Abstract:
:Strains of Bacteroides fragilis that produce a ca. 20-kDa heat-labile protein toxin (termed B. fragilis toxin [BFT]) have been associated with diarrheal disease of animals and humans. BFT alters the morphology of intestinal epithelial cells both in vitro and in vivo and stimulates secretion in ligated intestinal segments of rats, rabbits, and lambs. Previous genetic and biochemical data indicated that BFT was a metalloprotease which hydrolyzed G (monomeric) actin, gelatin, and azocoll in vitro. In this paper, the cloning and sequencing of the entire B. fragilis toxin gene (bft) from enterotoxigenic B. fragilis (ETBF) 86-5443-2-2 is reported. The bft gene from this ETBF strain consists of one open reading frame of 1,191 nucleotides encoding a predicted 397-residue holotoxin with a calculated molecular weight of 44,493. Comparison of the predicted BFT protein sequence with the N-terminal amino acid sequence of purified BFT indicates that BFT is most probably synthesized by ETBF strains as a preproprotein. These data predict that BFT is processed to yield a biologically active toxin of 186 residues with a molecular mass of 20.7 kDa which is secreted into the culture supernatant. Analysis of the holotoxin sequence predicts a 20-residue amphipathic region at the carboxy terminus of BFT. Thus, in addition to the metalloprotease activity of BFT, the prediction of an amphipathic domain suggests that oligomerization of BFT may permit membrane insertion of the toxin with creation of a transmembrane pore. Comparison of the sequences available for the bft genes from ETBF 86-5443-2-2 and VPI 13784 revealed two regions of reduced homology. Hybridization of oligonucleotide probes specific for each bft to toxigenic B.fragilis strains revealed that 51 and 49% of toxigenic strains contained the 86-5433-2-2 and VPI 13784 bft genes, respectively. No toxigenic strain hybridized with both probes. We propose that these two subtypes of bft be termed bft-1 (VPI 13784) and bft-2 (86-5433-2-2).
journal_name
Infect Immunjournal_title
Infection and immunityauthors
Franco AA,Mundy LM,Trucksis M,Wu S,Kaper JB,Sears CLdoi
10.1128/IAI.65.3.1007-1013.1997subject
Has Abstractpub_date
1997-03-01 00:00:00pages
1007-13issue
3eissn
0019-9567issn
1098-5522journal_volume
65pub_type
杂志文章abstract::In an attempt to clarify the mechanism(s) of increased susceptibility to oral infection in diabetics, we examined the levels of salivary antibacterial factors, including lysozyme, lactoperoxidase, and lactoferrin, in diabetic hamsters whose condition was induced with streptozotocin. Saliva was collected from these ham...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.48.2.389-394.1985
更新日期:1985-05-01 00:00:00
abstract::When phagocytosis of Staphylococcus aureus by human polymorphonuclear leukocytes (PMN) takes place on the surface of cultured human endothelial cells, the endothelial monolayers are damaged by lysosomal enzymes that are released by the PMN. Because PMN can phagocytose opsonized as well as unopsonized staphylococci on ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.55.6.1455-1460.1987
更新日期:1987-06-01 00:00:00
abstract::Adherence of blastoconidia to epidermal corneocytes is an early event in Candida colonization and infection of the skin. Pathogenic species adhere more avidly than nonpathogenic species, transform to hyphal growth, and invade the stratum corneum of the skin. Adherence was studied by scanning electron microscopy of exp...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.56.8.1942-1949.1988
更新日期:1988-08-01 00:00:00
abstract::Understanding the regulation of human immune responses is critical for vaccine development and treating infectious diseases. We have previously shown that simultaneous engagement of the T cell receptor (TCR) and complement regulator CD46 on human CD4(+) T cells in the presence of interleukin-2 (IL-2) induces potent se...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00513-10
更新日期:2010-12-01 00:00:00
abstract::Treatment of Rickettsia prowazekii-infected L929 cells with gamma interferon (IFN-gamma) immediately after infection altered the lipid metabolism of the host cells as determined by measurement of phospholipid hydrolysis and oleic acid incorporation into phospholipids and neutral lipids. At 48 h postinfection, there wa...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.61.8.3412-3415.1993
更新日期:1993-08-01 00:00:00
abstract::Wild-type isolates of Shigella flexneri bind the dye Congo red from solid media, thus producing red (Crb+) colonies. Mutants which fail to bind the dye produce white colonies (Crb-) and are avirulent in a variety of systems. In S. flexneri the ability to bind Congo red correlates with the ability to bind hemin and pro...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.55.6.1393-1398.1987
更新日期:1987-06-01 00:00:00
