Partners of patients with ulcerative colitis exhibit a biologically relevant dysbiosis in fecal microbial metacommunities.

AIM: To investigate alterations in the fecal microbiome using 16S rRNA amplicon sequencing in couples in the same cohabitation environment. METHODS: Fecal samples were collected from eight ulcerative colitis (UC) patients and their healthy partners at Lishui People's Hospital, Zhejiang Province, China. DNA was extracted and the variable regions V3 and V4 of the 16S rRNA genes were PCR amplified using a two-step protocol. Clear reads were clustered into operational taxonomic units (OTUs) at the 97% sequence similarity level using UCLUST v1.2.22. The Wilcoxon rank-sum test (R v3.1.2) was used to compare inter-individual differences. Differences with a P value < 0.05 were considered statistically significant. RESULTS: Fecal microbial communities were more similar among UC patients than their healthy partners (P = 0.024). UC individuals had a lower relative abundance of bacteria belonging to the Firmicutes, especially Blautia, Clostridium, Coprococcus and Roseburia (P < 0.05). Microbiota dysbiosis was detected in UC patients and their healthy partners. Relevant genera included Akkermansiam, Bacteroides, Escherichia, Lactobacillales, Klebsiella and Parabacteroides. The enriched pathways in fecal samples of UC patients were related to lipid and nucleotide metabolism. Additionally, the pathways involved in membrane transport and metabolism of cofactors and vitamins were more abundant in the healthy partners. CONCLUSION: Our results suggested that the microbial composition might be affected in healthy partners cohabiting with UC patients, especially in terms of microbiota dysbiosis.

Intra-host dynamics of Ebola virus during 2014.

Since 2013, West Africa has encountered the largest Ebola virus (EBOV) disease outbreak on record, and Sierra Leone is the worst-affected country, with nearly half of the infections. By means of next-generation sequencing and phylogeographic analysis, the epidemiology and transmission of EBOV have been well elucidated. However, the intra-host dynamics that mainly reflect viral-host interactions still need to be studied. Here, we show a total of 710 intra-host single nucleotide variations (iSNVs) from deep-sequenced samples from EBOV-infected patients, through a well-tailored bioinformatics pipeline. We present a comprehensive distribution of iSNVs during this outbreak and along the EBOV genome. Analyses of iSNV and its allele frequency reveal that VP40 is the most conserved gene during this outbreak, and thus it would be an ideal therapeutic target. In the co-occurring iSNV network, varied iSNV sites present different selection features. Intriguingly, the T-to-C substitutions at the 3'-UTR of the nucleoprotein (NP; positions 3008 and 3011), observed in many patients, result in the upregulation of the transcription of NP through an Ebola mini-genome reporting system. Additionally, no iSNV enrichment within B-cell epitopes of GP has been observed.

Genetic diversity and evolutionary dynamics of Ebola virus in Sierra Leone.

A novel Ebola virus (EBOV) first identified in March 2014 has infected more than 25,000 people in West Africa, resulting in more than 10,000 deaths. Preliminary analyses of genome sequences of 81 EBOV collected from March to June 2014 from Guinea and Sierra Leone suggest that the 2014 EBOV originated from an independent transmission event from its natural reservoir followed by sustained human-to-human infections. It has been reported that the EBOV genome variation might have an effect on the efficacy of sequence-based virus detection and candidate therapeutics. However, only limited viral information has been available since July 2014, when the outbreak entered a rapid growth phase. Here we describe 175 full-length EBOV genome sequences from five severely stricken districts in Sierra Leone from 28 September to 11 November 2014. We found that the 2014 EBOV has become more phylogenetically and genetically diverse from July to November 2014, characterized by the emergence of multiple novel lineages. The substitution rate for the 2014 EBOV was estimated to be 1.23 × 10(-3) substitutions per site per year (95% highest posterior density interval, 1.04 × 10(-3) to 1.41 × 10(-3) substitutions per site per year), approximating to that observed between previous EBOV outbreaks. The sharp increase in genetic diversity of the 2014 EBOV warrants extensive EBOV surveillance in Sierra Leone, Guinea and Liberia to better understand the viral evolution and transmission dynamics of the ongoing outbreak. These data will facilitate the international efforts to develop vaccines and therapeutics.