Abstract:
:Actinobacillus pleuropneumoniae, the causative agent of swine pleuropneumonia, secretes a hemolytic activity which is thought to be a factor involved in the pathogenesis of the disease. The biosynthesis of hemolysin by serotype 1 strain 4074 was strongly dependent on the activity of free Ca2+ in the growth medium. At activities of free Ca2+ below 50 microM, very low hemolytic activities could be detected in the growth medium and in cell extracts. Maximal hemolytic activities of up to 400 hemolytic units per ml could be measured in growth medium containing free Ca2+ activities above 3 mM. Other bivalent cations did not stimulate the production of hemolysin. Neither the growth rate nor the secretion of hemolysin was affected by increasing Ca2+ concentrations in the medium. The hemolysin of serotype 1 did not require Ca2+ as a cofactor for the lysis of erythrocytes. Ca2+ induced the expression of a 105-kilodalton protein, which was secreted. This protein comigrated with purified hemolysin on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and exhibited hemolysin activity upon purification. Inhibition experiments with rifampin suggest that the hemolysin of A. pleuropneumoniae is regulated by Ca2+ at the transcriptional level. The threshold of hemolysin induction was around 700 microM free Ca2+, a concentration which is similar to that found in blood serum. The Ca2+-inducible hemolysin represents a novel type of positively regulated bacterial gene expression.
journal_name
Infect Immunjournal_title
Infection and immunityauthors
Frey J,Nicolet Jdoi
10.1128/IAI.56.10.2570-2575.1988subject
Has Abstractpub_date
1988-10-01 00:00:00pages
2570-5issue
10eissn
0019-9567issn
1098-5522journal_volume
56pub_type
杂志文章abstract::Host resistance to African trypanosomiasis is partially dependent on an early and strong T-independent B-cell response against the variant surface glycoprotein (VSG) coat expressed by trypanosomes. The repetitive array of surface epitopes displayed by a monotypic surface coat, in which identical VSG molecules are clos...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.73.5.2690-2697.2005
更新日期:2005-05-01 00:00:00
abstract::Leishmaniae are protozoans which, depending upon both the host and parasite species, can cause either a healing or nonhealing infection. While C57BL/10 mice are able to heal following infection with Leishmania major, they fail to heal following infection with Leishmania amazonensis. In order to address the role of Th1...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.61.7.2952-2959.1993
更新日期:1993-07-01 00:00:00
abstract::Calprotectin, an S100 calcium-binding protein with broad-spectrum antimicrobial activity in vitro, is expressed in neutrophils, monocytes, and gingival keratinocytes. In periodontitis, calprotectin appears upregulated and is detected at higher levels in gingival crevicular fluid and tissue specimens. How calprotectin ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.69.7.4242-4247.2001
更新日期:2001-07-01 00:00:00
abstract::The serum opacity factor (SOF) of Streptococcus pyogenes is a serotyping tool and pathogenesis factor. Using SOF-coated latex beads in cell adherence assays and antiserum directed against SOF in S. pyogenes-HEp-2 cell adherence inhibition experiments, we demonstrate SOF involvement in the fibronectin-mediated adherenc...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.72.7.4302-4308.2004
更新日期:2004-07-01 00:00:00
abstract::Four monoclonal antibodies (MAbs) were produced by immunizing mice with a disrupted yeast cell homogenate of Histoplasma capsulatum. MAbs 1 and 2 reacted only with the yeast cell antigens of H. capsulatum and Blastomyces dermatitidis, whereas MAbs 3 and 4 showed broader cross-reactivity. MAb 3 cross-reacted with B. de...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.57.3.896-901.1989
更新日期:1989-03-01 00:00:00
abstract::Molecular approaches to the rapid analysis of the serotyping antigens of Neisseria meningitidis, the class 2 and 3 outer membrane proteins (OMPs), were developed, evaluated, and used to study 12 antigenic variants of these proteins. A primer set for the polymerase chain reaction (PCR) amplification of the genes encodi...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.60.9.3620-3629.1992
更新日期:1992-09-01 00:00:00
abstract::The relative roles of serum factors required for opsonization of type XIV Streptococcus pneumoniae were investigated by means of luminol-enhanced chemiluminescence (CL), bactericidal, and immunofluorescence assays employing adult sera containing high (>1,000 ng of antibody nitrogen per ml) or low (<200 ng of antibody ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.35.3.800-808.1982
