biofilm
Molecular PathogenesisRoles of OmpX, an Outer Membrane Protein, on Virulence and Flagellar Expression in Uropathogenic Escherichia coliUropathogenic Escherichia coli (UPEC) is a major pathogen that causes urinary tract infection (UTI). This bacterium adheres to and internalizes within urinary tract cells, where it aggregates and subsequently forms biofilm-like multicellular colonies that protect UPEC from antimicrobial agents and the host’s immune system.
Molecular PathogenesisThe Role of luxS in Histophilus somni Virulence and Biofilm FormationS-Ribosylhomocysteinase (LuxS) is required for the synthesis of the autoinducer-2 (AI-2) quorum-sensing signaling molecule in many Gram-negative bacteria. The bovine (and ovine) opportunistic pathogen Histophilus somni contains luxS and forms a biofilm containing an exopolysaccharide (EPS) in the matrix. Since biofilm formation is regulated by quorum...
Cellular Microbiology: Pathogen-Host Cell Molecular InteractionsThe Extracellular Polysaccharide Matrix of Pseudomonas aeruginosa Biofilms Is a Determinant of Polymorphonuclear Leukocyte ResponsesBacterial biofilms may cause chronic infections due to their ability to evade clearance by the immune system and antibiotics. The persistent biofilms induce a hyperinflammatory state that damages the surrounding host tissue. Knowledge about the components of biofilms that are responsible for provoking the harmful but inefficient immune response is limited. Flagella are known to stimulate the response of polymorphonuclear leukocytes (...
Bacterial InfectionsClarithromycin Exerts an Antibiofilm Effect against Salmonella enterica Serovar Typhimurium rdar Biofilm Formation and Transforms the Physiology towards an Apparent Oxygen-Depleted Energy and Carbon MetabolismUpon biofilm formation, production of extracellular matrix components and alteration in physiology and metabolism allows bacteria to build up multicellular communities which can facilitate nutrient acquisition during unfavorable conditions and provide protection toward various forms of environmental stresses to individual cells. Thus, bacterial cells within biofilms become tolerant against antimicrobials and the immune system. In the...
Cellular Microbiology: Pathogen-Host Cell Molecular InteractionsCigarette Smoke Exposure Promotes Virulence of Pseudomonas aeruginosa and Induces Resistance to Neutrophil KillingIt is widely known that cigarette smoke damages host defenses and increases susceptibility to bacterial infections. Pseudomonas aeruginosa, a Gram-negative bacterium that commonly colonizes the airways of smokers and patients with chronic lung disease, can cause pneumonia and sepsis and can trigger exacerbations of lung diseases....
Minireview | SpotlightThe Great ESKAPE: Exploring the Crossroads of Bile and Antibiotic Resistance in Bacterial PathogensThroughout the course of infection, many pathogens encounter bactericidal conditions that threaten the viability of the bacteria and impede the establishment of infection. Bile is one of the most innately bactericidal compounds present in humans, functioning to reduce the bacterial burden in the gastrointestinal tract while also aiding in digestion. It is becoming increasingly apparent that pathogens successfully resist the bactericidal...
MinireviewBacterial Defense Systems against the Neutrophilic Oxidant Hypochlorous AcidNeutrophils kill invading microbes and therefore represent the first line of defense of the innate immune response. Activated neutrophils assemble NADPH oxidase to convert substantial amounts of molecular oxygen into superoxide, which, after dismutation into peroxide, serves as the substrate for the generation of the potent antimicrobial hypochlorous acid (HOCl) in the phagosomal space. In this minireview, we explore the most recent...
Bacterial InfectionsA CpxR-Regulated zapD Gene Involved in Biofilm Formation of Uropathogenic Proteus mirabilisProteus mirabilis, a frequent uropathogen, forms extensive biofilms on catheters that are infamously difficult to treat. To explore the mechanisms of biofilm formation by P. mirabilis, we performed in vivo transposon mutagenesis. A mutant with impaired biofilm formation was isolated. The...
Bacterial InfectionsStaphylococcus aureus Fibronectin Binding Protein A Mediates Biofilm Development and InfectionImplanted medical device-associated infections pose significant health risks, as they are often the result of bacterial biofilm formation. Staphylococcus aureus is a leading cause of biofilm-associated infections which persist due to mechanisms of device surface adhesion, biofilm accumulation, and reprogramming of host innate immune responses. We found that the...
Host-Associated Microbial CommunitiesCooperativity between Stenotrophomonas maltophilia and Pseudomonas aeruginosa during Polymicrobial Airway InfectionsStenotrophomonas maltophilia is a Gram-negative bacterium found ubiquitously in the environment that has historically been regarded as nonpathogenic. S. maltophilia is increasingly observed in patient sputa in cystic fibrosis (CF), and while existing epidemiology indicates that patients with...