Image created by Dr. Michael J. Miller
A mild Canadian winter has led to an early tick season in Ontario, raising concerns about Lyme disease and other tick-borne illnesses.
Robert Colautti, a biologist at Queen’s, is leading the charge with his research being carried out in partnership with the myLyme project. Harini Satheeskumar, ArtSci ’27, Sofia Marino, ArtSci ’27, and Devin Abergel-Preston, ArtSci ’25 are three undergraduate students from Queen’s on the project alongside Colautti.
The collaboration between Colautti’s research and myLyme involves researchers collecting ticks from various field sites. Collaboratively, they extract the DNA and sequence these nucleic acids to identify bacterial pathogens. Put simply, they’re looking at the genetic material of ticks to find harmful bacteria. The project builds on research done with the Canadian Lyme Disease Research Network (CLDRN).
“The main idea of this project is to prevent the next Lyme disease epidemic. Humans and their pets tend to share exposure risk—that is, the ticks found on pets are a good sample of ticks that pose a threat to humans. This project will give us a better picture of the range of bacteria found in ticks in Ontario,” Colautti said in an interview with The Journal.
Colautti’s research involves developing a set of protocols that use high-throughput sequencing and machine learning to screen all bacteria simultaneously, contrasting with current screening methods which require a separate test for each pathogen.
“The more ticks we screen, the better chance we have to detect new and emerging pathogens that could pose a threat to human health,” Colautti said.
The myLyme project has developed the Bacterial Amplicon Tick Test (BATT). This test uses advanced genomics, which studies the genetic information of organisms, and machine learning, which extracts meaningful information from large datasets and builds models from this data to screen for all bacteria and genetic variants in ticks.
“We use machine learning to help identify the tick species, morphological variation in ticks, DNA sequences, and the particular bacterial species or variants that are present,” Colautti said.
BATT uses advanced bioinformatics—the use of computer tools to understand biological data—to study DNA sequences. Algorithms then sort and identify the DNA to find specific bacterial pathogens. This method quickly and accurately identifies both known and new bacteria.
“The rate of coinfections in ticks is higher than expected based on previously published studies using conventional testing. Coinfection means that the tick carries more than one pathogen and could potentially transmit multiple pathogens to humans,” Colautti said.
This research has shown there is a high diversity of bacterial communities within individual ticks as the creatures can carry multiple bacterial pathogens at the same time.
“Surveillance of ticks is expensive, which means that most ticks are only tested for a few pathogens and therefore won’t detect new and emerging pathogens or new genetic variants,” Colautti said.
The researcher spoke about how the project ensures accuracy and reliability in its testing methods.
“Controls are used at every stage of DNA extraction, sequencing and data analysis. Multiple replicates are employed and findings are validated with independent methods. The bioinformatics pipeline includes steps to remove potential contaminants and correct for sequencing errors,” he said.
The interconnectedness of animal and human health is a significant consideration in this research. According to Colautti, collaboration with veterinary clinics is crucial for a comprehensive approach to disease prevention.
“We have spent the last six years refining these methods, but this pilot study with vet clinics will be our first test of these methods in real life. These clinics provide valuable field data and access to tick samples from various hosts. This enhances our understanding of pathogen transmission cycles,” Colautti said.
The pilot study is set to launch this year, and veterinary clinics in southern Ontario will be provided with BATT.
The partnership with veterinary clinics facilitates the early detection of bacterial pathogens in animals and helps to prevent outbreaks before they reach human populations, Colautti added.
The project further maintains accuracy and reliability using advanced sequencing methods, he explained. Sequencing is more specific compared to traditional methods. For example, conventional techniques like Polymerase Chain Reaction (PCR) are used to detect genes in ticks, while antigen tests are employed to find antibodies produced by the immune system in infected hosts.
Antigen tests have limitations, especially in the early stages of infection, Colautti said. It can take several days to weeks for a host to produce a detectable immune response, making these tests less effective early on. On the other hand, PCR tests in ticks are more precise in detecting specific genetic targets.
Both antigen and PCR tests have their drawbacks, Colautti explained. They can only determine whether a pathogen is present or absent, or if the results are inconclusive. These tests do not differentiate between different genetic variants of a pathogen, similar to how COVID variants differ. Further, they cannot identify other unrelated pathogens that might be present.
By collaborating with veterinary clinics, this study not only advances scientific understanding of ticks but also directly impacts public health by identifying potential disease outbreaks early.