Molecular Detection of Leishmania spp. in Skin and Blood of Stray Dogs from Endemic Areas of Cutaneous Leishmaniasis in Saudi Arabia

Abstract

Background: Dogs can act as reservoirs of canine leishmaniasis, caused by Leishmania species. The aims of this study were to determine the prevalence of canine leishmaniasis using a PCR technique among stray dogs living in three provinces of Saudi Arabia, Riyadh, Al-Ahsa Oasis and Al-Qaseem, where the disease is endemic; and to identify and document different Leishmania to species levels.

Methods: This cross-sectional investigation was conducted, from Mar 2016 to Apr 2018, in three parts of Saudi Arabia: Central province (Riyadh), Eastern province (Al-Ahsa Oasis) and Al-Qaseem province. Blood samples were collected from 526 dogs; 40 presented cutaneous nodules so were suspected clinically of cutaneous leishmaniasis. Biopsy tissue collections and parasite cultures were performed. A generic kDNA was performed using different primers for Leishmania differentiation.

Results: All blood samples were negative for Leishmania infantum infection by molecular analysis, though forty dogs had thick cutaneous lesions in different parts of their body. Four dogs' skin lesions were associated with dermatitis, splenomegaly and lymphadenomegaly. Parasite culture was used to diagnose cutaneous leishmaniasis, identifying 31/40 (77.5%) positive samples. Overall, of 526 samples, the prevalence of L. major and L. tropica was found to be 4% and 1.9%, respectively. Gender and age had a significant effect on Leishmania prevalence: (P=0.0212 and 0.0357), respectively.

Conclusion: This was the first molecular study of dog leishmaniasis from Saudi Arabia of dogs confirmed to have cutaneous leishmaniasis. Further epidemiological and molecular investigations of domestic and wild canine infections with L. major, L. tropica and L. infantum in endemic and nonendemic areas of Saudi Arabia are required, for leishmaniasis control.

Keywords: Dogs; Leishmania; Saudi Arabia; kDNA.

Fig. 1:

Map of the study area locations in Saudi Arabia

Fig. 2:

Agarose gel electrophoresis (1.7%) of amplified DNA from collected samples using F/R. M, 100 bp molecular size marker (Generuler); Lane L.m, L. major-positive control DNA (200 bp and 620bp); L.t L. tropica-positive control DNA (738bp); Li, L. infantum-positive control DNA (447bp); N, negative PCR control (water); Lanes1–19, template DNA isolated from stray dog tissue samples from areas during this study shows positive infection with L. major and L. tropica and negative infection with L. infantum