title: [Changes over time in the distribution of dominant clonal complexes of methicillin-resistant Staphylococcus aureus in Medellín, Colombia].
abstract: BACKGROUND
  Part of the success of methicillin-resistant Staphylococcus aureus (MRSA) as a pathogen responds to the rapid spread of pandemic lineages with diverse virulence and antimicrobial susceptibility profiles. In Colombia, several healthcare-associated MRSA (HA-MRSA) clones have been found, including the pediatric clone (CC5-ST5-SCC mec IV), the Brazilian clone (CC8-ST239-SCC mec III), and the Chilean/Cordobés clone (CC5-ST5-SCC mec I). Moreover, the community-associated MRSA (CA-MRSA) clone USA300 has been reported as causing hospital-acquired infections.
  
  
  OBJECTIVE
  To describe the changes over time in the distribution of MRSA clones from a university hospital in Medellín collected at two time points a decade apart.
  
  
  METHODS
  A total of 398 MRSA strains were analyzed. Of these, 67 strains were collected in 1994, while the remaining 331 strains were collected between 2008 and 2010. Species identification and methicillin resistance were confirmed by detection of nuc and mec A genes, respectively. Molecular characterization included spa typing, SCC mec typing, PFGE and MLST.
  
  
  RESULTS
  Analysis of the MRSA strains collected in 1994 revealed that they belonged to a single clone, the CC5-SCC mec IV, whereas among the isolates from 2008-2010, two dominant clones were identified: CC8-SCC mec IVc, which included spa types t008 and t1610 and is closely related to the USA 300 clone, and CC5-SCC mec I ( spa type t149), related to the Chilean clone. The ST5-SCC mec IV clone from 1994 was not detected.
  
  
  CONCLUSIONS
  This study identifies temporal dynamics in MRSA clone diversity, and highlights the importance of local surveillance and dissemination of results, especially in countries like Colombia where MRSA is prevalent and knowledge regarding its epidemiology is still insufficient.
authors: Línea de Epidemiología Molecular Bacteriana, Grupo de Microbiología Molecular, Escuela de Microbiología, Universidad de Antioquia, Medellín, Colombia.
authors: Ana M
authors: AM
authors: Ocampo
authors: Grupo Investigador de Problemas en Enfermedades Infecciosas, Facultad de Medicina, Universidad de Antioquia.
authors: Lázaro A
authors: LA
authors: Vélez
authors: Unidad de Bacteriología y Micobacterias, Corporación para Investigaciones Biológicas (CIB), Medellín, Colombia.
authors: Jaime
authors: J
authors: Robledo
authors: Grupo de Investigación en Microbiología Básica y Aplicada, MICROBA, Escuela de Microbiología, Universidad de Antioquia.
authors: Judy Natalia
authors: JN
authors: Jiménez
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D015373:Bacterial Typing Techniques; D002999:Clone Cells / Q000187:drug effects; D003105:Colombia / Q000453:epidemiology; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology*; D016521:Electrophoresis, Gel, Pulsed-Field; D005798:Genes, Bacterial; D006785:Hospitals, University / Q000706:statistics & numerical data; D006786:Hospitals, Urban / Q000706:statistics & numerical data; D006801:Humans; D016106:Methicillin Resistance / Q000235:genetics; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D058885:Multilocus Sequence Typing; D046915:Penicillin-Binding Proteins; D011159:Population Surveillance; D011446:Prospective Studies; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D013205:Staphylococcal Protein A / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D046915:Penicillin-Binding Proteins; D013205:Staphylococcal Protein A; C487789:mecA protein, Staphylococcus aureus