Fig. 4: Susceptibility to B. salamandrivorans infection correlates with life stage dependent skin galactose presence.

a B. salamandrivorans infection loads (expressed as genomic equivalents (GE)) on fire salamander larvae (n = 37 biologically independent animals) and metamorphs (n = 6 biologically independent animals) 10 days after exposure to 1.5 × 10⁵ spores/ml for 24 h. In the boxplots, horizontal lines represent median and interquartile ranges, with the vertical line representing min/max. Dots represent outliers, whiskers indicate highest/lowest value within 1.5*IQR from hinge. B. salamandrivorans infection prevalence (IP) of fire salamander larvae and metamorphs are shown. b Macroscopic picture of infected fire salamander metamorphs, arrow indicates skin ulcerations. c Histogram of B. salamandrivorans infection log (GE load + 1) load and equivalent RCA scores of fire salamander larvae and metamorphs. d Probability of RCA scores in early larvae stage (n = 21 biologically independent animals), late larvae stage (n = 16 biologically independent animals), and fire salamander metamorphs (n = 6 biologically independent animals) predicted from ordinal logistical regression fit with polr(), error bars indicate RCA score probability +/− one standard error. Photomicrographs represent different RCA staining scores. RCA score: 1 = weak staining, 2 = strong staining, 3 = intense staining. RCA score of 0 is not shown because no slides were scored 0. Scale bars = 100 µm. Morphological characters of fire salamander larvae and metamorphs are shown. e B. salamandrivorans infection log (GE load + 1) load and respective RCA scores of individual fire salamander larvae and metamorphs. The line indicates linear regression, implemented with RCA score as an ordered categorical variable. Source data are provided as a Source Data file.