Abstract:
:Since the pH of the gingival crevice increases from below neutrality in health to above pH 8 in disease, we decided to investigate the effect of environmental pH on the growth and enzyme activity of Bacteroides gingivalis W50. Cells were grown in a chemostat under hemin-excess conditions over a range of pH values; stable growth was observed only between pH 6.7 and 8.3, with the maximum yields obtained between pH 7.0 and 8.0. The enzyme profile of cells varied markedly with pH. Enzymes with a specificity for gingival connective tissue (collagenase, hyaluronidase) were produced optimally at or below neutral pH, whereas trypsinlike activity increased with the growth pH and was maximal at pH 8.0. Chymotrypsinlike activity was generally low, although its activity was highest at the extremes of growth pH, i.e., at pH 6.7 and 8.3. Inhibitor studies provided evidence that the breakdown of collagen involved the concerted action of both a collagenase and the trypsinlike enzyme. The ratio of trypsin to collagenolytic activity rose from 1:1 during growth at neutral pH and below to almost 7:1 during growth at pH 8.3. Thus B. gingivalis appears to be uniquely adapted as a periodontopathic organism in that under environmental conditions likely to prevail during the initial stages of pocket development it produces maximally those enzymes with a tissue-damaging potential. Then, as the pH of the pocket rises during the host inflammatory response, the activity of the trypsinlike enzyme increases markedly, which may enable cells to inactivate key components of the host defenses such as immunoglobulins and complement.
journal_name
Infect Immunjournal_title
Infection and immunityauthors
McDermid AS,McKee AS,Marsh PDdoi
10.1128/IAI.56.5.1096-1100.1988subject
Has Abstractpub_date
1988-05-01 00:00:00pages
1096-100issue
5eissn
0019-9567issn
1098-5522journal_volume
56pub_type
杂志文章abstract::Three open reading frames (ORFs) were identified by a genome walking strategy in the genomes of serotype M49 group A streptococcal (GAS) strains CS101 and 591. These ORFs were located between the mga core regulon and the dipeptide permease operon. The deduced amino acid (aa) sequences contained signature sequences ind...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.70.9.4859-4869.2002
更新日期:2002-09-01 00:00:00
abstract::Mice immunized intravenously 10 days earlier (but not those immunized 2 months earlier) with an attenuated Salmonella typhimurium SL3261 aroA live vaccine and tested for delayed-type hypersensitivity by injection of crude Salmonella extracts in the footpad can die within 24 to 48 h of an unexplained allergic reaction....
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.6.2285-2288.1994
更新日期:1994-06-01 00:00:00
abstract::Comparisons of the course of coccidioidomycosis in two strains of inbred mice established that BALB/c mice are significantly more susceptible to pulmonary infection with Coccidioides immitis than are DBA/2 mice. The susceptibility of BALB/c mice does not reside in their inability to mount a delayed-type hypersensitivi...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.56.1.13-17.1988
更新日期:1988-01-01 00:00:00
abstract::Recombinant adenylate cyclase toxoids are shown to deliver inserted foreign CD4(+)-T-cell epitopes into the major histocompatibility complex class II presentation pathway, inducing a specific CD4(+)-T-cell response in vivo and yielding in vitro stimulation of specific CD4(+) T cells at a 100-times-higher molar efficie...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:
更新日期:2002-02-01 00:00:00
abstract::This study focuses on the interaction of the three components of the Bacillus cereus Nhe enterotoxin with particular emphasis on the functional roles of NheB and NheC. The results demonstrated that both NheB and NheC were able to bind to Vero cells directly while NheA lacked this ability. It was also shown that Nhe-in...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00247-10
更新日期:2010-09-01 00:00:00
abstract::A 60-kilodalton (kDa) immunodominant antigen of Legionella pneumophila is a heat shock protein (HSP) of the GroEL class of HSPs. The gene (htpB) coding the 60-kDa protein was localized to a 3.2-kilobase DNA fragment of L. pneumophila cloned into pUC19 (pSH16) (P. S. Hoffman, C. A. Butler, and F. D. Quinn, Infect. Immu...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.58.10.3380-3387.1990
更新日期:1990-10-01 00:00:00
abstract::The mechanism by which bacterial heat-stable enterotoxins (ST I STA) cause diarrhea in humans and animals has been linked to the activation of an intestinal membrane-bound guanylate cyclase. Guanylin, a recently discovered rat intestinal peptide, is homologous in structure to ST I and can activate guanylate cyclase pr...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.61.11.4710-4715.1993
更新日期:1993-11-01 00:00:00
abstract::Immunoglobulin binding proteins are one of several pathogenicity factors which have been associated with invasive disease caused by group A streptococci. The surface-bound M and M-like proteins of Streptococcus pyogenes are the most characterized of these immunoglobulin binding proteins, and in most cases they bind on...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.69.8.4851-4857.2001
更新日期:2001-08-01 00:00:00
abstract::This study determined the role of crl in the production of curli by, the hemagglutination activity of, and fibronectin binding by avian pathogenic Escherichia coli chi 7122. Curli, an extracellular structure that binds fibronectin, was recently described (A. Olsén, A. Jonsson, and S. Normark, Nature [London] 338:652-6...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.60.11.4460-4467.1992
更新日期:1992-11-01 00:00:00
abstract::The effects of 1,25-dihydroxy vitamin D3 and gamma interferon on the phenotypic changes associated with monocyte maturation in vitro were investigated. Human monocytes separated from peripheral blood mononuclear cell populations by adherence to plastic were cultured for 7 days on glass. Immunocytological analysis was ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.55.9.2017-2020.1987
更新日期:1987-09-01 00:00:00
