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Comparison of the Ticks and Tick-Borne Bacteria of Small Mammals in Western Canada

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Comparison of the Ticks and Tick-Borne Bacteria of Small Mammals in Western Canada COMPARISON OF THE TICKS AND TICK-BORNE BACTERIA OF SMALL MAMMALS IN WESTERN CANADA A Thesis Submitted to the College of Graduate Studies and Research In Partial Fulfillment of the Requirements For the Degree of Doctor of Philosophy In the Department of Biology University of Saskatchewan Saskatoon By Clare Alayne Anstead July, 2013 © Copyright Clare Alayne Anstead, July 2013. All rights reserved. Permission to Use In presenting this thesis/dissertation in partial fulfillment of the requirements for a Postgraduate degree from the University of Saskatchewan, I agree that the Libraries of this University may make it freely available for inspection. I further agree that permission for copying of this thesis/dissertation in any manner, in whole or in part, for scholarly purposes may be granted by the professor or professors who supervised my thesis/dissertation work or, in their absence, by the Head of the Department or the Dean of the College in which my thesis work was done. It is understood that any copying or publication or use of this thesis/dissertation or parts thereof for financial gain shall not be allowed without my written permission. It is also understood that due recognition shall be given to me and to the University of Saskatchewan in any scholarly use which may be made of any material in my thesis/dissertation. Disclaimer Reference in this thesis/dissertation to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not constitute or imply its endorsement, recommendation, or favouring by the University of Saskatchewan. The views and opinions of the author expressed herein do not state or reflect those of the University of Saskatchewan, and shall not be used for advertising or product endorsement purposes. Requests for permission to copy or to make other uses of materials in this thesis/dissertation in whole or part should be addressed to: Head of the Department of Biology !112 Science Place, University of Saskatchewan !Saskatoon, Saskatchewan S7N 5E2 Canada ! i! Abstract ! ! Ticks are important vectors of pathogenic agents that cause disease in humans, domestic animals, and wildlife. They are also hosts for a variety of bacterial endosymbionts. However, little is known about the microbial diversity of many tick species, particularly those species that parasitize small mammals in western Canada. In this thesis, I used a combined morphological and molecular approach to identify, to the species-level, ticks that parasitized small mammals from three localities in Saskatchewan and British Columbia. The genetic diversity and phylogenetic relationships of these tick species was also examined. Comparisons were also made of the composition and diversity of bacteria within individuals of each tick species. Questions relating to the biology, systematics, and vector ecology of the vole tick (Ixodes angustus), the rotund tick (Ixodes kingi), the sculptured tick (Ixodes sculptus) and the Rocky Mountain wood tick (Dermacentor andersoni) were also addressed. The results of my thesis work revealed that I. kingi and I. sculptus were the most encountered tick species on northern pocket gophers (Thomomys talpoides) and Richardson’s ground squirrels (Spermophilus richardsonii), respectively, in Saskatchewan, while I. angustus was the most abundant tick on red-backed voles (Clethrionomys gapperi) in Kootenay National Park (British Columbia). At least 40 genera of bacteria were detected in the four tick species; however, there were significant differences in the composition of the bacteria among tick species. Two novel species of Rickettsia and three putative new species of Rickettsiella were also discovered. The findings of this thesis make an important contribution to our understanding of the evolution and ecology of ticks and tick-borne bacteria. ! ii! Acknowledgements The first person I want to thank is my supervisor, Dr. Neil Chilton, for providing the opportunity for me to pursue a postgraduate degree. Without your support and encouragement, I would not be where I am today, or who I am today. You have had a profound positive influence on my personal and academic development, and have been an ideal mentor and role model. Thank you for giving me a chance. I would also like to thank my wonderful committee members, Dr. Yeen-Ten Hwang, Dr. Dick Neal, and Dr. Hugo Cota-Sánchez, for their valuable input and advice. I could not have asked for a better committee. Thank you Dr. Chris Todd for your pocket gopher trapping advice, your valuable proofreading, and for always taking the time to help and reassure. Thank you Dr. Vipen Sawhney for finding the time in your busy schedule (and while on sabbatical) to chair my thesis defense. It is much appreciated. To my present and former labmates (James Armstrong, Shaun Dergousoff, Veronica Duran, Ray Ko, Chantel Krakowetz, Cyndi Laduke, Tyler Little, Anish Mann, Ian Patterson, James Paul, Katie Sim, Alison Sproat and Scott Wallace): thank you for your help, encouragement, and for making the Chilton lab a fun place to conduct research. A special thank you to Dr. Shaun Dergousoff, my lab “big brother”, for your patience in training me in the beginning, and for your continued support and friendship today. Thank you to all the people who let me trap on their land (Dr. Chris Todd, Dr. Cedric Gillott, the Bothner family) and to those that provided me with samples (Dr. Yeen-Ten Hwang, Dr. Chris Todd, Winston Bothner, Wayne Lerch). Thank you Dr. Wilson, Dr. Carvalho and Kunal Baxi for the use of your laboratory equipment, and thank you Dr. Guosheng Liu and Marlynn Mierau for your help with SEM and photoshop, respectively. Thank you Joan Virgl, Deidre Wasyliw and Bonita Wong for always being there for a chat and for helping me keep all my ducks in a row. Thank you to my friends (Kristin Bielefeld, Brandon Demuth, Alan Hiebert, Carly Lindenbach, Adam McMurtry, Amy Noakes, Brittani Olson, Emily Pickett, Jodi Souter, Molly Thomas) and family (including the Rothenburgers) for always being there. Thank you to my mom, Sylvia and to my dad, Keith, for always knowing the right thing to say or do. I cannot express how valued your support and patience has been. Most importantly, thank you Chase for being so understanding when I spent too much time in the lab or in front of a computer. Thank you for your support and for not breaking up with me during the high-stress times. You’re the perfect partner. Funding for this research was provided to Neil Chilton by the National Sciences and Engineering Research Council (NSERC) and the Canadian Foundation for Innovation. Personal financial support was received from the Margaret MacKay Scholarship, the University of Saskatchewan and the R. Jan F. Smith Memorial Scholarship. ! iii! Table of Contents Permission to Use ........................................................................................................................... i Disclaimer ....................................................................................................................................... i Abstract .......................................................................................................................................... ii Acknowledgements.......................................................................................................................iii List of Tables ............................................................................................................................... vii List of Figures ................................................................................................................................ x Chapter 1. General Introduction ............................................................................................... 1 1.1 Background .................................................................................................................................. 1 1.2 Research objectives .................................................................................................................... 13 1.3 Anticipated significance of research .......................................................................................... 16 1.4 References Cited ........................................................................................................................ 17 Chapter 2. Ticks feeding on northern pocket gophers (Thomomys talpoides) in central Saskatchewan, and the unexpected detection of Ixodes scapularis larvae ............................. 39 2.1 Abstract ...................................................................................................................................... 39 2.2 Introduction ................................................................................................................................ 40 2.3 Materials and Methods ............................................................................................................... 41 2.4 Results ........................................................................................................................................ 43 2.5 Discussion .................................................................................................................................. 48 2.6 References Cited ........................................................................................................................ 53 Chapter 3. Ticks (Acari: Ixodidae) on Richardson’s ground squirrels (Spermophilus richardsonii) in southern Saskatchewan,
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