6;4(2):171-7. doi: 10.1016/j.ijppaw.2015.02.004. eCollection 2015 Aug.

Authors

Diego Montecino-Latorre¹, Xunde Li², Chengling Xiao³, Edward R Atwill²

Affiliations

¹ Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA ; Current address: Wildlife Health Center, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA.
² Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA ; Western Institute for Food Safety and Security, University of California, Davis, CA, 95616, USA.
³ Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA.

Abstract

Wildlife are increasingly recognized as important biological reservoirs of zoonotic species of Cryptosporidium that might contaminate water and cause human exposure to this protozoal parasite. The habitat range of the yellow-bellied marmot (Marmota flaviventris) overlaps extensively with the watershed boundaries of municipal water supplies for California communities along the foothills of the Sierra Nevada. We conducted a cross-sectional epidemiological study to estimate the fecal shedding of Cryptosporidium oocysts by yellow-bellied marmots and to quantify the environmental loading rate and determine risk factors for Cryptosporidium fecal shedding in this montane wildlife species. The observed proportion of Cryptosporidium positive fecal samples was 14.7% (33/224, positive number relative to total number samples) and the environmental loading rate was estimated to be 10,693 oocysts animal(-1) day(-1). Fecal shedding was associated with the elevation and vegetation status of their habitat. Based on a portion of the 18s rRNA gene sequence of 2 isolates, the Cryptosporidium found in Marmota flaviventris were 99.88%-100% match to multiple isolates of C. parvum in the GenBank.

Keywords: C. parvum; Cryptosporidium; Elevation; Mountains; Sierra Nevada; Yellow-bellied marmot.