PubMed Health⌕ Search

Biomedical subjects

S Geerts

Publications and source records attributed to S Geerts.

At least 109 records · Page 6Linked to original sources

Suspected resistance of Ostertagia ostertagi in cattle to levamisole.

Observations on a beef cattle farm in Flanders led to the suspicion of resistance to levamisole in a strain of Ostertagia ostertagi. After treating a group of six animals with levamisole (5 mg kg-1 L.W., i.m.) the reduction in the number of trichostrongylid eggs per gram of faeces varied between 0 and 66.6%, whereas a similar group treated with fenbendazole (7.5 mg kg-1 L.W., p.o.) showed a reduction in worm burdens of 100%. Coproculture showed that the remaining eggs in the first treatment group were all Ostertagia sp. The suspected field strain was compared with a reference strain of O. ostertagi by means of the in vitro larval paralysis test. This test showed LC95 values of 9.12 micrograms ml-1 and of 99.04 micrograms ml-1 for the reference and the field strain respectively, which indicates a resistance factor for the latter of 10.9. These results were not unequivocally confirmed by the post mortem findings on a tracer calf necropsied 4 days after treatment with levamisole.

Animals↗

A preliminary report on Meriones unguiculatus as an experimental host for Taenia saginata metacestodes.

Jirds (Meriones unguiculatus) were treated with dexamethasone and inoculated subcutaneously with 100-300 oncospheres of Taenia saginata. Ten of the jirds received 0.5 mg of the drug per animal twice weekly during the first month after inoculation and then once a week until necropsy and four of these became infected. Up to 20 viable metacestodes were recovered in the subcutaneous tissue at the site of inoculation three months after infection.

Animals↗

Isolation of fraction no. 10 from Taenia saginata and evaluation of its specificity for the diagnosis of bovine cysticercosis.

In an attempt to prove the specificity of the crude Taenia saginata antigen for the immunodiagnosis of bovine cysticercosis, a major and highly immunogenic fraction (F10), responsible for the formation of the typical "long band" reaction in immunoelectrophoresis, has been isolated from T. saginata proglottides by immunoaffinity chromatography. The immunoabsorbent was prepared by coupling a specifically raised hyperimmune serum (HIS) anti-F10 to Sepharose 4B. The purity of the isolated F10 was demonstrated by immunoprecipitation reactions. The HIS anti-F10, however, cross-reacted with several larval and adult Taenia spp. Consequently, F10 showed cross-reactions with the sera of animals infected with hydatid cysts or larval T. hydatigena. F10 also reacted with HIS anti-F5 (Echinococcus granulosus) but was shown to be non-identical with the well known F5 of E. granulosus. These data prove that F10 of T. saginata was not species-specific but showed a group specificity for the taeniid family - a situation analogous to F5 of E. granulosus.

Animals↗

Sheep as an experimental model of Taenia saginata cysticercosis.

Taenia saginata cysticercosis was experimentally produced in 4 Soay sheep, 1 four-horned sheep and 1 Texel sheep by oral administration of eggs of the parasite. Some of these sheep were given dexamethasone therapy. The evolution of T. saginata cysticercosis in this host is characterised by a rapid immune reaction so that by 6 weeks after infection almost all the cysts were dead. There were indications that the dexamethasone therapy may have assisted establishment of the infection and to some extent, postponed the process of degeneration.

Animals↗

Serodiagnosis of Taenia saginata cysticercosis in experimentally and naturally infected cattle by enzyme linked immunosorbent assay.

The sensitivity and specificity of enzyme linked immunosorbent assay (ELISA) for the diagnosis of Taenia saginata cysticercosis was studied among laboratory reared experimentally infected calves and conventionally raised naturally infected cattle by using a T crassiceps metacestode antigen. The intensity of the metacestode burden in experimentally infected animals had a direct effect on the first appreciable rise in the spectrophotometric extinction values and also on the progressive elevation of these values during the later stages of infection. The animals harbouring less than 100 metacestodes were the most difficult to detect by ELISA. Serum from sheep infected with Cysticercus tenuicollis showed cross-reaction. Among the naturally infected cattle the sensitivity of ELISA was poor; only 37.5 per cent of the 24 proven cases could be diagnosed. One of the nine cattle harbouring natural infection of Fasciola hepatica showed cross-reaction. Of the 69 animals 4.3 per cent showed false positive reactions.

Animals↗

Antigenic components of Taenia saginata and their relevance to the diagnosis of bovine cysticercosis by immunoelectrophoresis.

22 antigenic components of Taenia saginata proglottides were detected by immunoelectrophoretic (IEP) study. Cross-absorption of the hyperimmune serum, raised in rabbits against T. saginata, with heterologous and host antigens showed that two thirds of these components were not specific for the cestode. Among the calves experimentally infected with T. saginata eggs, 3 precipitation patterns in IEP were identified depending on the evolutionary stage of the infection. The hydrosoluble extract of T. saginata was used as antigen. A short precipitating arc present near the antigen well and appearing 3 to 4 weeks post-infection of the calves and a long precipitating arc extending towards the anodic end of the slide and appearing in later stages of infection were found of high diagnostic value. No false-positive reaction or cross-reaction were found. Among the calves harbouring less than 50 cysticerci, false-negative reactions were seen.

Animals↗

Localization of larvae of Metastrongylus apri (Gmelin, 1790) Vostokov, 1905, the lungworm of pigs, in the annelid Eisenia foetida Savigny, 1826.

The first stage larvae of Metastrongylus apri could be recovered from the crop of Eisenia foetida after 24 hours of their infection. These were found invading the calciferous glands of the annelid as early as 48 hours post-infection. The larvae were subsequently found localized in the calciferous glands. hearts, dorsal vessel, anterior part of crop and part of the oesophagus anterior to the calciferous glands of the annelid. In general, the larvae had a preference for the circulatory vessels of the annelid so that great majority of them inhabit in the vascular system and the blood sinuses of the above mentioned organs.

Animals↗

Ambrosia maritima: effects on molluscs and non-target organisms.

The actual knowledge about Ambrosia maritima is reviewed with emphasis on recent developments in the fields of plant morphology and taxonomy, the molluscicidal principles--the sesquiterpene lactones--present in the plant and the effects on snails and on non-target organisms. The use of the plant in traditional medicine is also discussed. Areas where more research is needed are outlined.

Africa, Northern↗

Prevalence of cysticercosis in epileptics and members of their families in Burundi.

In the province of Bururi in Burundi, 103 epileptics and 72 control subjects from the same households were examined for cysticercosis. Antigen was detected by enzyme-linked immunosorbent assay in 4.9% of epileptic persons and in 4.2% of controls. Antibody was detected by enzyme-linked electroimmunotransfer blot assay (EITB) in 11.7% of epileptics and in 2.8% of controls. Neither difference was statistically significant, nor was a history of taeniasis significantly more frequent in epileptics than in controls. However, cysticercosis was significantly more frequently diagnosed by EITB in people with a history of taeniasis than in those without such a history. The prevalence of taeniasis in schoolchildren ranged between 0 and 1.0%. Meat inspection detected cysticercosis in 2% and 39% of pigs in 2 localities, respectively.

Adolescent↗