Leishmania tarentolae expressing CXCL-10 as an efficient immunotherapy approach against Leishmania major-infected BALB/c mice.

Recent findings have demonstrated the suitability of interferon-gamma-induced protein 10 (IP-10) or CXCL-10 as an immunotherapy tool in treatment of leishmaniasis. This chemokine can overcome Leishmania (L.) infection through inducing nitric oxide (NO) production for parasite elimination. This study was undertaken to investigate the therapeutic effects of recombinant Leishmania tarentolae expressing CXCL-10 and an expression vector encoding CXCL-10 (pcDNA-CXCL-10-EGFP) in a model of BALB/c mice susceptible to infection by Leishmania major. The outcome of intervention was examined at 3 weeks post-treatment by evaluating the parameters of parasite burden (PB), arginase activity, NO and various cytokines such as IFN-γ, IL-4, IL-6 and IL-10. The results have shown that despite the efficacy of CXCL-10 expression vector as gene therapy, the live therapy strategy using L. tarentolae expressing CXCL-10 was more effective in terms of decreasing PB. Nitric oxide production increased, especially in the live therapy approaches. Arginase activity also decreased in all regimens, which demonstrates the potency of the treatment. The overall cytokine production shifted in favour of Th1 responses in the treated mice. Altogether, recombinant L. tarentolae expressing CXCL-10 represents a promising therapeutic strategy to improve treatment of cutaneous leishmaniasis.

Arginase activity of Leishmania isolated from patients with cutaneous leishmaniasis.

Cutaneous leishmaniasis (CL) is one of the most important vector-borne parasitic diseases, highly endemic in Iran, and its prevalence is increasing all over the country. Arginase (ARG) activity in isolated Leishmania parasites from CL patients is yet to be explored. This study aimed to compare the ARG activity of isolated Leishmania promastigotes from CL patients with a standard strain of Leishmania major and its influences on the disease pathogenesis. We recruited 16 confirmed CL patients from Qom Province, in central Iran; after detection of Leishmania species using PCR-RFLP, we assessed the levels of ARG in the isolated promastigotes and determined the parasites' growth rate. Only L. major was identified from CL patients. The level of ARG activity in the isolated Leishmania promastigotes from CL patients was significantly higher than that obtained from the standard strain of L. major. No significant correlations between ARG activity and lesion size, number or duration were observed; in contrast, a significant negative correlation was seen between ARG level and Leishmania' growth rate. The obtained results suggest that increased ARG expression and activity in the isolated Leishmania promastigotes might contribute to the higher parasite infectivity and play a major role in the pathogenicity of the CL.

Enhanced paromomycin efficacy by solid lipid nanoparticle formulation against Leishmania in mice model.

Leishmaniasis caused by protozoan parasites of the genus Leishmania. Intracellular infections treatment such as leishmaniasis is frequently hampered by limited access of drugs to infected cells. Moreover, most of the current drugs are confined to some toxic compounds, and there are increasing incidences of development of drug resistance. Hence, production of a new antileishmanial compound is crucial. Paromomycin sulphate (PM) is a promising antileishmanial drug. One strategy to improve drug effectiveness is to use appropriate delivery systems. Solid lipid nanoparticle (SLN) is as an excellent substitute delivery system to other colloidal carrier. In the present study, PM was loaded in solid lipid nanoparticles (PM-SLN) and the in vivo efficacy was studied against Leishmania (L.) major-infected BALB/c mice. For this reason, the footpad swelling was measured and real-time PCR was performed to quantify the parasite load after infectious challenge. The level of cytokines including interleukin-4 (IL-4) and gamma interferon (IFN-γ) and nitric oxide was evaluated. Altogether, this study showed that the PM-SLN formulation is a safe compound and SLN in PM-SLN compound is effective for treatment of leishmaniasis by improving the effectiveness of PM in killing the parasite and switching towards Th1 response.

Isolation of free-living amoebae from sarein hot springs in ardebil province, iran.

BACKGROUND: Free-living amoebae (FLA) are a group of ubiquitous protozoan, which are distributed in the natural and artificial environment sources. The main aim of the current study was to identify the presence of FLA in the recreational hot springs of Sarein in Ardebil Province of Iran. METHODS: Seven recreational hot springs were selected in Sarein City and 28 water samples (four from each hot spring) were collected using 500 ml sterile plastic bottles during three month. Filtration of water samples was performed, and culture was done in non-nutrient agar medium enriched with Escherichia coli. Identification of the FLA was based on morphological criteria of cysts and trophozoites. Genotype identification of Acanthamoeba positive samples were also performed using sequencing based method. RESULTS: Overall, 12 out of 28 (42.9%) samples were positive for FLA which Acanthamoeba and Vahlkampfiid amoebae were found in one (3.6%) and 11 (39.3%) samples, respectively. Sequence analysis of the single isolate of Acanthamoeba revealed potentially pathogenic T(4) genotype corresponding to A. castellanii. CONCLUSION: Contamination of hot springs to FLA, such as Acanthamoeba T(4) genotype (A. castellanii) and Vahlkampfiid amoebae, could present a sanitary risk for high risk people, and health authorities must be aware of FLA presence.