[Invasive streptococcal infections]. / Invazivní streptokokové infekce.

The severity of streptococcal infections depends upon different virulence of individual strains of its causative agent. The most important species are beta-haemolytic group A streptococci (GAS). Clinical manifestations include skin affections, respiratory tract infections and, in particular, serious systemic invasive infections. The pathogenicity of GAS is derived from cell wall components and extracellular products, especially toxins with properties of the so-called superantigens. Less invasive forms of the disease are include necrotizing fasciitis, myositis, pneumonia, sepsis without focus, arthritis, meningitis, puerperal sepsis, streptococcal toxic shock syndrome (STSS) and severe course of erysipelas and cellulitis with blood culture positive for GAS. In most cases, soft tissue infections dominate, often accompanied by chronic diseases of lower extremities in elderly patients. The other clinical forms are rather rare. In children, the condition is clearly frequently related to chickenpox. The generally accepted therapeutic management comprises comprehensive intensive care, early administration of penicillin in combination with clindamycin, and surgical intervention. The use of intravenous immunoglobulins (IVIG), elimination methods and hyperbaric oxygen are under discussion. The slight increase in cases and ineffective prevention require rapid assessment of diagnosis and adequate treatment as a protracted course of the condition is connected with a high mortality rate.

The inhibitory effect of neonatal rat smooth muscle cells and elastic extracellular matrix on development of the newly seeded cell population in culture.

Neonatal smooth muscle cells were seeded in standard plastic Falcon flasks, on top of another 2-month-old culture of the same cell population or on top of an acellular matrix prepared by removal of these cells. The effect of both complete and acellular layers on the production of elastin, collagen and total extracellular matrix (EM) proteins as well as on cell division was measured. Compared with the standard population grown on plastic, the complete cell layer almost completely prevented the newly seeded cells from dividing. The acellular matrix did not affect cell doubling but caused a distinct decrease in the production of EM components.