RESUMO
One of the candidate proteins for a mucosal vaccine antigen against Streptococcus pneumoniae is PsaA (pneumococcal surface antigen A). Vaccines targeting mucosal immunity may raise concerns as to possible alterations in the normal microbiota, especially in the case of PsaA, which was shown to have homologs with elevated sequence identity in other viridans group streptococci. In this work, we demonstrate that intranasal immunization with a cholera toxin B subunit-PsaA fusion protein is able to protect mice against colonization with S. pneumoniae but does not significantly alter the natural oral or nasopharyngeal microbiota of mice.
Assuntos
Anticorpos Antibacterianos/sangue , Proteínas de Bactérias/administração & dosagem , Toxina da Cólera/administração & dosagem , Vacinas Pneumocócicas/administração & dosagem , Proteínas Recombinantes de Fusão/administração & dosagem , Streptococcus pneumoniae/imunologia , Administração Intranasal , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Proteínas de Bactérias/metabolismo , Toxina da Cólera/genética , Toxina da Cólera/imunologia , Toxina da Cólera/metabolismo , Feminino , Bactérias Gram-Positivas/crescimento & desenvolvimento , Bactérias Gram-Positivas/isolamento & purificação , Imunização , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Camundongos , Camundongos Endogâmicos C57BL , Boca/microbiologia , Nasofaringe/microbiologia , Infecções Pneumocócicas/imunologia , Infecções Pneumocócicas/microbiologia , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/imunologia , Proteínas Recombinantes de Fusão/imunologia , Streptococcus pneumoniae/crescimento & desenvolvimentoRESUMO
One of the candidate proteins for a mucosal vaccine antigen against Streptococcus pneumoniae is PsaA (pneumococcal surface antigen A). Vaccines targeting mucosal immunity may raise concerns as to possible alterations in the normal microbiota, especially in the case of PsaA, which was shown to have homologs with elevated sequence identify in other viridans group streptococci. In this work, we demonstrate that intranasal immunization with a cholera toxin B subunit-PsaA fusion protein is able to protect mice against colonization with S. pneumoniae but does not significantly alter the natural oral or nasopharyngeal microbiota of mice.
Assuntos
Feminino , Animais , Ratos , Infecções Pneumocócicas/imunologia , Infecções Pneumocócicas/microbiologia , Infecções Pneumocócicas/prevenção & controle , Nasofaringe/microbiologia , Streptococcus pneumoniae/crescimento & desenvolvimento , Streptococcus pneumoniae/imunologia , Vacinas Pneumocócicas/administração & dosagem , Vacinas Pneumocócicas/imunologia , Bactérias Gram-Positivas/crescimento & desenvolvimento , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Proteínas de Bactérias/administração & dosagem , Proteínas de Bactérias/imunologia , Toxina da Cólera/genética , Toxina da Cólera/imunologiaRESUMO
Nasopharyngeal carriage of Streptococcus pneumoniae is a key factor in the development of invasive disease and the spread of resistant strains within the community. A single nasopharyngeal swab was obtained from 648 unvaccinated children aged <5 years, either healthy or with acute respiratory tract infection or meningitis, during the winters of 2000 and 2001. The overall pneumococcal carriage rate was 35.8% (95% CI 32.1-39.6). The pneumococcal serotypes found most frequently in the nasopharynx were 14, 6B, 6A, 19F, 10A, 23F and 18C, which included five of the seven serotypes in the currently licensed seven-valent conjugate vaccine (PCV7); serotypes 4 and 9V were less common. Serotypes 1 and 5 were isolated rarely from the nasopharynx. A comparison of 222 nasopharyngeal isolates with 125 invasive isolates, matched for age and time to the carrier isolates, showed a similar prevalence of penicillin non-susceptible pneumococci (PNSp) (19.8% and 19.2%, respectively). PNSp serotypes were similar (6B, 14, 19F, 19 A, 23B and 23F) for carriage and invasive disease isolates. The coverage of PCV7 for carriage isolates (52.2%) and invasive isolates (62.4%) did not differ significantly (p 0.06); similarly, there was no significant difference in PCV7 coverage for carriage isolates (34.5%) and invasive isolates (28.2%) of PNSp. These data suggest that PCV7 has the potential to reduce pneumococcal carriage and the number of carriers of PNSp belonging to vaccine serotypes.