Javier Antonio Escobar-Pérez1, Betsy Esperanza Castro1, Ricaurte Alejandro Márquez-Ortiz1, Sebastián Gaines1, Bibiana Chavarro1, Jaime Moreno2, Aura Lucía Leal3, Natasha Vanegas4. 1. Laboratorio de Genética Molecular Bacteriana, Universidad El Bosque, Bogotá, D.C, Colombia. 2. Grupo de Microbiología, Dirección de Investigación en Salud Pública, Subdirección de Investigación Científica y Tecnológica, Instituto Nacional de Salud, Bogotá, D.C, Colombia. 3. Grupo para el Control de la Resistencia Bacteriana en Bogotá, Universidad Nacional de Colombia, Bogotá, D.C, Colombia. 4. I3 Institute, Faculty of Science, University of Technology Sydney.
Abstract
INTRODUCTION: USA300 is a genetic lineage found both in methicillin-resistant (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) isolates. In Colombia, hospital and community MRSA infections are caused by a USA300-related community genotype MRSA (CG-MRSA) clone. The genetic origin of this clone is unknown yet. OBJECTIVE: To identify and characterize methicillin-resistant (MRSA) and methicillin-sensitive S. aureus (MSSA) isolates in order to improve the information about the origin of the CG-MRSA isolates in Colombia. MATERIALS AND METHODS: USA300-related MSSA isolates were detected and characterized from a study of 184 S. aureus isolates (90 MRSA and 94 MSSA) recovered from infections. The genetic relatedness of the isolates was established by means of pulsed field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and protein A gene typification ( spa typing). RESULTS: Among 184 isolates, 27 (14.7%) showed molecular characteristics and genetic relationship with the USA300 clone, of which 18 were MRSA and nine were MSSA. All USA300-related MRSA harbored Staphylococcal cassette chromosome mec (SCC mec ) IVc (3.1.2). In the MSSA isolates, SCC mec remnants or att B duplicate sites were not detected. CONCLUSIONS: In Colombia, the CG-MRSA isolates probably originated in the dissemination of an USA300-related MSSA clone which later acquired SCC mec IVc.
INTRODUCTION: USA300 is a genetic lineage found both in methicillin-resistant (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) isolates. In Colombia, hospital and community MRSA infections are caused by a USA300-related community genotype MRSA (CG-MRSA) clone. The genetic origin of this clone is unknown yet. OBJECTIVE: To identify and characterize methicillin-resistant (MRSA) and methicillin-sensitive S. aureus (MSSA) isolates in order to improve the information about the origin of the CG-MRSA isolates in Colombia. MATERIALS AND METHODS: USA300-related MSSA isolates were detected and characterized from a study of 184 S. aureus isolates (90 MRSA and 94 MSSA) recovered from infections. The genetic relatedness of the isolates was established by means of pulsed field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and protein A gene typification ( spa typing). RESULTS: Among 184 isolates, 27 (14.7%) showed molecular characteristics and genetic relationship with the USA300 clone, of which 18 were MRSA and nine were MSSA. All USA300-related MRSA harbored Staphylococcal cassette chromosome mec (SCC mec ) IVc (3.1.2). In the MSSA isolates, SCC mec remnants or att B duplicate sites were not detected. CONCLUSIONS: In Colombia, the CG-MRSA isolates probably originated in the dissemination of an USA300-related MSSA clone which later acquired SCC mec IVc.