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At least 649 records · Page 36Linked to original sources
PubMed1985

Active immunization of NMRI mice against Serratia marcescens.

Phenol-hot water lipopolysaccharide (LPS) extracts of Serratia marcescens strains CDC O3:H1, CDC O6:H3, NEW CDC O14:H12, and SH 186 (serotype O6/O14:H12) significantly protected NMRI mice against intraperitoneal challenge with the more mouse virulent homologous strains; overall, there was moderate cross-protection against the minority of heterologous challenge strains. Trichloroacetic acid LPS extracts and K-antigen extracts of strains NEW CDC O14:H12 and SH 186 also proved protective antigens. The purified metalloproteases of strains SH 186 and SF 178 (serotype O6/O14:H12) effected active murine immunization. Neither active nor passive immunization of NMRI mice with E. coli Rc mutant J5 afforded significant protection against various challenge strains of S. marcescens.

Animals↗
PubMed2001

Immunogenicity in mice of pneumococcal glycoconjugate vaccines using pneumococcal protein carriers.

Antibody response and protective immunity were evaluated in mice immunized with pneumococcal glycoconjugate vaccines using two pneumococcal protein carriers. Mice injected with type 9V polysaccharide (PS) conjugated to inactivated pneumolysin (Ply) or autolysin (Aly) produced high levels of IgG and IgM antibodies to both the PS and the protein carrier. Higher PS antibody titers to the pneumococcal PS conjugates were measured by ELISA using PS-Ply or PS-tetanus toxoid (TT) conjugate as a coating antigen compared with PS mixed with methylated human serum albumin. Type 9V PS (10 microg) inhibited most of the 9V IgM and IgG antibody binding to the 9V-TT coated plate. In contrast, absorption with 19F PS did not inhibit 9V antibody binding. The avidity index of IgG antibodies in the 9V PS-Ply serum was 55.5 +/- 0.9, compared with 47.8 +/- 1.4 for 9V PS-Aly serum. Thus, high avidity of serum antibodies in conjugate-immunized mice can provide more effective functional activity for protection against pneumococcal infection. Mice immunized with these glycoconjugates exhibited rapid bacterial clearance from blood and provided cross-protection against challenge with heterologous serotypes of virulent pneumococci. These results reveal that conjugates using pneumococcal protein carriers can induce opsonophagocytic activity to destroy homologous and heterologous pneumococci, indicating that such conjugates can confer broader protective immunity than conjugates using non-pneumococcal proteins.

Animals↗
PubMed1977

A polyvalent human gamma-globulin immune to Pseudomonas aeruginosa: passive protection of mice against lethal infection.

As a means to development of guidelines for therapeutic application to human disease, preparations of human polyvalent gamma-globulin immune to Pseudomonas aeruginosa (PG) were studied in acute infections in mice. PG was highly effective in controlling lethal infections induced in mice by the major immunotypes of P. aeruginosa; greater than or equal to 10 microgram of of gamma-globulin per mouse protected against challenge with less than or equal to 10(6) 50% lethal doses of P. aeruginosa. PG was less than or equal to 57 times more effective than normal human gamma-globulin. The active antibody component is specific for each immunotype; it is of the IgG type and undoubltedly is directed against the O-antigen. PG was was not protective against challenge with Escherichia coli, Enterobacter cloacae, Proteus mirabilis, or Klebsiella pneumoniae; a low degree of cross-protection was seen against Serratia marcescens. In a model infection involving mice in a terminal stage of advanced P. aeruginosa infection, human plasma immune to P. aeruginosa proved ineffective, but the gamma-globulin component showed moderate activity. The apparent irreversibility of this late-stage infection is not clearly ascribable to a toxin. It is postulated that the successful treatment of advanced P. aeruginosa infections in humans would require multiple therapeutic approaches, including passive immunization with a high-potency, specifically immune globulin.

Animals↗
PubMed1987

Demonstration of cross-reactive antibodies to smooth gram-negative bacteria in antiserum to Escherichia coli J5.

