Fig. 1

Microbiome analyses of fecal samples collected from V. vulnificus-infected mice. A Abundance of the bacterial phyla in fecal samples of V. vulnificus-infected mice. After the oral infection of mice with V. vulnificus, their fecal samples were collected from the cages individually containing dead mice (n = 5). Mice orally injected with V. vulnificus-free PBS were used as a negative control (n = 4). Each fecal sample was subjected to 16S rDNA sequencing to analyze the microbial community as described in “Methods.” The bacterial phyla are differently colored as indicated below the bar chart. All phyla comprising less than 1.0 % of the total abundance (whether classified or not) were combined into the “etc” category. B Principal coordinate analysis (PCoA) clustering of the bacterial communities in the mouse fecal samples. Community structures of microbiome derived from sequencing analysis of 16S rDNAs in the fecal samples of V. vulnificus-infected dead mice and PBS-treated control mice were subjected to PCoA based on Jensen-Shannon distance method. A resultant plot was generated across the samples, in which the black and red circles represent the species composition of PBS-treated mice and V. vulnificus-infected dead mice, respectively (PERMANOVA, P = 0.024). C and D Comparison of relative abundance of Bacteroidetes and Bacteroides vulgatus in the mouse fecal samples. The percentages of 16S rDNA copies belonged to the phylum Bacteroidetes (C) and the species of B. vulgatus (D) in the fecal samples of V. vulnificus-infected dead mice were compared with those of PBS-treated control mice. Their distribution was plotted with each median value, and statistical significance between two groups was determined using the Mann-Whitney U test