Parasite Burden Measurement in the Leishmania major Infected Mice by Using the Direct Fluorescent Microscopy, Limiting Dilution Assay, and Real-Time PCR Analysis

Identification of the parasites that cause children's cutaneous leishmaniasis and several types of immune response cells

Cutaneous leishmaniasis has received many epidemiological, diagnostic, therapeutic, quantitative and other studies. The current study aims to determine the type of leishmaniasis parasite that causes cutaneous leishmaniasis in children in the Al-Diwaniyah governorate in central Iraq to ​​assess the level of variations in globulins and immune cells in children with cutaneous leishmaniasis. Fifty-nine was a positive sample for the traditional laboratory examination of cutaneous leishmaniasis in children whose ages ranged between (8 months-10 and years). They were collected from the Maternity and Children Hospital from January 2020 to December 2021. The samples were subjected to molecular diagnostics to determine the type of leishmaniasis that causes the disease using Real-Time PCR. ELISA was approved to measure the levels of variation in the concentrations of IgG and IgM among the group of infected and healthy children. The results indicated that children's predominant type causing cutaneous leishmaniasis is L. major 52 samples (88.13%). The immunological study showed clear and statistically significant differences in the mean globulin concentrations for comparing the patient's L. major with the control group at a probability level (P≤0.05). The current study concluded that L. major is the dominant species responsible for cutaneous leishmaniasis. Keywords: Catenous leishmaniasis, L. major, Real-Time PCR.

Therapeutic effects of Lucilia sericata larval excretion/secretion products on Leishmania major under in vitro and in vivo conditions

BACKGROUND

Leishmaniasis is a neglected infectious disease caused by protozoa of the genus Leishmania. The disease generally manifests as characteristic skin lesions which require lengthy treatment with antimonial drugs that are often associated with adverse side effects. Therefore, a number of studies have focused on natural compounds as promising drugs for its treatment. This study aimed to evaluate the effects of larval excretion/secretion products (ES) of Lucilia sericata in crude and fractionated forms on Leishmania major, by using in vitro and in vivo models.

METHODS

The in vitro experiments involved evaluation of ES on both promastigotes and macrophage-engulfed amastigotes, whereas the in vivo experiments included comparative treatments of skin lesions in L. major-infected mice with Eucerin-formulated ES and Glucantime.

RESULTS

The half maximal inhibitory concentrations of the crude ES, > 10-kDa ES fraction, < 10-kDa ES fraction, and Glucantime were 38.7 μg/ml, 47.6 μg/ml, 63.3 μg/ml, and 29.1 μg/ml, respectively. Significant differences were observed between percentage viabilities of promastigotes treated with the crude ES and its fractions compared with the negative control (P < 0.0001). The crude ES was more effective on amastigotes than the two ES fractions at 300 μg/ml. The macroscopic measurements revealed that the reduction of lesion size in mice treated with the crude ES followed quicker cascades of healing than that of mice treated with Glucantime and the ES fractions.

CONCLUSIONS

The present study showed that the larval ES of L. sericata in both crude and fractionated forms are effective for both intracellular and extracellular forms of L. major. Also, the ES exert both topical and systemic effects on mice experimentally infected with L. major.