Detection and phylogenetic analysis of kinetoplast DNA of Leishmania infantum infected humans, domestic dogs and sandflies in Northwest Iran.

Leishmaniasis refers to a disease with a wide range of manifestations; and there are three main forms of disease, cutaneous, mucocutaneous, and visceral. Leishmaniasis is one of the diseases with a protozoan agent which is vector-borne. Visceral leishmaniasis (VL) is the most severe form that can be fiercely life-threatening if left untreated. VL can be caused by members of Leishmania donovani complex, in Iran, Leishmania infantum is considered the primary causative agent of VL, resulting in a zoonotic form of VL. The two main goals of our work, which followed our prior sero-epidemiological and entomological survey, were to characterize and conduct a phylogenetic analysis of the Leishmania species that infect people, dogs, and sandflies. The samples were collected throughout 2017, from January to December, so blood samples were collected from humans and dogs, while sandfly samples were collected with sticky traps. DNA extracted from all seropositive samples of humans and dogs, 10% of sero-negative human samples, and all collected sandflies were subjected to kDNA-nested-PCR for tracing parasites. A total of 30 samples, including 20 human samples, 8 dog samples, and 2 sandfly samples, were found positive for the kDNA gene of L. infantum. Sequences were evaluated to study the genetic diversity among the six discovered L. infantum. Based on kDNA, the phylogenetic study of L. infantum demonstrated a high level of genetic variety and a relationship between the host, the parasite's geographic origin, and its genetic diversity.

A Leishmania infantum FML-ELISA for the detection of symptomatic and asymptomatic canine visceral leishmaniasis in an endemic area of Iran.

BACKGROUND: Visceral leishmaniasis (VL) is caused by Leishmania infantum in Mediterranean basin and is an endemic disease in some parts of Iran. Canines are the main reservoirs of VL in most of the endemic areas. Different serological methods have been introduced for diagnosis of canine visceral leishmaniasis (CVL). OBJECTIVE: In this survey a Fucose-Mannose Ligand (FML) ELISA, using native L. infantum antigen, was developed and its validity for detection of infected dogs in comparison with direct agglutination test (DAT) and PCR was evaluated. METHODS: Blood samples of sixty ownership dogs (≤ 3 years old) were collected from Meshkin-shahr district in Ardabil province, North-west of Iran. Sera were separated for serological assays (DAT and FML-ELISA) and the buffy coats were collected for molecular evaluation. RESULTS: Two out of the 60 (3.33%) samples were found to be positive (antibody titer of ≥ 1/320) in DAT while seven of the 60 (11.66%) samples were positive by FML-ELISA. Nine out of 60 (15%) buffy coat samples showed a band about 680 bp indicative of L. infantum in PCR. Three out of 60 dogs had Kala-azar symptoms and were positive by PCR and FML-ELISA, while two of these three dogs had antibody titers >1/320 in their serum samples. The sensitivity and specificity of FML-ELISA for the detection of CVL in both symptomatic and asymptomatic dogs were found to be 77.8% and 100%, respectively. CONCLUSION: Considering the acceptable sensitivity and high specificity of FML-ELISA, use of this serological method can be recommended for epidemiological surveys of CVL.