Abstract:
:The gene products from an 8-kb region adjacent to the 3' end of the ptx operon are required by Bordetella pertussis for the export of pertussis holotoxin. At least one of these gene products (PtlC) is specifically required for the export of assembled holotoxin from the periplasmic space. ptlC mutants exhibit a 20-fold reduction in the amount of holotoxin present in the culture supernatant but have no effect upon the assembly or steady-state level of holotoxin present in the periplasmic space. Impaired export of holotoxin from the ptlC strain blocks expression of toxin at a posttranscriptional level, and wild-type levels of ptx mRNA are detected in the mutant strain. The transcription of ptl is subject to modulation by MgSO4 in the same manner as ptx is; however, in B. pertussis strains containing an E. coli tac promoter in place of the native ptx promoter, wild-type levels of ptx mRNA are present and holotoxin is synthesized and exported even in the presence of MgSO4. Promoter mapping of the region extending from the ptxS3 coding region to the ptlC coding region failed to detect the ptl transcription initiation site. Additional RNase protection experiments with ptx promoter deletion and substitution strains indicate that the ptl operon is transcribed from the ptx promoter as part of a > 11-kb mRNA.
journal_name
Infect Immunjournal_title
Infection and immunityauthors
Baker SM,Masi A,Liu DF,Novitsky BK,Deich RAdoi
10.1128/IAI.63.10.3920-3926.1995subject
Has Abstractpub_date
1995-10-01 00:00:00pages
3920-6issue
10eissn
0019-9567issn
1098-5522journal_volume
63pub_type
杂志文章abstract::The 25-kb linear plasmid lp25 and one of the 28-kb linear plasmids (lp28-1) are required for experimental infection in Borrelia burgdorferi, the etiologic agent of Lyme disease. The loss of these plasmids either eliminates infectivity (lp25) or significantly increases the 50% infective dose during a 2-week infection p...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.71.8.4608-4613.2003
更新日期:2003-08-01 00:00:00
abstract::The Lyme disease spirochete, Borrelia burgdorferi, exists in a zoonotic cycle involving an arthropod tick and mammalian host. Dissemination of the organism within and between these hosts depends upon the spirochete's ability to traverse through complex tissues. Additionally, the spirochete outruns the host immune cell...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01228-12
更新日期:2013-06-01 00:00:00
abstract::The pili of Serratia marcescens US5 isolated from a patient with urinary tract infection were purified and characterized. During the aeration culture, the pili were detached from the bacteria and were precipitated by the addition of ammonium sulfate. The purification of the pili was carried out by ion-exchange chromat...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.46.2.295-300.1984
更新日期:1984-11-01 00:00:00
abstract::Encapsulated Streptococcus pneumoniae of serotypes 2, 9N, 14, 21, and 23F and an unencapsulated variant of type 2 pneumococci were efficiently phagocytosed by both aerobically and anaerobically incubated human leukocytes. In the presence of O2, the pneumococci rapidly lost their viability, whereas during anaerobiosis,...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.47.1.277-281.1985
更新日期:1985-01-01 00:00:00
abstract::Coxiella burnetii is an intracellular pathogen that replicates in a lysosome-derived vacuole. A determinant necessary for C. burnetii virulence is the Dot/Icm type IVB secretion system (T4SS). The Dot/Icm system delivers more than 100 proteins, called type IV effectors (T4Es), across the vacuolar membrane into the hos...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00758-17
更新日期:2018-03-22 00:00:00
abstract::Recurrent urinary tract infections (UTIs) are a significant clinical problem for many women; however, host susceptibility factors have not been completely defined. The mouse model of induced UTI provides an experimental environment in which to identify specific host characteristics that are important in initial bacter...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.66.6.2798-2802.1998
更新日期:1998-06-01 00:00:00
abstract::HbhA of Mycobacterium tuberculosis is a multifunctional binding protein, binding to both sulfated sugars such as heparin and to human complement component C3. HbhA may therefore interact with host molecules and/or host cells during M. tuberculosis infection and play a role in the pathogenesis of this bacterium. The pu...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.70.12.6751-6760.2002
更新日期:2002-12-01 00:00:00
