Failure to observe cross-fertilization between the Echinococcus granulosus G1 and G6 strains after an experimental mixed infection of the definitive host

The classification within Echinococcus granulosus is currently under debate. To assess the reproductive potential between the G1 and G6 strains, an experimental double infection was carried out in a dog. First, two fertile hydatid cysts were collected in Algeria from a cow and a dromedary. They were identified as being G1 and G6 with the markers coxI and nadI. Subsequently, a dog was inoculated with protoscoleces from these two cysts. Sixty days after infection, 85 adult worms were recovered from the intestine of the dog. Then, the two cysts and each of these individual parasites were characterized with the multilocus microsatellite EmsB and compared. For all worms, the scolex and the gravid proglottids, separately analyzed, provided an identical profile: the G1 profile was observed in 70 adults, and the G6 profile in the 15 others. No single worm exhibited a hybrid G1/G6 profile. This result suggests the absence of cross-fertilizing between the two taxa under the given experimental conditions, and so, the presence of a strong cross-reproductive barrier. This observation corroborates with the recent reclassification of G1 and G6 within two distinct species.     

Humoral Response to 2 Inactivated Bluetongue Virus Serotype‐8 Vaccines in South American Camelids

Background: Bluetongue virus serotype 8 (BTV‐8) has caused disease in domestic ruminants in several countries of northern Europe since 2006. In 2008 a mass‐vaccination program was launched in most affected countries using whole virus inactivated vaccines. Objective: To evaluate 2 inactivated vaccines (Bovilis BTV 8; BTVPUR AlSap8) for immunogenicity and safety against BTV‐8 in South American camelids (SAC) in a field trial. Animals: Forty‐two SAC (25 Alpacas, 17 Llamas) aged between 1 and 16 years. Methods: The animals were vaccinated twice at intervals of 21 days. They were observed clinically for adverse local, systemic, or both reactions throughout the trial. Blood samples collected on days 0, 14, 21, 43, and 156 after vaccination were tested for the presence of BTV‐8 virus by real time‐polymerase chain reaction and of specific antibodies by competitive ELISA and a serum neutralization test. Results: All vaccinated animals developed antibodies to BTV‐8 after the 2nd administration of the vaccine. No adverse effects were observed except for moderate local swellings at the injection site, which disappeared within 21 days. Slightly increased body temperatures were only observed in the first 2 days after vaccination. The BTV was not detected in any of the samples analyzed. Conclusions and Clinical Importance: The administration of the 2 inactivated commercial vaccines was safe and induced seroconversion against BTV‐8 in all vaccinated animals. The results of this study suggest that 2 doses injected 3 weeks apart is a suitable vaccination regimen for SAC.     

Prevalence of parasite eggs and cysts in faeces from dairy cows in Colombia

Summary When 1, 711 bovine faecal samples from 113 farms in eight dairy areas of Colombia were examined for the presence of helminth eggsFasciola hepatica eggs were found in the faeces from 60% of the farms and samples from animals kept above 2,000 m. Strongyle eggs were found in faeces from 82% of the farms and in 18% of the samples.

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Resumen Se examinaron 1.711 muestras fecales provenientes de 113 fincas, localizadas en ocho zonas lecheras de Colombia. Se encontraron huevos deFasciola hapatica, en el 60% de fincas y muestras fecales de animales sobre los 2,000 m.s.n.m. Se encontraron tambien huevos de estrogilideos en heces del 82% de fincas y en el 18% de las muestras examinadas.

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Résumé La recherche d’oeufs d’helminthes sur 1711 échantillons de fécès provenant de 113 fermes de 8 districts laitiers de Colombie a permis de noter la présence d’oeufs deFasciola hepatica dans 60 p. 100 des fermes et échantillons originaires d’animaux vivant à plus de 2,000 m. Des oeufs de strongles ont été notés dans les fécès provenant de 82 p. 100 des fermes et 18 p. 100 des échantillons.

     

Host plant stimulation of detoxifying enzymes in a phytophagous insect

The midgut microsomal aldrin epoxidase of variegated cutworm larvae (Peridroma saucia, Hübner) fed bean or peppermint leaves was up to 10 and 45 times more active, respectively, than that of larvae fed a basic control diet. Large increases in oxidase activity and cytochrome P-450 levels also occurred in larvae fed mint plant constituents such as menthol menthone, α-pinene, and β-pinene. Mint-fed larvae were more tolerant of the insecticide, carbaryl, than bean-fed larvae.     

Phenobarbital induction of detoxifying enzymes in resistant and susceptible houseflies

Houseflies, Musca domestica, L., were treated with the drugs phenobarbital and 3-methylcholanthrene to study the effects of these compounds as inducing agents of the microsomal oxidases, heptachlor epoxidase, and p-nitroanisole O-demethylase, and of DDT-dehydrochlorinase. Phenobarbital was active when applied by injection or as part of the diet but inactive when topically applied. The resulting increases in heptachlor epoxidase activity were as much as 25-fold that of the untreated controls. The net increase in enzyme activity after phenobarbital treatment was greater in an insecticide-susceptible strain, WHO-SRS strain, than in a carbamate-resistant strain. However, the phenobarbital induced increases in DDT-dehydrochlorinase were greater, about 2-fold, in the resistant strains than in the susceptible strain.The optimum dose for phenobarbital was 1% in the diet for a period of 3 days. None of the treatments with 3-MC, feeding, injection, exposure to residues, or topical, were effective in induction.     

A trap perch for the control of the poultry red mite (Dermanyssus gallinae)

A method of controlling red mites by the use of a small amount of insecticide placed inside a hollow perch is described. 0.5 g. of 50 per cent Carbaryl (“Sevin”) wettable powder distributed along the inside of 2.1 m. trap perch controlled experimental infestations for up to 4 months.

This method of control is economical and protects the birds from unnecessary contamination with insecticide. Insecticides inside a trap perch are protected from conditions such as alkalinity which might otherwise lead to their inactivation. It is therefore suggested that insecticides used in this way may remain lethal to mites for a much longer time than if applied as a spray or dust to the inside surfaces of a poultry hut.