A Survey of Tick-Borne Bacterial Pathogens in Florida.

Zoe S White,Chanakya R Bhosale,William H Kessler,Gregory E Glass,Samantha M Wisely,Claudia Ganser,Carrie E De Jesus

doi:10.3390/insects10090297

Abstract

Within the past three decades, new bacterial etiological agents of tick-borne disease have been discovered in the southeastern U.S., and the number of reported tick-borne pathogen infections has increased. In Florida, few systematic studies have been conducted to determine the presence of tick-borne bacterial pathogens. This investigation examined the distribution and presence of tick-borne bacterial pathogens in Florida. Ticks were collected by flagging at 41 field sites, spanning the climatic regions of mainland Florida. DNA was extracted individually from 1608 ticks and screened for Anaplasma, Borrelia, Ehrlichia and Rickettsia using conventional PCR and primers that amplified multiple species for each genus. PCR positive samples were Sanger sequenced. Four species of ticks were collected: Amblyomma americanum, Amblyomma maculatum, Dermacentor variabilis, and Ixodes scapularis. Within these ticks, six bacterial species were identified: Borrelia burgdorferi, Borrelia lonestari, Ehrlichia ewingii, Rickettsia amblyommatis, Rickettsia andeanae, Rickettsia parkeri, and Rickettsia endosymbionts. Pathogenic Borrelia, Ehrlichia, and Rickettsia species were all detected in the North and North-Central Florida counties; however, we found only moderate concordance between the distribution of ticks infected with pathogenic bacteria and human cases of tick-borne diseases in Florida. Given the diversity and numerous bacterial species detected in ticks in Florida, further investigations should be conducted to identify regional hotspots of tick-borne pathogens.

Highlights

IntroductionState and federal surveillance efforts have increased, and the majority of those efforts have been concentrated in the Northeastern and Upper Midwest of the U.S to understand epidemiology and disease ecology of Borrelia burgdorferi, the causative agent of Lyme disease
The number of reported tick-borne pathogen infections has more than doubled in the UnitedStates over the past decade according to the U.S Center of Disease Control and Prevention (CDC) [1].In response, state and federal surveillance efforts have increased, and the majority of those efforts have been concentrated in the Northeastern and Upper Midwest of the U.S to understand epidemiology and disease ecology of Borrelia burgdorferi, the causative agent of Lyme disease
Amblyomma americanum was the most abundant tick sampled in Florida from which multiple bacterial pathogens were detected, which is consistent with tick surveys across the Southeastern U.S [43]

Summary

Introduction

State and federal surveillance efforts have increased, and the majority of those efforts have been concentrated in the Northeastern and Upper Midwest of the U.S to understand epidemiology and disease ecology of Borrelia burgdorferi, the causative agent of Lyme disease. U.S the number of tick-borne bacterial infections causing ehrlichiosis, spotted fever rickettsiosis and. Lyme disease is increasing [2,3] Surveillance in this region has detected multiple etiological agents (Borrelia, Rickettsia, Ehrlichia, and Anaplasma) that cause human and animal disease [2,3,4,5,6,7]. Within the past three decades, a diverse array of new bacterial etiological agents of tick-borne disease have been discovered in the U.S including E. chaffensis, E. ewingii, R. parkeri, and Panola Mountain Ehrlichia sp. Given the discovery and diversity of tick-borne bacterial pathogens detected in the U.S, there is a substantial need for ongoing pathogen surveillance of ticks nationally

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