摘要 |
<p>The present invention provides a nucleic acid encoding nicotinamide phosphoribosyltransferase (NadV) from a V-factor independent bacterium and provides methods for using the gene as a selection marker for constructing recombinant bacteria from V-factor dependent bacteria. The method is an improvement over methods which rely on nucleic acids which confer antibiotic resistance for constructing recombinant bacteria. Methods for constructing attenuated recombinant (Actinobacillus pleuropneumoniae) using the selection method of the present invention are also provided.</p> |