Abstract:
:Optimal growth conditions have been established for production of heat-labile enterotoxin (LT) by both porcine and human strains of enterotoxigenic (ENT(+)) Escherichia coli. There were no unusual growth factor requirements, and some strains produced fairly high levels of LT in a basal salts medium containing 0.5% glucose if the pH was carefully controlled. Several amino acids markedly stimulated LT synthesis when added to the basal salts-glucose medium. Methionine and lysine were the most stimulatory for both human and porcine strains. Either aspartic acid or glutamic acid further enhanced LT synthesis in the presence of methionine and lysine, with aspartic acid being more stimulatory for porcine strains and glutamic acid more stimulatory for human strains. There were no apparent vitamin requirements and no unusual cations needed for toxin synthesis except that Fe(3+) was slightly stimulatory for porcine strains. The stimulation by Fe(3+) was observed only in the presence of the three amino acids, suggesting that the effect was indirect rather than on toxin synthesis. The carbon source also influenced the yield of LT. Glucose supported maximal synthesis, but other carbon sources which exhibit a high degree of catabolite repression also supported high levels of synthesis. Little or no LT was released below pH 7.0; therefore, because the pH drops during growth from 7.5 to 6.8, even in highly buffered media, it was necessary to adjust the pH to 8.0 to effect complete release of cell-associated toxin. The defined medium containing three amino acids reduced the amount of UV-absorbing material in culture supernatants about fivefold and increased LT activity for various strains from two- to fivefold over a complex Casamino Acids-yeast extract medium. Conditions found to be optimal for synthesis of LT were inhibitory for the heat-stable enterotoxin.
journal_name
Infect Immunjournal_title
Infection and immunityauthors
Gilligan PH,Robertson DCdoi
10.1128/IAI.23.1.99-107.1979subject
Has Abstractpub_date
1979-01-01 00:00:00pages
99-107issue
1eissn
0019-9567issn
1098-5522journal_volume
23pub_type
杂志文章abstract::A study of the rise and fall in circulating tetanus antitoxin in a group of 15 adults after basic and booster immunization indicates that although individuals vary greatly in their responsiveness to toxoid, the falloff in antitoxin appears to be fractionally constant for each individual, and over periods of 5 to 6 yea...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.10.1.1-5.1974
更新日期:1974-07-01 00:00:00
abstract::Interactions between Yersinia enterocolitica and rabbit ileal mucus were examined. Strains carrying the Yersinia virulence plasmid, pYV, adhered to crude mucus but not to intestinal luminal contents that had been immobilized on polystyrene. Using an Y. enterocolitica O:9 mutant in which the yadA gene (formerly called ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.59.1.253-260.1991
更新日期:1991-01-01 00:00:00
abstract::Pathogenicity islands (PAIs) are chromosomal clusters of pathogen-specific virulence genes often found at tRNA loci. In the Yersinia pseudotuberculosis 32777 chromosome, we characterized a 98-kb segment that has all of the characteristic features of a PAI, including insertion in a (phenylalanine) tRNA gene, the presen...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.72.8.4784-4790.2004
更新日期:2004-08-01 00:00:00
abstract::Brucella spp. are intracellular bacteria that cause the most frequent zoonosis in the world. Although recent work has advanced the field of Brucella vaccine development, there remains no safe human vaccine. In order to produce a safe and effective human vaccine, the immune response to Brucella spp. requires greater un...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00994-09
更新日期:2010-01-01 00:00:00
abstract::Virulent and avirulent clones of Leishmania donovani promastigotes were examined for their acid phosphatase activity. The acid phosphatase activity of whole-cell lysates of virulent clones was 1.5 to 2.0 times higher than that of avirulent clones. Pellet fractions (260,000 x g, 30 min) from sonicated promastigotes of ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.56.11.2856-2860.1988
更新日期:1988-11-01 00:00:00
abstract::The structural gene of pneumolysin was randomly mutagenized. A screen, developed to identify mutants with reduced hemolytic activity, identified substitutions within the cysteine-containing region and also at residues toward the N terminus of the toxin. These are the first reported changes within the N-terminal region...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.2.757-758.1994
更新日期:1994-02-01 00:00:00
abstract::Live attenuated bacteria hold great promise as multivalent mucosal vaccines against a variety of pathogens. A major challenge of this approach has been the successful delivery of sufficient amounts of vaccine antigens to adequately prime the immune system without overattenuating the live vaccine. Here we used a live a...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.02443-14
更新日期:2015-01-01 00:00:00
abstract::Representative isolates of nonmucoid Pseudomonas aeruginosa were studied to investigate the hypothesis that mucinophilic and chemotactic properties in this species act as potential factors in the initial stages of pulmonary colonization in patients with cystic fibrosis (CF). Transmission electron microscopy with a sur...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.58.6.1489-1495.1990
更新日期:1990-06-01 00:00:00
abstract::Antigen-specific T-cell responses and histopathological changes were studied in mice experimentally inoculated with Borrelia burgdorferi B31. Inbred mice with different H-2 haplotypes and/or different genetic backgrounds were inoculated with B. burgdorferi organisms and tested for antigen-specific T-cell responses in ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.57.1.41-47.1989
更新日期:1989-01-01 00:00:00
abstract::We recently determined that passive transfer of serum directed against a synthetic peptide called LB1 or a recombinant fusion protein immunogen [LPD-LB1(f)(2,1,3)] could prevent otitis media after challenge with a homologous nontypeable Haemophilus influenzae (NTHI) isolate. NTHI residing in the nasopharynx was rapidl...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.68.5.2756-2765.2000
更新日期:2000-05-01 00:00:00
abstract::A system is described for studying adoptive immunity to tuberculosis in syngeneic mice. Donor mice were immunized with 10(4) BCG intravenously, and lymphoid cells were harvested 28 days later. Adoptive immunity was measured in recipient mice in terms of the inhibition of growth of BCG in the liver and spleen following...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.11.6.1174-1181.1975
更新日期:1975-06-01 00:00:00
abstract::The effect of the secondary infection with Toxoplasma gondii on antibody responses to unrelated antigens was examined in mice. A reinfection with 5 X 10(3) organisms did not affect either primary anti-sheep erythrocyte antibody responses, or anti-dinitrophenol antibody responses to dinitrophenylated keyhole limpet hem...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.48.3.686-689.1985
更新日期:1985-06-01 00:00:00
abstract::We previously showed the requirement of both T cells and gamma interferon (IFN-gamma)-producing non-T cells for the genetic resistance of BALB/c mice to the development of toxoplasmic encephalitis (TE). In order to define the role of IFN-gamma production and the perforin-mediated cytotoxicity of T cells in this resist...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.72.8.4432-4438.2004
更新日期:2004-08-01 00:00:00
abstract::Pseudomonas aeruginosa is a gram-negative bacillus that is a major cause of morbidity and mortality in immunosuppressed patients, burn patients, and patients with cystic fibrosis. Although immunity to these bacteria has been associated with serum antibody, more recent evidence suggests that T-cell-mediated immunity ma...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.40.2.670-674.1983
更新日期:1983-05-01 00:00:00
abstract::In the mouse model of Lyme borreliosis, the host immune response during infection with Borrelia burgdorferi results in the remission of carditis and arthritis, as well as global reduction of spirochete numbers in tissues, without elimination of infection. These events were recapitulated by passive transfer of immune s...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00469-06
更新日期:2006-08-01 00:00:00
abstract::Only 20 to 40% of human blood monocytes were capable of responding to chemotaxins in vitro. This limit is not due to restrictions of the in vitro system, but is due to the existence of a migrating subpopulation. Over a wide range, the number of cells migrating toward a given concentration of chemotaxin was directly pr...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:
更新日期:1980-09-01 00:00:00
abstract::Previous data from our laboratory suggest that the transitional epithelium of the urinary bladder secretes and binds to its surface a glycosaminoglycan. The presence of this substance at the bladder surface markedly reduces the ability of microorganisms to adhere to the mucosa. Furthermore, this glycosaminoglycan can ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.27.3.876-881.1980
更新日期:1980-03-01 00:00:00
abstract::We studied seven strains of group G streptococci isolated from clinically severe bacteremic infections in six intravenous drug abusers. These group G strains multiplied luxuriantly in fresh human blood. On electron microscopy, they exhibited surface fibrillae similar to those observed in M-protein-rich group A strepto...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.55.3.753-757.1987
更新日期:1987-03-01 00:00:00
abstract::Proteins from human polymorphonuclear leukocyte granules were extracted with 0.2 M acetate, pH 4.0, and fractionated by Sephadex G-100 column chromatography. The fractions demonstrated selective bactericidal action against a deep rough cell wall mutant of Escherichia coli O111:B4 with rough lipopolysacharide and cell ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.23.3.587-591.1979
更新日期:1979-03-01 00:00:00
abstract::The major antigenic determinants of the lipoglycans from Acholeplasma granularum and Acholeplasma axanthum were found to be the oligosaccharide sequences Glcp(beta 1 leads to 2)-Glcp(alpha 1 leads to 4)-Glcp and Glcp(beta 1 leads to 2)-Glcp(beta 1 leads to 2)-Glcp, respectively. The disaccharides sophorose and maltose...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.40.2.629-632.1983
更新日期:1983-05-01 00:00:00
abstract::Type 1 fimbrial phase-locked mutants of uropathogenic Escherichia coli cystitis isolate F11 were used to assess the role of the invertible element during urinary tract infection. Compared to the wild type, the phase-locked off mutant was attenuated, and constitutive production of type 1 fimbriae by the phase-locked on...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.74.2.1387-1393.2006
更新日期:2006-02-01 00:00:00
abstract::Previous studies have demonstrated that both Ixodes scapularis saliva and Borrelia burgdorferi antigens modulated lymphokines and monokines in vitro. The studies presented here were designed to delineate the role of I. scapularis and B. burgdorferi in modulation of the host immune response in vivo. Infestation of C3H/...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.65.8.3100-3106.1997
更新日期:1997-08-01 00:00:00
abstract::Cell-mediated immunity is pivotal in host resistance to Blastomyces dermatitidis infection. Immunization of mice with the WI-1 adhesin enhances resistance against experimental pulmonary infection but elicits features of a mixed T-helper-cell immune response. Immune mice acquire delayed-type hypersensitivity (DTH) but ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.68.12.7172-7174.2000
更新日期:2000-12-01 00:00:00
abstract::We previously reported that two surface-exposed high-molecular-weight proteins, HMW1 and HMW2, expressed by a prototypic strain of nontypeable Haemophilus influenzae (NTHI) mediate attachment to human epithelial cells. These proteins are members of a family of highly immunogenic proteins common to most nontypeable Hae...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.64.8.3032-3037.1996
更新日期:1996-08-01 00:00:00
abstract::The neurological syndrome caused by Plasmodium berghei ANKA in rodents partially mimics the human disease. Several rodent models of cerebral malaria (CM) exist for the study of the mechanisms that cause the disease. However, since common laboratory mouse strains have limited gene pools, the role of their phenotypic va...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.70.4.2049-2056.2002
更新日期:2002-04-01 00:00:00
abstract::Iron is an important element for the growth of microorganisms as well as in the defense of the host by serving as a catalyst for the generation of free radicals via the Fenton/Haber-Weiss reactions. The iron transporter natural resistance-associated macrophage protein 1 (Nramp1) confers resistance to the growth of a v...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.69.11.6618-6624.2001
更新日期:2001-11-01 00:00:00
abstract::Some species of the genus Mycoplasma code for the arginine deiminase pathway (ADI), which enables these bacteria to produce ATP from arginine by the successive reaction of three enzymes: arginine deiminase (ArcA), ornithine carbamoyltransferase (ArcB), and carbamate kinase (ArcC). It so far appears that independently ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00441-13
更新日期:2013-10-01 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::Specific pathogen-free guinea pigs were infected via the respiratory route with viable, attenuated Mycobacterium tuberculosis H37Ra and maintained on purified isocaloric diets. The control diet contained 30% protein (ovalbumin) and 50 ppm of added zinc (50 micrograms/g), the low protein diet contained 10% protein and ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.39.2.793-799.1983
更新日期:1983-02-01 00:00:00
abstract::Upon infection of a host, the pathogenic fungus Aspergillus fumigatus is attacked by the reactive oxygen species produced by phagocytic cells. Detoxification of hydrogen peroxide by catalases was proposed as a way to overcome this host response. A. fumigatus produces three active catalases; one is produced by conidia,...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.71.6.3551-3562.2003
更新日期:2003-06-01 00:00:00