virulence
Molecular PathogenesisDiscovery and Contribution of Nontypeable Haemophilus influenzae NTHI1441 to Human Respiratory Epithelial Cell InvasionNontypeable Haemophilus influenzae (NTHi) is the primary cause of bacterially induced acute exacerbations of chronic obstructive pulmonary disease (COPD). NTHi adheres to and invades host respiratory epithelial cells as a means to persist in the lower airways of adults with COPD. Therefore, we mined the genomes of NTHi strains isolated from the airways of adults with...
Bacterial InfectionsPotential Mechanisms of Mucin-Enhanced Acinetobacter baumannii Virulence in the Mouse Model of Intraperitoneal InfectionPorcine mucin has been commonly used to enhance the infectivity of bacterial pathogens, including Acinetobacter baumannii, in animal models, but the mechanisms for enhancement by mucin remain relatively unknown. In this study, using the mouse model of intraperitoneal (i.p.) mucin-enhanced A. baumannii...
Host Response and InflammationStaphylococcus aureus Lipoic Acid Synthesis Limits Macrophage Reactive Oxygen and Nitrogen Species Production To Promote Survival during InfectionMacrophages are critical mediators of innate immunity and must be overcome for bacterial pathogens to cause disease. The Gram-positive bacterium Staphylococcus aureus produces virulence factors that impede macrophages and other immune cells. We previously determined that production of the metabolic cofactor lipoic acid by the lipoic acid synthetase, LipA, blunts...
Molecular PathogenesisPeptidyl-Prolyl Isomerase ppiB Is Essential for Proteome Homeostasis and Virulence in Burkholderia pseudomalleiBurkholderia pseudomallei is the causative agent of melioidosis, a disease endemic to Southeast Asia and northern Australia. Mortality rates in these areas are high even with antimicrobial treatment, and there are few options for effective therapy. Therefore, there is a need to identify antibacterial targets for the development of novel treatments. Cyclophilins are a...
Bacterial InfectionsLink between Heterotrophic Carbon Fixation and Virulence in the Porcine Lung Pathogen Actinobacillus pleuropneumoniaeActinobacillus pleuropneumoniae is a capnophilic pathogen of the porcine respiratory tract lacking enzymes of the oxidative branch of the tricarboxylic acid (TCA) cycle. We previously claimed that A. pleuropneumoniae instead uses the reductive branch in order to generate energy and metabolites. Here...
Bacterial InfectionsNew Perspectives on Galleria mellonella Larvae as a Host Model Using Riemerella anatipestifer as a Proof of ConceptGalleria mellonella larvae have been used as a host model to study interactions between pathogens and hosts for several years. However, whether the model is useful to interrogate Riemerella anatipestifer infection biology remained unknown. This study aimed to exploit the potential of...
Molecular PathogenesisThe Second Messenger c-di-AMP Regulates Diverse Cellular Pathways Involved in Stress Response, Biofilm Formation, Cell Wall Homeostasis, SpeB Expression, and Virulence in Streptococcus pyogenesCyclic di-AMP (c-di-AMP) is a recently discovered second messenger in bacteria. The cellular level of c-di-AMP in Streptococcus pyogenes is predicted to be controlled by the synthase DacA and two putative phosphodiesterases, GdpP and Pde2.
Molecular Pathogenesis | SpotlightControl of Staphylococcus aureus Quorum Sensing by a Membrane-Embedded Peptidase...Gram-positive bacteria process and release small peptides, or pheromones, that act as signals for the induction of adaptive traits, including those involved in pathogenesis. One class of small signaling pheromones is the cyclic autoinducing peptides (AIPs), which regulate expression of genes that orchestrate virulence and persistence in a range of microbes, including staphylococci, listeriae, clostridia, and enterococci.
Fungal and Parasitic Infections | SpotlightThe Mouse Inhalation Model of Cryptococcus neoformans Infection Recapitulates Strain Virulence in Humans and Shows that Closely Related Strains Can Possess Differential VirulenceCryptococcal meningitis (CM) causes high rates of HIV-related mortality, yet the Cryptococcus factors influencing patient outcome are not well understood. Pathogen-specific traits, such as the strain genotype and degree of antigen shedding, are associated with the clinical outcome, but the underlying biology remains elusive.
Molecular PathogenesisStructural and Functional Insights into PpgL, a Metal-Independent β-Propeller Gluconolactonase That Contributes to Pseudomonas aeruginosa VirulenceBiofilm formation is a critical determinant in the pathopoiesis of Pseudomonas aeruginosa. It could significantly increase bacterial resistance to drugs and host defense.