更新日期:1982-03-01 00:00:00
abstract::In an attempt to understand the mechanism of serum resistance in Actinobacillus pleuropneumoniae, in the present study we examined various interactions among the bacterial surface constituents, serum antibodies, and complement. Analysis of swine sera revealed the presence of anticapsular antibodies in convalescent-pha...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.60.9.3852-3860.1992
更新日期:1992-09-01 00:00:00
abstract::The urease gene of Staphylococcus saprophyticus CCM883 was cloned and expressed in Staphylococcus carnosus TM300. In vitro translation of the cloned DNA sequences revealed six polypeptides (of 70, 47, 29, 27, 20, and 17 kilodaltons) that were associated with enzyme activity. Introduction of the cloned genes into a ure...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.57.10.2998-3002.1989
更新日期:1989-10-01 00:00:00
abstract::Sonicated preparations of capsulated Haemophilus influenzae type b, two of its spontaneous mutants, one containing patches of capsules (class I variant) and the other noncapsulated (class II variant), and a noncapsulated strain of H. influenzae type d were analyzed by crossed-immunoelectrophoresis using unadsorbed ant...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.13.6.1733-1742.1976
更新日期:1976-06-01 00:00:00
abstract::Several pathogenic fungal organisms enter eukaryotic cells and manipulate the host cell environment to favor their own growth and survival. Aspergillus fumigatus is a saprophytic fungus that causes invasive lung disease in the immunocompromised host. To determine whether A. fumigatus could enter eukaryotic cells, we s...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.70.6.3156-3163.2002
更新日期:2002-06-01 00:00:00
abstract::Mosquitoes are infected with Plasmodium falciparum by taking a blood meal from a gametocyte carrier. Since a mosquito takes a volume of 1 to 2 microl, a blood meal may contain 1 x 10(4) to 3 x 10(4) leukocytes (WBC). The majority of WBC are composed of neutrophils which may phagocytose and kill developing gametes insi...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.65.9.3834-3837.1997
更新日期:1997-09-01 00:00:00
abstract::Pathogenic biofilms have been associated with persistent infections due to their high resistance to antimicrobial agents, while commensal biofilms often fortify the host's immune system. Hence, controlling biofilm formation of both pathogenic bacteria and commensal bacteria is important in bacterium-related diseases. ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.05580-11
更新日期:2011-12-01 00:00:00
abstract::The interaction between bacteria and fibronectin is believed to play an important role in the pathogenicity of clinically important Gram-positive cocci. In the present study, we identified a gene encoding a predicted fibronectin-binding protein of Enterococcus faecium (fnm), a homologue of Streptococcus pneumoniae pav...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00885-15
更新日期:2015-12-01 00:00:00
abstract::Proteolysis is a common microbial virulence mechanism that enables the destruction of host tissue and evasion from host defense mechanisms. Antimicrobial peptides, also known as host defense peptides, are effector molecules of the innate immunity that demonstrate a broad range of antimicrobial and immunoregulatory act...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00648-09
更新日期:2009-12-01 00:00:00
abstract::A veronal buffer extract of Salmonella typhi was used as the reference antigen and its corresponding rabbit antiserum as the reference antibody in crossed immunoelectrophoresis to analyze antibodies in sera obtained from typhoid patients and carriers. Four precipitating antibodies were regularly detected. Three were a...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.43.3.1110-1113.1984
更新日期:1984-03-01 00:00:00
abstract::Susceptibility to Coccidioides spp. varies widely in humans and other mammals and also among individuals within a species. Among strains of mice with various susceptibilities, immunohistopathology revealed that C57BL/6 mice were highly susceptible to the disease following intranasal infection, DBA/2n mice were interme...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00885-08
更新日期:2008-12-01 00:00:00
abstract::The outer membrane (OM) of Gram-negative bacteria is an asymmetric lipid bilayer that consists of inner leaflet phospholipids and outer leaflet lipopolysaccharides (LPS). The asymmetric character and unique biochemistry of LPS molecules contribute to the OM's ability to function as a molecular permeability barrier tha...
