Abstract:
:In order to construct an effector strain for the replacement therapy of dental caries, we wished to combine the properties of low-level acid production and high-level colonization potential in a strain of Streptococcus mutans. To this end, we made a deletion in the lactate dehydrogenase (LDH) gene cloned from the bacteriocin-producing S. mutans strain JH1000. However, we were unable to substitute the mutant for the wild-type allele by transformation with linear DNA fragments. The mutated gene, carried on a suicide vector, was shown by Southern analysis to integrate into the JH1000 chromosome to yield transformants carrying both the wild-type gene and mutated LDH gene. Three spontaneous self-recombinants of one heterodiploid strain were isolated by screening 1,500 colonies for a loss of the tetracycline resistance encoded by the gene used to mark the LDH deletion. In all three cases, Southern analysis showed that a loss of tetracycline resistance was accompanied by a loss of the mutated LDH gene, resulting in restoration of the wild-type genotype. However, screening the same number of colonies for self-recombinants that did not make lactic acid during anaerobic growth in Todd-Hewitt broth failed to identify clones in which the wild-type allele was lost. A second, simpler screening of more than 80,000 colonies grown aerobically on glucose tetrazolium medium to identify low-level-acid-producing colonies was also unsuccessful. These results are interpreted as indicating that LDH deficiency is lethal in S. mutans under the cultivation conditions used in these experiments. The physiological bases for this hypothesis are described.
journal_name
Infect Immunjournal_title
Infection and immunityauthors
Hillman JD,Chen A,Duncan M,Lee SWdoi
10.1128/IAI.62.1.60-64.1994subject
Has Abstractpub_date
1994-01-01 00:00:00pages
60-4issue
1eissn
0019-9567issn
1098-5522journal_volume
62pub_type
杂志文章abstract::Mycoplasma genitalium is a sexually transmitted pathogen associated with several acute and chronic reproductive tract disease syndromes in men and women. To evaluate the suitability of a pig-tailed macaque model of M. genitalium infection, we inoculated a pilot animal with M. genitalium strain G37 in the uterine cervi...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01322-12
更新日期:2013-08-01 00:00:00
abstract::Reinfection of immune mice with Leishmania major elicits a secondary gamma interferon (IFN-gamma) response to which specific CD8+ T cells are essential. We have shown previously that specific CD8+ T cells from reinfected immune mice release substantially higher levels of IFN-gamma, a cytokine essential for the efficie...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.6.2575-2581.1994
更新日期:1994-06-01 00:00:00
abstract::Since we previously observed a remarkable decrease in the numbers of T cells in the Peyer's patches of the small intestines in C57BL/6 mice following peroral infection with Toxoplasma gondii, we performed studies to examine the mechanism(s) whereby this decrease in numbers of the T cells occurs. We found that apoptoti...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.65.11.4682-4689.1997
更新日期:1997-11-01 00:00:00
abstract::In this study, we investigated the cell wall-anchored fibronectin-binding proteins SpsD and SpsL from the canine commensal and pathogen Staphylococcus pseudintermedius for their role in promoting bacterial invasion of canine progenitor epidermal keratinocytes (CPEK). Invasion was examined by the gentamicin protection ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00542-15
更新日期:2015-10-01 00:00:00
abstract::Pathogenicity of Rickettsia tsutsugamushi for laboratory mice is known to be influenced by at least three factors: (i) route of inoculation, (ii) antigenic strain, and (iii) natural resistance of the host. By using Karp, Gilliam, and Kato strains of R. tsutsugamushi, we examined the effect of these three pathogenicity...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.57.5.1476-1482.1989
更新日期:1989-05-01 00:00:00
abstract::Antibodies directed against Pfs25, a protein present on the surface of zygotes and ookinetes of Plasmodium falciparum, completely block pathogen transmission. We evaluated the immunomodulatory effect of CpG oligodeoxynucleotides (ODN) on the immunogenicity of recombinant Pfs25 (rPfs25) formulated in alum (Al). Immuniz...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.72.1.584-588.2004
更新日期:2004-01-01 00:00:00
abstract::In nature, mixed Borrelia burgdorferi infections are common and possibly can be acquired by either superinfection or coinfection. Superinfection by heterologous B. burgdorferi strains has been established experimentally, although the ability of homologous B. burgdorferi clones to superinfect a host has not been studie...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01817-14