We investigated the discrepancy between the broad cross-protection against gram-negative infections afforded by antiserum to Escherichia coli J5 and its apparently narrow cross-reactivity in vitro. Rabbits immunized with J5 bacteria produced antibodies to both the J5 lipopolysaccharide (LPS; titer by ELISA, 1:60,000) and LPS from the Re mutant of Salmonella minnesota (i.e., to the ketodeoxyoctonate [KDO] and lipid A determinants; titer, 1:3,200). In highly diluted antiserum, titers of antibody to J5 LPS were reduced by 28%-41% after adsorption with seven strains of smooth gram-negative bacteria and by only 4% after adsorption with the Re mutant. Smooth gram-negative bacteria adsorbed virtually all antibody to Re LPS. Therefore, rabbit antiserum to J5 contains type-specific antibodies to core determinants distal to KDO that can obscure highly cross-reactive antibodies to lipid A-KDO in vitro. Cross-reactive antibodies are demonstrable by adsorption with whole bacteria at limiting concentrations of antibody.

Adsorption↗
PubMed1980

Slime glycolipoproteins and the pathogenicity of various strains of Pseudomonas aeruginosa in experimental infection.

Several strains of Pseudomonas aeruginosa were differentiated on the basis of the surface properties of the cells. Fisher immunotype, phage type, polysaccharide depolymerase type, and indirect hemagglutination reactions were used for this purpose. Each strain was then studied with respect to events known to occur during the experimental infection of mice with P. aeruginosa. The virulence of the viable cells varied significantly, although all strains were virulent. Glycolipoproteins were isolated from the slime of each strain, and they appeared similar chemically when they were analyzed for gross composition. The toxicity of the isolated glycolipoproteins varied insignificantly, except for that of one strain. Viable cells of each strain and their respective glycolipoproteins caused leukopenia, which occurs in the course of the lethal infection. The antisera to the glycolipoproteins protected mice in every case against infection by the homologous strains. In some cases, various degrees of cross-protection were observed.

Antibodies, Bacterial↗
PubMed1986

Trypanosoma cruzi: isolate dependence in the induction of lytic antibodies in the mouse and rabbit.

Lytic antibodies able to interact with the live trypomastigotes of Trypanosoma cruzi have been associated with both protection and active infection. There are T. cruzi isolates unable to induce lytic antibodies despite their capacity in eliciting agglutinins and precipitins for immunofluorescent labeling. The host's spontaneous cure was ruled out as being responsible for negative results. The test performed either at 4 C or in the presence of sodium azide proved that negative lytic assays could not be attributed to capping phenomena. The classification of the parasites as T. cruzi was confirmed by their behavior in tissue culture and in the vector, as well as by the cross-protection exhibited by chronically infected mice against other lethal T. cruzi isolates. Cross-resistance achieved by these mice also suggests that the host's protection during chronic infection is independent of the lytic antibody titer.

Agglutination Tests↗
PubMed2005

Efficacy of H5 influenza vaccines produced by reverse genetics in a lethal mouse model.

We studied the efficacy, in mice, of 2 H5 influenza vaccine viruses produced by reverse genetics. Mice were immunized with inactivated viruses and then inoculated with a human H5N1 1997 or 2003 virus or an avian H5N1 2001 virus. Vaccine viruses that we tested raised high levels of hemagglutination-inhibiting (1:160-1:1280) and virus-neutralizing (1:900-1:1900) antibodies on day 21 after a single dose of vaccine and decreased or prevented virus replication in mouse lungs; 54.5%-100% of immunized mice survived, whereas all control mice died. Protection was achieved despite antigenic differences and incomplete matching of the vaccine strain and the challenge virus. Therefore, high levels of cross-protection are predicted in the mouse model.

Animals↗
PubMed1999

Resistance of Escherichia coli and Salmonella against nisin and curvacin A.

