Pulicaria vulgaris Gaertn. essential oil: an alternative or complementary treatment for Leishmaniasis.

Leishmaniasis is a neglected parasitic protozoal disease that affects approximately 12 million people and represents a public health problem in Iran. The objectives of this study were to obtain the essential oil (EO) from Pulicaria vulgaris Gaertn. growing in Iran and to carry out in-vitro antileishmanial screening of the EO against promastigotes of Leishmania major and Leishmania infantum. The EO from the aerial parts of P. vulgaris was extracted by hydrodistillation. Serial dilutions of the EO were screened for in-vitro antileishmanial activity using 96-well microtiter plates. The P. vulgaris EO was active against the promastigote forms of L. major and L. infantum, with IC50 values of 244.70 and 233.65 µg/mL, respectively. Pulicaria vulgaris EO may serve as an alternative or complementary treatment for leishmaniasis.

Leishmaniasis laríngea. Presentación de un caso clínico / Laryngeal leishmaniasis. Presentation of a clinical case

La leishmaniasis aislada de laringe es una forma muy poco frecuente de leishmaniasis mucosa, hasta tal punto que su presentación en la clínica habitual es excepcional. En nuestro medio y en todo el área mediterránea, se asocia fundamentalmente con la infección por Leishmania donovani infantum. Presentamos un caso de leishmaniasis laríngea diagnosticado en nuestro hospital. Se trata de un paciente sin antecedentes de viajes al extranjero ni infección por el virus de la inmunodeficiencia humana (VIH). El único antecedente relevante es la toma crónica de esteroides inhalados como consecuencia del asma bronquial que padecía. El diagnóstico se realizó por observación directa del protozoo en la biopsia de la mucosa laríngea. El tratamiento empleado ha sido la anfotericina B y la evolución clínica ha sido satisfactoria (AU)

Isolated laryngeal leishmaniasis is a very uncommon form of leishmaniasis mucous membrane, up to such a point that its presentation in the usual clinical practice is rare. In both our setting and in the entire mediterranean area, it is fundamentally associated to Leishmania donovani infantum infection. We present a case of laryngeal leishmaniasis diagnosed in our hospital. This patient had no background of having travelled abroad or of HIV infection. The only relevant background is chronic administration of inhaled steroids due to his bronchial asthma. Diagnosis was by direct observation of the protozoan in the biopsy of the laryngeal mucous membrane. Treatment has been B-amphotericin with satisfactory clinical evolution (AU)

Protective immunity against the protozoan Leishmania chagasi is induced by subclinical cutaneous infection with virulent but not avirulent organisms.

Protective immunity against Leishmania major is provided by s.c. immunization with a low dose of L. major promastigotes or with dihydrofolate-thymidylate synthase gene locus (DHFR-TS) gene knockout L. major organisms. Whether these vaccine strategies will protect against infection with other Leishmania species that elicit distinct immune responses and clinical syndromes is not known. Therefore, we investigated protective immunity to Leishmania chagasi, a cause of visceral leishmaniasis. In contrast to L. major, a high dose s.c. inoculum of L. chagasi promastigotes was required to elicit protective immunity. Splenocytes from mice immunized with a high dose produced significantly greater amounts of IFN-gamma and lower TGF-beta than mice immunized with a low dose of promastigotes. The development of protective immunity did not require the presence of NK cells. Protection was not afforded by s.c. immunization with either attenuated L. chagasi or with L. major promastigotes, and s.c. L. chagasi did not protect against infection with L. major. Subcutaneous immunization with DHFR-TS gene knockouts derived from L. chagasi, L. donovani, or L. major did not protect against L. chagasi infection. We conclude that s.c. inoculation of high doses of live L. chagasi causes a subclinical infection that elicits protective immune responses in susceptible mice. However, L. chagasi that have been attenuated either by long-term passage or during the raising of recombinant gene knockout organisms do not elicit protective immunity, either because they fail to establish a subclinical infection or because they no longer express critical antigenic epitopes.

Cloning, characterization and overexpression of two iron superoxide dismutase cDNAs from Leishmania chagasi: role in pathogenesis.

We have isolated and characterized two superoxide dismutase (SOD) cDNAs from a Leishmania chagasi promastigote cDNA library using degenerate primers derived from conserved amino acid residues of previously isolated manganese and iron SODs. Comparison of these two L. chagasi SOD deduced amino acid sequences with previously isolated MnSOD and FeSOD amino acid sequences revealed that they have higher homology to, and complete conservation of, invariant residues found in iron-containing SODs. Southern blot analysis showed that one gene, L.c.FeSODA, is a single copy gene, whereas the other gene, L.c.FeSODB, belongs to a multi-gene family. Transcript levels and enzyme activities of L.c.FeSODA and L.c.FeSODB show differential stage expression, with higher levels present in the amastigote stage of the parasite compared to the promastigote stage. Expression of the L.c.FeSODs in an E. coli SOD null strain protected the bacteria against free radical generating agents. Overexpression of these FeSODs in L. chagasi parasites also showed enhanced protection against the free radical generating agents, paraquat and nitroprusside. The cloning, characterization and overexpression of the L.c.FeSODA and L.c.FeSODB genes and proteins demonstrates the possible role of SODs in Leishmania pathogenesis.