Bacterial gene and method of treating a gram negative bacterial infection

Abstract

Described are a novel gene (waaP) and a protein (WaaP) which has an enzymatic activity that is involved in heptose modification in the lipopolysaccharide of bacterial membranes. Also described is a method and series of compounds which are active against bacterial pathogens wherein the method comprises the administration of sufficient amount of an inhibitor of WaaP protein activity in gram negative bacteria.

1 . An isolated nucleic acid molecule containing a sequence encoding a protein having the activity associated with a WaaP protein.  
     
     
         2 . A nucleic acid sequence according to  claim 1  having a sequence shown in SEQ. ID. NO.: 1 or SEQ.ID.NO.:3 or SEQ.ID.NO.:5.  
     
     
         3 . An isolated nucleic acid molecule according to  claim 1  comprising: 
 (a) a nucleic acid sequence as shown in SEQ.ID.NO.:1 or SEQ.ID.NO.:3 or SEQ.ID.NO.:5, wherein T can also be U;    (b) nucleic acid sequences complementary to (a);    (c) nucleic acid sequences which are homologous to (a) or (b)    (d) a fragment of (a) to (c) that is at least 15 bases, preferably 20 to 30 bases, and which will hybridize to (a) to (d) under stringent hybridization conditions; or    (e) a nucleic acid molecule differing from any of the nucleic acids of (a) to (c) in codon sequences due to the degeneracy of the genetic code.    
     
     
         4 . An isolated protein having the activity of the WaaP protein.  
     
     
         5 . A protein according to  claim 4  having the amino acid sequence shown in SEQ.ID.NO.:2 or SEQ.ID.NO.:4 or SEQ.ID.NO.:6.  
     
     
         6 . A method of preventing or treating a gram negative bacterial infection comprising administering an effective amount of a substance that inhibits WaaP to an animal in need thereof.  
     
     
         7 . The method of  claim 6  wherein the bacterial infection is caused by bacteria selected from the group consisting of  Salmonella enterica, Escherichia coli, Vibrio cholerae, Yersinia enterocolitica, Shigella flexneri, Shigella dysenteriae,  and  Pseudomonas aeruginosa  serotypes 02, 05, 16, 18 and 20,  P. aeruginosa  serotypes 03 or 06 and other members of the family Pseudomonadaceae.  
     
     
         8 . The method of  claim 6  wherein the inhibitor is selected from the group consisting of an antibody to the activity of the WaaP protein; an antisense oligonucleotide which inhibits translation of the waaP gene; or an antibody which inhibits the interaction of substrate of the WaaP protein and the WaaP protein.  
     
     
         9 . The antisense oligonucleotide of  claim 8  wherein the oligonucleotide is complimentary to a nucleic acid sequence from a waaP gene.  
     
     
         10 . The method of any one of  claims 6  to  9  wherein the bacterial infection is in an animal.  
     
     
         11 . A method for assaying for inhibitors of WaaP activity in gram negative pathogens under appropriate conditions comprising the steps of incubating a gram negative pathogen in the presence of a test substance and assaying for WaaP activity and comparing the results to control results.  
     
     
         12 . A vaccine for preventing or treating a gram negative bacterial infection comprising an effective amount of a WaaP protein.  
     
     
         13 . The vaccine of  claim 12  where the WaaP protein is in admixture with a suitable diluent or carrier.  
     
     
         14 . A method of preventing or treating a gram negative bacterial infection comprising administering a vaccine containing an effective amount of a WaaP protein, to an animal in need thereof.  
     
     
         15 . The method of  claim 14  wherein the WaaP protein is in admixture with a suitable diluent or carrier.  
     
     
         16 . A composition for use in the attenuation of a virulent gram negative pathogen in an animal, comprising an inhibitor of WaaP activity.  
     
     
         17 . The composition of  claim 16  wherein the inhibitor is in admixture with a pharmaceutically acceptable diluent or carrier.  
     
     
         18 . An inhibitor of Waap activity in a gram negative pathogen.  
     
     
         19 . The inhibitor of  claim 18  wherein the pathogen is selected from the group consisting of  Salmonella enterica Escherichia coli, Vibrio cholerae, Yersinia enterocolitica, Shigella flexneri, Shigella dysenteriae, Pseudomonas aeruginosa  serotypes 02, 05, 16, 18 and 20,  P. aeruginosa  serotypes 03 or 06 or other members of the family Pseudomonadaceae.  
     
     
         20 . The inhibitor of  claim 18  which is a specific antibody to WaaP.  
     
     
         21 . The inhibitor of claims  18  which inhibits translation of the waaP gene.  
     
     
         22 . The inhibitor of  claim 21  which is an antisense oligonucleotide.  
     
     
         23 . The inhibitor of  claim 18  which inhibits interaction of substrate of the WaaP protein with the WaaP protein.  
     
     
         24 . The inhibitor of  claim 23  which is a specific antibody.