Sensitivity comparison for the Leishmania spp. detection in different canine tissues using PCR-HRM

Area of Science:

• Veterinary Parasitology
• Molecular Diagnostics
• Canine Infectious Diseases

Background:

• Leishmaniasis is a vector-borne protozoan disease caused by Leishmania parasites.
• Real-time PCR with High Resolution Melting (PCR-HRM) offers simultaneous pathogen detection and species identification.
• PCR-HRM analyzes melting temperature curves for pathogen identification.

Purpose of the Study:

• To estimate the sensitivity of PCR-HRM for Leishmania spp. detection in various canine tissues.
• To evaluate biological samples from lymph nodes, bone marrow, and ear pinnae.
• To assess diagnostic capabilities in stray dogs from Asunción, Paraguay.

Main Methods:

• Utilized real-time PCR with High Resolution Melting (PCR-HRM) for Leishmania detection.
• Collected samples from popliteal, submandibular, and pre-scapular lymph nodes, bone marrow, and ear pinnae.
• Employed the rk39 immunochromatographic test for antibody detection.

Main Results:

• 89% of dogs tested positive for Leishmania infantum antibodies via rk39 test.
• PCR-HRM detected Leishmania spp. in 80% of rk39-positive dogs, identifying L. infantum.
• High detection rates observed in popliteal (100%), submandibular (95%), and pre-scapular lymph nodes (90%), bone marrow (85%), and ear pinnae (85%).

Conclusions:

• Real-time PCR-HRM with the hsp70 marker is a highly sensitive method for simultaneous Leishmania detection and identification in canine tissues.
• Ear pinnae are highlighted as an accessible and effective tissue for molecular diagnosis of canine leishmaniasis.
• The study confirms PCR-HRM's utility in diagnosing canine leishmaniasis.