title: The cif Virulence Factor Gene Is Present in Isolates From Patients With Pseudomonas aeruginosa Keratitis.
abstract: OBJECTIVE
  To determine whether the cif gene is present in pathogenic Pseudomonas aeruginosa isolates from patients with bacterial keratitis at Aravind Eye Hospital, a referral eye care center in southern India, and from corresponding environmental isolates.
  
  
  METHODS
  Polymerase chain reaction amplification was performed on strains of P. aeruginosa isolated from ocular infections and environmental soil samples were collected from the area surrounding Aravind Eye Hospital. DNA sequencing of 16S ribosomal DNA amplicons was performed to verify strain identity.
  
  
  RESULTS
  We determined that 45 of 48 patient isolates carry a genomic copy of cif. Analysis of a catalog of environmental strains previously isolated from the surrounding area revealed that only 4 of 10 P. aeruginosa strains and 1 of 14 strains of related species carry the cif gene.
  
  
  CONCLUSIONS
  This is the first study to show that P. aeruginosa strains with ocular pathogenicity carry the cif gene and that the presence of this gene may be enriched over its prevalence in the environment. Taken together, these results suggest a potential role for Cif in acute bacterial keratitis.
authors.affiliation: *Department of Biochemistry & Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH. Dr Bahl is now with the Department of Biochemistry, University of Washington, Seattle, WA, and Dr St. Laurent is now with the Department of Obstetrics and Gynecology, Brigham, and Women's Hospital, Boston, MA; †Department of Ocular Microbiology, Dr G. Venkatasamy Eye Research Institute, Aravind Medical Research Foundation, Madurai, India; ‡Department of Surgery (Ophthalmology), Geisel School of Medicine at Dartmouth, Hanover, NH; and §Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Bahl
authors.forename: Jessica D
authors.initials: JD
authors.lastname: St Laurent
authors.forename: R Siva Ganesa
authors.initials: RS
authors.lastname: Karthikeyan
authors.forename: J Lakshmi
authors.initials: JL
authors.lastname: Priya
authors.forename: Lalitha
authors.initials: L
authors.lastname: Prajna
authors.forename: Michael E
authors.initials: ME
authors.lastname: Zegans
authors.forename: Dean R
authors.initials: DR
authors.lastname: Madden
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D003320:Corneal Ulcer / Q000382:microbiology*; D003430:Cross-Sectional Studies; D004269:DNA, Bacterial / Q000235:genetics; D004587:Electrophoresis, Agar Gel; D015818:Eye Infections, Bacterial / Q000382:microbiology*; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011552:Pseudomonas Infections / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000302:isolation & purification*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012189:Retrospective Studies; D017422:Sequence Analysis, DNA; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; C547935:Cif protein, Pseudomonas aeruginosa; D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D037521:Virulence Factors