Effects of isoprinosine onEchinococcus multilocularis andE. granulosus metacestodes

An in vivo study of the effect of Isoprinosine onEchinococcus multilocularis andE. granulosus metacestodes (Cestoda) was performed. Short- and longterm treatments with different doses were tested in experimental hosts: jirds forE. multilocularis and mice forE. granulosus. Modifications in the weight of animals as well as macroscopical and ultrastructural aspects were registered for each animal group. The results obtained showed a considerable ultrastructural alteration inE. multilocularis metacestodes after short-term treatment with the highest dose, and the tissue transplants were negative. InE. granulosus cysts the ultrastructural damage was also very important and its severity increased as the dose was raised. For the two parasites, the macroscopical aspect and weight of the lesions were profoundly changed.     

Serological differentiation of experimentally induced Candida dubliniensis and Candida albicans infections

Using a rabbit model of systemic infection, we show that it is possible to differentiate infections caused by Candida dubliniensis and other Candida species by detecting the antibody response mounted by the infected animals. These results confirm our previous observation in a patient with C. dubliniensis candidemia and suggest that detection of C. dubliniensis-specific antibodies is useful in the diagnosis of invasive candidiasis caused by this yeast.     

Immunoprophylaxis with BCG of experimental Echinococcus multilocularis infections.

Previous studies have demonstrated that prophylactic treatment with BCG protects cotton rats (Sigmodon hispidus) against experimental infections with Echinococcus multilocularis; this treatment can, however, induce granulomatous reactions. In an attempt to identify a minimum prophylactic dose of BCG which would not induce granulomas, cotton rats were treated intraperitoneally with various doses of BCG (10(1) to 10(7) colony-forming units [CFU]) and then inoculated intraperitoneally with one brood capsule of the parasite. Consistent and complete protection was obtained by the inoculation of as few as 10(3) CFU of BCG. A dose of 10(1) CFU gave no protection whatsoever, and 10(2) CFU gave only partial protection. Doses larger than 10(3) (10(5), 10(7) CFU) also afforded complete protection but gave rise to granulomatous lesions. At the time of the inoculation of the parasite, protection coincided with a general elevation of leukocytes, especially cells of the monocyte/macrophage series. It is proposed that these results support evidence for the macrophage being the principal potential effector cell in hydatid disease.     

Serological diagnosis of goose circovirus infections.

Infections with goose circovirus (GoCV) are associated with growth retardation and developmental problems in farmed geese. An indirect immunofluorescence assay for detecting virus-specific serum antibody was developed for diagnostic and epidemiological purposes. In the absence of a method for growing GoCV in cell culture, the assay was based on the reaction of antibodies with the GoCV capsid protein produced within baby hamster kidney cells using the eukaryotic Semliki forest virus expression vector. Using an optimized test that involved screening sera at 1:50 dilution and the use of a fluorescein isothiocyanate anti-duck immunoglobulin conjugate, GoCV-specific antibody was detected in 141 (88.6%) of 159 samples obtained from 27 of 28 breeder flocks aged from 1 to 6 years. Testing also showed the presence of GoCV-specific antibody in 85 (40.9%) of 208 serum samples from birds aged 30 weeks or less. Although maternally derived antibody was detected in birds when 1 and 4 days old, actively acquired antibody was first detected in birds aged 53 days. Following experimental inoculation of 21-day-old geese with tissue homogenate containing GoCV, virus-specific antibody was detected in serum samples collected at 27 and 34 days post inoculation. It is concluded that the SFV expression vector approach may prove useful for developing serological tests for other viruses, including other avian circoviruses, that do not grow in cell culture.     

Serological differentiation of Helicobacter pylori CagA(+) and CagA(-) infections

Many Helicobacterpylori strains causing gastroduodenal diseases have a cagA gene encoding CagA protein, a virulence factor of these bacteria. Anti-CagA antibodies produced by the majority of people infected with CagA(+) strains can indicate such an infection. In this study, the efficacy of three immunoenzymatic tests for detecting CagA(+) and CagA(-) infections were compared: immunoblot (Milenia ID Blot H. pylori IgG; MB) and ELISA conducted either with a recombinant immunodominant fragment of CagA (rCagA) or the full-length CagA molecule (flCagA). The 13C-urea breath test (13C-UBT) was used for establishing H. pylori status. The serum samples from 157 individuals were used for serodiagnosis. H. pylori CagA(+) infection was detected in H. pylori-infected individuals with similar frequencies by MB (64%) and flCagA-ELISA (60%) and a little less frequently by rCagA-ELISA (53%). There was a high coincidence between the negative results of these three tests for H. pylori-uninfected individuals with no anti-CagA IgG in the serum (96-100%). The results show that rCagA-ELISA and, especially, flCagA-ELISA are easy, inexpensive and useful noninvasive assays for the discrimination of CagA(+) and CagA(-) H. pylori infections in subjects examined by urea breath test.     

