Abstract:
:Burkholderia cenocepacia, a member of the B. cepacia complex, is an opportunistic pathogen that causes serious infections in patients with cystic fibrosis. We identified a six-gene cluster in chromosome 1 encoding a two-component regulatory system (BCAL2831 and BCAL2830) and an HtrA protease (BCAL2829) hypothesized to play a role in the B. cenocepacia stress response. Reverse transcriptase PCR analysis of these six genes confirmed they are cotranscribed and comprise an operon. Genes in this operon, including htrA, were insertionally inactivated by recombination with a newly created suicide plasmid, pGPOmegaTp. Genetic analyses and complementation studies revealed that HtrA(BCAL2829) was required for growth of B. cenocepacia upon exposure to osmotic stress (NaCl or KCl) and thermal stress (44 degrees C). In addition, replacement of the serine residue in the active site with alanine (S245A) and deletion of the HtrA(BCAL2829) PDZ domains demonstrated that these areas are required for protein function. HtrA(BCAL2829) also localizes to the periplasmic compartment, as shown by Western blot analysis and a colicin V reporter assay. Using the rat agar bead model of chronic lung infection, we also demonstrated that inactivation of the htrA gene is associated with a bacterial survival defect in vivo. Together, our data demonstrate that HtrA(BCAL2829) is a virulence factor in B. cenocepacia.
journal_name
Infect Immunjournal_title
Infection and immunityauthors
Flannagan RS,Aubert D,Kooi C,Sokol PA,Valvano MAdoi
10.1128/IAI.01581-06subject
Has Abstractpub_date
2007-04-01 00:00:00pages
1679-89issue
4eissn
0019-9567issn
1098-5522pii
IAI.01581-06journal_volume
75pub_type
杂志文章abstract::Actinomyces naeslundii and Streptococcus gordonii, oral bacteria that possess Gal/GalNAc- and sialic acid-reactive lectins, respectively, were adherent to immobilized secretory immunoglobulin A (IgA) and two IgA1 myeloma proteins but not to two IgA2 myeloma proteins. Apparently, O-linked oligosaccharides at the hinge ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.64.12.5421-5424.1996
更新日期:1996-12-01 00:00:00
abstract::We report the cloning and expression of Ac-GST-1, a novel glutathione S-transferase from the adult hookworm Ancylostoma caninum, and its possible role in parasite blood feeding and as a vaccine target. The predicted Ac-GST-1 open reading frame contains 207 amino acids (mass, 24 kDa) and exhibited up to 65% amino acid ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.73.10.6903-6911.2005
更新日期:2005-10-01 00:00:00
abstract::CD14, the leukocyte receptor for lipopolysaccharide (LPS), is important in the response of human polymorphonuclear leukocytes (PMNs) to infection with gram-negative bacteria. The level of CD14 on the PMN surface increases after exposure to some inflammatory stimuli such as N-formyl-methionyl-leucyl-phenylalanine (fMLP...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.65.11.4747-4753.1997
更新日期:1997-11-01 00:00:00
abstract::An experimental model of "chronic" diphtheria intoxication in the guinea pig was developed. Adult guinea pigs, subjected to a regimen of multiple sublethal doses of purified diphtheria toxin (total of 1.4 minimum lethal doses divided equally in four daily doses), developed a toxemia which terminated in death between 6...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.7.4.556-560.1973
更新日期:1973-04-01 00:00:00
abstract::The roles of different ribonucleotide reductases (RNRs) in bacterial pathogenesis have not been studied systematically. In this work we analyzed the importance of the different Pseudomonas aeruginosa RNRs in pathogenesis using the Drosophila melanogaster host-pathogen interaction model. P. aeruginosa codes for three d...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01212-10
更新日期:2011-07-01 00:00:00
abstract::The effects of 1,25-dihydroxy vitamin D3 and gamma interferon on the phenotypic changes associated with monocyte maturation in vitro were investigated. Human monocytes separated from peripheral blood mononuclear cell populations by adherence to plastic were cultured for 7 days on glass. Immunocytological analysis was ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.55.9.2017-2020.1987
更新日期:1987-09-01 00:00:00
abstract::Memory CD8+ T cells are essential for protective immunity against many intracellular pathogens; therefore, stimulation of this population of cells is an important goal of vaccination. We have previously shown that a detoxified derivative of Bacillus anthracis anthrax lethal toxin (LT) can deliver heterologous CD8+ T-c...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01208-07
更新日期:2008-03-01 00:00:00
