Burns, M. | Search bioRxiv

bioRxiv2018

Co-circulating mumps lineages at multiple geographic scales

Despite widespread vaccination, eleven thousand mumps cases were reported in the United States (US) in 2016-17, including hundreds in Massachusetts, primarily in college settings. We generated 203 whole genome mumps virus (MuV) sequences from Massachusetts and 15 other states to understand the dynamics of mumps spread locally and nationally, as well as to search for variants potentially related to vaccination. We observed multiple MuV lineages circulating within Massachusetts during 2016-17, evidence for multiple introductions of the virus to the state, and extensive geographic movement of MuV within the US on short time scales. We found no evidence that variants arising during this outbreak contributed to vaccine escape. Combining epidemiological and genomic data, we observed multiple co-circulating clades within individual universities as well as spillover into the local community. Detailed data from one well-sampled university allowed us to estimate an effective reproductive number within that university significantly greater than one. We also used publicly available small hydrophobic (SH) gene sequences to estimate migration between world regions and to place this outbreak in a global context, but demonstrate that these short sequences, historically used for MuV genotyping, are inadequate for tracing detailed transmission. Our findings suggest continuous, often undetected, circulation of mumps both locally and nationally, and highlight the value of combining genomic and epidemiological data to track viral disease transmission at high resolution.

genomics↗

bioRxiv2017

Interaction Between Host MicroRNAs and the Gut Microbiota in Colorectal Cancer

BackgroundAlthough variation in gut microbiome composition has been linked with colorectal cancer (CRC), the factors that mediate the interactions between CRC tumors and the microbiome are poorly understood. MicroRNAs (miRNAs) are known to regulate CRC progression and patient survival outcomes. In addition, recent studies suggested that host miRNAs can also regulate bacterial growth and influence the composition of the gut microbiome. Here, we investigated the association between miRNAs expression in human CRC tumor and normal tissues and the microbiome composition associated with these same tissues.\n\nMethodWe sequenced the small RNAs from patient-matched tumor and normal tissue samples collected from 44 human CRC patients performed an integrated analysis with microbiome taxonomic composition data from these same samples. We then interrogated the functions of the bacteria correlated with miRNAs that were differentially expressed (DE) between tumor and matched normal tissues, as well as the functions of miRNAs correlated with bacterial taxa that have been previously associated with CRC, including Fusobacterium, Providencia, Bacteroides, Akkermansia, Roseburia, Porphyromonas, and Peptostreptococcus.\n\nResultsWe identified 76 miRNAs as DE between CRC and normal tissue, including known oncogenic miRNAs miR-182, miR-503, and miR-17[~]92. These DE miRNAs were correlated with the relative abundance of several bacterial taxa, including Firmicutes, Bacteroidetes, and Proteobacteria. Bacteria correlated with DE miRNAs were enriched with distinct predicted metabolic categories. Additionally, we found that miRNAs correlated with CRC-associated bacteria are predicted to regulate targets that are relevant for host-microbiome interactions, and highlight a possible role for miRNA-driven glycan production in the recruitment of pathogenic microbial taxa.\n\nConclusionsOur work characterized a global relationship between microbial community composition and miRNA expression in human CRC tissues. Our results support a role for miRNAs in mediating a bi-directional host-microbiome interaction in CRC. In addition, we highlight sets of potentially interacting microbes and host miRNAs, suggesting several pathways that can be targeted via future therapies.

systems biology↗