Impact of the prescribed burning on tick-borne pathogen dynamics in Amblyomma americanum

Amblyomma americanum has a wide distribution across the eastern United States, from central Texas, Oklahoma, and Kansas to the Atlantic coast. As aggressive host-seeking ectoparasites, these ticks play a crucial role in the transmission of several pathogens that affect human and animal health. Long-term prescribed burning has been shown to significantly reduce tick abundance, particularly A. americanum. While some studies have reported decreases in pathogen prevalence, like Rickettsia spp., after fire application, the overall impact of fire on tick-borne pathogen dynamics remains unclear. Existing research presents mixed outcomes, highlighting the need for further investigation into how fire influences the presence of pathogens within tick populations. Therefore, this study aims to evaluate whether prescribed burning affects the prevalence of six pathogens in A. americanum. Ticks were collected during 2023 and 2024 from three seasonally burned pastures (spring, summer, and fall) and an unburned pasture. Two multiplex real-time TaqMan PCR reactions were developed and optimized to simultaneously screen for the following pathogens: Ehrlichia chaffeensis, E. ewingii, and Francisella tularensis (Reaction 1); Rickettsia rickettsii, R. parkeri, and R. amblyommatis (Reaction 2). Each reaction includes the A. americanum MIF gene as an internal control. We anticipate that prescribed burning will reduce the prevalence of these six tick-borne pathogens and that the timing of the burn may influence this effect. Findings from this study will contribute to understanding the potential of prescribed burning as a land management strategy for mitigating the risk of tick-borne diseases affecting both livestock and public health.