abstract::The outer membrane of pathogenic Leptospira species grown in culture media contains lipopolysaccharide (LPS), a porin (OmpL1), and several lipoproteins, including LipL36 and LipL41. The purpose of this study was to characterize the expression and distribution of these outer membrane antigens during renal infection. Ha...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.67.2.853-861.1999
更新日期:1999-02-01 00:00:00
abstract::Antimicrobial fatty acids (AFAs) protect the human epidermis against invasion by pathogenic bacteria. In this study, we questioned whether human skin fatty acids (FAs) can be incorporated into the lipid moiety of lipoproteins and whether such incorporation would have an impact on innate immune stimulation in the model...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00822-15
更新日期:2015-10-26 00:00:00
abstract::The LuxS protein is required for the biosynthesis of the type 2 autoinducer (AI-2), which is involved in quorum sensing in a wide range of bacterial species. We have determined the effects of a defined luxS mutation on the virulence of Streptococcus pneumoniae. Although the luxS mutant displayed reduced virulence rela...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.71.6.3206-3212.2003
更新日期:2003-06-01 00:00:00
abstract::Bordetella bronchiseptica is closely related to Bordetella pertussis, which produces respiratory disease primarily in mammals other than humans. However, its importance as a human pathogen is being increasingly recognized. Although a large amount of research on Bordetella has been generated regarding protein virulence...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.70.4.1791-1798.2002
更新日期:2002-04-01 00:00:00
abstract::Pathogen attachment to host cells is a key process during infection, and inhibition of pathogen adhesion is a promising approach to the prevention of infectious disease. We have previously shown that multivalent adhesion molecules (MAMs) are abundant in both pathogenic and commensal bacterial species, mediate early at...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00020-16
更新日期:2016-05-24 00:00:00
abstract::Strain superinfection occurs when a second pathogen strain infects a host already carrying a primary strain. Anaplasma marginale superinfection occurs when the second strain carries a variant repertoire different from that of the primary strain, and the epidemiologic consequences depend on the relative efficiencies of...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01518-08
更新日期:2009-04-01 00:00:00
abstract::Rubella virus was capable of replicating in both unstimulated and phytohemagglutinin-stimulated cultures of human mononuclear blood cells. Monocyte-derived macrophages were the main cell type responsible for viral replication. The susceptibility of macrophages increased during cultivation. Phytohemagglutinin-stimulate...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.27.2.309-314.1980
更新日期:1980-02-01 00:00:00
abstract::Knowledge of whether Mycobacterium tuberculosis resides within a relatively impermeable membrane-bound vacuole or is free within the cytoplasm within its host cell is central to an understanding of the immunobiology of this intracellular parasite but is a matter of controversy. To explore this issue, we assessed the a...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.70.10.5800-5807.2002
更新日期:2002-10-01 00:00:00
abstract::Antimicrobial factors were analyzed in samples of whole saliva from 31 children, aged 0.8 to 3.8 years. When compared with the adult reference group, the children displayed similar levels of lysozyme, salivary peroxidase, and hypothiocyanite (OSCN-), whereas the amounts of immunoglobulins (isotypes A, G, and M), lacto...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.51.1.49-53.1986
更新日期:1986-01-01 00:00:00
abstract::Pathogenic Leptospira spp. are likely to encounter higher concentrations of reactive oxygen species induced by the host innate immune response. In this study, we characterized Leptospira interrogans catalase (KatE), the only annotated catalase found within pathogenic Leptospira species, by assessing its role in resist...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00466-12
更新日期:2012-11-01 00:00:00
abstract::The skin microenvironment at the site of infection plays a role in the early events that determine protective T helper 1/type 1 immune responses during cutaneous leishmaniasis (CL) infection. During CL in nonhealing BALB/c mice, early interleukin-4 (IL-4) can instruct dendritic cells for protective Th1 immunity. Addit...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00710-18
更新日期:2018-11-20 00:00:00
abstract::Acute lethality was induced in rabbits by the sequential injection of Propionibacterium acnes and lipopolysaccharide (LPS). P. acnes induced the infiltration of inflammatory cells into the liver lobules during the early phase, and LPS in the late phase caused death in association with pathological changes mimicking he...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.63.12.4812-4817.1995
