pathogenesis
Research Article | SpotlightEnvelope Stress and Regulation of the Salmonella Pathogenicity Island 1 Type III Secretion SystemSalmonella causes worldwide foodborne illness, leading to massive disease burden and an estimated 600,000 deaths per year. Salmonella infects orally and invades intestinal epithelial cells using a type 3 secretion system that directly injects effector proteins into host cells. This first step in invasion is tightly regulated by a variety of inputs. In this work, we demonstrate that Salmonella senses the...
Research ArticleInvolvement of Chromosomally Encoded Homologs of the RRNPP Protein Family in Enterococcus faecalis Biofilm Formation and Urinary Tract Infection PathogenesisEnterococcus faecalis causes health care-associated infections and displays resistance to a variety of broad-spectrum antibiotics by acquisition of resistance traits as well as the ability to form biofilms. Even though a growing number of factors related to biofilm formation have been identified, mechanisms that contribute to biofilm formation are still largely...
Research Article | SpotlightIdentification of a Cytopathogenic Toxin from Sneathia amniiSneathia amnii is a very poorly characterized emerging pathogen that can affect pregnancy outcome and cause urethritis and other infections. To date, nothing is known about its virulence factors or pathogenesis. We have identified and isolated a cytotoxin, named CptA for cytopathogenic toxin, component A, that is produced by S. amnii. CptA is capable of...
Research Article | SpotlightFrancisella novicida CRISPR-Cas Systems Can Functionally Complement Each Other in DNA Defense while Providing Target FlexibilityCRISPR-Cas9 and CRISPR-Cas12a systems have been widely commandeered for genome engineering. However, they originate in prokaryotes, where they function as adaptive immune systems. The details of this activity and relationship between these systems within native host organisms have been minimally explored. The human pathogen Francisella novicida contains both of these...
Research ArticleHilD, HilC, and RtsA Form Homodimers and Heterodimers To Regulate Expression of the Salmonella Pathogenicity Island I Type III Secretion SystemThe SPI1 type three secretion system is a key virulence factor required for Salmonella to both cause gastroenteritis and initiate serious systemic disease. The system responds to numerous environmental signals in the intestine, integrating this information via a complex regulatory network. Here, we show that the primary regulatory proteins in the network function as both homodimers and heterodimers, providing information...
MinireviewTyrosine Phosphorylation as a Widespread Regulatory Mechanism in ProkaryotesPhosphorylation events modify bacterial and archaeal proteomes, imparting cells with rapid and reversible responses to specific environmental stimuli or niches. Phosphorylated proteins are generally modified at one or more serine, threonine, or tyrosine residues. Within the last ten years, increasing numbers of global phosphoproteomic surveys of prokaryote species have revealed an abundance of tyrosine-phosphorylated proteins.
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Meeting Review25th Annual Midwest Microbial Pathogenesis ConferenceThe 25th annual Midwest Microbial Pathogenesis Conference (MMPC) was held at the University of Iowa from 28 to 30 September 2018. The conference has a long-standing tradition of providing scientists from the Midwest with a forum to present and discuss cutting-edge advances in microbial pathogenesis with particular focus on bacterial interactions with the environment, host, and other microbes.
Research ArticleRickettsia Lipid A Biosynthesis Utilizes the Late Acyltransferase LpxJ for Secondary Fatty Acid AdditionLipopolysaccharide (LPS) triggers an inflammatory response through the TLR4-MD2 receptor complex and inflammatory caspases, a process mediated by the lipid A moiety of LPS. Species of Rickettsia directly engage both extracellular and intracellular immunosurveillance, yet little is known about rickettsial lipid A. Here, we demonstrate that the alternative lipid A...
MinireviewAfter the Fact(or): Posttranscriptional Gene Regulation in Enterohemorrhagic Escherichia coli O157:H7To adapt to ever-changing environments, pathogens quickly alter gene expression. This can occur through transcriptional, posttranscriptional, or posttranslational regulation.
- MinireviewReduce, Induce, Thrive: Bacterial Redox Sensing during Pathogenesis
The abundance of oxidants and reductants must be balanced for an organism to thrive. Bacteria have evolved methods to prevent redox imbalances and to mitigate their deleterious consequences through the expression of detoxification enzymes, antioxidants, and systems to repair or degrade damaged proteins and DNA.