We have determined the effects of the following factors on the resistance of Gram-negative bacteria against nisin and curvacin A: (i) chemotype of the lipopolysaccharide (LPS), (ii) addition of agents permeabilizing the outer membrane, (iii) the fatty acid supply of the growth medium, and (iv) the adaptation to acid and salt stress. Bacteriocin activity was determined against growing and resting cells as well as protoplasts. All smooth strains of Escherichia coli and Salmonella enterica serovar Typhimurium were highly resistant towards the bacteriocins, whereas mutants that possess the core of the LPS, but not the O antigen, as well as deep rough LPS mutants were sensitive. Antibiotics with outer membrane permeabilizing activity, polymyxin B and polymyxin B nonapeptide, increased the sensitivity of smooth E. coli towards nisin, but not that of deep rough mutants. Incorporation of 1 g l(-1) of either oleic acid or linoleic acid to the growth media greatly increased the susceptibility of E. coli LTH1600 and LTH4346 towards bacteriocins. Both strains of E. coli were sensitive to nisin and curvacin A at a pH of less than 5.5 and more than 3% (w/v) NaCl. Adaptation to sublethal pH or higher NaCl concentrations (pH 4.54 and 5.35 or 4.5% (w/v) NaCl) provided only limited protection against the bacteriocidal activity of nisin and curvacin A. Adaptation to 4.5% (w/v) NaCl did not result in cross protection to bacteriocin activity at pH 4.4, but rendered the cells more sensitive towards bacteriocins.

Anti-Bacterial Agents↗
PubMed1980

Heterogeneity of type-specific and cross-reactive antigenic determinants within a single M protein of group A streptococci.

The heterogeneity of a pepsin extract of type-24 M protein (pep M24) was demonstrated by absorption of type-specific and cross-reactive human antisera with M protein fragments and heterologous serotypes of M proteins, pepsin extract of type-5 M protein (pep M5) and pepsin extract of type-6 M protein (pep M6). 2 of 12 individuals immunized with pep M24 developed significant rises in antibody titers against pep M5 and pep M6, as measured by the enzyme-linked immunosorbent assay. The sam individuals also developed opsonic antibodies against type-6, but not type-5, streptococci, which suggested the development of cross-protective immunity. Inhibition studies of one of these sera with the heterologous pep M proteins showed that the cross-reactive antibodies against pep M6 could not be blocked by high concentrations of pep M24, the immunizing antigen; these antibodies could be blocked, however, by cyanogen bromide-derived peptide fragments of pep M24, which suggested that the cross-reactive antibody was raised against an inaccessible site(s) in the pep M24 molecule. Inhibition studies of type-specific immune sera with pep M24 and peptides derived therefrom indicated that the M protein molecule contained multiple distinct as well as identical type-specific antigenic determinants that are unequally distributed among the seven derived peptide fragments.

Bacterial Proteins↗
PubMed2004

Protectivity of an immunoaffinity-purified 39 kDa capsular protein of avian Pasteurella multocida in mice.

A 39 kDa protein of avian Pasteurella multocida strain P-1059 (serovar A:3) was purified from a crude capsular extract by immunoaffinity chromatography by using a ligand of purified mouse monoclonal antibody to the 39 kDa capsular protein of the strain. Protective activity of the purified 39 kDa protein antigen was determined by inoculation of ddY mice twice with 25 or 125 mug of the protein and challenge-exposure with 10 or 50 LD(50) of strains P-1059 or X-73 (serovar A:1). The results showed that the antigen gave high protection (60 to 100%). These results indicated that the 39 kDa protein of avian P. multocida is a cross-protective antigen over serovars A:1 and A:3.

Animals↗
PubMed2004

Vaccines for rotavirus gastroenteritis universally needed for infants.

