Abstract:
:Resistance to phagocytosis is a hallmark of virulent Streptococcus pyogenes (group A streptococcus). Surface-bound C5a peptidase reduces recruitment of phagocytes to the site of infection, and hyaluronic acid capsules and/or the M protein limit the uptake of streptococci. In this study the relative impact of M and M-like proteins and the C5a peptidase on the virulence of a serotype M49 strain was assessed. The capacities of isogenic strains with an insertion mutation in emm49; with a deletion mutation in scpA49 (C5a peptidase gene); and with a deletion that removes all three M-like genes, mrp49, emm49, and enn49, to colonize mice and resist phagocytosis were compared. Experiments confirmed results obtained in an earlier study, which showed that the M49 protein was not required for in vitro resistance to phagocytosis, and also showed that the M protein was not required for colonization of mice. Failure to produce all three M-like proteins, M49, Mrp, and Enn49, significantly reduced the ability of these streptococci to resist phagocytosis in vitro but did not significantly alter the persistence of streptococci on the oral mucosa. In vitro experiments indicate that M+ streptococci are phagocytized by polymorphonuclear leukocytes that have been activated with phorbol-12-myristate 13-acetate or recombinant human C5a. This observation may explain the finding that expression of M49 protein is not essential for short-term colonization of the mouse oral mucosa.
journal_name
Infect Immunjournal_title
Infection and immunityauthors
Ji Y,Schnitzler N,DeMaster E,Cleary Pdoi
10.1128/IAI.66.11.5399-5405.1998subject
Has Abstractpub_date
1998-11-01 00:00:00pages
5399-405issue
11eissn
0019-9567issn
1098-5522journal_volume
66pub_type
杂志文章abstract::In vivo- and in vitro-grown Mycoplasma hyopneumoniae organisms were inoculated onto newborn piglet tracheal organ cultures to provide a model for interaction of this organism with ciliated respiratory epithelium. Ciliostasis and loss of cilia in tracheal rings were induced by M. hyopneumoniae grown in vivo and with lo...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.12.5312-5318.1994
更新日期:1994-12-01 00:00:00
abstract::Increased protection against a virulent challenge with Mycobacterium tuberculosis is induced mainly by a previous immunization with living avirulent mycobacteria, usually Mycobacterium bovis BCG. Only a transient and marginal protection is obtained after immunization with bacterial extracts or dead bacteria. Both livi...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.61.2.742-750.1993
更新日期:1993-02-01 00:00:00
abstract::Forty-seven bacterial strains representing four different group C streptococcal species were tested for binding of human and bovine immunoglobulin G (IgG) subclasses. Specific binding sites for IgG were found in all bacterial species studied. The four species included differed, however, in their capacities to interact...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.27.3.808-816.1980
更新日期:1980-03-01 00:00:00
abstract::Leukosis viruses of seven subgroups were tested for oncogenicity in chickens susceptible to virus infection and to development of lymphoid leukosis (LL) tumors. All subgroup A viruses and the subgroup B virus tested produced a high incidence of LL and other related neoplasms. Viruses of subgroup C and RAV-61 of subgro...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.15.2.423-428.1977
更新日期:1977-02-01 00:00:00
abstract::Chlamydia trachomatis L2 is an obligate intracellular microorganism with a unique biphasic life cycle. The extracellular form, the elementary body (EB), is infectious but metabolically inactive. Attachment of EBs to host cells is medicated by a heparan sulfate-like glycosaminoglycan. Following attachment, the EB is in...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.11.4900-4908.1994
更新日期:1994-11-01 00:00:00
abstract::HbhA of Mycobacterium tuberculosis is a multifunctional binding protein, binding to both sulfated sugars such as heparin and to human complement component C3. HbhA may therefore interact with host molecules and/or host cells during M. tuberculosis infection and play a role in the pathogenesis of this bacterium. The pu...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.70.12.6751-6760.2002
更新日期:2002-12-01 00:00:00
abstract::Phagocytosis of unopsonized Salmonella typhimurium 395, MR-10, opsonized Salmonella typhimurium 395 MS, and Staphylococcus epidermidis by rabbit polymorphonuclear leukocytes was inhibited by heparin at concentrations as low as 0.5 U/ml. Inhibition was dose dependent and nearly complete at 20 U/ml. Provided that hepari...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.32.1.295-299.1981
更新日期:1981-04-01 00:00:00
