title: Targeting listeria monocytogenes rpoA and rpoD genes using peptide nucleic acids.
abstract: Treating intracellular pathogens remains a considerable medical challenge because of the inefficient intracellular delivery of antimicrobials and the frequent emergence of bacterial resistance to therapeutic agents deemed the drugs of last resort. We investigated the capability of antisense peptide nucleic acids (PNAs) conjugated to the (KFF)3K cell penetrating peptide to target RNA polymerase α subunit (rpoA) and RNA polymerase sigma 70 (rpoD) in the intracellular pathogen Listeria monocytogenes. The PNAs tested displayed a concentration dependent inhibition of L. monocytogenes growth in pure culture at the micromolar level and significantly reduced intracellular L. monocytogenes in infected cell culture and Caenorhabditis elegans whole animal model. In vitro, the combined PNAs treatment was synergistic resulting in a clearance of L. monocytogenes at 0.5× the individual PNA concentration. This study demonstrates the potential of anti-rpoA PNA as an antibacterial agent and will provide the basis for improving and developing these PNAs to better target intracellular pathogens like Listeria. This study also establishes C. elegans as a potential model for the screening of PNAs.
authors.affiliation: Department of Comparative Pathobiology, Purdue University College of Veterinary Medicine West Lafayette, Indiana, USA.
authors.forename: Ruba A
authors.initials: RA
authors.lastname: Alajlouni
authors.forename: Mohamed N
authors.initials: MN
authors.lastname: Seleem
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D017173:Caenorhabditis elegans / Q000382:microbiology; D002460:Cell Line; D057846:Cell-Penetrating Peptides / Q000737:chemistry; D015169:Colony Count, Microbial; D012321:DNA-Directed RNA Polymerases / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D004337:Drug Carriers; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development; D008264:Macrophages / Q000382:microbiology; D051379:Mice; D020135:Peptide Nucleic Acids / Q000138:chemical synthesis / Q000494:pharmacology*; D012808:Sigma Factor / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D057846:Cell-Penetrating Peptides; D004337:Drug Carriers; D020135:Peptide Nucleic Acids; D012808:Sigma Factor; C081775:RNA polymerase sigma 70; D012321:DNA-Directed RNA Polymerases; C113275:RNA polymerase alpha subunit