RESUMO
The aim of this study was to evaluate the titers of neutralizing antibodies in cattle inoculated with multivalent commercial clostridial vaccines containing C. botulinum type C (BoNTC), C. botulinum type D (BoNTD), and C. perfringens epsilon (ETX) toxoids for a period of one year. Cattle (Bos taurus), aged 4-6 months and not previously immunized, were vaccinated under four different protocols at days 0 and 30 and followed over one year. Individual serum titration was performed by a serum neutralization test in mice or in MDCK cells. The number of animals with detectable neutralizing antibodies ranged from 40.6% to 78.1%, but only 12.5% of animals showed neutralizing antibodies against all tested antigens. Neutralizing antibodies were found only until 60 days for ETX, 120 days for BoNTC, and 180 days for BoNTD. The absence of detectable neutralizing antibodies against the three antigens before 360 days, suggests that cattle remained unprotected for a long period before the recommended booster vaccination.
Assuntos
Toxinas Bacterianas/imunologia , Toxinas Botulínicas/imunologia , Imunidade Humoral , Toxoides/imunologia , Animais , Antitoxinas/sangue , Bovinos , Cães , Células Madin Darby de Rim Canino , Camundongos , Testes de Neutralização , Fatores de Tempo , Toxoides/administração & dosagemRESUMO
This study assessed the protective effect of active immunization of cattle to prevent the envenomation induced by B. asper venom. Two groups of oxen were immunized with a bothropic toxoid and challenged by an intramuscular injection of either 10 or 50 mg B. asper venom, to induce moderate or severe envenomations, respectively. Non-immunized oxen were used as controls. It was found that immunized oxen developed local edema similar to those observed in non-immunized animals. However, systemic effects were totally prevented in immunized oxen challenged with 10 mg venom, and therefore antivenom treatment was not required. When immunized oxen were challenged with 50 mg venom, coagulopathy was manifested 3-16 h later than in non-immunized oxen, demonstrating a delay in the onset of systemic envenomation. In these animals, active immunization did not eliminate the need for antivenom treatment, but increased the time lapse in which antivenom administration is still effective. All experimentally envenomed oxen completely recovered after a week following venom injection. Our results suggest that immunization of cattle with a bothropic toxoid prevents the development of systemic effects in moderate envenomations by B. asper, but does not abrogate these effects in severe envenomation.
Assuntos
Doenças dos Bovinos/prevenção & controle , Venenos de Crotalídeos/toxicidade , Mordeduras de Serpentes/veterinária , Toxoides/administração & dosagem , Vacinação , Animais , Antivenenos/imunologia , Antivenenos/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Testes de Coagulação Sanguínea , Bothrops/imunologia , Bovinos , Doenças dos Bovinos/induzido quimicamente , Doenças dos Bovinos/imunologia , Venenos de Crotalídeos/administração & dosagem , Relação Dose-Resposta a Droga , Edema/induzido quimicamente , Edema/imunologia , Edema/prevenção & controle , Injeções Intramusculares , Masculino , Substâncias Protetoras/administração & dosagem , Mordeduras de Serpentes/imunologia , Mordeduras de Serpentes/prevenção & controle , Análise de Sobrevida , Fatores de Tempo , Toxoides/imunologia , Resultado do TratamentoRESUMO
Cattle botulism is a fatal intoxication caused by botulinum neurotoxins (BoNTs) produced by Clostridium botulinum serotypes C and D resulting in economic losses. Vaccination is the most effective way to control botulism. However, the commercially available vaccines are difficult and hazardous to produce. Neutralizing antibodies against the C-terminal fragment of the BoNT heavy chain (HC) are known to protect against lethal doses of BoNTs. We report the vaccination of cattle with a previously tested recombinant chimera consisting of Escherichia coli heat-labile enterotoxin B subunit and the HC of BoNTs C and D. Vaccinated animals produced neutralizing antibodies against serotypes C and D averaging 5±0 and 6.14±1.06IU/mL, respectively. For BoNT D, the titers were greater than those measured for the commercial vaccine, which induced titers of 5±0 and 2.85±1.35 against the respective serotypes, suggesting that this chimera is effective against cattle botulism.