abstract::A major problem in the study of chlamydial genital infections in animal models has been the use of varied doses of chlamydiae for infection in different laboratories. It is clearly desirable to use a dose which approximates that of natural sexual infection, but that dose to date has not been determined because of the ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.71.11.6148-6154.2003
更新日期:2003-11-01 00:00:00
abstract::Porphyromonas gingivalis is reportedly capable of stimulating the expression of host cell matrix metalloproteinases (MMP), contributing to tissue destruction. However, the impact of this bacterium on specific molecules remains to be determined. In this study, we evaluate the effect of P. gingivalis on regulation of MM...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.64.12.4940-4945.1996
更新日期:1996-12-01 00:00:00
abstract::Ehrlichia chaffeensis is an obligately intracellular gram-negative bacterium and is the etiologic agent of human monocytic ehrlichiosis (HME). Although E. chaffeensis induces the generation of several cytokines and chemokines by leukocytes, E. chaffeensis lacks lipopolysaccharide and peptidoglycan. Bioinfomatic analys...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00056-08
更新日期:2008-08-01 00:00:00
abstract::The inhibition by Mycoplasma dispar of ciliary activity of organ cultures of bovine fetal trachea was found to be dependent on the presence of serum in the maintenance medium. Inhibitory activity was unaffected by catalase and no toxic substance was demonstrated in organ culture supernatant fluid. ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.10.2.405-408.1974
更新日期:1974-08-01 00:00:00
abstract::Cytotoxic T lymphocytes (CTL) against herpes simplex virus (HSV) were induced in vitro from human peripheral blood lymphocytes by stimulation with HSV antigen. CTL generated by HSV type 1 (HSV-1) antigen stimulation killed not only HSV-1-infected target cells but also HSV type 2 (HSV-2)-infected target cells, though a...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.40.1.190-197.1983
更新日期:1983-04-01 00:00:00
abstract::Helicobacter pylori mutants deficient in 6-phosphogluconate dehydratase (6PGD) were constructed. Colonization densities were lower and minimum infectious doses were higher for mutant strains than for wild-type strains. In spite of better colonization, however, wild-type strains did not displace the mutant in cocoloniz...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.71.5.2920-2923.2003
更新日期:2003-05-01 00:00:00
abstract::We investigated the effects of peripheral blood mononuclear cells expanded with irrelevant control and mycobacterial antigens on the intracellular growth of Mycobacterium bovis bacillus Calmette-Guérin (BCG) in human macrophages. More than 90% of the cells present after 1 week of in vitro expansion were CD3(+). T cell...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.71.4.1763-1773.2003
更新日期:2003-04-01 00:00:00
abstract::Four glycoproteins of Treponema pallidum were identified by intrinsic [14C]glucosamine labeling. Only two glycoproteins were demonstrated in T. phagedenis biotype Reiter with the same technique. Glycoproteins of both treponemes were characterized as antigens and shown to be localized within the outer membranes of the ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.46.3.867-869.1984
更新日期:1984-12-01 00:00:00
abstract::Cytomegalovirus (CMV) infections are common in renal transplant recipients. We studied 23 recipients prospectively to determine whether infections by other herpes-group and non-herpes-group viruses were also present. Sera, obtained at the time of surgery and periodically thereafter, were tested for antibody to CMV, he...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.14.4.970-975.1976
更新日期:1976-10-01 00:00:00
abstract::The mechanism of activation of intestinal guanylate cyclase by Escherichia coli heat-stable enterotoxin (STa) has been studied by using isolated rat intestinal epithelial cells and purified brush border membrane (BBM) preparations. Inhibitors of prostaglandin biosynthesis, quinacrine and 5,8,11,14-eicosatetraynoic aci...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.44.2.493-501.1984
更新日期:1984-05-01 00:00:00
abstract::Phagocytosis and mechanisms of killing of Aspergillus fumigatus conidia by murine alveolar macrophages (AM), which are the main phagocytic cells of the innate immunity of the lung, were investigated. Engulfment of conidia by murine AM lasts 2 h. Killing of A. fumigatus conidia by AM begins after 6 h of phagocytosis. S...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.71.6.3034-3042.2003
更新日期:2003-06-01 00:00:00
abstract::Toxin B from Clostridium difficile is cytopathic in vitro for various types of cells, including polymorphonuclear cells, lymphocytes, and monocytes. Since intestine lamina propria is rich in macrophages, we studied the effect of toxin B on human monocytes and on human macrophages generated in vitro by long-term cultur...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.61.3.1082-1090.1993
更新日期:1993-03-01 00:00:00
