Early-life development of the respiratory microbiome : -cystic fibrosis and healthy infants-

Background Negative and positive associations between bacterial species have been described in the respiratory tract. Vaccination is a modifier of these interactions. Although appreciable levels of success have been achieved with current pneumococcal conjugate vaccines, there is a need for alternative pneumococcal serotype-independent protection strategies. Over the past decades, most of CF research focused on respiratory end-stage lung disease. However, the origins and initiating factors in CF lung disease might determine the progression, severity, and disease burden later in life. Understanding the origins, quantifying the initial defects, and intervening early could make a long-term difference for people with Cystic Fibrosis disease. Methods We studied the immunogenicity of virulence proteins of S. pneumoniae and S. aureus. We also describe the long-term impact of the current pneumococcal conjugate vaccines (PCV7) on bacterial colonization with other potential pathogens that are living in a complex interaction with S. pneumoniae and the host. Furthermore we characterized respiratory microbiota community composition of 20 young cystic fibrosis (CF) patients and 45 healthy controls, by culture-dependent and novel culture independent techniques in the nasopharynx (NP), oropharynx (OP) and lower respiratory tract. Results We observed that colonization with S. pneumoniae and S. aureus leads to natural immunity against many proteins, predominantly proteins with immune-modulating functions, irrespective of PCV7 vaccination. None of the antibodies, however, appeared to be protective against new acquisition of either pathogen, possibly due to the polymorphic nature of those proteins. Furthermore we detected 3 and 4.5 years after PCV7 implementation in the NIP in the Netherlands higher carriage rates of S. aureus and H. influenzae among 11-month-old children and their parents. We determined that directly from birth on, the development of nasopharyngeal microbial colonization profiles including the commensal flora is different in CF infants compared to controls. Additionally, already the first antibiotic (AB) courses and prophylaxis early in life alter the respiratory microbiota, with a significant reduction in potential beneficial commensals and a significant increase in potentially pathogenic gram-negative bacteria although fortunately still in low abundance. With respect to microbial diagnostics in CF infants, OP microbiota profiles resemble lung microbiota more closely than NP microbiota for commensals but not for clinical important potential respiratory pathogens, which were most commonly detected in NP samples. Conclusions Our data underline that the optimal composition of a protein vaccine needs to be multi-component, that the candidate protein antigens should be surface exposed and that these proteins should be expressed by the majority of clinical isolates belonging to diverse lineages.Higher carriage rates of S. aureus and H. influenzae may have implications for (respiratory) disease incidence caused by these bacteria in the PCV7 vaccinated childhood population. Further, large, long-term, and placebo-controlled studies are required to prove the potential negative side-effects of diverse types of AB-prophylaxis in infants with CF. Finally, our data suggest that the lungs of infants with CF may have their own independent functional ecosystem that seems seeded by, but is not identical to, the URT ecosystem

Early-life development of the respiratory microbiome : -cystic fibrosis and healthy infants-