Assuntos
Vacinas Bacterianas/uso terapêutico , Toxinas Botulínicas/imunologia , Botulismo/veterinária , Bovinos/imunologia , Toxoides/imunologia , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Neutralizantes/sangue , Toxinas Bacterianas/imunologia , Botulismo/prevenção & controle , Clostridium botulinum , Enterotoxinas/imunologia , Proteínas de Escherichia coli/imunologia , Masculino , Proteínas Recombinantes/imunologia , Vacinação/veterináriaRESUMO
Due to the increasingly restricted use of antimicrobials in animal production systems, the prevention and control of Clostridium perfringens type A- and C-induced diarrhea in piglets should be based on passive immunization via the prepartum vaccination of sows. Given the current obstacles in the production of conventional clostridial vaccines, the use of recombinant proteins has been considered to represent a promising alternative. In the present study, the neutralizing antibody response of immunized sows and their litters to a bivalent vaccine containing the C. perfringens recombinant toxoids alpha (rTA) and beta (rTB) produced in Escherichia coli was assessed. Rabbits (n=8) and pregnant sows (n=7) were immunized with 200µg of each recombinant antigen using Al(OH)3 as adjuvant. The alpha and beta antitoxin titer detected in the rabbits' serum pool was 9.6 and 20.4IU/mL, respectively. The mean alpha and beta antitoxin titers in the sows' sera were 6.0±0.9IU/mL and 14.5±2.2IU/mL, and the corresponding individual coefficients of variation (CV) were 16.04% and 14.91%, respectively. The mean alpha and beta antitoxin titers in the litters' serum pools were 4.2±0.4IU/mL and 10.9±1.7IU/mL, and the CV between litters was 9.23% and 9.85%, respectively. The results showed that the rTA and rTB proteins produced and tested in the present study induced an immune response and can be regarded as candidates for the development of a commercial vaccine against C. perfringens type A- and C-induced diarrhea in pigs.
Assuntos
Vacinas Bacterianas/imunologia , Imunidade Humoral/imunologia , Imunização Passiva , Doenças dos Suínos/imunologia , Toxoides/imunologia , Animais , Animais Recém-Nascidos , Anticorpos Neutralizantes , Vacinas Bacterianas/genética , Vacinas Bacterianas/farmacologia , Infecções por Clostridium/prevenção & controle , Infecções por Clostridium/veterinária , Diarreia/microbiologia , Diarreia/prevenção & controle , Diarreia/veterinária , Escherichia coli/genética , Feminino , Gravidez , Coelhos , Suínos , Doenças dos Suínos/prevenção & controle , Toxoides/genética , Resultado do TratamentoRESUMO
A non-toxic protein (TsNTxP) isolated from the venom of the noxious scorpion Tityus serrulatus (Ts) induces polyclonal antibodies cross-reactive with several toxins from the venom, in sharp contrast to anti-toxin antibodies which are toxin specific. To try to uncover the molecular basis for these unusual properties, peptide scanning experiments were performed and indicated that the N- and C-terminal parts of TsNTxP enclose continuous epitopes (residues 1-15 and 47-61). Antibodies raised against peptides corresponding to these two regions were found to have neutralizing properties against a mixture of all toxic proteins from the T. serrulatus venom, indicating that residues 1-15 and 47-61 correspond to neutralizing epitopes. The identification of key antigenic residues within these two epitopes revealed that several of them are well conserved in the amino-acid sequences of the three main toxins (Ts II, Ts IV and Ts VII) from the venom: Glu 3, Tyr 5, Asp 8, Asp 50, Trp 55 and Lys 61. A single key-residue (Glu 58) is unique to TsNTxP. By using homology modeling, a model of the three-dimensional structure of TsNTxP was obtained. The antigenically important residues from TsNTxP were found to be surface exposed, with five of them clustered on the facet of the protein reported to enclose the active site of toxins. Residues equivalent to the seven key-residues of the anatoxin were also found to be exposed in the active toxins from T. serrulatus venom. These results show that antibodies elicited by the non-toxic protein TsNTxP recognized, within the N- and C-terminal parts of toxins of T. serrulatus, conserved and surface exposed residues which might also be involved in the toxic action of the proteins.
