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. 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.
Methodology: 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.
Results: 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.
Conclusions: 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.
The biofilm is a conglomerate of cells surrounded by an extracellular matrix, which contributes to the persistence of infections. The difficulty in removing the biofilm drives the research for new therapeutic options. In this work, the effect of terpenes (−)-trans-Caryophyllene, (S)-cis-Verbenol, (S)-(−)-Limonene, (R)-(+)-Limonene, and Linalool was evaluated, individually and in combinations on bacterial growth, by assay with resazurin; the formation of biofilm, by assay with violet crystal; and the expression of associated genes, by real-time PCR, in two clinical isolates of Staphyloccocus aureus, ST30-t019 and ST5-t311, responsible for more than 90% of pediatric infections by this pathogen in Paraguay. All combinations of terpenes can inhibit biofilm formation in more than 50% without affecting bacterial growth. The most effective combination was (−)-trans-Caryophyllene and Linalool at a 500 μg/mL concentration for each, with an inhibition percentage of 88%. This combination decreased the expression levels of the sdrD, spa, agr, and hld genes associated with the initial cell adhesion stage and quorum sensing. At the same time, it increased the expression levels of the cap5B and cap5C genes related to the production of capsular polysaccharides. The combinations of compounds tested are promising alternatives to inhibit biofilm formation in S. aureus.
Streptococcus pyogenes es ampliamente conocido como uno de los patógenos bacterianos más importantes en seres humanos. Este caso reporta a una paciente femenina de 3 años de edad, procedente de Lambaré, sin patología de base conocida, consultó en el Servicio de Urgencias del Instituto de Medicina Tropical por una lesión en cara externa de pierna derecha de 3 días de evolución que se extendió progresivamente, agregándose tumefacción y flictenas violáceas. Además vómitos 24 hs antes del ingreso en varias ocasiones. La paciente presentó cultivo de lesión por punción infiltrativa de zona afecta del miembro inferior derecho positivo a Streptococcus pyogenes multisensible que fue derivado al Departamento de Biología Molecular y Biotecnología del Instituto de Investigaciones en Ciencias de la Salud para caracterización molecular en el que se detectó la portación de los factores de virulencia speA, speB y speC. Palabras claves: Streptococcus pyogenes, factores de virulencia, choque séptico
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