Rickettsia amblyommatis: A review of a ubiquitous tick-borne species

Tick-borne disease cases have been steadily increasing, yet there is still much that is unknown about the pathogens ticks vector. Particularly, there has been one species of Rickettsia that has sparked debate and led to uncertainty over its pathogenicity and the inhibitory role it plays in the diagnosis of other Spotted Fever Rickettsioses. The ubiquitous Rickettsia amblyommatis is a species within the Rickettsia spotted fever group and is considered potentially pathogenic. Publications have reported high infection prevalence of R. amblyommatis in tick populations all over the US and abroad. Studies have found evidence that infection with R. amblyommatis can lead to symptoms of disease in animals while other studies have labeled it as simply an endosymbiont. This species is transmitted by the bite of a tick and with tick populations on the rise as well as the pathogens they carry, it is crucial that we understand the epidemiological importance of R. amblyommatis. Here, we compiled all known information on the geographical distribution, species of tick found infected, pathogenicity, and assessed the relatedness between various international strains of R. amblyommatis from ticks by phylogenetic analysis.