Comparative meta-analysis of host transcriptional response during Streptococcus pneumoniae carriage or infection.

Infection with Streptococcus pneumoniae causes over 150,000 cases of pneumonia annually in the United States alone. We performed a meta-analysis of publicly available RNA-sequencing data to compare the host-specific intracellular transcriptional responses that differ between infection and carriage with S. pneumoniae in humans and mice. We applied an automated preprocessing workflow to collections of publicly available fastq files that were categorized as either of two phenotypes-infection or carriage in humans and mice. We identified the differentially expressed genes and intracellular signaling pathways that changed in host cells during infection or carriage and whether these human phenotypes could be appropriately modeled at the molecular level in mice. Although we observed multiple differentially expressed genes shared among multiple comparisons, we found no overlapping significant signaling pathways between the mouse and human studies in either phenotype. Based on the samples included in this secondary analysis, we identified a minimal number of generalized transcriptional relationships between host infection and carriage phenotypes of S. pneumoniae that were consistently shared between the mouse and human hosts. Our findings suggest that additional controlled datasets in mouse and human carriage or infection models are needed to better understand the underlying mechanism(s) of invasion and pathogenesis. This knowledge could then contribute to the development of improved prophylactics and/or therapeutics against this pathogen.

Evaluation of ELISA-Based Multiplex Peptides for the Detection of Human Serum Antibodies Induced by Zika Virus Infection across Various Countries.

Zika virus (ZIKV) is a mosquito-borne Flavivirus with a positive-sense RNA genome, which are generally transmitted through the bite of an infected Aedes mosquito. ZIKV infections could be associated with neurological sequelae that, and otherwise produces similar clinical symptoms as other co-circulating pathogens. Past infection with one member of the Flavivirus genus often induces cross-reactive antibodies against other flaviruses. These attributes complicate the ability to differentially diagnose ZIKV infection from other endemic mosquito-borne viruses, making it both a public health issue as well as a diagnostic challenge. We report the results from serological analyses using arbovirus-specific peptides on 339 samples that were previously collected from 6 countries. Overall, we found that our multiplexed peptide-based ELISA was highly efficient for identifying ZIKV antibodies as early as 2 weeks post infection, and that it correlates with microneutralization, plaque reduction neutralization tests (PRNTs) and commercial tests for ZIKV in previously characterized samples. We observed that seropositivity varied by patient cohort, reflecting the sampling period in relation to the 2015-2016 ZIKV outbreak. This work evaluates the accuracy, specificity, and sensitivity of our peptide-based ELISA method for detecting ZIKV antibodies from geographically diverse regions. These findings can contribute to ongoing serological methods development and can be adapted for use in future studies.