Translator Disclaimer
1 May 2010 Detection of Vector-Borne Agents in Lone Star Ticks, Amblyomma americanum (Acari: Ixodidae), from Mississippi
Author Affiliations +

In this study, we evaluated Amblyomma americanum (lone star tick) in Mississippi for the presence of Ehrlichia chaffeensis, causative agent of human monocytic ehrlichiosis; Ehrlichia ewingii, causative agent of human and canine granulocytic ehrlichiosis; Borrelia lonestari, putative agent of southern tick-associated rash illness; Francisella tularensis, the agent of tularemia; and Rickettsia spp., particularly R. amblyommii, a suspected pathogen, We collected adult A. americanum from four regions of Mississippi: Northeast, Northwest, Southeast, and East. Of the ticks collected, 192 were dissected and DNA was extracted for nested polymerase chain reaction (PCR) assays to detect the above bacteria. In all, 3% of tick extracts had evidence of Borrelia sp., 4% for E. chaffeensis, 6% for E. ewingii, and 44% for a Rickettsia species. As determined by sequencing, most Rickettsia spp, were R. amblyommii. In addition, extracts from 42 pools (total of 950) of larval A. americanum collected in Southwest Mississippi were tested for the presence of E. chaffeensis and Rickettsia species. Of these extracts from pools, nine of 37 (24%) were PCR positive for a Rickettsia sp., most often, R. amblyommii; none had evidence of E. chaffeensis, supporting the ability of lone star ticks to transovarially transmit R. amblyommii, but not E. chaffeensis. This study demonstrates E. chaffeensis, E. ewingii, “B. lonestari”, and R. amblyommii in A. americanum by PCR for the first time in Mississippi. Understanding the prevalence and epidemiology of these agents in Mississippi should increase awareness of tick-borne disease in the medical community.

© 2010 Entomological Society of America
A. H. Castellaw, J. Showers, J. Goddard, E. F. Chenney, and A. S. Varela-Stokes "Detection of Vector-Borne Agents in Lone Star Ticks, Amblyomma americanum (Acari: Ixodidae), from Mississippi," Journal of Medical Entomology 47(3), 473-476, (1 May 2010).
Received: 3 November 2009; Accepted: 1 January 2010; Published: 1 May 2010

This article is only available to subscribers.
It is not available for individual sale.

Get copyright permission
Back to Top