abstract::Candida albicans serotype A (C. albicans A) possesses a specific antigen, designated antigen 6, which resides in mannans on the cell surface. To determine the role of the mannan moiety of the C. albicans cell wall in adherence to buccal epithelial cells, we used antigen 6-deficient mutants which had been isolated by s...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.60.6.2493-2499.1992
更新日期:1992-06-01 00:00:00
abstract::Protective immunity in mice to the infective third-stage larvae (L3) of Strongyloides stercoralis was shown to be dependent on immunoglobulin M (IgM), complement activation, and granulocytes. The objectives of the present study were to determine whether IgG was also a protective antibody isotype and to define the spec...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.71.12.6835-6843.2003
更新日期:2003-12-01 00:00:00
abstract::A family of high-molecular-weight (HMW) surface-exposed proteins important in the attachment of nontypeable Haemophilus influenzae (NTHi) to human epithelial cells was previously identified (J. W. St. Geme III, S. Falkow, and S. J. Barenkamp, Proc. Natl. Acad. Sci. USA 90:2875-2879, 1993). In the present investigation...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.10.4460-4468.1994
更新日期:1994-10-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00224-18
更新日期:2018-05-22 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.60.7.2605-2611.1992
更新日期:1992-07-01 00:00:00
abstract::Several strains of group B Streptococcus agalactiae were found to be lethal for young adult rats. When bacteria were heat killed and then injected intraperitoneally into rats, rapid death (14 to 18 h) of the rats occurred, characterized by labored breathing, hemolyzed serum, hemoglobinuria, and subungual hemorrhages. ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.48.2.560-564.1985
更新日期:1985-05-01 00:00:00
abstract::A secreted nuclease, SsnA, was identified in the virulent Streptococcus suis isolate SX332 and subsequently in each of the type strains of capsular serotypes 1 through 9. Screening of 258 porcine clinical isolates from surface (nasal mucosa or palatine tonsil) or internal (joint, brain or other internal organ) locatio...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.72.2.774-781.2004
更新日期:2004-02-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.63.10.3846-3850.1995
更新日期:1995-10-01 00:00:00
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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::Merozoite surface proteins of Plasmodium falciparum play a critical role in the invasion of human erythrocytes by the malaria parasite. Here we describe the identification of a novel protein with a molecular mass of 40 kDa that is found on the merozoite surface of P. falciparum. We call this protein merozoite surface ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.65.11.4460-4467.1997
更新日期:1997-11-01 00:00:00
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journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.27.1.231-234.1980
更新日期:1980-01-01 00:00:00
abstract::During the systemic phase of murine infection with Salmonella enterica serovar Typhimurium, bacterial virulence is correlated with the ability to grow and survive within host macrophages. Salmonella pathogenicity island 2 (SPI-2), encoding a type three secretion system, has emerged as an important contributor to Salmo...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.73.7.4354-4362.2005
更新日期:2005-07-01 00:00:00
abstract::Chromosomal DNA from a uropathogenic strain of Escherichia coli was partially digested with the restriction enzyme EcoRI. The partial digests were ligated into a cosmid containing an ampicillin-resistant determinant and packaged into lambda phage particles. An ampicillin-resistant transductant of E. coli HB101 was fou...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.38.2.739-744.1982
更新日期:1982-11-01 00:00:00
abstract::We demonstrate that a mucoid, alginate-producing strain of Pseudomonas aeruginosa isolated from the lungs of a cystic fibrosis (CF) patient secretes multiple enzymes with nucleoside diphosphate kinase (Ndk), ATPase, adenylate kinase, 5'-nucleotidase, and ATP-modifying enzymatic activities. The secretion is triggered a...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.67.10.5231-5242.1999
更新日期:1999-10-01 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::Severe pediatric malaria is an important risk factor for developing disseminated infections with nontyphoidal Salmonella serotypes (NTS). While recent animal studies on this subject are lacking, early work suggests that an increased risk for developing systemic NTS infection during malaria is caused by hemolytic anemi...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00887-09
更新日期:2010-04-01 00:00:00
abstract::The adjuvant action of various lipopolysaccharides on immune responses to syngeneic tissue extract in mice was examined. Only lipopolysaccharides possessing the linear mannose homopolysaccharides as O-specific polysaccharides exhibited definite adjuvant action on immune responses to the autoantigens. The intensity of ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.60.11.4953-4956.1992
更新日期:1992-11-01 00:00:00
abstract::Infectious agents are often considered potential triggers of chronic inflammatory disease, including autoimmunity; however, direct evidence is usually lacking. Here we show that following control of acute infection of mice with the myotropic Colombiana strain of Trypanosoma cruzi, parasites persisted in tissue at low ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01497-15
更新日期:2016-03-24 00:00:00
abstract::The adherence of Treponema denticola GM-1, TD-4, and MS25 to human gingival fibroblasts (HGFs) was studied to serve as an introduction to investigations into the interactions of these oral bacteria with human host cells. Under both aerobic (5% CO2) and anaerobic (85% N2 plus 10% H2 plus 5% CO2) environments, the inter...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.58.6.1720-1729.1990
更新日期:1990-06-01 00:00:00
abstract::Natural bactericidal resistance to Mycobacterium bovis BCG is under the control of a single gene, designated Bcg. Lung granuloma formation in susceptible (Bcgs) and resistant (Bcgr) mice was studied in two sets of Bcg-congenic systems, namely, the BALB/c (Bcgs)-C.D2 (BALB/c.Bcgr) pair and the B10.A (Bcgs)-B10.Ar (Bcgr...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.58.5.1210-1216.1990
更新日期:1990-05-01 00:00:00