title: Effect of povidone-iodine concentration and exposure time on bacteria isolated from endophthalmitis cases.
abstract: OBJECTIVE
  To determine the in vitro susceptibility of post-cataract surgery endophthalmitis bacterial isolates to different concentrations of povidone-iodine at different exposure times.
  
  
  METHODS
  Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  Ocular-fluid samples obtained from patients diagnosed with postoperative endophthalmitis were submitted to a microbiology laboratory for culture. One milliliter of microbial isolate suspension with a McFarland standard turbidity of 0.5 was mixed with 1 mL of 1%, 2%, 5%, and 10% povidone-iodine solutions. After 1 minute, 5 minutes, and 15 minutes of exposure at 37°C, each solution was transferred to appropriate culture media and incubated at 37°C for 24 hours.
  
  
  RESULTS
  Organisms were isolated in 30 (68%) of the 44 patients evaluated. Coagulase-negative Staphylococcus was identified in 14 cases (47%), Streptococcus species in 8 cases (27%), Staphylococcus aureus in 5 cases (17%), Bacillus cereus in 2 cases (6%), and Pseudomonas aeruginosa in 1 case (3%). Higher povidone-iodine concentrations and longer exposure times were more effective than lower povidone-iodine concentrations or shorter exposure in preventing growth of bacterial isolates. The most effective regimens were 5% povidone-iodine for 15 minutes and 10% povidone-iodine for at least 5 minutes. With a high bacterial load, 13% of bacterial isolates remain viable after exposure to 10% povidone-iodine, even with a long exposure time.
  
  
  CONCLUSIONS
  Results indicate that using 5% povidone-iodine for 15 minutes or 10% povidone-iodine for 5 minutes can prevent the growth of most post-cataract surgery endophthalmitis bacterial isolates.
authors: Department of Ophthalmology, Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
authors: Hamid
authors: H
authors: Hosseini
authors: Mohammad Javad
authors: MJ
authors: Ashraf
authors: Masoomeh
authors: M
authors: Saleh
authors: Mohammad Hosein
authors: MH
authors: Nowroozzadeh
authors: Behdokht
authors: B
authors: Nowroozizadeh
authors: Mohammad Bagher
authors: MB
authors: Abtahi
authors: Sarah
authors: S
authors: Nowroozizadeh
mesh_terms: D000891:Anti-Infective Agents, Local / Q000008:administration & dosage*; D001082:Aqueous Humor / Q000382:microbiology; D001419:Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D001431:Bacteriological Techniques; D015169:Colony Count, Microbial; D009877:Endophthalmitis / Q000382:microbiology* / Q000517:prevention & control; D015818:Eye Infections, Bacterial / Q000382:microbiology* / Q000517:prevention & control; D006801:Humans; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability; D018918:Phacoemulsification; D011183:Postoperative Complications; D011206:Povidone-Iodine / Q000008:administration & dosage*; D013997:Time Factors; D014822:Vitreous Body / Q000382:microbiology
chemical_list: D000891:Anti-Infective Agents, Local; D011206:Povidone-Iodine