title: CC8 MRSA strains harboring SCCmec type IVc are predominant in Colombian hospitals.
abstract: BACKGROUND
  Recent reports highlight the incursion of community-associated MRSA within healthcare settings. However, knowledge of this phenomenon remains limited in Latin America. The aim of this study was to evaluate the molecular epidemiology of MRSA in three tertiary-care hospitals in Medellín, Colombia.
  
  
  METHODS
  An observational cross-sectional study was conducted from 2008-2010. MRSA infections were classified as either community-associated (CA-MRSA) or healthcare-associated (HA-MRSA), with HA-MRSA further classified as hospital-onset (HAHO-MRSA) or community-onset (HACO-MRSA) according to standard epidemiological definitions established by the U.S. Centers for Disease Control and Prevention (CDC). Genotypic analysis included SCCmec typing, spa typing, PFGE and MLST.
  
  
  RESULTS
  Out of 538 total MRSA isolates, 68 (12.6%) were defined as CA-MRSA, 243 (45.2%) as HACO-MRSA and 227 (42.2%) as HAHO-MRSA. The majority harbored SCCmec type IVc (306, 58.7%), followed by SCCmec type I (174, 33.4%). The prevalence of type IVc among CA-, HACO- and HAHO-MRSA isolates was 92.4%, 65.1% and 43.6%, respectively. From 2008 to 2010, the prevalence of type IVc-bearing strains increased significantly, from 50.0% to 68.2% (p = 0.004). Strains harboring SCCmec IVc were mainly associated with spa types t1610, t008 and t024 (MLST clonal complex 8), while PFGE confirmed that the t008 and t1610 strains were closely related to the USA300-0114 CA-MRSA clone. Notably, strains belonging to these three spa types exhibited high levels of tetracycline resistance (45.9%).
  
  
  CONCLUSIONS
  CC8 MRSA strains harboring SCCmec type IVc are becoming predominant in Medellín hospitals, displacing previously reported CC5 HA-MRSA clones. Based on shared characteristics including SCCmec IVc, absence of the ACME element and tetracycline resistance, the USA300-related isolates in this study are most likely related to USA300-LV, the recently-described 'Latin American variant' of USA300.
authors: Grupo de Microbiología Molecular, Escuela de Microbiología, Universidad de Antioquia, Medellín, Colombia. judynatalia@yahoo.com
authors: J Natalia
authors: JN
authors: Jiménez
authors: Ana M
authors: AM
authors: Ocampo
authors: Johanna M
authors: JM
authors: Vanegas
authors: Erika A
authors: EA
authors: Rodriguez
authors: José R
authors: JR
authors: Mediavilla
authors: Liang
authors: L
authors: Chen
authors: Carlos E
authors: CE
authors: Muskus
authors: Lázaro A
authors: LA
authors: Vélez
authors: Carlos
authors: C
authors: Rojas
authors: Andrea V
authors: AV
authors: Restrepo
authors: Sigifredo
authors: S
authors: Ospina
authors: Carlos
authors: C
authors: Garcés
authors: Liliana
authors: L
authors: Franco
authors: Pablo
authors: P
authors: Bifani
authors: Barry N
authors: BN
authors: Kreiswirth
authors: Margarita M
authors: MM
authors: Correa
mesh_terms: D003105:Colombia / Q000453:epidemiology; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity*; D013203:Staphylococcal Infections / Q000453:epidemiology*; D037521:Virulence Factors / Q000235:genetics
chemical_list: D037521:Virulence Factors