title: USA300-related methicillin-resistant Staphylococcus aureus clone is the predominant cause of community and hospital MRSA infections in Colombian children.
abstract: OBJECTIVE
  Community-genotype methicillin-resistant Staphylococcus aureus (CG-MRSA) isolates are known to be more virulent and clinically aggressive in children. The goal of the present study was characterize the molecular epidemiology of MRSA isolates causing infections in Colombian children.
  
  
  METHODS
  An observational and prospective study was conducted between April 2009 and June 2011 at 15 hospitals in Bogotá, Colombia. A detailed epidemiological profile was made of 162 children infected with MRSA. The isolates were subjected to antimicrobial susceptibility testing, molecular characterization including 21 virulence genes, SCCmec, spa and agr typing, multilocus sequence typing (MLST), and pulsed-field gel electrophoresis (PFGE).
  
  
  RESULTS
  Among all isolates included in the study, 85.8% were obtained from patients whose infectious process was initiated in the community; of these, 69,8% occurred in patients without healthcare-associated risk factors. The molecular characterization of the isolates showed a high proportion (95.1%) containing a community-genotype profile with a high prevalence of SCCmec type IV, PVL-positives, and also related to CC8. Most CG-MRSA isolates (143, 92.9%) were genetically related to the pandemic clone USA300, differing by the presence of SCCmec IVc and the absence of the arginine catabolic mobile element (ACME).
  
  
  CONCLUSIONS
  An increase in the frequency of CG-MRSA infections has been reported worldwide. In this study we found that almost all MRSA infections in our pediatric population were caused by community-genotype isolates, supporting the success of the CG-MRSA clones.
authors.affiliation: Bacterial Molecular Genetics Laboratory, Universidad El Bosque, Bogotá, DC, Colombia.
authors.forename: Ricaurte Alejandro
authors.initials: RA
authors.lastname: Márquez-Ortiz
authors.affiliation: Pediatric Infectious Diseases, Pediatrics Department, Fundación Cardioinfantil IC, Bogotá, DC, Colombia.
authors.forename: Martha I
authors.initials: MI
authors.lastname: Álvarez-Olmos
authors.affiliation: Bacterial Molecular Genetics Laboratory, Universidad El Bosque, Bogotá, DC, Colombia. Electronic address: labgenmolecular@unbosque.edu.co.
authors.forename: Javier Antonio
authors.initials: JA
authors.lastname: Escobar Pérez
authors.affiliation: Research Group in Infectious Diseases, Universidad Nacional de Colombia, Bogotá, DC, Colombia.
authors.forename: Aura Lucia
authors.initials: AL
authors.lastname: Leal
authors.affiliation: Bacterial Molecular Genetics Laboratory, Universidad El Bosque, Bogotá, DC, Colombia.
authors.forename: Betsy Esperanza
authors.initials: BE
authors.lastname: Castro
authors.affiliation: Hospital Militar Central, Bogotá, DC, Colombia.
authors.forename: Ana Cristina
authors.initials: AC
authors.lastname: Mariño
authors.affiliation: Hospital el Tunal, Bogotá, DC, Colombia.
authors.forename: Esther Rocio
authors.initials: ER
authors.lastname: Barrero
authors.affiliation: Bacterial Molecular Genetics Laboratory, Universidad El Bosque, Bogotá, DC, Colombia.
authors.forename: Sandra Celina
authors.initials: SC
authors.lastname: Mujica
authors.affiliation: Bacterial Molecular Genetics Laboratory, Universidad El Bosque, Bogotá, DC, Colombia.
authors.forename: Sebastián
authors.initials: S
authors.lastname: Gaines
authors.affiliation: Bacterial Molecular Genetics Laboratory, Universidad El Bosque, Bogotá, DC, Colombia; The i3 Institute, Faculty of Science, University of Technology, Sydney, Australia.
authors.forename: Natasha
authors.initials: N
authors.lastname: Vanegas
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D003105:Colombia / Q000453:epidemiology; D017714:Community-Acquired Infections; D003428:Cross Infection; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D011446:Prospective Studies; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents
keywords: CG-MRSA; CO-MRSA; Children; Clonal replacement; Colombia; USA300