Age-seroprevalence curves for the multi-strain structure of influenza A virus

The relationship between age and seroprevalence can be used to estimate the annual attack rate of an infectious disease. For pathogens with multiple serologically distinct strains, there is a need to describe composite exposure to an antigenically variable group of pathogens. In this study, we assay 24,402 general-population serum samples, collected in Vietnam between 2009 to 2015, for antibodies to eleven human influenza A strains. We report that a principal components decomposition of antibody titer data gives the first principal component as an appropriate surrogate for seroprevalence; this results in annual attack rate estimates of 25.6% (95% CI: 24.1% – 27.1%) for subtype H3 and 16.0% (95% CI: 14.7% – 17.3%) for subtype H1. The remaining principal components separate the strains by serological similarity and associate birth cohorts with their particular influenza histories. Our work shows that dimensionality reduction can be used on human antibody profiles to construct an age-seroprevalence relationship for antigenically variable pathogens.

Large scale multiple sequence alignment of intraspecies samples: conserved sequence analysis of influenza A virus HA segment and its application in rapid typing

Background The high mutation rate of influenza A virus hemagglutinin segment brings great challenges to its long-term effective testing and subtyping. Method We analyzed the conserved sequences of hemagglutinin subtype H1-H9 by breadth first, and designed primers for HA subtyping based on conserved sequences. Results Our conserved sequence searching method get high specificity conserved sequences on H1-H9 subtypes respectively. And PCR experiments show that primers based on conserved sequences can be used in influenza A virus HA subtyping. Conclusions Conserved sequences based primers are expected to be the long-term effective influenza A virus HA subtyping tools.

Skin microbiome modulation induced by probiotic solutions

BackgroundThe skin is colonized by a large number of microorganisms, of which most are beneficial or harmless. However, disease states of skin have specific microbiome compositions that are different from those of healthy skin. Gut microbiome modulation through fecal transplant has proven as a valid therapeutic strategy in diseases such as Clostridium difficile infections. Therefore, techniques to modulate the skin microbiome composition may become an interesting therapeutic option in diseases affecting the skin such as psoriasis or acnes vulgaris.Here we have used mixtures of different skin microbiome components to alter the composition of a recipient skin microbiome.ResultsWe show that after sequential applications of a donor microbiome, the recipient microbiome becomes similar to that of the donor. After intervention, an initial, week-long phase is characterized by dominance of donor strains. The level of engraftment depends on the composition of the recipient and donor microbiomes, and the applied bacterial load. We observed higher engraftment using a multi-strain donor solution with recipient skin rich in Cutibacterium acnes subtype H1 and Leifsonia.ConclusionsWe have demonstrated the use of living bacteria to modulate skin microbiome composition.