[Antigenic drift of a strain of influenza equi virus isolated in France during the winter of 1978-1979]. / Dérive antigénique d'une souche de virus influenza equi isolée en France au cours de l'hiver 1978-1979.

A strain of Influenza Equi virus isolated during winter 1978-1979 has been compared with Influenza A/Equine/Miami/1/63 (H3N8) strain by cross reactions performed by radial haemolysis (RH) and hemagglutination inhibition (HAI) test. Specific antisera were prepared on hens and guinea-pigs. Results differed according to the species on which the sera were prepared and the two methods of titration of the antibodies. Hens sera were unable to differenciate by HAI the newly-isolated strain Influenza A/Equine/Joinville/1/78 from the Influenza A/Equine/Miami/1/63 (H3N8) strain, but an antigenic drift of Influenza A/Joinville/1/78 from the original Influenza A/Equine/Miami/1/63 virus could be demonstrated with guinea-pigs' sera either by HAI or by RH. By HAI, Influenza A/Equine/Joinville/1/78 virus seemed dominant over Influenza A/Equine/Miami/1/63 (H3N8) virus, while in opposite Influenza A/Equine/Miami/1/63 (H3N8) seemed dominant over Influenza A/Equine/Joinville/1/78 when the viruses were compared by RH. Thus, antigenic sites and correspondant antibodies involved in HAI and RH reactions appeared at least partially differents.

High-pressure liquid chromatographic analysis of veterinary anthelmintics I: Quantitative determination of tetramisole.

High-pressure liquid chromatography was used with a 10-micron C8-type bonded silica gel column to quantitate the tetramisole in veterinary anthelmintic preparations. The chromatographic elution time was less than 10 min, and other compounds present in the products analyzed did not interefere.

Enzootic bovine leukosis: an epidemiological survey among cattle in the west of France by precipitating antibody detection.

In order to inform the sanitary veterinaty authorities, an epidemiological survey was carried out in the West of France to appreciate the level of infection by BLV in cattle. More than 10,000 sera from 763 herds were tested by agar gel immuno-diffusion. The animals were more than one-year-old dairy cattle. 23 sera (0.22%) from 11 herds (1.44%) were found positive. In the 11 herds the levels of serologically positive animals ranged from 1.6 to 40% with a 9% average. These levels are comparatively low and are almost in correspondence with the number of leukotic tumours recorded in the slaughter houses and knackeries.

[Comparison between the official indirect method and the direct method of control of vaccines against sheep enterotoxemia]. / Comparaison entre la méthode officielle indirecte et la méthode directe de contrôle des vaccins contre les enterotoxémies du mouton

The official methods of control of vaccines against sheep enterotoxemia are indirect in two ways : on the one hand they are carried out on animals for which the vaccine is not intended, and on the other hand they test only an immunological serum reaction. Another method consisting of direct testing by intravenous injection of toxin has been carried out on mice previously vaccinated with different doses. It has been shown that it is possible to obtain a certain level of protection giving a good dose-effect relation. However, immunity provided by this direct method is weak although the vaccine utilized is considered very efficacious with regard to the official norms of the direct test. These results, which are both encouraging and disappointing, will be the subject of a more intensive study of the different parameters in question.

[Immunization of ewes against experimental Brucella melitensis infection: comparison of eleven vaccines]. / Immunisation de la brebis contre l'infection expérimentale à Brucella melitensis: comparison de onze vaccins

A comparative study of 11 antibrucellic vaccines has been carried out in the Limousin region of 360 ewe-lambs divided into groups of 30, a 12th group serving as control. After being vaccinated at 8 months, the ewe-lambs were covered between 9 1/2 and 10 1/2 months, then infected at 11 months with Br. melitensis strain 53 H 38 by instillation of 4 x 10(6) germs on the conjonctiva. Six of these vaccines reduced the number of abortions and the excretion of brucella at parturition: three consisted of an inactivated suspension of a virulent S strain of Br. melitensis in oily adjuvant, another consisted of an inactivated suspension of a modified non-agglutinogenic strain of Br. melitensis also in oily adjuvant, the fifth was prepared from Br. melitensis H 105 and Br. abortus B 112 with saponin and the sixth from a strain of Br. melitensis modified with aluminium hydroxide as adjuvant.

[Comparative dose-effect relationship of a tuberculin standard on guinea pig sensitivity, using living and dead tuberculosis bacilli]. / Loe dose-effet comparative d'une tuberculine étalon sur cobayes sensibilisés soit par bacilles tuberculeux vivants, soit par bacilles tués

The sensitization of guinea pigs utilized for tuberculin titration may be obtained by a BCG primo-vaccination followed by an inoculation of live, virulent Myc. tuberculosis. This method, which results in a sub-evolutive form of tuberculosis, gives a satisfactory sensitization level but has the disadvantage of utilizing animals which are germ carriers and therefore dangerous. A method has been tested employing killed germs (Jamaica strain) coated with Freund's complete adjuvant H37Ra which utilizes animals presenting no danger in handling. The results of 105 titrations made on 453 guinea pigs during two years show that the reactions obtained are clear, easy to read and remain stable over a long period (F equals 0.1). The comparison of values thus obtained shows that in the case of killed bacilli in relation to live bacilli: the mean dimensions of the reaction with 5, 10 and 20 IU are significantly more important (P is less than 0.0001) and the dose-response slope is significantly steeper (P is less than 0.01) which offers more precise results. Sensitization by killed germs therefore offers the double advantage of handling non-dangerous animals and obtaining results which are more precise and easier to read.