title: Antimicrobial and antibiofilm activity of secondary metabolites of lichens against methicillin-resistant Staphylococcus aureus strains from cystic fibrosis patients.
abstract: OBJECTIVE
  Three secondary metabolites of lichens - usnic acid, atranorin and fumarprotocetraric acid - were evaluated for their in vitro antibacterial and antibiofilm activities against three strains each of methicillin-susceptible and methicillin-resistant Staphylococcus aureus (MRSA) from cystic fibrosis patients.
  
  
  METHODS
  Antibacterial activity was assessed by broth microdilution, while antibiofilm activity was evaluated by spectrophotometry or viable count.
  
  
  RESULTS
  Usnic acid was significantly more active than atranorin against planktonic cells, while fumarprotocetraric acid exhibited no activity. Atranorin was the most effective in counteracting adhesion to polystyrene, although usnic acid was more active against MRSA. Usnic acid and atranorin showed comparable activity against biofilm formation, although atranorin was more active against MRSA. Usnic acid was significantly more active than atranorin against preformed biofilms.
  
  
  CONCLUSIONS
  Secondary metabolites of lichens may be considered to be 'lead compounds' for the development of novel molecules for the treatment of S. aureus infections in cystic fibrosis patients.
authors: Department of Experimental & Clinical Sciences, 'G D'Annunzio' University of Chieti-Pescara, Chieti, Italy.
authors: Arianna
authors: A
authors: Pompilio
authors: Stefano
authors: S
authors: Pomponio
authors: Valentina
authors: V
authors: Di Vincenzo
authors: Valentina
authors: V
authors: Crocetta
authors: Marcello
authors: M
authors: Nicoletti
authors: Marisa
authors: M
authors: Piovano
authors: Juan A
authors: JA
authors: Garbarino
authors: Giovanni
authors: G
authors: Di Bonaventura
mesh_terms: D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology*; D001572:Benzofurans / Q000302:isolation & purification / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D001688:Biological Products / Q000302:isolation & purification / Q000494:pharmacology; D015169:Colony Count, Microbial; D003550:Cystic Fibrosis / Q000150:complications; D005650:Fumarates / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D062385:Hydroxybenzoates / Q000302:isolation & purification / Q000494:pharmacology*; D008011:Lichens / Q000737:chemistry; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification / Q000502:physiology; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology; D013203:Staphylococcal Infections / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D001572:Benzofurans; D001688:Biological Products; D005650:Fumarates; D062385:Hydroxybenzoates; D010936:Plant Extracts; C073339:usnic acid; C026304:atranorin; C026307:fumarprotocetraric acid