ATTENUATED MYCOPLASMA GALLISEPTICUM STRAINS
The present invention provides live, attenuated Mycoplasma gallisepticum bacteria that exhibit reduced expression of a protein identified as MGA_0621. In certain embodiments, the attenuated bacteria may additionally exhibit reduced expression of one or more proteins selected from the group consisting of pyruvate dehydrogenase, phosphopyruvate hydratase, 2-deoxyribose-5-phosphate aldolase, and ribosomal protein L35, relative to a wild-type M. gallisepticum bacterium. Also provided are vaccines and vaccination methods involving the use of the live, attenuated M. gallisepticum bacteria, and methods for making live attenuated M. gallisepticum bacteria. An exemplary live, attenuated strain of M. gallisepticum is provided, designated MGx+47, which was shown by proteomics analysis to exhibit significantly reduced expression of MGA_0621, and was shown to be safe and effective when administered as a vaccine against M. gallisepticum infection in chickens.
1 - 38 . (canceled)
39 . A method of attenuating Mycoplasma gallisepticum bacteria, said method comprising: subjecting an initial population of Mycoplasma gallisepticum bacteria to attenuating conditions wherein said conditions decrease the level of a protein having the amino acid sequence comprising SEQ ID NO: 1 in said Mycoplasma gallisepticum bacteria.
40 . The method of claim 39 wherein said attenuating conditions comprise passaging said initial population of Mycoplasma gallisepticum bacteria at least 2 times in vitro.
41 . The method of claim 39 , wherein said attenuating conditions comprise passaging said initial population of Mycoplasma gallisepticum bacteria at least 5 times in vitro.
42 . The method of claim 39 , wherein said attenuating conditions comprise passaging said initial population of Mycoplasma gallisepticum bacteria at least 10 times in vitro.
43 . The method of claim 39 wherein said attenuating conditions comprise passaging said initial population of Mycoplasma gallisepticum bacteria at least 20 times in vitro.
44 . The method of claim 39 wherein said attenuating conditions comprise passaging said initial population of Mycoplasma gallisepticum bacteria at least 30 times in vitro.
45 . The method of claim 39 wherein said attenuating conditions comprise passaging said initial population of Mycoplasma gallisepticum bacteria at least 40 times in vitro.
46 . The method of claim 39 , wherein said attenuating conditions comprise transforming said initial population of Mycoplasma gallisepticum with a transposon which randomly inserts into the Mycoplasma gallisepticum genome.
47 . The method of claim 39 , wherein said attenuating conditions comprise exposing said initial population of Mycoplasma gallisepticum to a chemical mutagen or ultra violet light.
48 . A live, attenuated Mycoplasma gallisepticum bacteria produced by the method of claim 39 .
49 . A vaccine composition comprising the attenuated Mycoplasma gallisepticum bacteria of claim 39 and a pharmaceutically acceptable carrier.
50 . A method of vaccinating an animal to prevent Mycoplasma gallisepticum infection said method comprising administering an immunologically effective amount of the vaccine composition of claim 49 .
51 . The method of claim 50 wherein said vaccine composition is administered to said animal by direct injection, spray administration or drinking water administration.