更新日期:1995-12-01 00:00:00
abstract::The immune response of humans and mice to temperature-specific, plasmid- or chromosome-encoded proteins of yersinia pestis and Yersinia enterocolitica was investigated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting. Extracts from Y. pestis and Y. enterocolitica strains with and witho...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.48.3.676-685.1985
更新日期:1985-06-01 00:00:00
abstract::ExoU, a phospholipase injected into host cells by the type III secretion system of Pseudomonas aeruginosa, leads to rapid cytolytic cell death. Although the importance of ExoU in infection is well established, the mechanism by which this toxin kills host cells is less clear. To gain insight into how ExoU causes cell d...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.74.5.2552-2561.2006
更新日期:2006-05-01 00:00:00
abstract::In studies of immunity to malaria, the absence of febrile malaria is commonly considered evidence of "protection." However, apparent "protection" may be due to a lack of exposure to infective mosquito bites or due to immunity. We studied a cohort that was given curative antimalarials before monitoring began and docume...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01358-08
更新日期:2009-05-01 00:00:00
abstract::Staphylococcus aureus can produce a wide variety of exotoxins, including toxic shock syndrome toxin 1 (TSST-1), staphylococcal enterotoxins, and staphylococcal enterotoxin-like toxins. These toxins share superantigenic activity. To investigate the beta chain (Vbeta) specificities of each of these toxins, TSST-1 and al...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01388-08
更新日期:2009-05-01 00:00:00
abstract::We used a murine model to determine whether chronic corticosteroid therapy has uniform effects on bacterial clearance processes in different tissues. After a 2-week regimen of oral prednisolone, Swiss Webster mice were challenged with Pseudomonas aeruginosa strain PAO1 or virulent derivatives of PAO1 (IP-8 and IT-10)....
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.43.3.901-905.1984
更新日期:1984-03-01 00:00:00
abstract::Nucleotide-binding oligomerization domain (NOD) protein 1 (NOD1) and NOD2 are pathogen recognition receptors that sense breakdown products of peptidoglycan (PGN) (muropeptides). It is shown that a number of these muropeptides can induce tumor necrosis factor alpha (TNF-alpha) gene expression without significant TNF-al...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01597-06
更新日期:2007-02-01 00:00:00
abstract::A cell wall complex has been isolated by gentle methods from both the medium supernatant fluid and whole organisms of Neissieria meningitidis cultures. The two types of preparations have been shown to be essentially identical on the basis of chemical composition, electron microscopy, and polyacrylamide gel electrophor...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.6.5.835-851.1972
更新日期:1972-11-01 00:00:00
abstract::The cyst cell wall β-glucans of Pneumocystis have been shown to stimulate immune responses in lung epithelial cells, dendritic cells, and alveolar macrophages. Little is known about how the trophic life forms, which do not have a fungal cell wall, interact with these innate immune cells. Here, we report differences in...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00519-16
更新日期:2016-11-01 00:00:00
abstract::Sensitized mouse spleen cells decrease the spread of herpes simplex virus infection in cell culture lines derived from human and murine tissues. These washed, sensitized cells act alone and additively in combination with antibody to diminish the ability of single virus-infected cells to spread infection to contiguous ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.7.6.898-904.1973
更新日期:1973-06-01 00:00:00
abstract::Carbon storage regulator A (CsrA) is an RNA binding protein that has been characterized in many bacterial species to play a central regulatory role by modulating several metabolic processes. We recently showed that a homolog of CsrA in Borrelia burgdorferi (CsrA(Bb), BB0184) was upregulated in response to propagation ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00882-10
更新日期:2011-02-01 00:00:00
abstract::Clostridium perfringens type B causes enteritis and enterotoxemia in domestic animals. By definition, these bacteria must produce alpha toxin (CPA), beta toxin (CPB) and epsilon toxin (ETX) although most type B strains also produce perfringolysin O (PFO) and beta2 toxin (CPB2). A recently identified Agr-like quorum-se...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00438-12
更新日期:2012-09-01 00:00:00