Background Negative and positive associations between bacterial species have been described in the respiratory tract. Vaccination is a modifier of these interactions. Although appreciable levels of success have been achieved with current pneumococcal conjugate vaccines, there is a need for alternative pneumococcal serotype-independent protection strategies. Over the past decades, most of CF research focused on respiratory end-stage lung disease. However, the origins and initiating factors in CF lung disease might determine the progression, severity, and disease burden later in life. Understanding the origins, quantifying the initial defects, and intervening early could make a long-term difference for people with Cystic Fibrosis disease. Methods We studied the immunogenicity of virulence proteins of S. pneumoniae and S. aureus. We also describe the long-term impact of the current pneumococcal conjugate vaccines (PCV7) on bacterial colonization with other potential pathogens that are living in a complex interaction with S. pneumoniae and the host. Furthermore we characterized respiratory microbiota community composition of 20 young cystic fibrosis (CF) patients and 45 healthy controls, by culture-dependent and novel culture independent techniques in the nasopharynx (NP), oropharynx (OP) and lower respiratory tract. Results We observed that colonization with S. pneumoniae and S. aureus leads to natural immunity against many proteins, predominantly proteins with immune-modulating functions, irrespective of PCV7 vaccination. None of the antibodies, however, appeared to be protective against new acquisition of either pathogen, possibly due to the polymorphic nature of those proteins. Furthermore we detected 3 and 4.5 years after PCV7 implementation in the NIP in the Netherlands higher carriage rates of S. aureus and H. influenzae among 11-month-old children and their parents. We determined that directly from birth on, the development of nasopharyngeal microbial colonization profiles including the commensal flora is different in CF infants compared to controls. Additionally, already the first antibiotic (AB) courses and prophylaxis early in life alter the respiratory microbiota, with a significant reduction in potential beneficial commensals and a significant increase in potentially pathogenic gram-negative bacteria although fortunately still in low abundance. With respect to microbial diagnostics in CF infants, OP microbiota profiles resemble lung microbiota more closely than NP microbiota for commensals but not for clinical important potential respiratory pathogens, which were most commonly detected in NP samples. Conclusions Our data underline that the optimal composition of a protein vaccine needs to be multi-component, that the candidate protein antigens should be surface exposed and that these proteins should be expressed by the majority of clinical isolates belonging to diverse lineages.Higher carriage rates of S. aureus and H. influenzae may have implications for (respiratory) disease incidence caused by these bacteria in the PCV7 vaccinated childhood population. Further, large, long-term, and placebo-controlled studies are required to prove the potential negative side-effects of diverse types of AB-prophylaxis in infants with CF. Finally, our data suggest that the lungs of infants with CF may have their own independent functional ecosystem that seems seeded by, but is not identical to, the URT ecosystem

Detection of natural antibodies and serological diagnosis of pneumococcal pneumonia using a bead-based high-throughput assay

Surface-exposed proteins of pathogenic bacteria play a critical role during infections. The vast majority of these molecules are able to trigger strong immune responses. Measuring the humoral immune response against pathogenic bacteria through less-time consuming tests is necessary to reduce the window time for the diagnosis of diseases that may be associated with high morbidity and mortality rates. Due to the multiplex setup, Luminex xMAP® technology allows analysis of immune responses against many antigens in a single assay. Therefore, less volumes of sera samples are needed and inter assay coefficient of variation is much lower in comparison with other immunoassays. With this methodology, the carboxyl groups on the surface of the polystyrene microspheres must first be activated with a carbodiimide derivative prior to coupling antigens. After the antigen is coupled to a microsphere, different microspheres (all having a unique color) can be combined whereafter the presence of specific antibodies directed against the different antigens in sera can be determined simultaneously. The platform here described can also be useful for epidemiological surveillance programs and vaccine studies.</p

Nasopharyngeal Colonization Elicits Antibody Responses to Staphylococcal and Pneumococcal Proteins That Are Not Associated with a Reduced Risk of Subsequent Carriage

Knowledge of the immunological correlates of Staphylococcus aureus and Streptococcus pneumoniae colonization is required for the search for future protein vaccines. We evaluated natural antibody levels against pneumococcal and staphylococcal proteins in relation to previous bacterial colonization with both pathogens. In a randomized controlled trial, nasopharyngeal samples were obtained from children at 1.5, 6, 12, 18, and 24 months and cultured for S. aureus and S. pneumoniae. Approximately 50% of the children were PCV7 vaccinated. Serum IgG against 18 pneumococcal and 40 staphylococcal proteins was semiquantified by Luminex technology from 111 12 month olds and 158 24 month olds. Previous culture-proven S. aureus colonization was associated with higher IgG levels against 6/40 staphylococcal proteins (ClfB, ClfA, Efb, CHIPS, LukD, and LukF [P <= 0.001]) compared to noncarriers. Previous pneumococcal colonization was associated with increased IgG levels against 12/18 pneumococcal proteins compared to noncarriers (P <= 0.003). Increasing age was associated with higher levels of antibodies to most pneumococcal proteins and lower levels of antibodies to over half the staphylococcal proteins, reflecting natural colonization dynamics. Anti-S. pneumoniae and anti-S. aureus protein antibodies at the age of 12 months were not negatively correlated with subsequent colonization with the homologous species in the following year and did not differ between PCV7-vaccinated and nonvaccinated children. Colonization with S. aureus and S. pneumoniae induces serum IgG against many proteins, predominantly proteins with immune-modulating functions, irrespective of PCV7 vaccination. None of them appeared to be protective against new acquisition with both pathogens, possibly due to the polymorphic nature of those proteins in the circulating bacterial population