[0001] The invention relates to an in vitro screening method to identify inhibitors of intracellular bacterial growth and persistence and uses thereof as medicament, preferably as antibiotics. Furthermore, the present invention also relates to the inhibitors for use in the treatment and/or prevention of intracellular bacterial infections.
1. An INDAR inhibitor for use as medicament, preferably an antibiotic. 2. An INDAR inhibitor for use in the treatment and/or prevention of intracellular bacterial infections. 3. An INDAR inhibitor for use according to any of claims 1 or 2 wherein the INDAR inhibitors recognize a PBP protein selected from the list consisting of: a PBP protein having at least 80% identity with SEQ ID NO: 2 and/or a PBP protein having at least 80% identity with SEQ ID NO: 4, preferably recognize a PBP protein comprises the sequences as set forth in SEQ ID NO: 2 and/or SEQ ID NO: 4. 4. An INDAR inhibitor for use according to any of claims 1 or 3 wherein the bacteria are selected from the list consisting of: Salmonella spp., Citrobacter spp., Enterobacter spp., Klebsiella spp., Leciercia spp., Lelliottia spp., Cedecea spp., Raoultella spp., Kluyvera spp,, Pantoea spp, Erwinia spp., Mixta spp., Serratia spp., Escherichia spp., Pluribacter spp., Rosenbergiella spp., Morganella spp., Tatumella spp., Acinetobacter spp., and Haemophilus spp. 5. An INDAR inhibitor for use according to claim 4 wherein the bacteria are selected from the list consisting of: Salmonella spp., preferably the species selected from the list consisting of: S. enterica and S. bongori, and Citrobacter spp. preferably the species selected from the list consisting of: C. koseri, C. freundii, C. youngae, C. braakii, C. werkmanii, C. murliniae, C. gillenii, C. sedlakii, C. pasteurii, C. eropaeus, C. amalonaticus, C. farmeri, C. rodentium and C. portucalensis. 6. Method in vitro to identify INDAR inhibitors wherein the method comprises: a) Contacting a candidate compound with a bacterial culture of pathogenic bacteria, wherein the pathogenic bacteria comprises a non-functional gene encoding for a PBP protein selected from the list consisting of: a PBP protein having at least 80% identity with SEQ ID NO: 6 and/or a PBP protein having at least 80% identity with SEQ ID NO: 8; b) Incubate the candidate compound with the bacterial culture of step a) in an acidic pH range from 4.0 to 5.0; c) Comparing the growth of bacterial culture of step b) with the growth of the corresponding pathogenic wild-type bacterial culture in the presence of the candidate compound; wherein a decreased growth of the pathogenic bacterial culture comprises the non-functional gene encoding for a PBP protein selected from the list consisting of: a PBP protein having at least 80% identity with SEQ ID NO: 6 and/or a PBP protein having at least 80% identity with SEQ ID NO: 8, regarding the growth of corresponding pathogenic wild-type bacterial culture, indicates that the candidate compound is an INDAR inhibitor. 7. Method according to claim 6 wherein the non-functional gene encoding for a PBP protein comprises the sequences as set forth in SEQ ID NO: 6 and/or SEQ ID NO: 8. 8. Method according to any of claims 6 to 7 wherein the pathogenic bacteria are selected from the list consisting of: Salmonella spp., Citrobacter spp., Enterobacter spp., Klebsiella spp., Leciercia spp., Lelliottia spp., Cedecea spp., Raoultella spp., Kluyvera spp,, Pantoea spp, Erwinia spp., Mixta spp., Serratia spp., Escherichia spp., Pluribacter spp., Rosenbergiella spp., Morganella spp., Tatumella spp., Acinetobacter spp., and Haemophilus spp. 9. Method according to claim 8 wherein the pathogenic bacteria are selected from the list consisting of: Salmonella spp., preferably the species selected from the list consisting of: S. enterica and S. bongori, and Citrobacter spp. preferably the species selected from the list consisting of: C. koseri, C. freundii, C. youngae, C. braakii, C. werkmanii, C. murliniae, C. gillenii, C. sedlakii, C. pasteurii, C. eropaeus, C. amalonaticus, C. farmeri, C. rodentium and C. portucalensis. 10. Method according to any of claims 6 to 9 wherein the acidic pH ranges from 4.3 to 4.8, preferably 4.6. 11. Method according to any of claim 6 to 10 wherein the INDAR inhibitor recognize a PBP protein having at least 80% identity with SEQ ID NO: 2 and/or a PBP protein having at least 80% identity with SEQ ID NO: 4, preferably, the sequences as set forth in SEQ ID NO: 2 and/or SEQ ID NO: 4. 12. An INDAR inhibitor obtainable from the method as defined in any of the claims 6 to 11. 13. Use of a pathogenic bacterial cell comprising a non-functional gene encoding for a PBP for the in vitro identification and/or validation of INDAR inhibitors. 14. A Salmonella Typhimurium mutant cell characterized in that does not express at least one polynucleotide sequence encoding at least one polypeptide selected from the list consisting of: PBP2 (SEQ ID NO: 6), PBP2SAL (SEQ ID NO: 2), PBP3 (SEQ ID NO: 8), PBP3SAL (SEQ ID NO: 4) or any combinations thereof. 15. A Salmonella Typhimurium mutant host cell according to claim 14 wherein the mutant does not express the polynucleotide sequence encoding the PBP2 polypeptide (SEQ ID NO: 6); or the mutant does not express the polynucleotide sequence encoding the PBP2SAL polypeptide (SEQ ID NO: 2), or the mutant does not express the polynucleotide sequence encoding the PBP2 polypeptide (SEQ ID NO: 6) and the PBP3 polypeptide (SEQ ID NO: 8), or the mutant has been replaced the PBP2SAL gene (SEQ ID NO. 1) in its native chromosomal location by the PBP2 gene (SEQ ID NO: 5), or the mutant has been replaced the PBP3SAL gene (SEQ ID NO. 3) in its native chromosomal location by the PBP3 gene (SEQ ID NO: 7), or the mutant does not express the polynucleotide sequence encoding the PBP2SAL polypeptide (SEQ ID NO: 2) and the polynucleotide sequence encoding the PBP3SAL polypeptide (SEQ ID NO: 4), preferably the mutant does not express the polynucleotide sequence encoding the PBP2 polypeptide (SEQ ID NO: 6) and the PBP3 polypeptide (SEQ ID NO: 8) or the mutant does not express the polynucleotide sequence encoding the PBP2 polypeptide (SEQ ID NO: 6).