Spilling the guts: Tick midgut microbiome and its implications for an alternative tick management strategy

Tick-borne diseases are the number one vector-borne illnesses in the United States and cause a significant economic burden to the healthcare system. The continued rise in the incidence of tick-borne illness, and the increased expansion in tick geographical distribution, reflects the need for alternative measures for tick control. We previously reported that certain species of hard ticks, including the lone star tick (A. americanum), can voluntarily drink water containing inorganic salts, resulting in 100% tick mortality within 3 days. In addition, we found that ticks can ingest water-containing bacteria, which can be recovered from the tick midgut after several days. Furthermore, the abundance of culturable plant and soil-associated bacterial taxa from field-collected A. americanum, suggests ticks can acquire bacteria through water ingestion from the environment. While ticks are suggested to have strong gut immunity, we hypothesized that the tick microbiome and the tick microhabitats hold the key to uncovering novel bacterial strains with tick toxicity and establishment potential. We demonstrated that ingestion of live cells and spores of the widely used entomopathogenic bacterium Bacillus thuringiensis and other field-collected bacterial strains, induced tick mortality in different tick species, including A. americanum. A novel direction for tick control and the study of tick gut-microbiome interactions will be discussed.