title: Bacterial communications in implant infections: a target for an intelligence war.
abstract: The status of population density is communicated among bacteria by specific secreted molecules, called pheromones or autoinducers, and the control mechanism is called ""quorum-sensing"". Quorum-sensing systems regulate the expression of a panel of genes, allowing bacteria to adapt to modified environmental conditions at a high density of population. The two known different quorum systems are described as the LuxR-LuxI system in gram-negative bacteria, which uses an N-acyl-homoserine lactone (AHL) as signal, and the agr system in gram-positive bacteria, which uses a peptide-tiolactone as signal and the RNAIII as effector molecules. Both in gram-negative and in gram-positive bacteria, quorum-sensing systems regulate the expression of adhesion mechanisms (biofilm and adhesins) and virulence factors (toxins and exoenzymes) depending on population cell density. In gram-negative Pseudomonas aeruginosa, analogs of signaling molecules such as furanone analogs, are effective in attenuating bacterial virulence and controlling bacterial infections. In grampositive Staphylococcus aureus, the quorum-sensing RNAIII-inhibiting peptide (RIP), tested in vitro and in animal infection models, has been proved to inhibit virulence and prevent infections. Attenuation of bacterial virulence by quorum-sensing inhibitors, rather than by bactericidal or bacteriostatic drugs, is a highly attractive concept because these antibacterial agents are less likely to induce the development of bacterial resistance.
authors.affiliation: Center for Biofilms, School of Dentistry, University of Southern California, Los Angeles, California, USA.
authors.forename: J W
authors.initials: JW
authors.lastname: Costerton
authors.forename: L
authors.initials: L
authors.lastname: Montanaro
authors.forename: C R
authors.initials: CR
authors.lastname: Arciola
mesh_terms: D048908:Aliivibrio fischeri / Q000472:pathogenicity; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development / Q000472:pathogenicity*; D024881:Drug Resistance, Bacterial; D006801:Humans; D016459:Prosthesis-Related Infections / Q000188:drug therapy / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000472:pathogenicity; D053038:Quorum Sensing / Q000187:drug effects; D013211:Staphylococcus aureus / Q000472:pathogenicity; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents