Subject(s)
Antibodies, Bacterial/biosynthesis , Bacterial Proteins/immunology , Bacterial Vaccines/immunology , Escherichia coli Infections/veterinary , Immunization/veterinary , Pregnancy, Animal , Sheep Diseases/prevention & control , Sheep/immunology , Adhesins, Escherichia coli , Animals , Animals, Newborn/immunology , Colostrum/immunology , Escherichia coli Infections/prevention & control , Female , Milk/immunology , Pregnancy , Vaccination/methods , Vaccination/veterinaryABSTRACT
Serum samples of piglets infected artificially or naturally, respectively, with Leptospira pomona were treated with 2-mercapto-ethanol (ME) and tested in the microscopic agglutination test in comparison with untreated sera. Serum-treatment with ME showed two beneficial effects, one being the total elimination of heterotypic reactions, the other the reduction or elimination, respectively, of early antibodies, presumably belonging to the IgM class. Accordingly, two practical implications can be derived from our results. The ratio of ME-sensitive and ME-resistant antibody titers allows the recognition of early leptospira infections. The total suppression by ME of heterotypic agglutination eliminates the danger of determining the wrong leptospira type as causative agent, a crucial problem encountered not infrequently with agglutination testing of untreated sera. Recognition of early cases of swine leptospirosis by ME-treatment of sera is particularly useful, as the complement fixative reaction, successfully used in other species for the same purpose, is inappropriate in swine sera owing to their autolytic properties. Furthermore by elimination of all heterotypic reactions the ME-method gives better chances for the determination of the causative agent and hence for correct interpretation of serological results. ME-treatment is considered as a useful help in serodiagnosis of field samples, in which determination of duration of infection is essential or in which heterotypic agglutination is obscuring the etiological leptospira type.
Subject(s)
Leptospirosis/diagnosis , Mercaptoethanol , Swine Diseases/diagnosis , Agglutination Tests , Animals , Antibodies, Bacterial/analysis , Antibodies, Heterophile/immunology , Species Specificity , SwineABSTRACT
Procedures for the hygienic inspection of animal rendering plants should include the bacteriological investigation of the meat meal, the bacteriological control of the used methods of disinfection of the contaminated rooms, of the transport vehicles and of the sewage of the contaminated side. Meat meal has to be free of Clostridium perfringens and Salmonellae. Clostridium perfringens is an indicator of the sterilizing effect of the rendering procedures. After an effective disinfection of rooms no gramnegative and only a small numbers of grampositive bacteria like aerobic bacilli should be demonstrable. Sewage of the contaminated side has to be free of Clostridium perfringens spores.
