The Immunological Basis for Disease Dilution Sheena Wheeler Dr.
Anna Jolles
Slide 2
Many human diseases are transmitted from non-human animals
(Zoonotic diseases) Many human diseases are transmitted from
non-human animals (Zoonotic diseases) Some species are better at
transmitting diseases than others Some species are better at
transmitting diseases than others Biodiversity is important to
ecosystem services Biodiversity is important to ecosystem services
RELEVANCE
Slide 3
BACKGROUND Disease Dilution: Empirical Findings high
biodiversity = reduced risk of disease low biodiversity = increased
risk of disease Sin Nombre Virus in Deer Mice (Laurie J.
Dizney)
Slide 4
BACKGROUND BIODIVERSITY = = DISEASE Why is the deer mouse good
at transmitting disease?
Slide 5
HYPOTHESIS We hypothesize that short-lived species invest less
in certain aspects of their immune system, which may make them
better at transmitting diseases. Ex:VS.
Slide 6
MY OBJECTIVE To examine the immune differences between
short-lived and long-lived rodent species
Slide 7
METHODS: FIELD 1.Trap different rodent species throughout
Oregon (Sherman and Tomahawk traps) 2.Collect blood, feces, and
ectoparasites from each rodent 3.Ear tag, measure, weigh and
release
Slide 8
TRAPPING LOCATIONS 1.Local 2.Rogue River- Siskiyou National
Forest 3.Willamette National Forest 4.Steens Mountain Eastern
OR
Slide 9
MY OBJECTIVE To examine the immune differences between
short-lived and long-lived rodent species 1.Determine the
differences in white blood cell composition between rodent
species.
Slide 10
BACKGROUND White blood cells (WBC): travel in bloodstream to
infected areas and destroy responsible bacteria Complete Blood
Count: Determine numbers and types of white blood cells (WBC) in an
animal Good general way to see how the immune system of an animal
functions WBC BACTERIA
Slide 11
METHODS: LAB 1.Perform complete blood counts (CBC) on each
rodent: A) White blood cell counts B) Cell differentiation
Lymphocyte Neutrophil Band Monocyte Eosinophil Basophil
Slide 12
MY OBJECTIVE Examine the immune differences between short-
lived and long-lived rodent species 1.Determine the differences in
blood cell composition between rodent species. 2.Evaluate the
health of different rodent species via fecal parasite
analysis.
Slide 13
METHODS: LAB 1. Fecal Float to examine the types of parasite
eggs 2. Fecal McMasters to count the different parasite eggs within
the feces
Slide 14
PICTURES
Slide 15
PRELIMINARY RESULTS Table 1: Average and standard deviation of
total white blood cells/l for six species of rodents. 1. Complete
Blood Counts SpeciesSample SizeAverage WBC/lSt. Dev. WBC California
Ground Squirrel1010234.576270.63 Chipmunk38666.67 Dusky Footed
Woodrat98812.52863.89 Norway Rat83581.113821.13 Black
Rat29527.782710.58 Deer Mouse793488.482360.07
Slide 16
PRELIMINARY RESULTS Table 2: Percent of species with fecal
parasites and percent of each type of parasite in each species. 2.
Fecal Analysis SpeciesSample Size Fecal
ParasitesCoccidiaCapillariaOther California Ground Squirrel1080.00%
10.00%70.00% Chipmunk3100% 0% Dusky Footed Woodrat9100.00%
75.00%0.00% Norway Rat850.00%67.00%33.00%0.00% Deer
Mouse7925.53%21.28%0.00%0.02% Pinyon
Mouse4100.00%33.00%0.00%67.00%
Slide 17
WHATS NEXT? Continue data collection of rodents around Oregon
Trap larger/longer lived rodents (beaver, nutria) Analyze data
Slide 18
ACKNOWLEDGEMENTS Howard Hughes Medical Institute (HHMI)
Undergraduate Research, Innovation, Scholarship and
Creativity(URISC) Dr. Anna Jolles Dr. Rhea Hanselmann Dr. Kevin
Ahern