Detection of Amblyomma maculatum and Rickettsia parkeri in prairies of Central Missouri

Abstract

The destruction and decline of prairie habitats due to landscape repurposing have profoundly impacted the diversity of plant, animal, and insect life. In the Central United States, the reconstruction of prairie habitats from farmland is a widely applied strategy to raise diversity and recreate a healthy, complex ecosystem. In Central Missouri, we examine the consequences of reconstruction efforts on the prevalence of zoonotic diseases and their associated pathogens by performing tick-flagging at two prairie sites. In doing so, we have observed large populations of Dog ticks, Dermacentor variabilis, and Lone Star ticks, Amblyomma americanum, as well as the first recorded instance of the Gulf Coast tick, Amblyomma maculatum, in Callaway County. The Gulf Coast tick is traditionally found mainly along the Atlantic and Gulf Coast regions but has been undergoing geographic expansion in the last decade. Since detection in 2020, the number of Gulf Coast ticks has increased. Upon screening 193 Gulf Coast ticks in 105 pools via PCR, we found that 6.67 % of ticks were positive for pathogenic Rickettsia parkeri, which causes spotted fever rickettsiosis in animals and humans, with most ticks coming from the reconstructed prairie site. These observations suggest that reconstruction of prairie habitat has the potential to support the sylvatic cycle of Rickettsia parkeri. Collectively, our observations show that the reconstructed prairie are capable of harboring large tick populations as compared to remnant prairies and demonstrates a potential increase in disease risk as a result. This works highlights the importance of proactive surveillance of ticks, especially with land-use change.