Assuntos
Anticorpos/imunologia , Venenos de Escorpião/imunologia , Toxoides/imunologia , Sequência de Aminoácidos , Animais , Reações Cruzadas , Mapeamento de Epitopos , Feminino , Cavalos , Camundongos , Dados de Sequência Molecular , Coelhos , Venenos de Escorpião/química , Toxoides/químicaRESUMO
BACKGROUND: In recent years additional parenteral vaccines have been recommended for routine immunization of infants in the US and elsewhere. The ability to administer multiple vaccines as a single injection without unacceptably increasing reactogenicity or decreasing immunogenicity of any component would offer many practical advantages. METHODS: A randomized, open, controlled trial was conducted to assess the tolerance profile and immunogenicity, as well as to identify potential antigenic interferences, resulting from administration of a parenteral combination vaccine for infants. The vaccine contains diphtheria and tetanus toxoids, acellular pertussis antigens (DTaP), enhanced inactivated poliovirus (eIPV) and Haemophilus influenzae type b-tetanus toxoid conjugate (PRP-T). Infants (n=711) were randomly assigned to receive 1 of 5 regimens as the primary series at 2, 4 and 6 months of age, by group: (1) DTaP plus oral polio vaccine (OPV); (2) DTaP plus eIPV (separate injections); (3) DTaP-eIPV combined as a single injection; (4) DTaP-eIPV combined, plus a separate injection of PRP-T; or (5) DTaP-eIPV combined and reconstituting PRP-T, as a single injection. At 3, 5 and 7 months Groups 1, 2 and 3 received PRP-T. At 12 months all infants received a booster dose of DTaP reconstituting PRP-T as a single injection, plus a separate injection of measles, mumps and rubella vaccine. Groups 2, 3, 4 and 5 received OPV at 7 months, and all infants received OPV at 13 months. Serum immune responses were measured to the primary series at 2 and 7 months and to the booster dose at 12 and 13 months. RESULTS: Reaction rates were similar among groups. In the primary series combining eIPV with DTaP decreased geometric mean titers (GMTs) to diphtheria, tetanus and pertussis. In addition concomitant PRP-T (either simultaneous or combined) with DTaP-eIPV lowered anti-PRP and further decreased tetanus GMTs. Nonetheless in 100% of infants protective titers were achieved against diphtheria and tetanus (>0.01 IU/ml each) and against the poliovirus types 1, 2 and 3 after eIPV (Groups 2 to 5); 99% of infants (Groups 4 and 5) had protective titers against PRP (> or = 0.15 microg/ml). After boosting with DTaP/PRP-T decreased GMTs to diphtheria and PRP antigens were observed in the groups that received DTaP and eIPV combined. Nonetheless protective titers to diphtheria, tetanus and PRP occurred consistently. In contrast concomitant PRP-T with DTaP-eIPV enhanced the pertussis GMTs. CONCLUSIONS: We conclude that combined DTaP, eIPV and PRP-T in a single injection is well-tolerated and elicits an acceptable immune response to each component.
Assuntos
Vacina contra Difteria, Tétano e Coqueluche/administração & dosagem , Vacinas Anti-Haemophilus/administração & dosagem , Vacina Antipólio de Vírus Inativado/administração & dosagem , Toxoide Tetânico/administração & dosagem , Fatores de Virulência de Bordetella , Adesinas Bacterianas/imunologia , Anticorpos Antibacterianos/sangue , Anticorpos Antivirais/sangue , Chile , Toxina Diftérica/imunologia , Vacina contra Difteria, Tétano e Coqueluche/efeitos adversos , Vacina contra Difteria, Tétano e Coqueluche/imunologia , Feminino , Vacinas Anti-Haemophilus/efeitos adversos , Vacinas Anti-Haemophilus/imunologia , Haemophilus influenzae/imunologia , Hemaglutininas/imunologia , Humanos , Esquemas de Imunização , Imunização Secundária , Lactente , Masculino , Poliovirus/imunologia , Vacina Antipólio de Vírus Inativado/efeitos adversos , Vacina Antipólio de Vírus Inativado/imunologia , Vacina Antipólio Oral/administração & dosagem , Vacina Antipólio Oral/efeitos adversos , Vacina Antipólio Oral/imunologia , Toxina Tetânica/imunologia , Toxoide Tetânico/efeitos adversos , Toxoide Tetânico/imunologia , Toxoides/imunologia , Vacinas Combinadas/administração & dosagem , Vacinas Combinadas/efeitos adversos , Vacinas Combinadas/imunologia , Vacinas Conjugadas/administração & dosagem , Vacinas Conjugadas/efeitos adversos , Vacinas Conjugadas/imunologiaRESUMO
For ethical, economic and technical reasons in vivo assays need to be replaced in routine laboratory procedures. Based on a method which is already accepted by the British authorities, an indirect ELISA has been developed and evaluated for Clostridium perfringens type D-containing vaccines. Individual and pooled sera of vaccinated rabbits were tested at a single dilution level, the results transferred into IU/ml, and compared with the conventional toxin neutralization test in mice. The ELISA was found to give reproducible estimates of antitoxin levels and showed good correlation with the conventional in vivo test in mice.
