title: In vitro efficacy of a povidone-iodine 0.4% and dexamethasone 0.1% suspension against ocular pathogens.
abstract: OBJECTIVE
  To assess the efficacy of a povidone-iodine 0.4%-dexamethasone 0.1% suspension against bacterial, fungal, and Acanthamoeba clinical isolates.
  
  
  METHODS
  Bascom Palmer Eye Institute, McKnight Research Building, Miami, Florida, USA.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  One hundred milliliters of 10(4) colony-forming units/mL of ocular isolates of methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Serratia marcescens, Candida albicans, Fusarium solani, and Acanthamoeba castellanii were inoculated into 100 μL of a povidone-iodine 0.4%-dexamethasone 0.1% suspension in a 96-well microtiter plate incubated at room temperature. Organism viability was assessed at 15, 30, and 60 seconds by removing 10 μL aliquots and streaking onto a 5.0% sheep blood agar plate (fungi and bacteria) and agar-agar (Acanthamoeba) using a 0.001 calibrated loop. The plates were then incubated at 35 °C and monitored for up to 7 days. Isolates were inoculated into 200 μL of trypticase soy broth as controls. The number of colonies was counted and compared with controls to determine the kill rate.
  
  
  RESULTS
  A 99.9% kill was observed for MRSA, P aeruginosa, S marcescens, and C albicans after 15 seconds of exposure and for F solani after 60 seconds. Acanthamoeba castellanii cyst viability was not inhibited by exposure to the povidone-iodine and dexamethasone suspension. Organism growth was achieved on all control broth.
  
  
  CONCLUSIONS
  Povidone-iodine 0.4%-dexamethasone 0.1% suspension killed all bacterial and candida isolates within 15 seconds of exposure. It killed Fusarium isolates at 60 seconds but was ineffective against Acanthamoeba cysts.
  
  
  BACKGROUND
  Drs. Pelletier and Miller have no financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.
authors.affiliation: Ocean Ophthalmology Group, North Miami Beach, Miami, Florida, USA. jessepelletier@yahoo.com
authors.forename: Jesse S
authors.initials: JS
authors.lastname: Pelletier
authors.forename: Darlene
authors.initials: D
authors.lastname: Miller
authors.forename: Bo
authors.initials: B
authors.lastname: Liang
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Capriotti
mesh_terms: D000048:Acanthamoeba / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D015169:Colony Count, Microbial; D003907:Dexamethasone / Q000494:pharmacology*; D004338:Drug Combinations; D005123:Eye / Q000382:microbiology / Q000469:parasitology; D005658:Fungi / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D011206:Povidone-Iodine / Q000494:pharmacology*; D016896:Treatment Outcome
chemical_list: D000891:Anti-Infective Agents, Local; D004338:Drug Combinations; D003907:Dexamethasone; D011206:Povidone-Iodine