abstract::Campylobacter jejuni is a major cause of human inflammatory enteritis. During the course of human disease numerous proinflammatory cytokines are produced. Little is known, however, about the cytokine responses produced during the interaction of this bacterium with the avian host. Campylobacter has been considered a co...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.73.4.2094-2100.2005
更新日期:2005-04-01 00:00:00
abstract::In mice infected with virulent blood (trypomastigote) forms of Trypanosoma cruzi, complement depletion with cobra venom factor caused a marked exacerbation of the disease evidenced by significantly increased parasitemia levels and early mortality as compared with those of untreated infected animals. The effect was gre...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.11.1.86-91.1975
更新日期:1975-01-01 00:00:00
abstract::The ultrastructural organization of Mycoplasma pneumoniae membranes and spatial relationships of this pathogen to epithelial cells in tracheal organ cultures were examined ultrastructurally by freeze-fracture techniques. Areas of morphologically distinct cell membrane variability characterized by membrane blebs and al...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:
更新日期:1980-09-01 00:00:00
abstract::Tuberculosis is rising in the developing world due to poor health care, human immunodeficiency virus type 1 infection, and the low protective efficacy of the Mycobacterium bovis BCG vaccine. A new vaccination strategy that could protect adults in the developing world from tuberculosis could have a huge impact on publi...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.73.6.3814-3816.2005
更新日期:2005-06-01 00:00:00
abstract::Metastatic infection after hematogenous dissemination of Candida species is presumably dependent on the fungus traversing the vascular endothelium. An in vitro model of the earliest events of metastatic Candida infection was developed with whole vascular strips. Freshly obtained porcine blood vessels were secured in a...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.42.1.374-384.1983
更新日期:1983-10-01 00:00:00
abstract::Monoclonal antibodies were raised against a bactericidal protein fraction that was purified from an extract of bovine neutrophil granules and that was previously shown (A. Savoini, R. Marzari, L. Dolzani, D. Serranò, G. Graziosi, R. Gennaro, and D. Romeo, Antimicrob. Agents Chemother. 26:405-407, 1984) to inhibit bact...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.56.8.2193-2197.1988
更新日期:1988-08-01 00:00:00
abstract::Bordetella bronchiseptica secreted a hydroxamate siderophore when grown in Fe-depleted medium. A Tn5lac insertion mutant of B. bronchiseptica, DBB22, did not produce this hydroxamate siderophore and was incapable of using lactoferrin as an Fe source. Our data suggest that B. bronchiseptica uses a siderophore for remov...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.61.6.2698-2702.1993
更新日期:1993-06-01 00:00:00
abstract::Secretion of immunoglobulin A1 (IgA1) proteases is a characteristic of Haemophilus influenzae and several other bacterial pathogens causing infectious diseases, including meningitis. Indirect evidence suggests that the proteases are important virulence factors. In this study, we cloned the iga gene encoding immunoglob...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.57.10.3097-3105.1989
更新日期:1989-10-01 00:00:00
abstract::The Corynebacterium diphtheriae hmuO gene encodes a heme oxygenase that is involved in the utilization of heme as an iron source. Transcription of hmuO is activated by heme or hemoglobin and repressed by iron and DtxR. Previous studies with Escherichia coli showed that heme-dependent transcriptional activation of an h...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.73.11.7406-7412.2005
更新日期:2005-11-01 00:00:00
abstract::Helicobacter pylori strains frequently express Lewis X (Le(x)) and/or Le(y) on their cell surfaces as constituents of the O antigens of their lipopolysaccharide molecules. To assess the effect of Le(x) and Le(y) expression on the ability of H. pylori to colonize the mouse stomach and to adhere to epithelial cells, iso...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.70.6.3073-3079.2002
更新日期:2002-06-01 00:00:00
abstract::The antihistoplasma activity of recombinant murine gamma interferon (rMuIFN-gamma)-treated macrophages of the RAW 264.7 cell line depends on the generation of nitric oxide (NO.) from L-arginine. Macrophages of the P388D1 cell line treated with rMuIFN-gamma do not produce NO. or inhibit the intracellular growth of Hist...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.62.4.1478-1479.1994
更新日期:1994-04-01 00:00:00
abstract::Despite effective antimicrobial chemotherapy, control of Chlamydia trachomatis urogenital infection will likely require a vaccine. We have assessed the protective effect of an outer membrane protein-based vaccine by using a murine model of chlamydial genital infection. Female mice were first vaccinated with Chlamydia ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00622-10
