Dissertation/Thesis Abstract

The Influence of Prescribed Fire on Tick Abundance and Borrelia Burgdorferi Prevalence in Amblyomma americanum
by Gilliam, Mary Elizabeth, M.S., Western Illinois University, 2017, 38; 10607237
Abstract (Summary)

The bacteria Borrelia burgdorferi sensu lato is the causative agent of Lyme disease. Lyme disease is transmitted by the blacklegged deer tick (Ixodes scapularis Say) and is the most common vector-borne illness in the U.S. Studies examining the effects of prescribed fire on tick abundance and B. burgdorferi prevalence in West-Central Illinois is limited. We collected a total of 1,099 ticks in 2015 and 1,746 ticks in 2016, respectively. Species collected were American dog tick (Dermacentor variabilis Say), blacklegged deer tick (Ixodes scapularis Say) and lone star tick (Amblyomma americanum L.), from areas burned in 2015 (B15), 2014 (B14) and 2004 (B04). Results from a repeated measures analysis of variance (ANOVA) on ranks indicated there was no difference in tick abundance among treatment types or sample years and there was no interaction between treatment and sample year (P > 0.05). DNA was extracted and amplified from adult and nymphal A. americanum ticks and B. burgdorferi was present in all treatment areas. Sanger sequencing revealed that 7 of 26 positive samples, from 2015, were a 99% or greater match for B. burgdorferi. Total infection prevalence among all treatment types in 2015 was 48.3% and 41.1% in 2016. There were no significant differences in infection among treatment types during 2015 (χ2 = 3.964; P = 0.138; df = 2) or during the 2016 sampling period (χ2 = 5.601; P = 0.061; df = 2). Infection rates were highest in ticks collected from areas burned 1 year prior to sampling (46.4% in 2015 and 52.2% in 2016). There was a significant difference in infection prevalence when ticks collected 1 year post burn (1YPB) were compared to B04, 2 years post burn (2YPB) and year of burn (YOB) (χ2 = 9.262; P = 0.026 ; df = 3). When 1YPB was compared to B04 for both years, there was a significant difference in infection prevalence (χ2 = 7.168; P = 0.007; df = 1). Additionally, seasonal occurrence of ticks was documented to establish the temporal distribution of ticks at the study site. Although, we found significantly less infection when B04 was compared to 1YPB, the use of prescribed fire is still recommended for other ecosystem benefits. In order to decrease B. burgdorferi prevalence, burning would need to be conducted annually. Future studies should evaluate the seasonality and frequency of burning, which could lead to the development of a burn plan to decrease tick abundance and B. burgdorferi prevalence.

Indexing (document details)
Advisor: Jenkins, Sean E., Miller-Hunt, Catherine
Commitee: McCravy, Kenneth W.
School: Western Illinois University
Department: Biology
School Location: United States -- Illinois
Source: MAI 56/05M(E), Masters Abstracts International
Subjects: Molecular biology, Ecology, Entomology
Keywords: Lone star, Lyme disease, Prescribed fire, Ticks
Publication Number: 10607237
ISBN: 9780355226898