ABSTRACT
Survival of hog cholera virus (HCV) was determined in several sausage meat products (Italian salami) prepared with meats from experimentally infected hogs slaughtered at the peak of disease. Meats were processed following the technology applied by the main factories of the typical Italian production. The survival of HCV was assessed through inoculation in both PK 15 cell monolayers and fully susceptible piglets. In all types of sausages examined HCV was detected up to 75 days of curing by piglet inoculation. This technique was much more sensitive than use of cell culture.
Subject(s)
Classical Swine Fever Virus/growth & development , Classical Swine Fever/microbiology , Food Microbiology , Meat Products/microbiology , Animals , Classical Swine Fever/transmission , SwineABSTRACT
A tendency has emerged for some years to replace the challenge infection of cattle for the assessment of foot-and-mouth disease (FMD) vaccine potency. This can be actually evaluated by means of antibody assays on cattle sera, at about 3/4 weeks after the vaccination. Serological results can be worked out as single titres (to be compared with a pre-determined threshold level) or as mean antibody titres induced by different vaccine dilutions. However, the assessment of FMDV-specific antibody titres would not fully depict the extent and the efficacy of the immune response of cattle; moreover, the antibody response would not be proportional if potent vaccines are used (greater than or equal to 10-12 PD50). Thus, a particular approach is suggested for the serological procedures, which enable credible estimates of potent FMD vaccines to be formulated.
Subject(s)
Antibodies, Viral/blood , Aphthovirus/immunology , Viral Vaccines/immunology , Animals , Cattle , Cattle Diseases/prevention & control , Enzyme-Linked Immunosorbent Assay , Foot-and-Mouth Disease/prevention & control , Viral Plaque Assay , Viral Vaccines/administration & dosage , Viral Vaccines/analysisABSTRACT
Determination of the survival of foot- and-mouth disease virus (FMDV) in fresh meat from experimentally infected swine and in several types of sausage meat (Italian salami) produced according to the technology widely applied by the principal Italian producers has been carried out. The purpose of the experiment was to assess if typical Italian salami can be considered safe with regard to the spread of FMD through international trade. The results obtained showed: (a) high titers of FMDV were detected in both muscle and fat tissues from animals slaughtered at the peak of the experimental disease; and (b) FMDV was not detectable in the above tissues 72 h after slaughtering and the same applies to the different types of salami tested 7 days after production. The above results were obtained in tissue cultures and confirmed through piglet inoculation.
Subject(s)
Aphthovirus/growth & development , Food Microbiology , Meat Products , Meat , Adipose Tissue/microbiology , Animals , Aphthovirus/isolation & purification , Hydrogen-Ion Concentration , Muscles/microbiology , SwineABSTRACT
Inactivation of foot-and-mouth disease virus (FMDV) by means of virion-associated endonuclease was found to be suited to the production of safe and potent vaccines, which proved to be equal or better than those containing formaldehyde or ethyleneimine in guinea-pig potency tests. First order inactivation kinetics were regularly shown, with half life values which varied according to the different temperatures used. Inactivation brought about extensive degradation of FMDV RNA, while it did not adversely influence the integrity of critical viral epitopes on FMDV VP1.
Subject(s)
Aphthovirus/immunology , Vaccines, Attenuated/standards , Animals , Aphthovirus/drug effects , Endonucleases/pharmacology , Enzyme-Linked Immunosorbent Assay , Evaluation Studies as Topic , Guinea Pigs , Mice , RNA, Viral/isolation & purificationSubject(s)
Adjuvants, Immunologic/pharmacology , Aluminum Hydroxide/pharmacology , Aphthovirus/immunology , Oils/pharmacology , Saponins/pharmacology , Viral Vaccines/immunology , Animals , Antibodies, Viral/biosynthesis , Cattle , Emulsions , Foot-and-Mouth Disease/prevention & control , Mice , Neutralization TestsSubject(s)
Culture Media , Culture Techniques , Filtration/instrumentation , Sterilization/methods , Animals , Cell Line , Cricetinae , KidneyABSTRACT
The roller bottle plant at the Istituto Zooprofilattico of Brescia is described and the following topics are discussed: (1) results of ten years cell and virus culture; (2) critical approach to advantages and disadvantages of applied technology, and (3) FMD vaccine requirements and cell substrate characterization.
Subject(s)
Aphthovirus/growth & development , Viral Vaccines , Virus Cultivation/methods , Cells, Cultured , Drug Industry , ItalyABSTRACT
A survey of problems connected with the cell suspension culture for the production of FMD vaccine is presented, in order to stimulate a discussion. Introductory remarks are made on the following topics: 1) suspension cell lines used for FMD vaccine production, 2) terminology, 3) criteria for the characterization of a cell culture, 4) evaluation of FMD virus produced according to the cell suspension technique and correlation existing between in vitro tests and antigenicity in domestic animals, 5) criteria which must be met by FMD vaccine produced from virus cultivated on cell suspension.
