Efficacy of epsiprantel against Echinococcus granulosus infections in dogs.

Dogs with 41-day-old experimental infections of Echinococcus granulosus were treated orally with epsiprantel. Single doses of 2.5 mg kg-1, 5.0 mg kg-1 or 7.5 mg kg-1 were effective in removing more than 99 per cent of these parasites, but total clearances of worms only occurred in dogs given the highest dose.

[Comparative analysis of the rhythm of cercariae emergence in three strains of Schistosoma bovis (trematoda: Schistosomatidae)]. / Analyse comparative du rhythme d'emission des cercaires de trois souches de Schistosoma bovis (Trematoda: Schistosomatidae).

A comparative experimental study of the rhythmic shedding of three geographic strains of Schistosoma bovis cercariae (Sardinian, Sudanese and Spanish) by Bulinus truncatus showed a significant difference in the emergence patterns. The results support the existence of a genetic variability of the emergence rhythms. The origin of the variability is discussed and could be found in the pastoral practice and the ecological characteristics of the different transmission foci.

Karyotype delineation in Isidora truncata (Gastropoda: Planorbidae).

Metaphase chromosomes of a single Sardinian population of Isidora truncata were examined in an attempt to provide a picture of a standard karyotype to which Sardinian populations could be referred. Several new foci were identified and mapped.

Echinococcus granulosus: specific quantification of the two most immunoreactive antigens in hydatid fluids.

Preparations of the two most immunoreactive Echinococcus granulosus antigens (antigens 4 and 5) from sheep hydatid fluid, purified by a simplified method, and monospecific antisera against antigens 4 and 5, prepared by a new procedure, were used to measure the antigenic concentrations of antigens 4 and 5 in swine, sheep, and human hydatid fluids from pulmonary or hepatic cysts. Two bovine samples and two commercial preparations were also tested. The concentration of both antigens was significantly higher in sheep and human hydatid fluids than in swine hydatid fluid. The antigenic content of the two bovine samples and of the two commercial preparations was below the sensitivity level of the method employed. Independently of the species tested, the amount of Echinococcus antigens was greater in hepatic than in pulmonary cysts. The ratio between the concentrations of antigens 4 and 5 was constant at about 1:10 in the samples from various organs and from different species. When there were enough samples for statistical analysis a linear correlation was found between the contents of these two antigenic components but there was none between the amounts of proteins and the antigenic concentrations in the single cysts. Sheep hydatid fluid must therefore be considered the best source of antigenic material for diagnostic purposes even though in human cysts the antigenic fraction is less contaminated by serum proteins. We describe a reliable method of standardising antigenic material for the immunodiagnosis of hydatid disease.

Echinococcus granulosus: identification of subunits of the major antigens.

This paper describes a procedure for obtaining the two "major" Echinococcus granulosa antigens (antigens 4 and 5) from sheep hydatid fluid. Purified antigen 4 (m.w. 400,000 and over) and antigens 5 (m.w. 150,000) were separated in order to identify molecular subunits of each. SDS 12.5% polyacrylamide gel electrophoresis of antigen 4 gave a single band for which a m.w. of 67,000 was calculated. When 5% 2-mercaptoethanol was added to the antigen 4 preparation, SDS 12.5% polyacrylamide gel electrophoresis gave two bands (m.w. 47,000 and 20,000). SDS 12.5% polyacrylamide electrophoresis of antigen 5, with or without 2-mercaptoethanol, gave at least three bands with m.w. ranging from 10,500 to 20,000. Low m.w. subunits of both antigens were eluted in a single peak from a preparatory SDS 7.5% acrylamide gel electrophoresis; these subunits were found to be immunogenic and antigenic.

Isolation of the most immunoreactive antigenes of echinococcus granulosus from sheep hydatid fluid.

This paper describes a simplified procedure for obtaining purified Echinococcus granulosus antigens from sheep hydatid fluid by using affinity chromatography on concanavalin A-Sepharose. The presence of two "major" antigens (4 and 5) was confirmed. Antigen 5 was isolated by preparative polyacrylamide gel electrophoresis. Antigen 4, eluted by diffusion from the gel, was seen to be "contaminated" by antigen 5 and was isolated by using anti-5 Sepharose-linked serum. These two major antigens were then tested separately against the sera of hydatidosis patients by using very simple immunolgic tests. The best results were obtained in passive hemagglutination with antigen 4. Antigen 4 is the most immunoreactive parasitic antigen; antibodies against it were found in the sera of all hydatidosis patients showing positive reaction. Apart from the direct use of this antigen in serologic tests, it appears possible to standarize the most frequently used and commerically available antigenic materials by titrating this component.