Abstract: The present invention is directed to compositions and methods for the production for the prevention of disease due to P. haemolytica. In particular, the present invention provides P. haemolytica strains that produce inactive leukotoxin for vaccine and other uses. The present invention also provides compositions and methods for genetic manipulations in P. haemolytica.

Abstract: Novel chemical compounds, recombinant plasmids pUC1026 and pUC1027, which are obtained by covalent linkage of the E. coli plasmid pBR322 to the Streptomyces espinosus plasmid pUC6. These plasmids are produced by a novel process which can be used to stabilize unstable potential plasmid vectors. These plasmids are useful as cloning vehicles in recombinant DNA work. For example, using DNA methodology, a desired gene, for example, the insulin gene, can be inserted into the plasmids and the resulting plasmids can then be transformed into a suitable host microbe which, upon culturing, produces the desired insulin. The stabilization process disclosed herein can be used to make other stable plasmids.

Abstract: Novel chemical compound plasmid pUC1061 obtained by deletion of .about.2.0 kilobases of DNA from the Streptomyces espinosus plasmid pUC6. This plasmid is useful as a cloning vehicle in recombinant DNA work. For example, using DNA methodology, a desired gene, for example, the glucose isomerase gene, can be inserted into the plasmid and the resulting plasmid can then be transformed into a suitable host microbe which, upon culturing, produces the desired glucose isomerase.

Abstract: Novel chemical compounds, cointegrate plasmids pUC1012 and pUC1013, which are obtained by covalent linkage of the E. coli plasmid pBR322 to the Streptomyces espinosus plasmid pUC6, and plasmids pUC1015 and pUC1022 which are obtained by restructuring plasmid pUC1012, and plasmids pUC1016 and pUC1023 which are obtained by restructuring plasmid pUC1013. These plasmids are useful as cloning vehicles in recombinant DNA work. For example, using DNA methodology, a desired gene, for example, the insulin gene, can be inserted into the plasmids and the resulting plasmids can then be transformed into a suitable host microbe which, upon culturing, produces the desired insulin.

Abstract: Novel chemical compounds, recombinant plasmids pUC1026 and pUC1027, which are obtained by covalent linkage of the E. coli plasmid pBR322 to the Streptomyces espinosus plasmid pUC6. These plasmids are produced by a novel process which can be used to stabilize unstable potential plasmid vectors. These plasmids are useful as cloning vehicles in recombinant DNA work. For example, using DNA methodology, a desired gene, for example, the insulin gene, can be inserted into the plasmids and the resulting plasmids can then be transformed into a suitable host microbe which, upon culturing, produces the desired insulin. The stabilization process disclosed herein can be used to make other stable plasmids.

Abstract: Novel chemical compounds, recombinant plasmids pUC1019 and pUC-1020, which are obtained by covalent linkage of ca. 4.2 kb BclI restriction endonuclease fragment of the Streptomyces espinosus plasmid pUC6 into the BamHI endonuclease site of the E. coli plasmid pBR322. Plasmid pUC1024 is obtained by restructuring plasmid pUC1019. These plasmids are useful as cloning vehicles in recombinant DNA work. For example, using DNA methodology, a desired gene, for example, the insulin gene, can be inserted into the plasmids and the resulting plasmids can then be transformed into a suitable host microbe which, upon culturing, produces the desired insulin.