更新日期:2010-10-01 00:00:00
abstract::Salmonella enterica serovar Typhimurium causes self-limiting gastroenteritis in humans and a typhoid-like disease in mice that serves as a model for typhoid infections in humans. A critical step in Salmonella pathogenesis is the invasion of enterocytes and M cells of the small intestine via expression of a type III se...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.72.4.2002-2013.2004
更新日期:2004-04-01 00:00:00
abstract::Treatment of mouse embryo fibroblasts (MEF) grown in vitro with purified staphylococcal exfoliative toxin (ET) increased the concanavalin A (Con A) agglutinability of MEF 3.5-fold over control cells. Possible explanations for this phenomenon were investigated. ET lacked proteolytic activity on denatured casein. Con A,...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.10.6.1260-1265.1974
更新日期:1974-12-01 00:00:00
abstract::A defect in lymphocyte function could be responsible for persistent infection by the equine infectious anemia virus. The number of lymphocytes bearing surface immunoglobulin, as detected by immunofluorescence, and lymphocyte response to mitogens were the same in uninfected and equine infectious anemia-infected animals...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.8.4.679-682.1973
更新日期:1973-10-01 00:00:00
abstract::Chronic granulomatous disease (CGD) is a genetic disorder of NADPH oxidase in which phagocytes are defective in generating reactive oxidants. CGD patients suffer from recurrent infections and exuberant and persistent tissue granuloma formation. We hypothesized that abnormal granulomata in CGD may result from aberrant ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:
更新日期:1999-04-01 00:00:00
abstract::Exposure of mycobacterial growth inhibitory factor (MycoIF) to trypsin, chymotrypsin, or neuraminidase decrease its ability to produce intracellular inhibition of mycobacterial growth within macrophages, suggesting that MycoIF was a glycoprotein. MycoIF was unaffected by deoxyribonuclease or ribonuclease. Supernatant ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.12.4.841-850.1975
更新日期:1975-10-01 00:00:00
abstract::Fimbriae, lipopolysaccharide (LPS), and extracellular polymeric substance (EPS) all contribute to biofilm formation by the periodontopathogen Aggregatibacter actinomycetemcomitans. To understand how individual biofilm determinants respond to changing environmental conditions, the transcription of genes responsible for...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00126-09
更新日期:2009-07-01 00:00:00
abstract::Subunits of a proline-rich coccidioidal antigen (Ag2/PRA) of Coccidioides immitis were analyzed by comparison as vaccines in mice. The optimal dose of plasmid vaccine encoding full-length Ag2/PRA was determined to be between 10 and 100 microg. Mice vaccinated with plasmids encoding amino acids (aa) 1 to 106 were as pr...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.70.7.3330-3335.2002
更新日期:2002-07-01 00:00:00
abstract::The short-term kinetics of fluoride uptake by cells from 20- to 22-h cultures of Streptococcus mutans strain 6715 were studied using rapid filtration and centrifugation techniques. Saline-suspended organisms were diluted with fluoride-containing solutions buffered at four different pH values (2.0, 4.0, 5.5, and 8.2). ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.18.3.680-687.1977
更新日期:1977-12-01 00:00:00
abstract::While investigating the virulence traits of Staphylococcus aureus adhering to the skin of atopic-dermatitis (AD) patients, we identified a novel open reading frame (ORF) with structural similarity to a superantigen from genome sequence data of an isolate from AD skin. Concurrently, the same ORF was identified in a bov...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00360-19
更新日期:2020-01-22 00:00:00
abstract::Streptococcus suis serotype 2 is a porcine and human pathogen with adhesive and invasive properties. In other streptococci, large surface-associated proteins (>100 kDa) of the MSCRAMM family (microbial surface components recognizing adhesive matrix molecules) are key players in interactions with host tissue. In this s...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.00359-06
更新日期:2006-11-01 00:00:00
abstract::The purified recombinant V antigen from Yersinia pestis, expressed in Escherichia coli and adsorbed to aluminum hydroxide, an adjuvant approved for human use, was used to immunize outbred Hsd:ND4 mice subcutaneously. Immunization protected mice from lethal bubonic and pneumonic plague caused by CO92, a wild-type F1+ s...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.64.11.4580-4585.1996
更新日期:1996-11-01 00:00:00