Fig 1.
Physicochemical and culture data of water samples.
For each water supply: n = 3 sites for unchlorinated and 2 sites for chlorinated parts of the supply–total 15 sites. “HighFe”, “MidFe” and “LowFe” mark the three remote water supplies. The colours signify the chlorination status (blue unchlorinated vs orange chlorinated). The bars show the mean and the error bars one standard error. Red “+Bf” mark culture positive biofilms at the corresponding sites. “HPC” Heterotrophic Plate Count, “CFU” Colony Forming Units. A) Total Iron; B) Dissolved Organic Carbon (DOC); C) Redox; D) Heterotrophic plate count; E) free-living amoebae; F) B. pseudomallei positive samples.
Table 1.
Geographical and virulence genetic markers of six B. pseudomallei isolates.
Fig 2.
Phylogenetic tree of B. pseudomallei isolates from the Northern Territory.
Maximum-parsimony phylogenetic tree of 89 B. pseudomallei isolates from the Northern Territory isolated from soil, water or of clinical origin. The tree is based on 174,905 orthologous core-genome SNPs with a consistency index of 0.2. All WGS are accessible on NCBI (S2 Table). Isolates marked with stars are isolates recovered in this study. See Table 1 for details.
Fig 3.
Bacterial relative abundance and composition in water supplies.
Top: Bacterial relative abundance based on 16s rRNA gene qPCR—results grouped by water supply, sample type and chlorination status. Error bars mark one standard deviation. The y axis is in log-10 scale. The order of groups is according to the hierarchical cluster analysis (Mid). Mid: Hierarchical cluster analysis of the corresponding microbiota with rarefied SVs averaged per group of samples. Bottom: Bar plot of the 30 most abundant taxa at family level (where known). Group labels starting with H, M and L indicate the water supply i.e. HighFe, MidFe, LowFe, followed by W (Water) or Bf (Biofilm) and Cl (chlorinated or treated) vs No (untreated).
Table 2.
PERMANOVA analysis.
Fig 4.
Venn diagram of SVs unique and shared between water supplies.
Venn diagrams showing the percentage of SVs unique or shared between water supplies for untreated (left) and treated samples (right). Bulk water and biofilm samples were combined. Only SVs which occurred in minimum two samples were considered.
Fig 5.
Phylogenetic tree of SVs and relative abundance in sample groups.
Phylogenetic tree of 16s rRNA gene SVs of all samples including negative controls after exclusion of contaminant and rare SVs. The average SV abundance in different groups of samples (outer circles) is shown across different levels of taxa resolution (tree). The midpoint-rooted tree was generated in QIIME-2 using the FastTree-2 routine [40] on a multiple alignment using MAFFT (Multiple Alignment Fast Fourier Transform) and with gaps across all sequences removed. The tree and metadata were visualized in iTOL (https://itol.embl.de/).