The two-component system ArlRS is essential for wall teichoic acid glycoswitching in .

is among the leading causes of hospital-acquired infections. Critical to biology and pathogenesis are the cell wall-anchored glycopolymers wall teichoic acids (WTA). Approximately one-third of isolates decorates WTA with a mixture of α1,4- and β1,4--acetylglucosamine (GlcNAc), which requires the dedicated glycosyltransferases TarM and TarS, respectively.

Forssman and the staphylococcal hemolysins.

Forssman was a Swedish pathologist and microbiologist who, in the 1920s and 1930s conducted a long series of experiments that led to unique insights into surface antigens of blood cells, as well as added to the discrimination of toxins produced by staphylococci that lyse red blood cells. This review takes offset in the studies published by Forssman in APMIS addressing the hemolytic properties of staphylococcal toxins displayed against erythrocytes of animal and human origin. In light of current knowledge, we will discuss the insights we now have and how they may pave the way for curing infections with pathogenic staphylococci, including Staphylococcus aureus.

A short-lived peptide signal regulates cell-to-cell communication in Listeria monocytogenes.

Quorum sensing (QS) is a mechanism that regulates group behavior in bacteria, and in Gram-positive bacteria, the communication molecules are often cyclic peptides, called autoinducing peptides (AIPs). We recently showed that pentameric thiolactone-containing AIPs from Listeria monocytogenes, and from other species, spontaneously undergo rapid rearrangement to homodetic cyclopeptides, which hampers our ability to study the activity of these short-lived compounds. Here, we developed chemically modified analogues that closely mimic the native AIPs while remaining structurally intact, by introducing N-methylation or thioester-to-thioether substitutions.

Staphylococcus aureus response and adaptation to vancomycin.

Antibiotic resistance is an increasing challenge for the human pathogen Staphylococcus aureus. Methicillin-resistant S. aureus (MRSA) clones have spread globally, and a growing number display decreased susceptibility to vancomycin, the favoured antibiotic for treatment of MRSA infections.

CI:Mor interactions in the lysogeny switches of TP901-1 and φ13 bacteriophages.

To structurally characterize in detail the interactions between the phage repressor (CI) and the antirepressor (Mor) in the lysis-lysogeny switches of two Gram-positive bacteriophages, the lactococcal TP901-1 and staphylococcal φ13. We use crystallographic structure determination, computational structural modeling, and analysis, as well as biochemical methods, to elucidate similarities and differences in the CI:Mor interactions for the two genetic switches. By comparing a newly determined and other available crystal structures for the N-terminal domain of CI (CI-NTD), we show that the CI interface involved in Mor binding undergoes structural changes upon binding in TP901-1.