Annales de recherches veterinaires. Annals of veterinary research最新文献

The authors isolated 2 Isospora species from ducks: Isospora mandari and Isospora sp. This was the first report of the genus Isospora from the duck in France. One of the 2 isolated species (Isospora sp) has not been described in the duck before.

Variation of milk IgG1, IgG2, IgM, and IgA measured by radial immunodiffusion was studied in monthly samples of 224 lactating dairy cows. Cows were assigned to one of 2 treatment groups: vitamin E supplemented and controls. Vitamin E supplementation was started when cows were dried and continued until 90 days post partum at the rate of 1,000 IU per cow daily and then reduced to 500 IU for the remaining lactation. There were no significant differences between the 2 treatment groups for the different Ig classes. Concentrations of IgG1 were significantly higher in milk from mastitic than non-mastitic cows.

One hundred and three strains of Actinomyces pyogenes isolated from ruminants were examined for morphological, cultural and biochemical properties by standard tests and by the Api 50 CH and Api Coryne methods. No biotype could be demonstrated, but a few atypical non- or practically non-proteolytic strains were detected which should be differentiated from Arcanobacterium haemolyticum. Criteria for laboratory identification of A pyogenes were established: Gram stain; culture on blood agar; deep agar and Loeffler's medium; catalase, nitrate reduction, acid formation from xylose; Hugh and Leifson test. The Api Coryne system correctly identified only 58 of 103 A pyogenes cultures, which implies that it should be re-evaluated before use in veterinary diagnosis laboratories.

An epidemiological survey on avian chlamydiosis, carried out by serological probing in 8 pigeon breeders representative of New Caledonian livestock, combined with bacteriological research on pigeon organs and droppings was set up in New Caledonia in order to determine the prevalence rate of this infection and to adapt sanitary regulations concerning pigeon imports. All sera collected (230) were analysed by complement fixation test (CFT). The organs were diluted in sucrose solution, then stored frozen (-70 degrees C), until inoculation of the yolk-sac of 3 6-8-day-old embryonated eggs (2 blind passages). Yolk-sac smears stained according to the Gimenez method were made in order to detect intracellular chlamydial organisms. Seventeen sera out of 230 were found to be positive, ie 7.4% of the test sample (confidence interval to 95% = 4.0 to 10.8%). The carrier pigeons were significantly more infected (17.8%) than pigeons of other breeds in New Caledonia. These results resulted in the sanitary authorities easing restrictions on imports of seropositive pigeons by imposing a 45-day compulsory quarantine with daily administration of chlortetracycline at the rate of 150 mg per 1 of drinking water.

Experimental infections with an enteropathogenic strain of Escherichia coli 0103 were studied in SPF rabbits of different ages. Whatever the age, the weight gains in all animals were reduced more or less significantly. However, mortality differed considerably according to the age. Four to 5-week-old rabbits were most susceptible to the infection, with 80-100% mortality associated with diarrhoea, generally of the hemorrhagic type. Peak mortality was observed between 5-10 days post-inoculation. In general, 21-day-old rabbits died from the second week post-inoculation onwards. After the 6th week of age, mortality was rare. Study of the microflora showed that the colonization of the gut by E coli 0103 occurred whatever the age as 10(6)-10(9) bacteria per g of feces of the inoculated strain were recovered. The role of specific receptors has been discussed.