Rotavirus causes severe and often lifethreatening illness. Universal application of a safe and protective vaccine is justified in both developed and developing nations. Two vaccine candidates, one monovalent (Rotarix) and one multivalent (Rotateq), appear to meet these requirements and are likely to be licensed in the United States in the next 2 or 3 years. Both vaccines exhibited similar safety characteristics. There is little doubt that Rotateq and Rotarix will be shown to be effective for routine protection of infants. Unfortunately, despite numerous clinical trials, the most common serotype (PlaGa) commonly has been encountered as a natural challenge. Therefore, it is not known whether either vaccine possesses advantages in different epidemiological situations. Continuing the analogy with influenza virus, it may be that optimum protection against different serotypes requires a vaccine that is precisely homologous in antigen composition. If so, Rotateq would provide protection against the most common serotype PlaG1 because in includes both Pla and G1 rotavirus reassortants. Further, it would be expected to provide superior protection against G2, G3, and G4 wild-type virus because it contains reassortants of those specificities. In the case of a natural challenge with a serotype that was not G1, G2, G3, or G4, a Rotateq preparation containing a WC3 reassortant expressing the new G serotype could be formulated readily. The monotypic Rotarix may provide ideal protection against the PlaG1 rotavirus because it is composed solely of the PlaG1 strain. It may also provide cross-protection against other rotavirus serotypes adequate to protect against severe and life-threatening disease. In such a case, its monotypic composition may also provide significant economic savings in manufacturing. The resolution of these questions may have to await extensive post-licensure experience with each vaccine. In the future, possible application of rotavirus vaccine for other situations also should be explored, including use in older children to limit nosocomial infection, use in geriatric populations, use in the immunocompromised host, and possibly use in parents and other adults in contact with infants with rotavirus. Both Rotarix and Rotateq likely are to be launched at prices beyond those affordable in the poorest and neediest less-developed countries. It is essential that there be vigorous pursuit of new technologies to manufacture these products at drastically reduced cost if their true lifesaving potential is to be achieved.

Child Welfare↗
PubMedDate not supplied

Laboratory and field trials with formalin-inactivated Escherichia coli (O78)-Pasteurella anatipestifer bacterin in white pekin ducks.

A combination Escherichia coli serotype O78 and Pasteurella anatipestifer bacterin was developed and tested in white pekin ducks in laboratory and field trials. Inoculations with bacterin at 2 and 3 weeks of age provided significant protection against challenge with virulent E. coli O78 and Pasteurella anatipestifer serotypes 1, 2, and 5. No significant cross-protection was observed against heterologous E. coli serotypes, although there was a slight reduction in mortality in ducklings challenged with E. coli serotypes O2a and O119. In field trials, the E. coli-P. anatipestifer bacterin produced significant reduction of mortality in commercial white pekin ducks compared with P. anatipestifer bacterin.

Animals↗
PubMed1990

Vaccination of sheep with cell culture grown orf virus.

Orf virus, derived from contagious pustular dermatitis (scabby mouth) lesions in sheep, was adapted to cell culture and subsequently evaluated as a potential vaccine for sheep. The traditional vaccine virus, prepared from the infected scabs of orf virus lesions in sheep, was used to vaccinate sheep by scratching with an applicator (mounted pins) dipped in virus. Less than 10 TCID50 (50% tissue culture infectious doses) of virus was required to produce large lesions (greater than 5 mm diameter) which developed during a period of 10 to 14 d prior to onset of healing which was complete by 28 to 30 d. A serum neutralising antibody response was also detected and protection against challenge by application of virulent virus to abraded skin was demonstrated in that challenge lesions developed and healed more quickly (14 d against 30 d). However, cell culture-adapted virus required more than 10(5) TCID50 to induce even small lesions (less than 2 mm diameter). An antibody response could not be detected and no evidence of protection against challenge with virulent virus was demonstrated. In contrast, a recent field isolate has yielded a cell culture-adapted virus preparation that readily infects sheep, produces large lesions, detectable antibody and protects against challenge. This isolate is distinct from the traditional vaccine strain on the basis of restriction enzyme analysis but provides cross-protection in sheep inmmunisation and challenge studies. These results demonstrate that a cell culture produced scabby mouth vaccine is feasible.

Animals↗
PubMed1993

Bordetella pertussis and Bordetella parapertussis: two immunologically distinct species.

