Keywords
1. TickPath Layerplex
2. Real-time PCR
3. Tick-borne diseases
4. Molecular surveillance
5. Veterinary diagnostics
Introduction
In the era where tick-borne diseases (TBDs) pose an escalating threat to both animal and human health, groundbreaking advancements in diagnostic technology are more vital than ever. The recent development of the TickPath Layerplex, a real-time PCR (qPCR) methodology, marks a significant breakthrough in the diagnostic realm for simultaneous detection and molecular surveillance of pathogens responsible for TBDs in domestic dogs. Authored by Joseph J. Modarelli et al., the study was published under the DOI 10.1038/s41598-019-43424-y in Scientific Reports, highlighting this novel approach’s capability to streamline disease detection and enhance preventive strategies.
Emergence of the TickPath Layerplex Assay
The need for advanced diagnostic assays arises from the increasing incidence of TBDs—notably, borreliosis, anaplasmosis, rickettsiosis, ehrlichiosis, and babesiosis—that are frequently reported across the United States. These diseases, while initially impacting veterinary populations, are zoonotic and threaten human health through vector transmission, primarily by ticks (Chomel et al., 2011; Dantas-Torres et al., 2012). Existing molecular diagnostic tests, such as traditional qPCR assays, face limitations due to their inability to differentiate between multiple fluorogenic labels in a single reaction—hindering their effectiveness in broad-spectrum pathogen detection.
Amidst this growing concern and necessity for efficient surveillance, the study conducted by Modarelli et al. at Texas A&M University, alongside contributions from the USDA-ARS Knipling-Bushland U.S. Livestock Insects Research Laboratory and the Texas A&M Veterinary Medical Diagnostic Laboratory, introduced the TickPath Layerplex assay. This novel diagnostic tool is designed to detect 11 pathogens linked to the five most prevalent TBDs in dogs.
Methodology and Findings
The methodology of the Layerplex assay is rooted in the qPCR technique but incorporates refinements that enable concurrent identification of diverse pathogens. The analytical and diagnostic performance was rigorously tested, showing high sensitivity and specificity without any observed inhibition or sensitivity reduction. The assay’s limit of detection stood at an impressive near 16 genome copy equivalents per microliter, indicating its potential to identify infections at an early stage when pathogen levels are still low.
Validation of the TickPath Layerplex assay demonstrated its compatibility with common molecular diagnostic instruments, suggesting that it could be seamlessly integrated into existing laboratory workflows. No significant obstacles were noted, showcasing the assay’s adaptability and readiness for broader implementation in veterinary diagnostics (Modarelli et al., 2020).
Implications for Veterinary Practices and Public Health
The introduction of the TickPath Layerplex assay into veterinary diagnostic practices signifies a transformative change in how domestic dogs are screened for TBDs. The multiplex capability of this assay not only reduces the time and resources required to diagnose infections but also improves the accuracy of detection for coinfections, which can be challenging to identify and are often overlooked by single-target tests (Lopez et al., 2016).
The broader implications of this technology extend to public health, as early and accurate detection of TBDs in animal hosts can inform more effective control and prevention strategies while also serving as an indicator of disease prevalence in given regions (Rosenberg et al., 2018). Understanding the dynamics of these diseases in animal populations can offer pivotal insights into the risks for human transmission, emphasizing a One Health approach to disease management.
Advancements and Future Directions
The development of the TickPath Layerplex assay aligns with a growing body of research focused on enhancing multiplex diagnostic tools for vector-borne diseases (Ojeda-Chi et al., 2019). With the potential for future adaptations, this assay could be modified to incorporate additional targets as new pathogens emerge, sustaining its relevance and application in the field.
In terms of future directions, the application of the Layerplex assay may not be limited to domestic dogs. With further validation, this method could be adapted for use in a wide array of species, both wild and domestic, providing a valuable asset for wildlife conservation and livestock management efforts (Sudhakara Reddy et al., 2016).
Conclusion
The TickPath Layerplex assay represents a pivotal step forward in the detection of TBDs, offering a high-performance tool that supports both veterinary health and public safety. By enabling simultaneous screening for multiple pathogens, veterinarians can now diagnose TBDs in dogs more accurately and efficiently, potentially reducing the incidence of chronic diseases and enhancing the quality of life for our four-legged companions.
As this technology continues to evolve, it holds promise to redefine the standards of care in veterinary diagnostics, contributing significantly to the concerted efforts of combating tick-borne diseases worldwide.
References
1. Chomel, B. (2011). Tick-borne infections in dogs-an emerging infectious threat. Veterinary Parasitology, 179(3-4), 294–301. doi:10.1016/j.vetpar.2011.03.040
2. Dantas-Torres, F., Chomel, B. B., & Otranto, D. (2012). Ticks and tick-borne diseases: a One Health perspective. Trends in Parasitology, 28(10), 437–446. doi:10.1016/j.pt.2012.07.003
3. Lopez, J. E., Krishnavahjala, A., Garcia, M. N., & Bermudez, S. (2016). Tick-borne relapsing fever spirochetes in the Americas. Veterinary Sciences, 3(3), 16. doi:10.3390/vetsci3030016
4. Rosenberg, R., et al. (2018). Vital Signs: Trends in Reported Vectorborne Disease Cases – United States and Territories, 2004–2016. MMWR Morb Mortal Wkly Rep, 67(17), 496–501. doi: 10.15585/mmwr.mm6717e1
5. Ojeda-Chi, M. M., et al. (2019). Ticks infesting dogs in rural communities of Yucatan, Mexico and molecular diagnosis of rickettsial infection. Transbound Emerg Dis, 66(1), 102–110. doi: 10.1111/tbed.12990
Modarelli, J. J., Ferro, P. J., de León, A. P., & Esteve-Gasent, M. D. (2020). TickPath Layerplex: adaptation of a real-time PCR methodology for the simultaneous detection and molecular surveillance of tick-borne pathogens. Scientific Reports, 9(1), 6950. doi: 10.1038/s41598-019-43424-y