journal_title:Infection and immunity
pub_type: 杂志文章,评审
doi:10.1128/IAI.00920-19
更新日期:2020-06-22 00:00:00
abstract::Numerous studies have reported that asialo-GM(1), gangliotetraosylceramide, or moieties serve as epithelial cell receptors for Pseudomonas aeruginosa. Usually this interaction is confirmed with antibodies to asialo-GM(1). However, few, if any, of these reports have evaluated the binding of fresh clinical isolates of P...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.69.2.719-729.2001
更新日期:2001-02-01 00:00:00
abstract::The lipopolysaccharide (LPS)-potentiating effect of serum is due to LPS-binding protein (LBP), which facilitates the binding of LPS to CD14 receptors. We observed a remarkable heat sensitivity of recombinant LBP and various sera with respect to both immunoreactivity (measured by enzyme-linked immunosorbent assay) and ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.63.1.363-365.1995
更新日期:1995-01-01 00:00:00
abstract::Previous studies have demonstrated that the Moraxella catarrhalis surface antigen UspA1 is an adhesin for Chang human conjunctival cells. The present report demonstrates that lack of UspA1 expression does not affect the adherence of strain O35E to A549 human lung cells or primary cultures of human middle ear epithelia...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.71.9.4977-4984.2003
更新日期:2003-09-01 00:00:00
abstract::Oligosaccharide (OS)-protein conjugates are promising candidate vaccines against encapsulated bacteria, such as Haemophilus influenzae, Neisseria meningitidis, and Streptococcus pneumoniae. Although the effects of several variables such as OS chain length and protein carrier have been studied, little is known about th...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.71.12.6915-6920.2003
更新日期:2003-12-01 00:00:00
abstract::The protective immunity conferred by T-cell subsets against infection with Treponema pallidum subsp. pertenue was studied. We demonstrated that hamster T cells can be separated into two subsets by monoclonal antibody (MAb) GK 1.5 (anti-L3T4) and MAb 38. Eighty-five percent of hamster thymocytes were L3T4+ and 87% were...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.59.2.529-536.1991
更新日期:1991-02-01 00:00:00
abstract::Analyses of chemical composition in whole cells of Rickettsia tsutsugamushi were performed and compared with those of the other rickettsiae and gram-negative bacteria. The results indicated that R. tsutsugamushi does not contain detectable amounts of 3-deoxy-D-mannooctulosonic acid, heptose, muramic acid, or glucosami...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.55.9.2290-2292.1987
更新日期:1987-09-01 00:00:00
abstract::Athymic nude mice (nu/nu), heterozygous litter mates (nu/+), and thymic reconstituted homozygous animals (nu/nu TxR) were infected with Trypanosoma rhodesiense. A reduced parasitemia and prolonged survival were observed in the nu/nu animals after infection and cure or after immunization with irradiated organisms. Thes...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.20.3.714-720.1978
更新日期:1978-06-01 00:00:00
abstract::Experiments were performed to investigate the usefulness of an enzyme-linked immunosorbent assay utilizing avidin-biotin interaction as a diagnostic tool for detection of Toxoplasma antigen in blood. The lower limit of sensitivity of the assay by this method was ca. 4 ng/ml, and standard assays provided a linear plot ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.48.1.269-272.1985
更新日期:1985-04-01 00:00:00
abstract::Staphylococcal enterotoxins A through D (SEA through SED) and toxic shock syndrome toxin-1 display superantigen properties, i.e., they stimulate a great fraction of T cells expressing certain T-cell receptor V beta sequences. Using a newly established rat model of septic Staphylococcus aureus arthritis, we have recent...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.63.10.4185-4187.1995
更新日期:1995-10-01 00:00:00
abstract::Bovine digital dermatitis (BDD), an infectious disease of the bovine foot with a predominant treponemal etiology, is a leading cause of lameness in dairy and beef herds worldwide. BDD is poorly responsive to antimicrobial therapy and exhibits a relapsing clinical course; an effective vaccine is therefore urgently soug...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00050-20
更新日期:2020-04-20 00:00:00
abstract::A genomic library of meningococcal DNA from a clinical isolate of Neisseria meningitidis was constructed in the expression vector lambda gt11. Outer membrane complex was prepared from the same strain and used to immunize rabbits to raise polyclonal anti-outer membrane complex serum. The amplified library was probed wi...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.55.11.2734-2740.1987
更新日期:1987-11-01 00:00:00
abstract::The screening of several inbred strains of mice suggested that the capacity of their spleen cells to respond to the mitogenic effect of lipopolysaccharide (LPS) of gram-negative bacteria was correlated with their resistance to intraperitoneal infection with Salmonella typhimurium. An infection of LPS into mice caused ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.15.1.26-33.1977
更新日期:1977-01-01 00:00:00