Antibacterial polypeptides and use thereof

Abstract

The present invention discloses polypeptides with antibacterial properties and use said polypeptides and/or polynucleotides encoding said polypeptides in the preparation of medicament for the treatment of infectious diseases. The inventors also provide vectors encoding and adapted for expression of the polypeptides and polynucleotides of the invention. The vectors may be used in the preparation of a medicament for the treatment of bacterial infections. Further, the vector of the invention may be used to reduce the load of bacteria in food and/or feed.

1 . An isolated antibacterial polypeptide selected from the group consisting of:
 (a) a polypeptide encoded by SEQ ID NO: 1 (dinQ gene sequence), wherein said polypeptide is selected from the group consisting of: SEQ ID NO:17 (DinQ ORF-V peptide with N-term Met), SEQ ID NO:5 (DinQ ORF-II peptide), SEQ ID NO:7 (DinQ ORF-III peptide), SEQ ID NO:9 (DinQ ORF-IV peptide) and SEQ ID NO:11 (DinQ ORF-V peptide),   (b) a functionally equivalent subsequence of (a) of at least 15 amino acids, and   (c) a functionally equivalent polypeptide with a sequence identity of at least 85% to (a) or (b).   
     
     
         2 - 30 . (canceled) 
     
     
         31 . The polypeptide according to  claim 1 , wherein said polypeptide is selected from the group consisting of: SEQ ID NO:17 (DinQ ORF-V peptide with N-term Met), SEQ ID NO:5 (DinQ ORF-II peptide), SEQ ID NO:7 (DinQ ORF-III peptide), SEQ ID NO:9 (DinQ ORF-IV peptide), and SEQ ID NO:11 (DinQ ORF-V peptide). 
     
     
         32 . The polypeptide according to  claim 1 , where said antibacterial polypeptide comprises the amino acid sequence set forth in SEQ ID NO:17 (DinQ ORF-V peptide with N-terminal Met). 
     
     
         33 . The polypeptide according to  claim 1 , wherein said functionally equivalent polypeptide is selected from the group consisting of: SEQ ID NO:19 (G10K variant of DinQ ORF-V peptide), SEQ ID NO:20 (L23I variant of DinQ ORF-V peptide), SEQ ID NO:21 (I7V variant of DinQ ORF-V peptide), and SEQ ID NO:22 (L12I, I13V double mutant variant of DinQ ORF-V peptide). 
     
     
         34 . A vector comprising a nucleic acid sequence encoding a polypeptide according to  claim 1 , wherein said vector is adapted for expression of said polypeptide and, wherein said polypeptide is selected from the list consisting of:
 (a) a polypeptide encoded by SEQ ID NO:1 (dinQ gene sequence), wherein said nucleic acid sequence is selected from the group consisting of: SEQ ID NO:10 (DinQ ORF-V CDS DNA sequence), SEQ ID NO:4 (DinQ ORF-II CDS DNA sequence), SEQ ID NO:6 (DinQ ORF-III CDS DNA sequence), and SEQ ID NO:8 (DinQ ORF-IV CDS DNA sequence),   (b) a functionally equivalent subsequence of (a) of at least 15 amino acids, and   (c) a functionally equivalent polypeptide with a sequence identity of at least 85% to (a) or (b).   
     
     
         35 . The vector according to  claim 34 , wherein said vector comprises a nucleic acid sequence selected from the group consisting of: SEQ ID NO:10 (DinQ ORF-V CDS DNA sequence), SEQ ID NO:4 (DinQ ORF-II CDS DNA sequence), SEQ ID NO:6 (DinQ ORF-III CDS DNA sequence), and SEQ ID NO:8 (DinQ ORF-IV CDS DNA sequence). 
     
     
         36 . The vector according to  claim 34 , wherein said polypeptide is SEQ ID NO:17 (DinQ ORF-V peptide with N-terminal Met). 
     
     
         37 . The vector according to  claim 34 , wherein said functionally equivalent polypeptide is selected from the group consisting of: SEQ ID NO:19 (G10K variant of DinQ ORF-V peptide), SEQ ID NO:20 (L23I variant of DinQ ORF-V peptide), SEQ ID NO:21 (I7V variant of DinQ ORF-V peptide), and SEQ ID NO:22 (L12I, I13V double mutant variant of DinQ ORF-V peptide). 
     
     
         38 . The vector according to  claim 34 , with the proviso that said nucleic acid sequence and said vector does not encode SEQ ID NO:3 (DinQ ORF-I peptide). 
     
     
         39 . The vector according to  claim 34 , wherein said vector is a phage. 
     
     
         40 . A pharmaceutical composition comprising:
 a vector according to  claim 34 , or   an antibacterial polypeptide according to  claim 1 , and at least one pharmaceutically acceptable additive.   
     
     
         41 . A method of treating a bacterial infection in a subject, comprising administering an effective amount of the pharmaceutical composition of  claim 40  to said subject. 
     
     
         42 . The method of  claim 41 , further comprising administering to said subject an effective amount of at least one other antibiotic. 
     
     
         43 . The method of  claim 42 , wherein said at least one other antibiotic is selected from the group consisting of: rifamycine, aminoglycosides, carbapenems, cephalosporins, cephems, glycopeptides, fluoroquinolones/quinolones, macrolides, oxazolidinones, penicillins, streptogramins, sulfonamides, tetracyclines, nalidixic acid, mitomycin C, ampicillin, and erythromycin. 
     
     
         44 . The method of  claim 41 , wherein said infection is sepsis. 
     
     
         45 . The method of  claim 41 , wherein said infection is an infected wound. 
     
     
         46 . The method of  claim 41 , wherein said vector is a phage. 
     
     
         47 . An in vitro method for reducing the load of or inhibition of propagation of a bacterium, comprising introducing a polypeptide in said bacterium, wherein said polypeptide is selected from the group consisting of:
 (a) a polypeptide encoded by SEQ ID NO:1 (dinQ gene sequence) selected from the group consisting of: SEQ ID NO:17 (DinQ ORF-V peptide with N-tem Met), SEQ ID NO:5 (DinQ ORF-II peptide), SEQ ID NO:7 (DinQ ORF-III peptide), SEQ ID NO:9 (DinQ ORF-IV peptide), and SEQ ID NO:11 (DinQ ORF-V peptide),   (b) a functionally equivalent subsequence of (a) of at least 15 amino acids, and   (c) a functionally equivalent polypeptide with a sequence identity of at least 85% to (a) or (b).   
     
     
         48 . The in vitro method of  claim 47 , wherein said functionally equivalent polypeptide is selected from the group consisting of: SEQ ID NO:19 (G10K variant of DinQ ORF-V peptide), SEQ ID NO:20 (L23I variant of DinQ ORF-V peptide), SEQ ID NO:21 (I7V variant of DinQ ORF-V peptide), and SEQ ID NO:22 (L12I, I13V double mutant variant of DinQ ORF-V peptide). 
     
     
         49 . A method of inhibiting a bacterial infection in a subject in need thereof, comprising providing to said subject an amount of the polypeptide of  claim 1  or an amount of the vector of  claim 34  that is effective to inhibit said bacterial infection.