Abstract: The present invention discloses attenuated Clostridium perfringens organisms that express a substantially nontoxic alpha-toxin. The expressed alpha-toxin is a deletion mutein that relative to the alpha-toxin of the mature alpha-toxin of Clostridium perfringens strain 13, is missing at least nine consecutive amino acid residues including His68. The present invention also discloses attenuated organisms that encode the muteins, as well as the use of such attenuated organisms as vaccines.

Abstract: The present invention discloses attenuated Clostridium perfringens organisms that express a substantially nontoxic alpha-toxin. The expressed alpha-toxin is a deletion mutein that relative to the alpha-toxin of the mature alpha-toxin of Clostridium perfringens strain 13, is missing at least nine consecutive amino acid residues including His68. The present invention also discloses attenuated organisms that encode the muteins, as well as the use of such attenuated organisms as vaccines.

Abstract: The present invention discloses attenuated Clostridium perfringens organisms that express a substantially nontoxic alpha-toxin. The expressed alpha-toxin is a deletion mutein that relative to the alpha-toxin of the mature alpha-toxin of Clostridium perfringens strain 13, is missing at least nine consecutive amino acid residues including His68. The present invention also discloses attenuated organisms that encode the muteins, as well as the use of such attenuated organisms as vaccines.

Abstract: This invention provides a bacterin comprising a virulent Mycoplasma hyopneumoniae isolate, inactivated with binary ethyleneimine, in an amount effective to immunize a swine against infection by Mycoplasma hyopneumoniae and a suitable physiologically acceptable carrier. The invention also provides a method of producing this bacterin. The invention further provides a method of inactivating a virulent strain of Mycoplasma hyopneumoniae by contacting the Mycoplasma hyopneumoniae with binary ethyleneimine. Finally, the invention also provides a method of immunizing swine against infection by Mycoplasma hyopneumoniae comprising administering to the swine a dose of the bacterin so as to immunize the swine.

Abstract: This invention involves a chemically transformed chicken hepatocyte derived cell line which is capable of efficiently supporting replication of infectious laryngotracheitis virus (ILTV) and methods for cultivating ILTV using this hepatocellular carcinoma cell line. The virus harvested from these continuous cell culture methods can be used as a vaccine against ILTV infection.

Abstract: A purified antigenic protein has been obtained which is capable of inducing in a chicken an immune response conferring protection against infection by Eimeria necatrix or Eimeria tenella. The protein has a molecular weight of about 26,000 and is composed of two polypeptides joined by a disulfide bond. The two polypeptide subunits have molecular weights of about 18,000 and about 8,000, respectively. The gene encoding the protein has been sequenced and the amino acid sequence of the protein deduced therefrom.The protein and antigenic polypeptides having an amino acid sequence included within the protein may be incorporated into a vaccine for conferring upon a chicken active immunity against infection by E. necatrix or E. tenella.