Abstract:
:The gonococcal pilus is a primary virulence factor, providing the initial attachment of the bacterial cell to human mucosal tissues. Pilin, the major subunit of the pilus, can carry a wide spectrum of primary amino acid sequences which are generated by the action of a complex antigenic variation system. Changes in the pilin amino acid sequence can produce different pilus-dependent colony morphotypes, which have been previously shown to reflect phase variation of pili on the bacterial cell surface. In this study, we further examined the relationships between changes in pilus-dependent colony morphology, pilin sequence, pilus expression, and pilus function in Neisseria gonorrhoeae FA1090. A group of FA1090 colony variants expressed different pilin sequences and demonstrated different levels of pilin, S-pilin, and pilus expression. The analysis of these colony variants shows that they do not represent two distinct phases of pilus expression, but that changes in pilin protein sequence produce a spectrum of S-pilin production, pilus expression, and pilus aggregation levels. These different levels of pilus expression and aggregation influence not only colony morphology but also DNA transformation efficiency and epithelial cell adherence.
journal_name
Infect Immunjournal_title
Infection and immunityauthors
Long CD,Madraswala RN,Seifert HSdoi
10.1128/IAI.66.5.1918-1927.1998subject
Has Abstractpub_date
1998-05-01 00:00:00pages
1918-27issue
5eissn
0019-9567issn
1098-5522journal_volume
66pub_type
杂志文章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; sta...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.56.5.1096-1100.1988
更新日期:1988-05-01 00:00:00
abstract::Escherichia coli O45 isolates associated with swine postweaning diarrhea in Québec were characterized with respect to virulence determinants genetically and investigated for their attaching and effacing (A/E) activities by experimental inoculation of gnotobiotic piglets and by the HEp-2 cell adherence assay. All of 32...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.10.4153-4159.1994
更新日期:1994-10-01 00:00:00
abstract::As reported elsewhere, an enterotoxigenic strain of Escherichia coli serotype O25:K98:NM was epidemiologically incriminated as the etiological agent in a shipboard outbreak of diarrheal illness. This enterotoxigenic E. coli strain and possibly other enteric isolates were found to produce heat-labile toxin and not heat...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.24.3.793-797.1979
更新日期:1979-06-01 00:00:00
abstract::One of the first steps in the development of cerebral toxoplasmosis is the penetration of the blood-brain barrier, which is comprised of microvascular endothelial cells. We examined the capacity of human brain microvascular endothelial cells (HBMEC) to interact with Toxoplasma gondii. We found that stimulation of HBME...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.69.10.6527-6531.2001
更新日期:2001-10-01 00:00:00
abstract::Guinea pigs were treated with anti-CD18 antibody (M8), and subsequently middle ears (ME) were infected with nontypeable Haemophilus influenzae. Forty-eight hours after infection, the ME washes of these animals had significantly lower polymorphonuclear leukocyte numbers but higher bacterial counts compared with washes ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.61.3.1132-1135.1993
更新日期:1993-03-01 00:00:00
abstract::Conditions for the release of streptococcal type 12 M protein from whole cells by cyanogen bromide are described; they demonstrated that methionine is not essential to the structural arrangements which account for some of its immunological and biological properties. The released M protein was separated from other prot...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.21.2.546-555.1978
更新日期:1978-08-01 00:00:00
abstract::Staphylococcus aureus peptidoglycan displayed a marked dose-dependent mitogenic activity for mouse splenocytes and human peripheral blood lymphocytes in vitro, as measured by increased [3H]thymidine incorporation. Similarly it was mitogenic for athymic nude mouse spleen cells, whereas no blastogenic effect was observe...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.23.3.706-710.1979
更新日期:1979-03-01 00:00:00
abstract::Legionella pneumophila is a gram-negative facultative intracellular parasite of macrophages. Although L. pneumophila is the causative agent of a severe pneumonia known as Legionnaires' disease, it is likely that most infections caused by this organism are cleared by the host innate immune system. It is predicted that ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.02049-05
