Detection of Leishmania infantum Infection in Reservoir Dogs Using a Multiepitope Recombinant Protein (PQ۱۰)

Mediterranean visceral leishmaniasis is a zoonotic disease caused by Leishmania infantum and transmitted by the bites of infected female sand flies.  Iran is one of the endemic areas of this disease. Dogs and canines are the major reservoir hosts of Leishmania infantum in the new and old world, including Iran. If visceral leishmaniasis is left untreated, it may result in a ۹۰% mortality rate. The identification and elimination of infected dogs are efficient ways to control this disease. The diagnostic methods used to identify these animals cannot yield ۱۰۰% detection. Therefore, in the present study, we used a multiepitope recombinant protein (PQ۱۰) to distinguish between symptomatic and asymptomatic infections caused by Leishmania infantum in animal reservoirs (dogs). The coding sequence of PQ۱۰ recombinant protein was sub-cloned in pET۲۸ expression vector and was commercially synthesized by GENERAY Biotechnology, China. In the following process, sequencing was performed with plasmid-specific primers and followed by the expression, optimization of expression. The purified recombinant protein was confirmed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot. The efficacy of recombinant PQ۱۰ protein was evaluated by an indirect enzyme-linked immunosorbent assay (ELISA) test using ۱۵۰ dog sera (۲۵ symptomatic positive sera, ۲۵ asymptomatic positive sera, ۸۰ negative sera, and ۲۰ sera of dogs with other infectious diseases). Direct agglutination test (DAT) as the standard method was used to compare and determine specificity and sensitivity. The results indicated that the sensitivity and specificity of ELISA using infected dog sera were ۹۴% and ۸۶%, respectively. Positive and negative predictive values for dog sera were reported as ۸۷.۰۳% and ۹۳.۴۷%, respectively. This protein was able to identify ۹۲% of asymptomatic dogs with visceral leishmaniasis. The results showed that the recombinant protein PQ۱۰ is able to identify positive cases of canine visceral leishmaniasis, especially asymptomatic cases.

کلیدواژه ها:

Visceral leishmaniasis ، Leishmania Infantum ، PQ۱۰ ، Recombinant Protein ، Serodiagnosis ، Dog ، Iran