Assuntos
Toxinas Bacterianas/imunologia , Vacinas Bacterianas/normas , Clostridium perfringens/imunologia , Ensaio de Imunoadsorção Enzimática/veterinária , Toxoides/imunologia , Animais , Antígenos de Bactérias/sangue , Antígenos de Bactérias/imunologia , Toxinas Bacterianas/sangue , Vacinas Bacterianas/análise , Calibragem , Testes de Fixação de Complemento , Eletroforese em Gel de Poliacrilamida/veterinária , Camundongos , Coelhos , Padrões de Referência , Reprodutibilidade dos TestesRESUMO
OBJECTIVE: To compare the immunogenicity and reactogenicity of a diphtheria and tetanus toxoids and three-component acellular pertussis vaccine (DTaP) with a diphtheria and tetanus toxoids and whole-cell pertussis vaccine (DTwP) when administered as a booster dose to infants 15 through 20 months of age. DESIGN: Randomized, double-blind, comparative study. SETTING: Three pediatric practices (two private; one hospital-based). PARTICIPANTS: One hundred and sixty-five healthy 15- through 20-month old infants. SELECTION PROCEDURES AND INTERVENTIONS: Infants were randomly assigned in a 2:1 ratio to receive vaccine from a single lot of DTaP or from commercially available DTwP. DTaP contained 25 micrograms of pertussis toxoid, 25 micrograms of filamentous hemagglutinin, 8 micrograms of pertactin (69-kilodalton outer membrane protein), 25 flocculating units of diphtheria toxoid, and 10 flocculating units of tetanus toxoid per 0.5-mL dose. DTwP contained one half the concentrations of diphtheria and tetanus toxoids compared with DTaP and a pertussis component with a potency of 4 U/0.5-mL dose. Serum samples were obtained on the day of immunization and 4 weeks later. Adverse reactions were recorded by parents for 7 days after immunization. An interval history was obtained 4 weeks after immunization. MEASUREMENTS AND RESULTS: IgG antibody to pertussis toxoid, filamentous hemagglutinin, pertactin, diphtheria toxoid, and tetanus toxoid was measured by an indirect enzyme-linked immunosorbent assay (ELISA) method. One month after immunization, the geometric mean antibody levels after DTaP compared with DTwP were: pertussis toxoid, 70.6 vs 28 ELISA U/mL (P = .003); filamentous hemagglutinin, 183.4 vs 43 ELISA U/mL (P < .001); pertactin, 216 vs 49.9 ELISA U/mL (P < .001); diphtheria, 14.1 vs 14.9 IU/mL (P = .74); and tetanus, 11.9 vs 14.8 IU/mL (P = .089). After immunization with DTaP, most local and systemic adverse experiences were significantly fewer compared with DTwP (P < .05). CONCLUSIONS: This three-component DTaP vaccine demonstrates significantly greater immune responses to pertussis toxoid, filamentous hemagglutinin, and pertactin, equivalent immune responses to diphtheria and tetanus toxoids, and significantly less reactogenicity compared with a licensed DTwP.
Assuntos
Vacina contra Difteria, Tétano e Coqueluche/efeitos adversos , Vacina contra Difteria, Tétano e Coqueluche/imunologia , Anticorpos Antibacterianos/sangue , Toxoide Diftérico/imunologia , Método Duplo-Cego , Feminino , Humanos , Imunização Secundária , Lactente , Masculino , Toxoide Tetânico/imunologia , Toxoides/imunologiaRESUMO
Se describe una técnica para la preparación de un toxoide a partir de la fracción hemorrágica del veneno de Bothrops asper. Este método conserva un alto grado de inmunogenecidad aunque elimina los efectos letales. Ninguno de los animales vacunados con el toxoide de esta fracción presentó lesiones hemorrágicas cuando les fue inyectado el veneno de la fracción hemorrágica
Assuntos
Animais , Fracionamento Químico , Intoxicação/prevenção & controle , Venenos de Serpentes/imunologia , Venenos de Serpentes/toxicidade , Toxoides/imunologia , Toxoides/isolamento & purificaçãoRESUMO
A technique is described for preparing a toxoid from the hemorrhagic fraction of the Bothrops asper venom. This method conserves a high degree of immunogenicity although it eliminates lethal effects. None of the animals vaccinated with the toxoid from this fraction had hemorrhagic lesions after they were injected the venom from the hemorrhagic fraction.