Typification Methods and Molecular Epidemiology of Staphylococcus aureus with Methicillin Resistance

Abstract

Recent interest in the study of Staphylococcus aureus derives from the high frequency of antibiotic-resistant strains that cause frequent outbreaks of infection, especially methicillin-resistant S. aureus (MRSA). The objective of this chapter was to study the population genetic structure and the origin of MRSA isolation. Classification of staphylococcal cassette chromosome mec (SCCmec) is the most important method to identify and define the S. aureus methicillin-resistant clonal nature. Molecular epidemiological studies have demonstrated dissemination patterns of few strains which are responsible for the important worldwide problem. There is a predominance of pandemic clones of MRSA associated to hospital-acquired infections (HA-MRSA) which has been replaced today by communityacquired strains (CA-MRSA). Understanding the epidemiology and clonality of S. aureus infections has important implications for future efforts to control of the emergence of multidrug-resistant strains and the spread of clones resistant and sensible to methicillin.

Características clínicas y mortalidad en pacientes con sepsis intra y extra hospitalaria en un hospital de referencia en el periodo 2016-2017

“…Se ha reportado en la literatura que el presentar comorbilidad es un factor de riesgo de sepsis (4,20) . El estudio realizado por Escobar et al (9) reportó entre los factores asociados a la mortalidad la presencia de una patología de base.…”

“…El choque séptico es una grave complicación de la sepsis, se presentan hasta en un 50 % de los pacientes con sepsis internados a la unidad de cuidados intensivos y se acompaña de una alta mortalidad (21,22) . En nuestro estudio, al igual que Escobar et al (9) , la mortalidad fue elevada en los pacientes que desarrollaron esta condición (70,4%) comparada con la observada en Europa y América del Norte (20) . En Alemania (17) , la mortalidad por choque séptico a los 30 días fue del 38,78%, en el resto de Europa 38,8%, y en América del Norte 34,41% (14) .…”

Isolation, Detection and Molecular Characterization of Staphylococcus aureus from Postoperative Infections

“…Molecular approaches are of paramount importance in showing clonality and spreading patterns of S. aureus strains in hospital settings; however, variation exists about their effectiveness, cost and general applicability [10]. Polymerase chain reaction (PCR) based approach of characterising Staphylococcal cassettes mec types and the determination of sequence polymorphism in the variable X region of the Staphylococcal protein a (spa) has been shown to be relatively less expensive, easier, less time consuming and clearly discriminatory compared to other approaches, such as multilocus sequence typing (MLST) and pulse field gel electrophoresis (PFGE) [11]. We present S. aureus by means of spa sequence typing and SCCmec genotyping.…”