更新日期:2014-11-01 00:00:00
abstract::A series of experiments was conducted to study the influence of embryonal bursectomy (EBX) on the early and late pathogenesis of Marek's disease (MD). The early lytic infection in the lymphoid organs normally associated with oncogenic MD virus infection in intact chickens was not seen in EBX chickens. Therefore, the d...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.31.1.199-207.1981
更新日期:1981-01-01 00:00:00
abstract::Affinity-purified rabbit polyclonal (PAB96-1) and mouse monoclonal (1G9-1C2) antibodies to synthetic H-DDDDDDD-OH, an antimicrobial anionic peptide (AP) originally isolated from ovine pulmonary surfactant, were prepared and used to assess the concentrations of AP-like molecules in human respiratory tract samples. In b...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.67.8.4256-4259.1999
更新日期:1999-08-01 00:00:00
abstract::Species-specific antibody epitopes within several major immunoreactive protein orthologs of Ehrlichia species have recently been identified and molecularly characterized. In this study, dominant B-cell epitopes within the acidic (pI 5.35) ankyrin repeat-containing 200-kDa major immunoreactive protein (gp200) of Ehrlic...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00041-07
更新日期:2007-10-01 00:00:00
abstract::Ehrlichia chaffeensis, an obligatory intracellular bacterium of monocytes or macrophages, is the etiologic agent of human monocytic ehrlichiosis. Our previous study showed that gamma interferon (IFN-gamma) added prior to or at early stage of infection inhibited infection of human monocytes with E. chaffeensis; however...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.66.6.2514-2520.1998
更新日期:1998-06-01 00:00:00
abstract::The hallmarks of enteropathogenic Escherichia coli (EPEC) infection are formation of attaching and effacing (A/E) lesions on mucosal surfaces and actin-rich pedestals on cultured cells, both of which are dependent on the type III secretion system effector Tir. Following translocation into cultured cells and clustering...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00291-15
更新日期:2015-09-01 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::Hamster respiratory epithelial cells were cultured in a monolayer format, and 20% of the cells were ciliated. Mycoplasma pneumoniae attached to the epithelial cells in a neuraminidase-specific fashion and induced ciliostasis and cytonecrosis. ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.21.1.333-336.1978
更新日期:1978-07-01 00:00:00
abstract::Toxigenic Vibrio cholerae strains are lysogens of CTXPhi, a filamentous phage which encodes cholera toxin. The receptor for CTXPhi for invading V. cholerae cells is the toxin-coregulated pilus (TCP), the genes for which reside in a larger genetic element, the TCP pathogenicity island. We analyzed 146 CTX-negative stra...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.66.12.5819-5825.1998
更新日期:1998-12-01 00:00:00
abstract::A GroEL-like protein from Bordetella pertussis was purified. This protein was found to have the tetradecameric subunit structure typical of the GroEL family of proteins and to contain epitopes similar to those of other members of this family, including a human GroEL-like protein. Active immunization of neonatal mice w...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.59.4.1417-1422.1991
更新日期:1991-04-01 00:00:00
abstract::Macrophage-dependent killing of facultative intracellular bacteria was markedly impaired by overt erythrocytic Plasmodium yoelii or Plasmodium berghei infection of mice. P. yoelii infection was capable of ablating not only the macrophage microbicidal capacity of "normal" animals but also the bactericidal capacities of...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.31.1.396-407.1981
更新日期:1981-01-01 00:00:00
abstract::The inactivation of Coxiella burnetii in suspension or in cultures of guinea pig peritoneal macrophages by ultraviolet (UV) light was studied. The effect of UV treatment on the activity of macrophage organelle marker enzymes and their subsequent equilibration in linear sucrose gradients was also determined. It was sho...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.27.3.837-841.1980
更新日期:1980-03-01 00:00:00
abstract::Murine monoclonal and rabbit, murine, and human polyclonal antibodies against chlamydial lipopolysaccharide (LPS) were characterized by the passive hemolysis and passive hemolysis inhibition assays and by absorption experiments with LPSs of Chlamydia psittaci, Chlamydia trachomatis, and a recombinant strain of Salmone...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.58.1.205-213.1990
