Oligonucleotides specific for the marORAB operon

Abstract

Disclosed are synthetic oligonucleotides complementary to a transcript of the marORAB operon which inhibit expression of a gene in the operon. Also disclosed are methods of reducing bacterial resistance to antibiotics, and pharmaceutical formulations containing marORAB-specific oligonucleotides of the invention.

What is claimed is:  
     
         1 . A synthetic oligonucleotide complementary to a transcript of the marORAB operon which inhibits expression of the operon.  
     
     
         2 . The oligonucleotide of  claim 1  wherein the gene whose expression is inhibited is selected from the group consisting of marO, marO/R, marR, marR/A, and marA.  
     
     
         3 . The oligonucleotide of  claim 1  wherein the oligonucleotide contains at least one internucleotide linkage selected from the group consisting of alkylphosphonates, phosphorothioates, phosphorodithioates, alkylphosphonothioates, phosphoramidates, phosphate esters, carbamates, acetamidate, carboxymethyl esters, carbonates, and phosphate triesters.  
     
     
         4 . The oligonucleotide of  claim 3  wherein the synthetic oligonucleotide contains at least one phosphorothioate internucleotide linkage.  
     
     
         5 . The oligonucleotide of  claim 1  comprising at least one deoxyribonucleotide.  
     
     
         6 . The oligonucleotide of  claim 1  comprising at least one ribonucleotide.  
     
     
         7 . The oligonucleotide of  claim 5  comprising at least one ribonucleotide.  
     
     
         8 . The oligonucleotide of  claim 1  wherein the oligonucleotide is from about 15 to 21 nucleotides in length.  
     
     
         9 . The oligonucleotide of  claim 1  having a nucleotide sequence selected from the group consisting of SEQ ID NO: 1, NO:2, NO: 3, NO:4, NO: 5, and NO: 6.  
     
     
         10 . A method of inhibiting expression of the marORAB operon comprising the step of contacting a transcript of the marORAB operon nucleic acid with a synthetic oligonucleotide complementary to the transcript.  
     
     
         11 . The method of  claim 10  wherein the oligonucleotide is complementary to a transcript of a gene selected from the group consisting of marO, marO/R, marR, marR/A, and marA.  
     
     
         12 . The method of  claim 11  wherein the oligonucleotide comprises a nucleotide sequence selected from the group consisting of SEQ ID NO: 1, NO: 2, NO: 3, NO: 4, NO: 5, and NO: 6.  
     
     
         13 . A method of reducing bacterial resistance to an antibiotic comprising exposing a bacteria in a subject with an infection to a synthetic oligonucleotide complementary to a transcript of the marORAB operon such that bacterial resistance to an antibiotic is reduced.  
     
     
         14 . The method of  claim 13  wherein said oligonucleotide is administered to the subject in a pharmaceutical carrier.  
     
     
         15 . The method of  claim 14 , comprising administering in addition at least one antibiotic to the subject.  
     
     
         16 . The method of  claim 15 , wherein the antibiotic is selected from the group consisting of a penicillin, a cephalosporin, an aminoglycoside, a sulfonamide, a macrolide, a tetracycline, a lincoside, a quinolone, a chloramphenicol, a vancomycin, a rifampin, an isoniazid, or a trimethoprim.  
     
     
         17 . The method of  claim 13 , wherein the oligonucleotide is complementary to a transcript of a locus selected from the group consisting of marO, marO/R, marR, marR/A, and marA.  
     
     
         18 . The method of  claim 13 , wherein the oligonucleotide comprises a nucleotide sequence selected from the group consisting of SEQ ID NO: 1, NO: 2, NO: 3, NO: 4, NO: 5, and NO: 6.  
     
     
         19 . The method of  claim 18 , wherein the bacteria are exposed to at least two synthetic oligonucleotides having a nucleotide sequence selected from the group consisting of SEQ ID NO: 1, NO: 2, NO: 3, NO: 4, NO: 5, and NO: 6.  
     
     
         20 . The method of  claim 13 , wherein the infection in the subject is a species of Escherichia, Salmonella, Shigella, Klebsiella, Citrobacter, Hafnia, or Enterobacter.  
     
     
         21 . A method of treatment for a bacterial infection in a subject by administering to the subject a therapeutic amount of a synthetic oligonucleotide complementary to a transcript of the marORAB operon.  
     
     
         22 . The method of  claim 21 , wherein the bacterial infection comprises infection with at least one bacterium having multiple drug resistance.  
     
     
         23 . The method of  claim 21  wherein the subject is additionally administered an antibiotic.  
     
     
         24 . The method of  claim 23 , wherein the antibiotic is selected from the group consisting of a penicillin, a cephalosporin, an aminoglycoside, a sulfonamide, a macrolide, a tetracycline, a lincoside, a quinolone, a chloramphenicol, a vancomycin, a rifampin, an isoniazid, or a trimethoprim.  
     
     
         25 . The method of  claim 21 , wherein the infection comprises an Escherichia, a Salmonella, a Shigella, a Klebsiella, a Citrobacter, a Hafnia, or an Enterobacter.  
     
     
         26 . The method of  claim 21  wherein the oligonucleotide is complementary to a transcript of a gene selected from the group consisting of marO, marO/R, marR, marR/A, and marA.  
     
     
         27 . The method of  claim 26  wherein the oligonucleotide comprises a nucleotide sequence selected from the group consisting of SEQ ID NO: 1, NO: 2, NO: 3, NO: 4, NO: 5, and NO: 6.  
     
     
         28 . A pharmaceutically acceptable composition comprising a synthetic oligonucleotide complementary to a transcript of marORAB operon which inhibits the expression of a locus in the operon; and a physiologically acceptable carrier.  
     
     
         29 . The pharmaceutically acceptable composition of  claim 28  wherein the oligonucleotide is complementary to a transcript of a gene selected from the group consisting of marO, marO/R, marR, marR/A, and marA.  
     
     
         30 . The pharmaceutically acceptable composition of  claim 28  wherein the oligonucleotide has a nucleotide sequence consisting essentially of SEQ ID NO: 1, NO: 2, NO: 3, NO: 4, NO: 5, and NO: 6.