Leishmania tropica: The comparison of two frequently-used methods of parasite load assay in vaccinated mice

Objective:To compare limiting dilution assay and real-time PCR methods in Leishmania tropica parasite load measurement in vaccinated mice.Methods:BALB/c mice were vaccinated by Leishmania tropica soluble Leishmania antigen or recombinant Leishmania tropica stressinducible protein-1 with/without adjuvant.After three vaccinations,mice were challenged by Leishmania tropica promastigotes.Two months after challenge,the draining lymph nodes of mice footpad were removed and parasite load was assayed by limiting dilution assay and real-time PCR methods.Limiting dilution assay was done by diluting tissue samples to extinction in a biphasic medium.For real-time PCR,DNA of the lymph nodes was extracted,equal dilutions of each sample were prepared and hot-start real-time PCR was done using appropriate primers.The data of the two methods were compared by appropriate statistical methods.Results:Both methods were able to measure different levels of parasite load in vaccinated/unvaccinated mice.In addition,wherever parasite load of a group was estimated high(or low)by one method,the estimated parasite load by another method was the same,although statistically significant differences were found between some groups.Conclusions:Both methods lead to approximately similar results in terms of differentiating parasite load of the experimental groups.However,due to the lower errors and faster process,the real-time PCR method is preferred.

Comparison between Quanti-FERON-TB Gold In-Tube test and tuberculin skin test for diagnosis of latent tuberculosis in children: A cross-section study

Objective: To compare Quanti-FERON-TB Gold In-Tube (QFT-GIT) test and tuberculin skin test (TST) for the diagnosis of latent tuberculosis infection in children. Methods: In this cross-sectional study, 64 participants who were between 3 months and 14 years old and had close contact with smear-positive pulmonary tuberculosis were included. Both QFT-GIT test and TST were done and the results were analyzed by SPSS software and Kappa test. Results: The distribution of gender and age according to QFT-GIT and TST results were matched (P>0.05). Overall agreement between QFT-GIT and TST for diagnosis of latent tuberculosis infection in children was 75%. In addition, the contingency coefficient was 0.257, and the Kappa measure of agreement was 0.246 (P=0.034). Conclusions: Compared to TST, QFT-GIT shows no apparent advantage for diagnosis of latent tuberculosis infection in children.

Effect of Vigna radiata, Tamarix ramosissima and Carthamus lanatus extracts on Leishmania major and Leishmania tropica: An in vitro study

Objective:Current therapy strategies of leishmaniasis have some problems such as high cost,toxicity and side effects.Plant extracts can be a source of drugs to control leishmaniasis.In this study,the effect of hydroalcoholic and chloroformic extracts of Vigna radiata,Tamarix ramosissima,and Carthamus lanatus on Leishmania major and L.tropica was studied.Methods:The plant samples were collected from west of Iran and their extracts were prepared.Antipromastigote activity assay of all extracts was done using tetrazolium-dye assay.Results:Only high concentrations of V.radiata and C.lanatus were able to inhibit Leishmania,while both high and low concentrations of T.ramosissima had antileishmanial effect.No difference was observed between hydroalcoholic with chloroformic extract of each plant.Conclusion:Altogether,the results revealed the antileishmanial activity of T.ramosissima extracts against L.major and L.tropica,indicating its potential as an antileishmanial agent.