Molecular Epidemiology and Clinical Course of Panton-Valentine Leukocidin Positive S. aureus Infection in Children of Latvia. Summary of the Doctoral Thesis

Abstract

S. aureus is a major cause of purulent infections. The spectrum of staphylococcal infections varies from mild superficial to invasive life-threatening diseases due to the ability of S. aureus to produce a wide range of virulence factors. Panton – Valentine leukocidin (PVL) is an extracellular pore forming S. aureus gamma toxin, which consists of two subunits F and S that together are leucocidal. PVL is encoded by lukS/lukF-PV genes. In humans PVL is associated with skin abscesses and necrotizing pneumonia. S. aureus strains which are positive for PVL are usually associated with community-acquired infections which generally affect previously healthy children and young adults. Although Panton-Valentine leukocidin is strongly associated with community acquired methicillin – resistant S. aureus (CA – MRSA), lukS/lukF-PV genes can be carried also by methicillin susceptible S. aureus isolates. Recent investigations suggest that PVL-positive S. aureus exhibits enhance virulence and are responsible for severe infections such as bone and joint infections and necrotising pneumonia. In Lavia studies of the prevalence and efffect of PVL positive S. aureus on the clinical course of disease in children have not been done. To gather information about the situation in Latvia and take effective and scientifically-based measures for the limitation of the spread of PVL producing S. aureus it is necessary to carry out investigation into PVL positive S. aureus molecular epidemiology and define the clinically important pathogenicity factors.