abstract::Biological properties of two strains of simian virus 40 (SV40) from brains of two patients with progressive multifocal leukoencephalopathy (PML) have been compared to those of a standard laboratory strain of SV40. Infectivity of both SV40-PML viruses was resistant to treatment with chloroform, low pH, and 50 C for 120...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.10.1.173-179.1974
更新日期:1974-07-01 00:00:00
abstract::Hookworm glutathione S-transferases (GSTs) are critical for parasite blood feeding and survival and represent potential targets for vaccination. Three cDNAs, each encoding a full-length GST protein from the human hookworm Necator americanus (and designated Na-GST-1, Na-GST-2, and Na-GST-3, respectively) were isolated ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00848-09
更新日期:2010-04-01 00:00:00
abstract::A 46-kDa hemolytic protein, referred to as cystalysin, from Treponema denticola ATCC 35404 was overexpressed in Escherichia coli LC-67. Both the native and recombinant 46-kDa proteins were purified to homogeneity. Both proteins expressed identical biological and functional characteristics. In addition to its biologica...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.65.8.3231-3238.1997
更新日期:1997-08-01 00:00:00
abstract::The effects of temperature and treatment with sodium dodecyl sulfate, Tween 20, dithiothreitol, trypsin, or guanidine on the hemagglutinating capacity of six strains of type A influenza virus (A(0)/PR8/34, A(1)/CAME/46, A(2)/J305/57, A(2)/Bethesda/63, A(2)/HK/Aichi/68, and A(2)/HK/80/68), one strain of swine virus (A/...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.5.3.324-331.1972
更新日期:1972-03-01 00:00:00
abstract::Cells infected by Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever, display unusual intracellular morphological changes characterized by dilatation of the membranes of the endoplasmic reticulum and outer nuclear envelope. These changes are consistent with those that might be expected to occur...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.56.12.3110-3115.1988
更新日期:1988-12-01 00:00:00
abstract::Severe combined immunodeficient (SCID)-beige mice inoculated with the intracellular parasite Eimeria papillata produced significantly more oocysts during primary infections than inoculated immunodeficient SCID mice. Therefore, the addition of the beige mutation, which detrimentally affects neutrophil and natural kille...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.65.8.3165-3170.1997
更新日期:1997-08-01 00:00:00
abstract::A gene, dmcA, expressing a methyl-accepting chemotaxis protein (MCP) from the oral spirochete Treponema denticola has been characterized. The gene was initially identified as an open reading frame immediately upstream from the previously characterized prtB protease gene of strain ATCC 35405. Nucleotide sequencing of t...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.65.10.4011-4016.1997
更新日期:1997-10-01 00:00:00
abstract::Streptococcus pneumoniae infection leads to multifold increases in sialyltransferase, galactosyltransferase, alpha 2-fucosyltransferase, and alpha 3-fucosyltransferase activity of rat liver. Such changes may reflect an increased demand for glycosylation of acute-phase proteins synthesized and secreted by the liver dur...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.29.1.114-118.1980
更新日期:1980-07-01 00:00:00
abstract::Growth in colonies with type 1 morphology and the presence of pili are characteristics that have been associated with virulence of gonococci for humans. To determine whether the presence of pili per se might be responsible for colony type 1 morphology, the relationship of pili to colony type was examined in various sp...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.15.2.594-600.1977
更新日期:1977-02-01 00:00:00
abstract::Staphylococcal alpha-toxin was purified from Staphylococcus aureus growth medium using adsorption chromatography on controlled pore glass beads. Elution of alpha-toxin from the unmodified glass surface of the beads with various anions generally followed the chaotropic series. Alpha-toxin, purified by glass bead chroma...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.13.3.982-986.1976
更新日期:1976-03-01 00:00:00
abstract::Vero cytotoxin-producing Escherichia coli (VTEC) strains have been associated with sporadic cases and outbreaks of hemorrhagic colitis and with the hemolytic uremic syndrome in humans. Since adherence of enteric pathogens to epithelial surfaces is often a prerequisite for the subsequent delivery of bacterial enterotox...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.56.4.756-761.1988
更新日期:1988-04-01 00:00:00
abstract::Mice injected intravenously with a commercially available extract of Coxiella burnetii prepared for use as the antigen in the complement fixation diagnostic test for Q fever were subsequently resistant to infection with Babesia microti, Babesia rodhaini, and Plasmodium vinckei petteri. The parasites appeared to die in...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.24.2.319-325.1979
更新日期:1979-05-01 00:00:00