Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) clones from Paraguayan children.

Fátima Rodriguez,Gloria Gomez,Monica Rodriguez,Wilma Basualdo,Gladys Velázquez,Beatriz Quiñónez,Sol Haim,Claudia Salinas,Rosa Guillén,Lorena Grau,Gloria Samudio,Marta Mollerach,Hector Castro,Rocio Arguello,Patricia Almada,Silvina Fernandez,Carmen Espínola,Juana Ortellado,Ana Campuzano

doi:10.3855/jidc.12108

Abstract

Staphylococcus aureus is considered one of the most important human pathogens, and its levels of resistance to methicillin have increased even in strains isolated from people without nosocomial risk factors. Molecular analysis is essential for understanding the patterns of dissemination. The objective of this study was to identify community-acquired methicillin-resistant S. aureus (CA-MRSA) clones that infected Paraguayan children patients in two periods of time. An observational, descriptive study was designed to determine the genetic variability of 115 isolates of CA-MRSA recovered from children who attended four reference centers in Paraguay between 2009-2010 and 2012-2013. The combined use of Pulsed Field Gel Electrophoresis (PFGE), Multi-Locus Sequencing Typing, Multi-Locus Variable Analysis (MLVA) and Spa typing techniques allowed the identification of two dominant clones: ST30-IV-t019 (77%) and ST5-IV-t311 (10%), and the establishment of the former as the leading cause of CA-MRSA infections in children during the study period. This is the first study that provides epidemiological information as well as microbiological and molecular characteristics of CA-MRSA isolates recovered from children from Asunción and the Central Department of Paraguay.

Highlights

Staphylococcus aureus is considered one of the most important human pathogens, and its levels of resistance to methicillin have increased even in strains isolated from people without nosocomial risk factors
community-acquired methicillin-resistant S. aureus (CA-Methicillin-resistant Staphylococcus aureus (MRSA)) recovered from both study phases were characterized molecularly
The limited number of reports that refer to molecular data and genetic variability of S. aureus include only one description of two nosocomial clones recovered from adults: most isolates analyzed were CC5-ST221I-t049, similar to the Cordobés/Chilean clone that expanded through South America in the past decade and the minority belonged to CC8-ST239-III-t037 clone [24]

Summary

Introduction

Staphylococcus aureus is considered one of the most important human pathogens, and its levels of resistance to methicillin have increased even in strains isolated from people without nosocomial risk factors. The objective of this study was to identify community-acquired methicillin-resistant S. aureus (CA-MRSA) clones that infected Paraguayan children patients in two periods of time. Since the 1990s, virulent community-acquired MRSA (CA-MRSA) clones spread worldwide, first in the community in healthy young patients, but later in healthcare facilities [1]. They have been associated predominantly with skin and soft tissue infections (SSTIs), but due to the invasive nature of this pathogen and the carriage of antibiotic resistance and virulence factors genes (mainly the toxin Panton-Valentine Leukocidin, PVL), they have been linked to severe clinical syndromes such as necrotizing pneumonia, osteomyelitis, meningitis, sepsis, and death. This global ST239 was common in other countries, such as China and Rodríguez et al – CA-MRSA clones from Paraguayan children

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