更新日期:2006-06-01 00:00:00
abstract::Haemophilus ducreyi is resistant to killing by normal serum antibody and complement. We discovered an H. ducreyi outer membrane protein required for expression of serum resistance and termed it DsrA (for "ducreyi serum resistance A"). The dsrA locus was cloned, sequenced, and mutagenized. An isogenic mutant (FX517) of...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.68.3.1608-1619.2000
更新日期:2000-03-01 00:00:00
abstract::The effects of passive administration of neutralizing monoclonal antibodies (MAB) to respiratory syncytial virus glycoproteins (GP90 and VP70) was evaluated in cotton rats challenged with respiratory syncytial virus. Animals injected with MAB to VP70 had lower mean viral titers in lung tissues than did controls (log10...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.43.2.756-758.1984
更新日期:1984-02-01 00:00:00
abstract::The possibility that preexisting specific serum antibody could suppress a defined mucosal immune response to a topically applied antigen was studied in rats. Hyperimmune serum antibody induced by parenteral immunization of rats with cholera toxoid markedly suppressed the mucosal immune response to enterically applied ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.30.1.62-68.1980
更新日期:1980-10-01 00:00:00
abstract::Escherichia coli strains isolated from newborn infants were injected intraperitoneally into infant rats. Strains possessing the K1 capsular polysaccharide antigen were significantly more virulent than strains lacking this antigen. When 5-day-old animals were injected with 1.2 X 10(1) colony forming units of a K1 E. co...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.22.2.480-485.1978
更新日期:1978-11-01 00:00:00
abstract::We have previously reported that a wild strain of Francisella tularensis is much less efficiently killed by human polymorphonuclear leukocytes than is an attenuated strain. In the present study, the killing of the attenuated strain was found to be strictly oxygen dependent. The wild and the attenuated strains both ind...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.43.2.730-734.1984
更新日期:1984-02-01 00:00:00
abstract::Porphyromonas gingivalis is a periodontal pathogen capable of invading primary cultures of normal human gingival epithelial cells (NHGEC). Involvement of P. gingivalis fimbriae in the invasion process was examined. Purified P. gingivalis 33277 fimbriae blocked invasion of this organism into NHGEC in a dose-dependent m...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.65.1.313-316.1997
更新日期:1997-01-01 00:00:00
abstract::Previous studies showed that Pseudomonas aeruginosa exotoxin A (PA toxin) catalyzes nicotinamide adenine dinucleotide (NAD)-dependent inhibition of protein synthesis in a rabbit reticulocyte lysate and transfer of radioactivity from [14C]adenine-labeled NAD to a protein having the same molecular weight as elongation f...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.15.1.138-144.1977
更新日期:1977-01-01 00:00:00
abstract::Previous studies have suggested that interleukin-4 (IL-4) has a protective effect in host defense to Borrelia burgdorferi infection, both in limiting the severity of arthritis and in controlling spirochete numbers in tissues, and a mapping study revealed suggestive linkage to a cluster of genes on mouse chromosome 11,...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.68.10.5603-5609.2000
更新日期:2000-10-01 00:00:00
abstract::Previous studies have demonstrated that expression of virulence in Shigella spp. is controlled by growth temperature. To study the regulation of virulence (vir) genes, we set out to develop a rapid, easily-assayed phenotype with which to measure expression of virulence. This report described a procedure for isolating ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.45.3.642-648.1984
更新日期:1984-09-01 00:00:00
abstract::Serotype b-specific polysaccharide antigen (SPA) of Actinobacillus actinomycetemcomitans Y4 consists of D-fucose and L-rhamnose. To clarify the role of SPA in phagocytosis of the organism by human polymorphonuclear leukocytes (PMNs), monoclonal antibodies (MAbs) against SPA and SPA-defective mutants, which were constr...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.63.12.4589-4594.1995
更新日期:1995-12-01 00:00:00
