title: Comparison of Biofilm Formation Capacities of Two Clinical Isolates of Staphylococcus Epidermidis with and without icaA and icaD Genes on Intraocular Lenses.
abstract: OBJECTIVE
  To compare biofilm formations of twoStaphylococcus epidermidis (S. epidermidis)isolates with known biofilm formation capacities on four different intraocular lenses (IOL) that have not been studied before.
  
  
  METHODS
  Two isolates obtained from ocular surfaces and identified in previous studies and stored at -86 °C in 15% glycerol in the microbiology laboratory of the Anadolu University Department of Biology were purified and used in the study. The isolates wereS. epidermidisKA 15.8 (ICA+), a known biofilm producer isolate positive foricaA, icaDandbapgenes, andS. epidermidisKA 14.5 (ICA-), known as a non-biofilm producer isolate negative foricaA, icaDandbapgenes. The biofilm formation capacities of the 2 isolates on 4 different IOLs were compared. Two of the IOLs were acrylic (UD613 [IOL A], Turkey; SA60AT [IOL B], USA), and the other two were polymethyl methacrylate (PMMA) (B60130C [IOL C], India; B55125C [IOL D], India). Bacterial enumeration and optical density measurements were done from biofilms that formed on the IOLs. Biofilms were imaged using scanning electron microscopy.
  
  
  RESULTS
  Mean bacterial counts on the IOLs were 7.1±0.4 log10CFU/mL with the ICA+ isolate, and 6.7±0.8 log10CFU/mL with the ICA- isolate; there were no statistically significant differences. Biofilm formation was lower with acrylic lenses than PMMA lenses with both isolates (p=0.009 and p=0.013). The highest biofilm production was obtained on IOL C (PMMA) (p<0.001) and the lowest was obtained on IOL A (hydrophilic acrylic) (p<0.001).
  
  
  CONCLUSIONS
  Bacterial counts after biofilm formation were lower on acrylic lenses, especially hydrophilic acrylic with hydrophobic properties. Further animal andin vivostudies are required to support the findings of this study.
authors.affiliation: Uludağ University Faculty of Medicine, Department of Ophthalmology, Bursa, Turkey.
authors.forename: Sertaç Argun
authors.initials: SA
authors.lastname: Kıvanç
authors.affiliation: Anadolu University Faculty of Science, Department of Biology, Eskişehir, Turkey.
authors.forename: Merih
authors.initials: M
authors.lastname: Kıvanç
authors.affiliation: Anadolu University Faculty of Science, Department of Biology, Eskişehir, Turkey.
authors.forename: Volkan
authors.initials: V
authors.lastname: Kılıç
authors.affiliation: Armedica Eye Center, Ophthalmology Clinic, Darıca, Turkey.
authors.forename: Gülay
authors.initials: G
authors.lastname: Güllülü
authors.affiliation: Uludağ University Faculty of Medicine, Department of Ophthalmology, Bursa, Turkey.
authors.forename: Ahmet Tuncer
authors.initials: AT
authors.lastname: Özmen
keywords: Biofilm; Staphylococcus epidermidis; hydrophilic; hydrophobic; intraocular lenses