Characterization of proteolytic activities of Fusobacterium nucleatum.

This investigation attempted to detect the proteolytic activity of Fusobacterium nucleatum in living cells, lysate cells, and supernatant of cultures. The reactions were optimized in their pH, temperature, reaction time, enzyme source, and substrate volume. Synthetic substrates beta-naphthylamides (Cys-Na, Ser-Na, Leu-Na, Glu-Na, Lys-Na and BANA), carbobenzoxy L-tirosine p-nitrophenylester (CTN), and natural substrate azoalbumin were used.

Protective immunity against Trypanosoma cruzi provided by oral immunization with Phytomonas serpens: role of nitric oxide.

We have previously demonstrated that Phytomonas serpens, a tomato parasite, shares antigens with Trypanosoma cruzi, the protozoa that causes Chagas' disease. These antigens are recognized by human sera and induce protective immunity in Balb/c mice. In the present study, inducible nitric oxide synthase (iNOS) knockout (KO) mice and C57BL/6 mice treated with the nitric oxide inhibitor, aminoguanidine (AG, 50 mg kg(-1)) infected with T.

Protease and phospholipase inhibition protect Veneza zonata (Hemiptera Coreidae) against septicemia caused by parasite trypanosomatid 563DT.

Veneza zonata (Hemiptera Coreidae) is an insect which causes losses in several crops, and it is also an important vector of lower trypanosomatids. V. zonata specimens were collected on rural properties in Londrina, state of Paraná, Southern Brazil.

Phytomonas serpens, a tomato parasite, shares antigens with Trypanosoma cruzi that are recognized by human sera and induce protective immunity in mice.

The immune cross-reactivity between Trypanosoma cruzi, the protozoan that causes Chagas' disease, and Phytomonas serpens, a trypanosomatid that infects tomatoes, was studied. Sera from patients with Chagas' disease presented a strong reactivity with P. serpens antigens by conventional serological assays such as indirect immunofluorescence (IIF) and direct agglutination test (DAT), confirmed after cross-absorption experiments.

Evaluation of antigens from various Leishmania species in a Western blot for diagnosis of American tegumentary leishmaniasis.

A Western blot method that uses antigens from culture promastigote forms of Leishmania (Viannia) braziliensis, L. (Leishmania) amazonensis, L. (Leishmania) tropica, and a trypanosomatid (strain 268T) isolated from naturally infected tomatoes was evaluated for laboratory diagnosis of American tegumentary leishmaniasis (ATL).