Pathogenesis
Staphylococcus Vaccines
Nosocomial infections: Staphylococcus aureus
from Alice G. Cheng, Olaf Schneewind and Dominique Missiakas writing in Vaccine Design: Innovative Approaches and Novel Strategies
Staphylococcus aureus is the most frequent cause of human skin and soft tissue, bloodstream and respiratory tract infections. Staphylococcal strains have acquired antibiotic resistance traits against available therapies and drug-resistant strains (MRSA, methicillin-resistant S. aureus) are currently isolated in up to 80% of hospital and 60% of community-acquired infections (CA-MRSA). Unlike pneumococci and group A streptococci; S. aureus infections do not raise immunity against subsequent infections. Consistent with this observation, early efforts to develop vaccines from whole-cell killed preparations of staphylococci have failed. More recent work characterized proteins and carbohydrates in the staphylococcal envelope and examined these molecules as protective antigens in vaccine studies. A recent article reviews the pathogenesis of S. aureus infections as well as past and current efforts that have been pursued to develop effective vaccines.
Further reading: Vaccine Design: Innovative Approaches and Novel Strategies | Staphylococcus: Molecular Genetics
from Alice G. Cheng, Olaf Schneewind and Dominique Missiakas writing in Vaccine Design: Innovative Approaches and Novel Strategies
Staphylococcus aureus is the most frequent cause of human skin and soft tissue, bloodstream and respiratory tract infections. Staphylococcal strains have acquired antibiotic resistance traits against available therapies and drug-resistant strains (MRSA, methicillin-resistant S. aureus) are currently isolated in up to 80% of hospital and 60% of community-acquired infections (CA-MRSA). Unlike pneumococci and group A streptococci; S. aureus infections do not raise immunity against subsequent infections. Consistent with this observation, early efforts to develop vaccines from whole-cell killed preparations of staphylococci have failed. More recent work characterized proteins and carbohydrates in the staphylococcal envelope and examined these molecules as protective antigens in vaccine studies. A recent article reviews the pathogenesis of S. aureus infections as well as past and current efforts that have been pursued to develop effective vaccines.
Further reading: Vaccine Design: Innovative Approaches and Novel Strategies | Staphylococcus: Molecular Genetics
Salmonella virulence factors
Salmonella secreted virulence factors
from Fred Heffron, George Niemann, Hyunjin Yoon, Afshan Kidwai, Roslyn Brown, Jason McDermott, Richard Smith and Joshua Adkins writing in Salmonella: From Genome to Function
Research in the past twenty years has shown that Salmonella precisely manipulates their host by hierarchical secretion of virulence factors (effectors). More than 40 secreted virulence factors have been identified in Salmonella, but the function and mammalian targets of only a few are known. Effectors are directed to specific sub-cellular compartments and mammalian targets, and they mediate a diverse array of activities. Thus, the first half of this review focuses upon our understanding of effector mechanisms and their roles during infection.
However, the known effector repertoire is incomplete and the second half of this review places an emphasis on discovery. Computer analysis identified common secretion motifs and predicted that as many as 300 additional proteins may be secreted by Salmonella. In fact, mass spectrometry analysis identified a more complete secretome and found many novel, uncharacterized effector proteins. Several effectors identified in this study were small proteins of only 30-100 amino acids in length, suggesting that they are not enzymes but agonists or antagonists of specific host factors. One surprise from the mass spectrometry analysis was the identification of proteins that are secreted to mammalian cells via outer membrane vesicles. Complete characterization of the bewildering array of secreted proteins will take many years.
Further reading: Salmonella: From Genome to Function | Bacterial Secreted Proteins
from Fred Heffron, George Niemann, Hyunjin Yoon, Afshan Kidwai, Roslyn Brown, Jason McDermott, Richard Smith and Joshua Adkins writing in Salmonella: From Genome to Function
Research in the past twenty years has shown that Salmonella precisely manipulates their host by hierarchical secretion of virulence factors (effectors). More than 40 secreted virulence factors have been identified in Salmonella, but the function and mammalian targets of only a few are known. Effectors are directed to specific sub-cellular compartments and mammalian targets, and they mediate a diverse array of activities. Thus, the first half of this review focuses upon our understanding of effector mechanisms and their roles during infection.
However, the known effector repertoire is incomplete and the second half of this review places an emphasis on discovery. Computer analysis identified common secretion motifs and predicted that as many as 300 additional proteins may be secreted by Salmonella. In fact, mass spectrometry analysis identified a more complete secretome and found many novel, uncharacterized effector proteins. Several effectors identified in this study were small proteins of only 30-100 amino acids in length, suggesting that they are not enzymes but agonists or antagonists of specific host factors. One surprise from the mass spectrometry analysis was the identification of proteins that are secreted to mammalian cells via outer membrane vesicles. Complete characterization of the bewildering array of secreted proteins will take many years.
Further reading: Salmonella: From Genome to Function | Bacterial Secreted Proteins