Serological differences in Legionella pneumophila infections

Guinea pigs were infected with two subtypes of Legionella pneumophila serogroup 1 (UH1 and RH1). Seroconversion by indirect fluorescent-antibody assay was demonstrated in 94 to 97% of guinea pigs when the challenge strain was used as the antigen. The standard Philadelphia 1 antigen demonstrated seroconversion in 94% UH1-challenged animals, but in only 66% of RH1-challenged animals.     

Serological activity of tissue lipids in man

Summary A method of serological quantitative reaction was developed with lirad test-antigens fixed on paper, i.e., complement fixation test with 50% titer and reaction of specific addition of protein in paper antigen. The serological activity of various tissue lipids (free lipids) isolated directly from the tissues and combined (obtained from the saline extracts after preliminary hydrolysis) was demonstrated by these methods. Tissue lipids of man, dog, swine and large cattle react only with homologous antiserum.This allows the suggestion that the tissue lipid fraction is species-specific.Presented by N.N. Zhukov-Verezhnikov, Active Member Acad. Med. Sci. USSR     

Effect of mebendazole againstEchinococcus granulosus andTaenia hydatigena cysts in naturally infected sheep and relevance to larval tapeworm infections in man

The ability of three treatment schedules of mebendazole to kill well-established hydatid cysts was studied. Pregnant sheep, naturally infected withEchinococcus granulosus and/orTaenia hydatigena, were treated daily with mebendazole at a dose rate of 50 mg/kg body weight for either five days, one month, or three months.At autopsy, seven months after the commencement of treatment, no evidence was found that the 5-day treatment schedule had any damaging effect onE. granulosus cysts. The effects of the one month treatment were equivocal. There was evidence of a damaging effect from the 3-month treatment schedule and protoscoleces were not infective to dogs. NoT. hydatigena cysts survived the 1- and 3-month treatments, but organisms from the 5-day treatment were infective to dogs.These results forE. granulosus in sheep suggest that long-term treatment with mebendazole may be required in hydatid disease in man. The results obtained forT. hydatigena in sheep are discussed in relation to the treatment of cysticercosis fromT. solium in man. Mebendazole showed no untoward effect on the sheep or their lambs.     

Serological recognition of feline infectious peritonitis virus spike gene regions expressed as synthetic peptides andE. coli fusion protein

Summary Cats exposed to feline infectious peritonitis virus (FIPV) or feline enteric coronavirus (FECV) cannot be differentiated by serological analysis. Three synthetic peptides and anE. coli recombinant fusion protein generated from FIPV 79-1146 spike gene sequence were produced. Coronavirus positive cat sera reacted to peptide aa 950–990 but were non-reactive to aa137–151 and aa 150–180 peptides as demonstrated by ELISA. Amino acid sequence 97–222 expressed as a galk fusion protein inE. coli was tested against coronavirus positive cat sera by western blot analysis. Only sera from cats exposed to the FIPV type-II strains DF-2 or 79–1146 that were exhibiting signs of FIP recognized the fusion protein. Sera from FECV exposed cats did not recognize the 97–222 fusion protein in western blot analysis.     

Serological markers during dengue 3 primary and secondary infections.

BACKGROUND: The detection of the IgM antibody for the dengue virus in serum by ELISA has become one of the most important and useful methods for diagnosis of dengue using a single acute-phase serum sample. Currently, this system is an invaluable tool for the surveillance of dengue fever (DF) and dengue hemorrhagic fever (DHF). The usefulness of other serological markers such as IgA and IgE have been less studied. OBJECTIVE: To study the IgM, IgA and IgE specific antibody response in dengue 3 infected patients with different clinical picture and type of infection. STUDY DESIGN: One hundred and twenty-seven serum samples collected on days 5-7 at the onset of fever from clinically and serologically confirmed dengue cases were studied. Forty-two were classified as primary dengue fever cases, 48 as secondary dengue fever cases and 37 as secondary dengue hemorrhagic fever cases. All samples were tested by capture ELISA in order to detect dengue IgM, IgA and IgE antibodies. RESULTS AND CONCLUSIONS: In this study, significant differences were observed in the IgM, IgA and IgE response between the study groups. High IgA and IgE OD ratios in secondary dengue cases were found. The usefulness of serotype specific IgM antibody detection is also analyzed and discussed. A priority for future dengue research in terms of protection, recovery of infection and immunopathogenesis is to elucidate the role of these immunoglobulins. The cross reactivity response to IgM between dengue virus serotypes in primary and secondary cases should also be more studied.     

