title: Effect of antibiotic prophylaxis on Coagulase-negative Staphylococcus virulence factor profiles in patients undergoing cataract surgery.
abstract: OBJECTIVE
  In this prospective study, multiplex polymerase chain reaction (PCR) was used to identify genes encoding virulence factors (ica, atlE and mecA) in Coagulase-negative Staphylococcus (CNS) isolates from the ocular microbiota of patients undergoing cataract surgery and to investigate possible changes in the CNS profile due to antibiotic prophylaxis.
  
  
  METHODS
  Between 09/2011 and 08/2013, patients undergoing cataract surgery were recruited at the Department of Ophthalmology, National University of Asuncion, Paraguay. In the eye to be operated on, patients received moxifloxacin 0.5 % eye drops four times at the day before surgery and a last drop 1 hour before surgery (T1). The other eye remained as control (T0). Conjunctival swabs were taken from both eyes 1 hour after the last drop. The presence of genes encoding biofilm formation (ica and atlE) and methicillin resistance (mecA) was detected by a multiplex PCR.
  
  
  RESULTS
  Of the 162 patients (162 study eyes, 162 fellow eye as control group), 87 (53.7 %) eyes were positive for CNS at T0 yielding 96 CNS isolates; 70 eyes (43.2 %) were positive at T1 yielding 77 CNS isolates. For this study, 43 CNS isolates (44.8 %) from T0 and 45 (64.3 %) from T1 were used. Of the total isolates, 81.8 % (72/88) had at least one virulence factor gene (37/43 from T0 and 35/45 from T1) (p = 0.314). Simultaneous detection of ica and atlE genes was higher in T0 (58.0 %) than T1 (46.7 %), but the difference was not significant (p = 0.28).
  
  
  CONCLUSIONS
  A high frequency of genes encoding virulence factors was observed in the coagulase-negative Staphylococcus isolates. The use of moxifloxacin did not significantly modify the CNS virulence factor profiles.
authors.affiliation: Instituto de Investigaciones en Ciencias de la Salud (IICS), National University of Asunción, San Lorenzo, Paraguay.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: López
authors.affiliation: Instituto de Investigaciones en Ciencias de la Salud (IICS), National University of Asunción, San Lorenzo, Paraguay. margarita.samudio@gmail.com.
authors.forename: Margarita
authors.identifier: http://orcid.org/0000-0003-2813-218X
authors.initials: M
authors.lastname: Samudio
authors.affiliation: Instituto de Investigaciones en Ciencias de la Salud (IICS), National University of Asunción, San Lorenzo, Paraguay.
authors.forename: Norma
authors.initials: N
authors.lastname: Fariña
authors.affiliation: Department of Ophthalmology, National University of Asunción, San Lorenzo, Paraguay.
authors.forename: Verónica
authors.initials: V
authors.lastname: Castillo
authors.affiliation: Instituto de Investigaciones en Ciencias de la Salud (IICS), National University of Asunción, San Lorenzo, Paraguay.
authors.forename: Sonia
authors.initials: S
authors.lastname: Abente
authors.affiliation: Department of Ophthalmology, Julius-Maximilians-University, Würzburg, Germany.
authors.forename: Martin M
authors.initials: MM
authors.lastname: Nentwich
authors.affiliation: Instituto de Investigaciones en Ciencias de la Salud (IICS), National University of Asunción, San Lorenzo, Paraguay.
authors.forename: Nilsa
authors.initials: N
authors.lastname: González-Britez
authors.affiliation: Instituto de Investigaciones en Ciencias de la Salud (IICS), National University of Asunción, San Lorenzo, Paraguay.
authors.forename: Florentina
authors.initials: F
authors.lastname: Laspina
authors.affiliation: Department of Ophthalmology, National University of Asunción, San Lorenzo, Paraguay.
authors.forename: Agustín
authors.initials: A
authors.lastname: Carron
authors.affiliation: Department of Ophthalmology, National University of Asunción, San Lorenzo, Paraguay.
authors.forename: Diógenes
authors.initials: D
authors.lastname: Cibils
authors.affiliation: Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: Herminia Miño
authors.initials: HM
authors.lastname: de Kaspar
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D019072:Antibiotic Prophylaxis / Q000379:methods*; D002387:Cataract Extraction / Q000009:adverse effects*; D003030:Coagulase / Q000378:metabolism; D004269:DNA, Bacterial / Q000032:analysis; D015818:Eye Infections, Bacterial / Q000382:microbiology / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D013203:Staphylococcal Infections / Q000382:microbiology / Q000517:prevention & control*; D013210:Staphylococcus / Q000201:enzymology / Q000235:genetics / Q000472:pathogenicity*; D013530:Surgical Wound Infection / Q000382:microbiology / Q000517:prevention & control*; D037521:Virulence Factors
chemical_list: D000900:Anti-Bacterial Agents; D003030:Coagulase; D004269:DNA, Bacterial; D037521:Virulence Factors
keywords: Coagulase-negative Staphylococci; Moxifloxacin; Prophylaxis; Virulence factors; atleA; ica; mecA genes