Browsing tag: GAS

Epidemiologia zakażeń Streptococcus pyogenes, struktura klonalna populacji i antybiotykooporność

Epidemiology of Streptococcus pyogenes infections, clonal structure population and antibiotic resistance
K. Szczypa, J. Wilemska, W. Hryniewicz, I. Sitkiewicz

1. Wstęp. 2. Zakażenia wywoływane przez S. pyogenes. 3. Nosicielstwo i drogi szerzenia się zakażeń S. pyogenes. 4. Ustalanie pokrewieństwa genetycznego pomiędzy szczepami S. pyogenes. 5. Oporność S. pyogenes na antybiotyki. 6. Profilaktyka zakażeń S. pyogenes. 7. Podsumowanie

Abstract: Streptococcus pyogenes (GAS) is one of the major human pathogens responsible for infections worldwide. It may cause mild infections of the skin and mucosal surfaces, as well as severe invasive infections. It has been estimated that S. pyogenes is responsible for half a million deaths a year, and is considered as one of the most important pathogens.
Many clinical investigations on S. pyogenes focus on characterization of pathogenic strains, heterogeneity/homogeneity of the population clonal spread, transfer between patients and tracing sources of antibiotic resistance. Advanced studies on vaccines that prevent GAS infections are in progress.

1. Introduction. 2. S. pyogenes infections. 3. Carrier state and epidemiology of infections. 4. S. pyogenes strains genetic affinity. 5. S. pyogenes resistance to antibiotics. 6. The prophylactics of S. pyogenes infections. 7. Summary

Mechanizmy wirulencji paciorkowców β-hemolizujących

Virulence mechanisms factors and pathogenic of β-hemolytic streptococci
K. Obszańska, I. Kern-Zdanowicz, I. Sitkiewicz

1. Wstęp. 2. Paciorkowce grupy A (GAS). 3. Charakterystyka paciorkowców grupy B. 3.1. Czynniki wirulencji GBS. 4. Charakterystyka grup C i G. 4.1. Czynniki wirulencji GCS/GGS. 5. Charakterystyka grupy anginosus. 6. Podsumowanie

Abstract: Streptococcus is a highly diverse genus of gram positive bacteria. They can be divided into different groups based on their phenotypic properties. Usually criteria include hemolysis (α, β or γ) or type of surface carbohydrate (Lancefield antigen). Classification often includes phylogenetic groups (divisions) such as pyogenic, anginosus (milleri), mitis/oralis, salivarius and bovis. β-hemolytic streptococci are usually classified as pyogenic and anginosus groups, while others (with α-hemolysis) are commonly called viridans streptococci.
Among over 40 streptococcal species, several cause infections in humans and animals. For several species changes of host range and severity of infections were observed. Over the last four decades multiple virulence factors produced by pathogenic streptococci responsible for infection dynamics were identified and characterized.

1. Introduction. 2. Group A streptococci. 3. The characteristis of group B streptococci. 3.1. GBS virulence factors. 4. The characteristis of group C and G. 4.1. Virulence factors of GCS/GBS. 5. Characteristis anginosus group. 6. Summary