A New Rickettsia Species Unveiled: A Potential Threat to Canine Health
In a recent discovery, researchers from North Carolina State University have identified and confirmed a novel species of Rickettsia bacteria, which has been observed in dogs since 2018. This new species, creatively named Rickettsia finnyi, presents symptoms akin to those of Rocky Mountain spotted fever (RMSF) in our canine companions, yet it remains undetected in humans thus far.
Rickettsia pathogens are classified into four distinct groups, with the spotted-fever group, transmitted by ticks, being the most familiar and comprising the largest number of identified species. Globally, there are over 25 known tick-borne, spotted-fever group Rickettsia species, with R. rickettsii, the cause of RMSF, standing out as one of the most severe and dangerous.
The symptoms of RMSF in both dogs and humans are remarkably similar, encompassing fever, lethargy, and vascular inflammation-related issues such as swelling, rash, and pain.
Dr. Barbara Qurollo, an associate research professor at NCState and the corresponding author of this groundbreaking study, shares, "We first reported this novel Rickettsia species in a 2020 case series involving three dogs. Since then, we have received samples from an additional 16 dogs, primarily from the Southeast and Midwest, all infected with the same pathogen. We were even able to culture the new species from the blood of one of these naturally infected dogs."
Naming a new Rickettsial bacterial species is a meticulous process, involving culturing the bacteria, sequencing its genome, publishing the findings, and depositing the cultures in two biobanks for further research. Dr. Qurollo's team successfully cultured Rickettsia finnyi from the infected dog, a significant step towards understanding this new pathogen.
"Rickettsia species are notoriously challenging to culture due to their intracellular growth," explains Dr. Qurollo. "While we haven't identified the specific tick species responsible for transmitting Rickettsia finnyi, we suspect it might be associated with the lone star tick, as a research group in Oklahoma detected R. finnyi DNA in a lone star tick."
The researchers chose to name the new species after Finny, the first dog in which it was discovered. "By naming it after an individual dog, we wanted to honor all companion dogs that have played a crucial role in uncovering new pathogens that pose a potential threat to both dogs and humans," Dr. Qurollo adds.
This research, published in Emerging Infectious Diseases, was supported by the American Kennel Club Canine Health Foundation (grant number 02983). The study's co-first authors, Praveen Korla and Michael Karounos, along with other NCState contributors, including Sarah Clarke, Cynthia Robveille, James Wilson, Edward Breitschwerdt, and Adam Birkenheuer, have made significant contributions to this important discovery.
And here's where it gets intriguing: Could this new Rickettsia species pose a threat to human health in the future? While it hasn't been detected in humans yet, the similarities in symptoms between RMSF and Rickettsia finnyi in dogs raise important questions. What are your thoughts on this potential health concern? Feel free to share your insights and opinions in the comments below!