Echinococcus multilocularis infections in dogs from urban and peri-urban areas in France

Echinococcus multilocularis is the causative agent of alveolar echinococcosis, a severe zoonotic disease. It is maintained through a sylvatic life cycle based on predator–prey interactions mainly between foxes and rodents. Dogs are also good definitive hosts; and due to their close proximity to humans, they may represent a major risk factor for the occurrence of human cases. In two medium-sized cities of Eastern France (Annemasse and Pontarlier), located in highly endemic areas, 817 dog feces samples were collected and analyzed by a flotation technique followed by a multiplex PCR assay. For the first time in France, we assessed the presence of E. multilocularis DNA in four dog feces samples, in which it represents an estimated prevalence of 0.5 % (95% CI; 0.1 % <> 1.3 %). Eight other samples presented taeniid infections from three different species (Taenia crassiceps, Taenia serialis, and Taenia polyacantha). When considering both E. multilocularis and Taenia sensu lato, prevalence rose to 0.6 % in Annemasse and 2.6 % in Pontarlier. In this highly endemic context, proper application of the usual deworming recommendations (70 % of the dogs were treated twice a year or more) failed to prevent dog infection, particularly for hunting dogs. Our results stressed the need to adapt treatment to the environmental context and to the specific activity of dogs. Further epidemiological surveys in domestic dogs and cats using this coprological approach are still needed to obtain a better overview of infection and the associated zoonotic risk.     

Protection of cotton rats against experimental Echinococcus multilocularis infections with BCG cell walls.

Previous works has indicated that cotton rats treated with Mycobacterium bovis strain BCG are effectively protected against an infection with the metastatically proliferating metacestodes of Echinococcus multilocularis. In an attempt to induce a similar protection in the absence of tubercular granulomatous lesions, cotton rats were treated with BCG cell walls. A single injection of 150 micrograms of cell walls, emulsified in mineral oil-Tween-saline, 2 weeks before the inoculation of the parasite completely protected the animals against infection with E. multilocularis. This protection was correlated with an increase in the numbers of monocytes and, as judged by acid phosphatase activity, an activation of these cells. This study shows that BCG cell walls are as effective in protecting animals against E. multilocularis as the viable organism.     

Serological evidence of human adenovirus infections in animals

Twenty-two individual avian and mammalian sera from a zoo were investigated by the haemagglutination inhibition (HAI) and virus neutralization (VN) tests for the presence of specific antibodies to common and less common human adenovirus serotypes, viz. types 5 (Ad 5) and 8 (Ad 8), respectively. Sera positive by both tests were considered to contain presumptive antibody to the adenovirus. One serum contained HAI and VN activities for both viruses; 11 sera were positive by both tests for Ad 5 and three for Ad 8. Four sera were positive for Ad 5 by either test and were of uncertain serological status. Two hundred and forty-three individual farm animals and stray dogs from a rural environment were similarly investigated in the HAI test and three were seropositive for Ad 5; further examination by VN showed that only one of these was positive.     

Studies on the adhesion of protoscoleces from Echinococcus multilocularis and E. granulosus to artificial substrates and human endothelial cells in vitro

This paper describes experiments in vitro to investigate the interaction between isolated protoscoleces from Echinococcus granulosus and E. multilocularis and human endothelial cells in monolayer culture. During a maximum coculture period of 48 h neither protoscoleces nor endothelial cells showed evidence of cytotoxicity. However, protoscoleces adherent to either endothelial cells or artificial substrata developed a glycocalyx-like coat. Adherence of protoscoleces to endothelial cells requires serum (pooled human serum or foetal calf serum) in a dose-dependent fashion. However, protoscolex adhesion to artificial substrates such as glass with or without gelatin coating was markedly inhibited by serum. Thus, even 0.001% serum reduced adhesion by 46% compared with the control value. Whilst the chemical nature of the serum components have not been identified, these experiments show that serum contains both inhibitory and promoting factors for protoscolex adhesion, a finding of possible significance for the therapeutic prevention of systemic spread of established Echinococcus infections.