abstract::To determine whether an ongoing response to Leishmania major would affect the response to a non-cross-reacting, non-leishmanial antigen, susceptible BALB/c mice and resistant C3H mice were infected with L. major parasites expressing Escherichia coli beta-galactosidase (beta-GAL); this parasite was designated L. major-...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.68.2.809-814.2000
更新日期:2000-02-01 00:00:00
abstract::Two distinct monoclonal antibodies, one to pertussis toxin subunit S2, called 9G8, and another to subunits S2 and S3, called 11E6, were generated from the hybridomas of myeloma SP2/0 and spleen cells of BALB/c mice immunized mainly with the subunit S234 complex. Binding ability of 9G8 and 11E6 to the subunits was conf...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.55.4.909-915.1987
更新日期:1987-04-01 00:00:00
abstract::Evidence obtained from gene knockout studies supports the role of Toll-like receptor 4 (TLR4) in intestinal inflammation and microbiota recognition. Increased epithelial TLR4 expression is observed in patients with inflammatory bowel disease. However, little is known of the effect of increased TLR4 signaling on intest...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01374-15
更新日期:2016-01-11 00:00:00
abstract::The cyst cell wall β-glucans of Pneumocystis have been shown to stimulate immune responses in lung epithelial cells, dendritic cells, and alveolar macrophages. Little is known about how the trophic life forms, which do not have a fungal cell wall, interact with these innate immune cells. Here, we report differences in...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00519-16
更新日期:2016-11-01 00:00:00
abstract::The EUO gene (for early upstream open reading frame) of Chlamydia psittaci was previously found to be transcribed better at 1 than at 24 h postinfection. We found that the EUO gene encodes a minor protein that is expressed within 1 h of infection of host cells with C. psittaci 6BC but that protein quantity peaks durin...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.66.3.1167-1173.1998
更新日期:1998-03-01 00:00:00
abstract::The mouse system provides an excellent model for studying host resistance to Naegleria fowleri, the agent of primary amoebic meningoencephalitis. Innate resistance to infection with N. fowleri was examined with respect to infecting dose and the age, sex, and strain of mice. Intravenous inoculation with 10(7) amoebae p...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.20.1.73-77.1978
更新日期:1978-04-01 00:00:00
abstract::The Plasmodium falciparum liver-stage antigen 3 (LSA3), a recently identified preerythrocytic antigen, induces protection against malaria in chimpanzees. Using antibodies from individuals with hyperimmunity to malaria affinity purified on recombinant or synthetic polypeptides of LSA3, we identified four non-cross-reac...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.69.6.3845-3952.2001
更新日期:2001-06-01 00:00:00
abstract::We have developed an improved scheme for the classification of environmental and clinical isolates of Histoplasma capsulatum that is based on analysis of mitochondrial DNA (mtDNA) and ribosomal DNA (rDNA). Strains were initially divided into mtDNA groups according to restriction digests of whole-cell DNA and Southern ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.57.5.1409-1412.1989
更新日期:1989-05-01 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::Since secondary Streptococcus pneumoniae infections greatly increase the mortality of influenza infections, we determined the relative roles of neutrophil-dependent and -independent mechanisms in increased susceptibility to S. pneumoniae during influenza infection. Mice infected with influenza for 6 days, but not 3 da...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00789-06
更新日期:2006-12-01 00:00:00
abstract::It was shown that a strain of Serratia liquefaciens harbors a conjugative R-plasmid responsible for reistance to the following 14 antibiotics: ampicillin, carbenicillin, cephalothin, butirosin, neomycin, paramomycin, kanamycin, lividomycin, gentamicin, tobramycin, streptomycin, tetracycline, sulfonamide, and chloramph...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:
更新日期:1980-06-01 00:00:00
abstract::Chlamydia pneumoniae is a human respiratory pathogen. Unlike the other two Chlamydia species, no species-specific antigen has been defined for C. pneumoniae. An immunoreactive clone containing a 0.8-kb fragment was isolated from a C. pneumoniae (AR-39) genomic library by using anti-C. pneumoniae rabbit immune serum. B...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.3.880-886.1994
更新日期:1994-03-01 00:00:00