title: Characterization of Vibrio parahaemolyticus strains isolated in Chile in 2005 and in 2007.
abstract: BACKGROUND
  Vibrio (V.) parahaemolyticus has endemically established in Chilean sea shores, causing outbreaks every year, with an important number of cases. In order to know the genetic relationship, genotype dominance and antibiotic resistance of isolates obtained from two outbreaks, this study characterized 110 strains isolated from environmental and clinical samples in years 2005 and 2007 in Chile.
  
  
  METHODS
  Genotyping was performed by determination of PFGE profiles, and pandemic group and integrons were screened by PCR. Antimicrobial susceptibility was studied by the disk diffusion method.
  
  
  RESULTS
  High antibiotic susceptibility frequency was found, mainly among 2007 isolates, except to ampicillin, cephalothin, cefoxitin, cefpodoxime, amikacin, streptomycin and kanamycin. Strains belonging to the pandemic group in clinical isolates account for 88% in 2005, decreasing to 66% in 2007 and among environmental isolates were detected in 20% of the strains from 2005, rising to 36% in 2007. In 2005, nine different PFGE profiles were identified, with 78% of the strains corresponding to a single clone. In 2007, sixteen different PFGE profiles were detected, with 61% of the strains included into a sole clone. The same clone was prevalent in both years. None of class 1, 2, 3 and SXT integrases genes was detected; however, the superintegron integrase gene (intIA) was present in almost all strains.
  
  
  CONCLUSIONS
  These results suggest the persistence and dominance of a unique PFGE clone of V. parahaemolyticus during 2005 and 2007, and the absence of genetic elements that capture antibiotic resistance genes described in other species of Vibrio.
authors.affiliation: Laboratorio de Antibióticos, Departamento de Microbiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Chile.
authors.forename: Priscila
authors.initials: P
authors.lastname: Dauros
authors.forename: Helia
authors.initials: H
authors.lastname: Bello
authors.forename: Mariana
authors.initials: M
authors.lastname: Domínguez
authors.forename: Juan C
authors.initials: JC
authors.lastname: Hormazábal
authors.forename: Gerardo
authors.initials: G
authors.lastname: González
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002677:Chile / Q000453:epidemiology; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000235:genetics; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D019353:Endemic Diseases; D004783:Environmental Microbiology; D005838:Genotype; D006801:Humans; D032023:Integrons; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D058889:Molecular Typing; D010641:Phenotype; D016133:Polymerase Chain Reaction; D014735:Vibrio Infections / Q000453:epidemiology* / Q000382:microbiology*; D014736:Vibrio parahaemolyticus / Q000145:classification* / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial