Abstract:
:To develop targeted gene integration in the periodontal pathogen Actinobacillus actinomycetemcomitans, a ColE1-based, spectinomycin-resistant plasmid containing a segment of the leukotoxin gene was electroporated into strain JP2. In all of the stable spectinomycin-resistant transformants that arose, the plasmid had recombined into the genomic leukotoxin locus since ColE1-based vectors cannot replicate extrachromosomally in A. actinomycetemcomitans. Directed genomic integration was then used to construct a leukotoxin-negative strain by transforming the leukotoxin-producing strain JP2 with a ColE1-based plasmid containing an internal fragment of the leukotoxin gene. Cytotoxicity assays proved that these transformants had < 0.1% of the leukotoxin activity of the parental strain. These results demonstrate that integration-based approaches can be used for generating isogenic mutants in specific virulence genes in A. actinomycetemcomitans.
journal_name
Infect Immunjournal_title
Infection and immunityauthors
Kolodrubetz D,Phillips LH,Ezzo PJ,Kraig Edoi
10.1128/IAI.63.7.2780-2784.1995subject
Has Abstractpub_date
1995-07-01 00:00:00pages
2780-4issue
7eissn
0019-9567issn
1098-5522journal_volume
63pub_type
杂志文章abstract::Herpes simplex virus (HSV) infection of mouse liver after partial hepatectomy was studied. Partial hepatectomy resulted in the rapid onset of cellular DNA synthesis and the appearance of many mitotic figures (peak, 3 days after surgery). Similar changes were not seen in control animals. After partial hepatectomy, the ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.42.1.402-408.1983
更新日期:1983-10-01 00:00:00
abstract::Tritium-labeled, water-soluble components of Streptococcus pyogenes type M6 absorbed to cardiac tissue in vitro. Tissue binding was time dependent, saturable, and reversible. Chromatography of the crude bacterial extract on Bio-Gel P-300 indicated a molecular weight greater than 300,000 for the heart-binding component...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.35.1.335-342.1982
更新日期:1982-01-01 00:00:00
abstract::Defensins are antibiotic peptides expressed in human and animal myeloid and epithelial cells. Due to the limited availability of natural peptides, the properties of human epithelial defensins have not been studied. We assayed the microbicidal activity of recombinant human intestinal defensin 5 (rHD-5) in the presence ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.65.6.2396-2401.1997
更新日期:1997-06-01 00:00:00
abstract::Total and insoluble dextransucrase activities were measured in cell-associated and supernatant fractions of Streptococcus mutans GS-5 grown in several media. Although the amount of cell-associated and supernatant activity varied greatly as a function of medium, the total activity appeared constant. The distribution of...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.18.3.629-635.1977
更新日期:1977-12-01 00:00:00
abstract::The adsorption of (3)H-labeled Streptococcus mutans 6715 cells to disks of hydroxyapatite (HA) was studied. The number of streptococci that adsorbed was logarithmically related to the concentration of cells available up to at least 2 x 10(8) per ml; equilibrium occurred within 45 min. Assay reliability was verified by...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.18.2.514-523.1977
更新日期:1977-11-01 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::Although excystation is crucial to the initiation of infection by Giardia lamblia, little is known about the regulation of this important process. We have been able to reliably induce excystation in vitro by mimicking cyst passage through the stomach and upper small intestine by the exposure of in vitro-derived cysts ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.64.6.2151-2157.1996
更新日期:1996-06-01 00:00:00
abstract::Neonatal administration of 16 mg of cyclophosphamide in inbred chickens resulted in a transient, but profound, deficiency in the in vitro proliferative response of spleen cells. Functional T-cell deficiency was accompanied by a marked morphological degeneration in the thymus and thymus-dependent areas in the spleen. ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.17.1.227-230.1977
更新日期:1977-07-01 00:00:00
abstract::Whole blood and plasma from animals in the acute stage of leptospirosis contained a toxic factor which produced a cytopathic effect on fibroblastic L cell monolayers. Firm adsorption of cytotoxic factor (CTF) to L cells occurred within 1 h. The highest titer of CTF in plasma was reached at 24 h and declined after 48 h...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.8.3.401-405.1973
更新日期:1973-09-01 00:00:00
abstract::One mechanism by which interferons (IFNs) can inhibit chlamydial infection is by the induction of the enzyme indoleamine 2,3-dioxygenase (IDO), which restricts the availability of tryptophan, which is required for chlamydial growth. Other immunomodulating agents, including interleukin-1 (IL-1), can interact synergisti...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.63.5.1870-1875.1995
更新日期:1995-05-01 00:00:00
abstract::Lysogenic conversion of Shigella flexneri type antigens was studied with the aid of wild-type and thermosensitive mutant phages. With all wild-type phages, the appearance of glycosylated antigen was accompanied by the appearance of polyprenyl phosphate glucose synthetase activity. With some of the mutant phages, the a...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.14.6.1290-1292.1976
更新日期:1976-12-01 00:00:00
abstract::The humoral and cell-mediated immune responses of murine lymphocytes exposed to lead in vivo and in vitro were investigated. In vivo Pb was administered via the drinking water (0 to 10 mM) for 1 to 10 weeks. In vivo exposure of the mice to Pb did not alter significantly their plaque-forming cell response to sheep eryt...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.31.1.136-143.1981
更新日期:1981-01-01 00:00:00
abstract::The effects of cyclophosphamide (CY) treatment on acute murine cytomegalovirus (MCMV) infection were studied to explore the potential usefulness of MCMV as a means of detecting immune dysfunction and to identify host defense mechanisms important for protection against MCMV. Conditions found optimal for enhancing MCMV ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.38.3.1046-1055.1982
更新日期:1982-12-01 00:00:00
abstract::To assess the humoral immunological responses at the subclass level in shigellosis, specific antibody responses against Shigella dysenteriae 1 lipopolysaccharide (LPS), S. flexneri Y LPS, invasion plasmid-coded protein antigens (Ipa), and Shiga toxin were analyzed. Antibody responses of 41 patients with S. dysenteriae...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.63.5.2054-2061.1995
更新日期:1995-05-01 00:00:00
abstract::Mutant cultures that lacked the ability to produce filamentous hemagglutinin were obtained by UV irradiation of Bordetella pertussis strain 18-323. Various biological activities of these mutants were compared with those of the parent culture. It was found that the leukocytosis-promoting, histamine-sensitizing, and mou...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.35.3.1018-1023.1982
更新日期:1982-03-01 00:00:00
abstract::A 75-kilodalton major protein (75K protein) was purified to homogeneity from the cell lysate fraction and the envelope of Bacteroides gingivalis 381. The 75K protein was originally present in the outer membrane or the outermost part of this organism as a large, stable complex with an apparent molecular weight of about...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.57.11.3646-3652.1989
更新日期:1989-11-01 00:00:00
abstract::Twenty monoclonal antibodies have been prepared to the erythrocytes from CBA/Ca mice infected with the rodent malaria Plasmodium chabaudi. By immunofluorescence, 15 of these antibodies recognized parasite antigens expressed only during the development of mature trophozoites to schizonts and merozoites, 2 recognized pa...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.38.1.94-102.1982
更新日期:1982-10-01 00:00:00
abstract::A monoclonal immunoglobulin M antibody, HP15/36, was produced by a hybridoma cell line prepared by fusion of mouse myeloma cell line Sp2/O with spleen cells of mice immunized with Helicobacter pylori D273 (French strain). Immunoelectron microscopy of whole bacteria and ultrathin sections showed that the determinant wa...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.61.6.2732-2736.1993
更新日期:1993-06-01 00:00:00
abstract::Larvae of the helminth parasite Schistosoma mansoni are efficiently killed in vitro by lymphokine-activated macrophages, leading to the hypothesis that these cells may participate in the effector mechanism of protective immunity against schistosomiasis. Larvacidal activity has also been demonstrated in the IC-21 macro...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.55.12.3174-3180.1987
更新日期:1987-12-01 00:00:00
abstract::A monoclonal antibody was used to characterize a 135-kDa surface-located membrane protein (Lmp1) generally present in Mycoplasma hominis strains. The monoclonal antibody, 552, was applied to identify the corresponding gene in an expression library of M. hominis PG21 DNA. The M. hominis PG21 lmp1 gene was sequenced, an...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.63.1.212-223.1995
更新日期:1995-01-01 00:00:00
abstract::The protection and immune response to infection caused by the parasite Schistosoma mansoni were studied by comparison of two murine irradiated-vaccine models. Mice were exposed from 1 to 4 times to infective-stage cercariae attenuated with either a moderate dose (15 kilorads) or a high dose (50 kilorads) of radiation....
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.60.1.90-94.1992
更新日期:1992-01-01 00:00:00
abstract::Intracellular bacterial infections affect all vertebrates. Cultured fish are particularly vulnerable because no effective protection measures have been established since such infections emerged approximately 50 years ago. As in other vertebrates, the induction of cell-mediated immunity (CMI) plays an important role in...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00459-19
更新日期:2019-10-18 00:00:00
abstract::A DNA microarray containing fragments of 137 Borrelia burgdorferi B31 putative lipoprotein genes was used to examine Lyme disease spirochetes. DNA from B. burgdorferi sensu stricto B31, 297, and N40; Borrelia garinii IP90; and Borrelia afzelii P/Gau was fluorescently labeled and hybridized to the microarray, demonstra...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.70.6.3300-3303.2002
更新日期:2002-06-01 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::A total of five bacteriological samples from the periodontal pockets of two sisters with localized juvenile periodontitis and their mother with advanced periodontitis was studied. Gram-negative anaerobic rods were predominant in the samples. Bacteroides intermedius and Bacteroides loescheii were the most predominant s...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.45.1.118-121.1984
更新日期:1984-07-01 00:00:00
abstract::Genetic diversity and relationships among 109 isolates of Neisseria meningitidis obtained from throat cultures of healthy individuals in Norway in 1984 were assessed by analyzing electrophoretically demonstrable allelic variation at 15 enzyme-encoding chromosomal genes. Seventy-eight distinctive electrophoretic types ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.56.8.2060-2068.1988
更新日期:1988-08-01 00:00:00
abstract::Peptidoglycans of Leptotrichia buccalis ATCC 14201 and ATCC 19616 were isolated by extraction with sodium dodecyl sulfate and subsequent digestion of the sodium dodecyl sulfate-insoluble residue with proteases and alpha-amylase. Cell wall fractions obtained by sodium dodecyl sulfate extraction and protease digestion w...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.39.1.132-136.1983
更新日期:1983-01-01 00:00:00
abstract::l-Arginine (1 M) eluted measles virus adsorbed on monkey erythrocytes without affecting the infectious and hemagglutinating activities of the virus. This phenomenon was also observed for encephalomyocarditis virus and Newcastle disease virus. ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.11.6.1407-1408.1975
更新日期:1975-06-01 00:00:00
abstract::Quorum-sensing systems are critical regulators of the expression of virulence factors of various organisms, including Pseudomonas aeruginosa. Las and Rhl are two major quorum-sensing components, and they are regulated by their corresponding autoinducers, N-3-oxododecanoyl homoserine lactone (3-oxo-C(12)-HSL) and N-but...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.71.10.5785-5793.2003
更新日期:2003-10-01 00:00:00
abstract::In this study we found that serum inhibitory activity against Blastomyces dermatitidis was principally mediated by albumin. This was confirmed in experiments using albumin from several mammalian species. Analbuminemic rat serum did not inhibit B. dermatitidis growth in vivo; however, the addition of albumin restored i...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.71.11.6648-6652.2003
更新日期:2003-11-01 00:00:00