A Prospective Cohort Multicenter Study of Molecular Epidemiology and Phylogenomics of Staphylococcus aureus Bacteremia in Nine Latin American Countries

Arias, Cesar A.; Reyes, Jinnethe; Carvajal, Lina Paola; Rincon, Sandra; Diaz, Lorena; Panesso, Diana; Ibarra, Gabriel; Rios, Rafael; Munita, Jose M.; Salles, Mauro J.; Alvarez-Moreno, Carlos; Labarca, Jaime; García Apac, Coralith Marlinda; Luna, Carlos M.; Mejia-Villatoro, Carlos; Zurita, Jeannete; Guzman-Blanco, Manuel; Rodriguez-Noriega, Eduardo; Narechania, Apurva; Rojas, Laura J.; Planet, Paul J.; Weinstock, George M.; Gotuzzo Herencia, José Eduardo; Seas Ramos, Carlos Rafael · urn:issn:1098-6596 (2017) · DOI: 10.1128/aac.00816-17

Resumen

Staphylococcus aureus is an important pathogen causing a spectrum of diseases ranging from mild skin and soft tissue infections to life-threatening conditions. Bloodstream infections are particularly important, and the treatment approach is complicated by the presence of methicillin-resistant S. aureus (MRSA) isolates. The emergence of new genetic lineages of MRSA has occurred in Latin America (LA) with the rise and dissemination of the community-associated USA300 Latin American variant (USA300-LV). Here, we prospectively characterized bloodstream MRSA recovered from selected hospitals in 9 Latin American countries. All isolates were typed by pulsed-field gel electrophoresis (PFGE) and subjected to antibiotic susceptibility testing. Whole-genome sequencing was performed on 96 MRSA representatives. MRSA represented 45% of all (1,185 S. aureus) isolates. The majority of MRSA isolates belonged to clonal cluster (CC) 5. In Colombia and Ecuador, most isolates (≥72%) belonged to the USA300-LV lineage (CC8). Phylogenetic reconstructions indicated that MRSA isolates from participating hospitals belonged to three major clades. Clade A grouped isolates with sequence type 5 (ST5), ST105, and ST1011 (mostly staphylococcal chromosomal cassette mec [SCCmec] I and II). Clade B included ST8, ST88, ST97, and ST72 strains (SCCmec IV, subtypes a, b, and c/E), and clade C grouped mostly Argentinian MRSA belonging to ST30. In summary, CC5 MRSA was prevalent in bloodstream infections in LA with the exception of Colombia and Ecuador, where USA300-LV is now the dominant lineage. Clonal replacement appears to be a common phenomenon, and continuous surveillance is crucial to identify changes in the molecular epidemiology of MRSA.

Instituciones: Universidad Peruana Cayetano Heredia