abstract::Burkholderia pseudomallei is a facultative intracellular gram-negative bacterium that can survive and multiply inside macrophages. One of the mechanisms by which B. pseudomallei escapes macrophage killing is by interfering with the expression of inducible nitric oxide synthase (iNOS). However, the bacterial components...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00285-07
更新日期:2007-09-01 00:00:00
abstract::Pseudomonas aeruginosa utilizes a number of distinct pathways to secrete proteins that play various roles during infection. These include the type II secretion system, which is responsible for the secretion of the majority of exoproducts into the surrounding environment, including toxins and degradative enzymes. In co...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.73.3.1695-1705.2005
更新日期:2005-03-01 00:00:00
abstract::The diphtheria toxin repressor (DtxR) is an iron-dependent regulator of diphtheria toxin production and iron uptake in Corynebacterium diphtheriae. It is activated in vitro by divalent metal ions including Fe2+, Cd2+, Co2+, Mn2+, Ni2+, and Zn2+. We characterized 20 different mutations in dtxR induced by bisulfite muta...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.5.1600-1608.1994
更新日期:1994-05-01 00:00:00
abstract::The objective of this study was to identify disease-related changes in lymphocyte populations within ileal mucosae of calves with cryptosporidiosis. Groups of five neonatal calves were orally infected at 3 days of age with 10(8) oocysts and maintained in enteric-pathogen-free conditions until clinical disease was esta...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.65.1.185-190.1997
更新日期:1997-01-01 00:00:00
abstract::The human pathogen enterohemorrhagic Escherichia coli (EHEC) O157:H7 has two histidine sensor kinases, QseC and QseE, which respond to the mammalian adrenergic hormones epinephrine and norepinephrine by increasing their autophosphorylation. Although QseC and QseE are present in nonpathogenic strains of E. coli, EHEC e...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.05921-11
更新日期:2012-02-01 00:00:00
abstract::C57BL/6 mice infected with Leishmania mexicana showed depression of the in vitro immunoglobulin M-plaque-forming cell response to sheep erythrocytes. Immunodepression was present 3 weeks after inoculation and was maximal at 11 weeks. Thereafter, there was a gradual return to normal immunoresponsiveness correlated with...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.32.2.415-419.1981
更新日期:1981-05-01 00:00:00
abstract::Monoclonal antibodies against 12 of the 17 IATS serotype strains of Pseudomonas aeruginosa were produced. Eighty-seven hybridoma clones were isolated, and the antibodies secreted were found to be reactive with both Formalin-fixed whole cells and purified lipopolysaccharide of homologous strains in enzyme-linked immuno...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.55.5.1051-1057.1987
更新日期:1987-05-01 00:00:00
abstract::Campylobacter jejuni is a microaerobic bacterium that produces an acute, self-limiting, watery or bloody diarrhea in humans. Little is known about how C. jejuni causes disease or even what specific capabilities it requires for survival in vivo. The enzyme, superoxide dismutase (SOD), which catalyzes the breakdown of s...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.7.2687-2694.1994
更新日期:1994-07-01 00:00:00
abstract::The role of receptor binding in the toxicity, immunogenicity, and adjuvanticity of the heat-labile enterotoxin of Escherichia coli (LT) was examined by comparing native LT and LT(G33D), a B-subunit receptor binding mutant, with respect to the ability to bind to galactose and to GM1, toxicity on mouse Y-1 adrenal tumor...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.65.12.4943-4950.1997
更新日期:1997-12-01 00:00:00
abstract::A receptor specific for lipoglycans from Acholeplasma axanthum and Acholeplasma granularum was isolated from sheep erythrocyte stroma by extraction with n-pentanol and permeation chromatography. The purified receptor appeared as one band on sodium dodecyl sulfate-polyacrylamide gels and stained with Coomassie blue, pe...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.38.3.1078-1087.1982
更新日期:1982-12-01 00:00:00
abstract::Salmonella enterica serovar Paratyphi A O-specific polysaccharide (O-SP) was activated with 1-cyano-4-dimethylaminopyridinium tetrafluoroborate (CDAP) and bound to tetanus toxoid (TT) with adipic acid dihydrazide as a linker (SPA-TT(1)) or directly (SPA-TT(2)). In mice, these two conjugates elicited high levels of imm...