Bordetella pertussis and Bordetella parapertussis are closely related species. Both are responsible for outbreaks of whooping cough in humans and produce similar virulence factors, with the exception of pertussis toxin, specific to B. pertussis. Current pertussis whole-cell vaccine will soon be replaced by acellular vaccines containing major adhesins (filamentous hemagglutinin and pertactin) and major toxin (pertussis toxin). All of these factors are antigens that stimulate a protective immune response in the murine respiratory model and in clinical assays. In the present study, we examined the protective efficacies of these factors, and that of adenylate cyclase-hemolysin, another B. pertussis toxin, against B. parapertussis infection in a murine respiratory model. As expected, pertussis toxin did not protect against B. parapertussis infection, since this bacterium did not express this protein, but the surprising result was that none of the other factors were protective against B. parapertussis infection. Furthermore, B. parapertussis adenylate cyclase-hemolysin, although it protected against B. parapertussis infection, did not protect against B. pertussis infection. Despite a high degree of homology between both B. pertussis and B. parapertussis species, no cross-protection was observed. Our results outline the fact that, as in other gram-negative bacteria, Bordetella surface proteins vary immunologically.

Adenylate Cyclase Toxin↗
PubMed1995

Protein-protein interactions in colicin E9 DNase-immunity protein complexes. 2. Cognate and noncognate interactions that span the millimolar to femtomolar affinity range.

The in vivo and in vitro cross-binding of the colicin endonuclease-specific immunity proteins toward the DNase domain of colicin E9 is described. In vivo cross-protection was tested by toxin plate assays in which bacterial cells overexpressing each immunity (Im2, Im7, Im8, and Im9) were challenged with the ColE9 toxin. Im9, the cognate immunity protein, renders cells completely resistant toward very high concentrations of the toxin (> 1 mg/mL), whereas the noncognate immunities display a spectrum of weaker cross-reactivities (< 0.01 mg/mL). The order of biological protection in this assay was Im9 >> Im2 > Im8, with Im7 providing no colicin E9 resistance. In vitro binding between the immunity proteins and the E9 DNase was analyzed by determining the dissociation constants for E9 DNase-Im protein complexes at pH 7.0 in the presence of 200 mM salt and at 25 degrees C. Stopped-flow fluorescence experiments suggest that both Im2 and Im8 associate with the E9 DNase by a two-step mechanism, in which the rate constants for both the bimolecular association (k1 = approximately 6 x 10(7) M-1 s-1) and the subsequent conformational change (k2 + k-2 = 4-5 s-1) are very similar to Im9 binding under the same conditions. Fluorescence chase experiments defined the dissociation rate constants for Im2 and Im8. The estimated values are 10(6)- and 10(8)-fold, respectively, faster than the off-rate for the Im9 protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial Proteins↗
PubMed2003

A DNA vaccine directed against a rainbow trout rhabdovirus induces early protection against a nodavirus challenge in turbot.

A DNA vaccine encoding the envelope glycoprotein from a fish rhabdovirus, viral hemorrhagic septicemia virus (VHSV), has previously been shown to induce both early and long time protection against the virus in rainbow trout. Challenge experiments have revealed that the immunity established shortly after vaccination is cross-protective against heterologous fish rhabdoviruses. In this study, we show that the DNA vaccine encoding the VHSV glycoprotein also induces early protection against a non-enveloped, positive-sense RNA virus belonging to the Nodavirus family, the Atlantic halibut nodavirus (AHNV). In a vaccine efficacy test using juvenile turbot as model fish, the fish injected with the VHSV vaccine were completely protected against a nodavirus challenge performed 8 days post vaccination, while the cumulative mortality in the control group reached 54%. A DNA vaccine carrying the gene encoding the capsid protein of AHNV revealed no protective properties against the nodavirus challenge. Histological examination of muscle tissue sections from the vaccine injection site showed that the DNA vaccine against VHSV triggered a pronounced inflammatory response in turbot similar to what has earlier been observed in rainbow trout.

Animals↗
PubMed1989

Comparison of different vaccines and induced immune response against Campylobacter jejuni colonization in the infant mouse.

The degree of protection conferred by vaccinated dams on infant mice against colonization by Campylobacter jejuni depended on the bacterial strain, preparation, and route of administration of the vaccine. In some instances of homologous protection, serum bactericidal titres correlated well with protection. However, boiled C. jejuni vaccine, which was non-protective, also elicited a strong bactericidal antibody response. Conversely, bactericidal activity could not be demonstrated against strains capable of cross-protection. There was a good correlation between high campylobacter-specific IgG response and bactericidal activity.

Administration, Oral↗