Regulatory systems agr and sar in Staphylococcus Aureus

Staphylococcus aureus is an opportunistic pathogen causing many serious human and animal diseases . Infection is associated with the expression of virulence factors , mainly controlled by two regulatory systems agr and sar . Agr locus consists of two transcripts : RNAIII that is RNAII and the regulatory molecule encoding four proteins required for the stimulation of transcription of RNAII and RNAIII . Sar locus encoding a protein SarA and agr activator which binds to DNA is composed of three overlapping reading frames .

The mechanism of action of antimicrobial peptides

The peptides of the killing activity of anti- micro-organism are an important part of the innate immune response of the organism. They are produced by plants and animals constitutively or in response to infection by microorganisms . This paper presents the current knowledge and views on the interaction of antimicrobial peptides from microbial cell structures and on the probable mechanisms of action of these compounds. Antimicrobial peptides may exert its effect by the suicide : formation of membrane pores ( hypothesis ? Forming drums) or ion channels , membrane disintegration model ?

The Editorial Board
Andrzej Łukaszyk - przewodniczący, Zofia Bielańska-Osuchowska, Szczepan Biliński, Mieczysław Chorąży, Aleksander Koj, Włodzimierz Korochoda, Leszek Kuźnicki, Aleksandra Stojałowska, Lech Wojtczak

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