journal_title:Infection and immunity
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1128/iai.68.3.1529-1534.2000
更新日期:2000-03-01 00:00:00
abstract::The virulence of Candida albicans in a mouse model of invasive candidiasis is dependent on the phospholipids phosphatidylserine (PS) and phosphatidylethanolamine (PE). Disruption of the PS synthase gene CHO1 (i.e., cho1Δ/Δ) eliminates PS and blocks the de novo pathway for PE biosynthesis. In addition, the cho1Δ/Δ muta...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01612-14
更新日期:2014-10-01 00:00:00
abstract::Immunity to reinfection in the genital tract of female guinea pigs with the agent of guinea pig inclusion conjunctivitis was found to be dependent upon an intact humoral immune response. Cell-mediated immunity in the absence of humoral immunity had no apparent role in resistance to challenge infection. ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.39.1.463-465.1983
更新日期:1983-01-01 00:00:00
abstract::It was shown in this work that the infectivity of metacyclic forms of Trypanosoma cruzi was affected upon interaction with the monoclonal antibody (10D8), which reacts with a carbohydrate epitope of the 35- and 50-kilodalton (kDa) surface glycoconjugates. The invasion of Vero cells by metacyclic forms of strains Tulah...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.57.6.1663-1667.1989
更新日期:1989-06-01 00:00:00
abstract::The in vivo behavior of revertants of Staphylococcus aureus L-phase variants were studied in mice. The Giorgio strain of S. aureus was induced into L-phase variants by methicillin. After 13 serial passages in methicillin agar and six passages in antibiotic-free agar, reversion occurred. Six revertants, all phage untyp...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.11.6.1182-1186.1975
更新日期:1975-06-01 00:00:00
abstract::The mechanisms of immunity to salmonellae conferred by immunization with live vaccines were studied by adoptive transfer using the mouse-virulent strain Salmonella typhimurium C5 and innately susceptible BALB/c (ltys) mice. This organism cannot establish a sublethal infection in naive BALB/c mice. Animals immunized 2 ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.61.9.3981-3984.1993
更新日期:1993-09-01 00:00:00
abstract::While investigating the requirement for phagosomal alkalinization in the host defense against pulmonary aspergillosis, we observed high morbidity of p47(phox)(-/-) mice infected with pH-insensitive Aspergillus nidulans mutants despite a paucity of fungal growth. Fatal infection also resulted from a normally avirulent ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.73.8.5204-5207.2005
更新日期:2005-08-01 00:00:00
abstract::Two virulence factors of Listeria monocytogenes, listeriolysin O (LLO) and phosphatidylinositol-specific phospholipase C (PI-PLC), mediate escape of this pathogen from the phagocytic vacuole of macrophages, thereby allowing the bacterium access to the host cell cytosol for growth and spread to neighboring cells. We ch...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.73.10.6639-6646.2005
更新日期:2005-10-01 00:00:00
abstract::To determine whether lipopolysaccharide (LPS) structures of Campylobacter species are immunologically related to those of 11 other gram-negative organisms, we immunoblotted from polyacrylamide gels the LPS of these strains with immune rabbit serum raised against six Campylobacter jejuni strains and two Campylobacter f...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.51.1.204-208.1986
更新日期:1986-01-01 00:00:00
abstract::Mycobacterium marinum grows at an optimal temperature of 33 degrees C, far lower than that for M. tuberculosis. Consequently, M. marinum infection of mammals is restricted largely to the cooler surfaces of the body, such as the extremities, but it causes a systemic infection in a large number of poikilothermic animals...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.65.2.767-773.1997
更新日期:1997-02-01 00:00:00
abstract::Tuberculous pleurisy allows the study of human cells at the site of active Mycobacterium tuberculosis infection. In this study, we found that among pleural fluid (PF) lymphocytes, natural killer (NK) cells are a major source of early gamma interferon (IFN-gamma) upon M. tuberculosis stimulation, leading us to investig...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00381-07
更新日期:2007-11-01 00:00:00
abstract::Enteropathogenic strains of Yersinia enterocolitica harbor a virulence plasmid (70 kilobases) which specifies, at 37 degrees C, a calcium requirement for growth, autoagglutinability, resistance to the bactericidal activity of human serum, and the expression of some outer membrane proteins (OMPs). To map the genes enco...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.48.3.782-786.1985
更新日期:1985-06-01 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