(Montana State University - Bozeman, College of Letters & Science, 2005) Swanekamp, Leatrice June; Chairperson, Graduate Committee: Lynn Irby
Hemorrhagic septicemia (HS) is a fatal disease affecting domestic and wild ruminants caused by the bacterium Pasteurella multocida. Although uncommon in the U.S, outbreaks of HS in elk (Cervus elaphus) occurred on the National Elk Refuge (NER) in the winters of 1986, 1987, 1993, 1995, 1999, and 2001. DNA fingerprinting of P. multocida from the 1987 and 1993 outbreaks (B:3,4 HhaI 036/HpaII 001) revealed the same organism was responsible for mortality in both years. However, testing has failed to find this genetic variant in healthy elk on the NER, suggesting reservoirs other than elk might play a role in HS epidemiology. I investigated the potential for rodents to serve as biological reservoirs for bacteria responsible for HS on the NER. Rodents are known to harbor P. multocida, may be carriers of variants capable of causing HS, and have been observed at sites where elk are fed during winter on the NER. I used mark-recapture techniques to determine densities of rodents on feedgrounds, feed-storage areas and other sites and removal trapping to collect tissues to determine prevalence of P. multocida in rodents on the NER.