更新日期:1990-01-01 00:00:00
abstract::Strains of indigenous Escherichia coli, Bacteroides, and Lactobacillus were isolated from the gastrointestinal tracts of specific pathogen-free (SPF) mice. Nonvaccinated SPF mice exhibited in their spleens low numbers of plaque-forming cells (PFC) and rosette-forming cells reacting with antigens of these andigenous ba...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.11.2.320-329.1975
更新日期:1975-02-01 00:00:00
abstract::The antigenic relationship of glucosyltransferases (GTF) produced by different serotypes of Streptococcus mutans was studied by using a functional inhibition assay. Rat, rabbit, or hamster immune fluids, directed to cell-associated or supernatant-derived GTF, were tested against ammonium sulfate-precipitated culture s...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.15.1.91-103.1977
更新日期:1977-01-01 00:00:00
abstract::The Lyme disease spirochete Borrelia burgdorferi reduces the expression of outer surface protein C (OspC) in response to the development of an anti-OspC humoral response, leading to the hypothesis that the ability to repress OspC expression is critical for the pathogen to proceed to chronic infection. B. burgdorferi w...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00713-06
更新日期:2006-09-01 00:00:00
abstract::The mechanism by which hamsters acquire resistance to yaws or frambesia is poorly understood. This investigation has shown that immune lymphoid cells (spleen and lymph node) could confer on hamsters resistance to infection with Treponema pertenue. Treatment of these immune cells with a specific antithymocyte serum (AT...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.25.1.208-212.1979
更新日期:1979-07-01 00:00:00
abstract::The effects of pathologically relevant concentrations (0.38 to 12.5 microM) of the proinflammatory, Pseudomonas aeruginosa-derived pigment 1-hydroxyphenazine (1-hp) on Ca2+ metabolism and intracellular cyclic AMP (cAMP) in N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP; 1 microM)-activated human neutrophils, as w...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.67.10.5157-5162.1999
更新日期:1999-10-01 00:00:00
abstract::Monoclonal antibodies to the capsular polysaccharide of Cryptococcus neoformans produce distinct capsular reactions and have biological activities that are determined by serotype specificity. In the present study, polyclonal rabbit anticapsular antibodies were cross-absorbed to produce serotype specificities similar t...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.69.2.1189-1191.2001
更新日期:2001-02-01 00:00:00
abstract::A rapid and reproducible method of bacteriocin typing is described based on leakage of ultraviolet light-absorbing material (UVAM), detectable in supernatants of bacteriocin-sensitive cultures, by means of a spectrophotometer. The prerequisites for reproducible results, with nonsignificant fluctuations in standard err...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.16.1.12-19.1977
更新日期:1977-04-01 00:00:00
abstract::Recent reports have suggested that oral vaccination of mice against Helicobacter pylori is dependent on a Th1-mediated immune response. However, oral vaccination in mice neither induces sterilizing immunity nor leads to complete protection from disease. Therefore, in this study we investigated whether a systemic subcu...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.72.2.1029-1035.2004
更新日期:2004-02-01 00:00:00
abstract::Bacterial superantigens (SAgs) have been implicated in inflammatory disease, and SAg-treated mice have increased jejunal T cells. Here we show that T84 cells (a human epithelial cell line) display increased MCP-1 and RANTES mRNA expression and protein production in response to conditioned medium from Staphylococcus au...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.67.11.6198-6202.1999
更新日期:1999-11-01 00:00:00
abstract::Mice immunized with infections of 500, 5,000, or 20,000 oocysts of E. falciformis var. pragensis were reinfected with 20,000 and 100,000 oocysts at 20 and 38 days, respectively, after the initial infection. After the first challenge infection, none of the immunized mice showed clinical signs of coccidiosis; a few mice...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.23.1.108-114.1979
更新日期:1979-01-01 00:00:00
abstract::The effect of route of administration, dosage, and number of boosts employed during immunization with the polymyxin-release form of Escherichia coli heat-labile (LT) enterotoxin on the degree and duration of protection afforded was evaluated in rats which were challenged by the ligated loop technique. Increasing the b...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.27.1.81-86.1980
更新日期:1980-01-01 00:00:00