Spirocerca lupi (Nematoda, Spirurida) is a life-threatening parasitic nematode of dogs that is presently emerging in several countries. Nonetheless, canine spirocercosis is neglected and underestimated, mainly due to diagnostic limitations inherent to clinico-pathologic, diagnostic imaging and laboratory methodologies. Given the significant benefit of improved diagnosis, the present work evaluated the reliability of a recently described copromicroscopic approach, the FLOTAC technique, as well as a PCR-based assay with that of traditional coproscopic techniques to diagnose S. lupi infection. Ninety-four faecal field samples were collected from two endemic areas (i.e. 29 and 65 from Kenya and Israel, respectively) and processed using different coproscopic examination techniques. In particular, set I (Kenyan samples) comprised the modified flotation with Sheather's sugar solution and merthiolate-iodine-formalin technique, while set II (Israeli samples) comprised a flotation technique with zinc sulphate solution, a modified sugar flotation procedure and the FLOTAC method. All samples were also subjected to a semi-nested PCR protocol specific for a region internal to the mitochondrial cytochrome c oxidase subunit 1 gene of S. lupi. The coproscopic examinations showed low sensitivity and high variability, demonstrating the unreliability of the conventional methods for detecting S. lupi eggs. Nonetheless, the FLOTAC technique scored the highest number of positives and significantly higher number of S. lupi eggs per microscopic field compared to the other coproscopic methods. Additionally, of the coproscopically negative samples, 9 (45%) Kenyan and 21 (38.2%) Israeli samples scored molecularly positive using the PCR-based approach. The potential implications and perspectives for canine spirocercosis of these coproscopic and molecular diagnostic methodologies evaluated herein are discussed.
Bibliographical noteFunding Information:
The Kenyan samples were collected during “Mt. Kulal dogs preventive vaccination” project, supported by CNLI and Mevet s.r.o., and assisted by District Veterinary Office, Marsabit, Kenya, State Veterinary Institute, Prague, Czech Republic, Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences Brno, Czech Republic, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine, Cluj-Napoca, Romania, and by SHADE, Samburu Health Advancement, Diagnosis & Education, Tuum, Kenya. DM, KA and ADM are greatly indebted to Steve and Danielle Fitch and Mark and Alison Lesingirian for support and co-operation. Also, DM, KA and ADM would like to acknowledge the work of all field assistants, namely Rashid, Shukri and Saatho, and thank the communities of Gatab and Tuum for hospitality and cooperation.
- Mitochondrial DNA
- cox1 gene