and B. dendrobatidis.
B. salamandrivorans Strain Isolation and Culture Conditions. Chytrid isolation
on tryptone-gelatin hydrolysate-lactose (TGhL) agar plates containing penicillin/streptomycin
(200 mg/L) at 20 °C was attempted from the dead S.
salamandra as described previously for the isolation of B. dendrobatidis (7).
Skin samples without contaminating bacterial or fungal growth were
transferred to TGhL broth once zoospores were seen on the agar plates. The
isolate was subsequently subcultured in TGhL broth in cell culture flasks at
15–20 °C. A 10-d-old subculture was frozen in liquid nitrogen (20). To obtain
zoospores, 1 mL of a culture growing in TGhL broth was transferred to a TGhL
agar plate and incubated for 5–10 d at 15 °C. Zoospores were obtained by
washing the agar plate with 2 mL of 0.2-μm filtered pond water. The number
of zoospores in the suspension was determined using a hemocytometer.
To determine thermal growth conditions, 200 μL of a 5-d-old
B. salamandrivorans culture in TGhL broth at 15 °C was transferred to the wells
of a 24-well plate, and 0.8 mL of TGhL broth was added. The plates were incubated
at 5 °C, 10 °C, 15 °C, 20 °C, 22 °C, 23 °C, 24 °C, 25 °C, and/or 30 °C ± 1 °C
for 10 d. Growth was defined as a significant increase of the surface of the
well covered by the fungus compared with wells incubated at 30 °C (which is
above the lethal temperature for B. salamandrivorans) and the presence of
motile zoospores. The surface coverage was determined by image analysis
(GNU Image Manipulation Program) of pictures, taken through an inverted
light microscope (Nikon Eclipse ts100, 20× magnification). Each condition was
tested in triplicate. If no growth was seen after 10 d of incubation, the plates
were further incubated at 15 °C. Cultures were considered dead if no growth
occurred within 10 d
and B. dendrobatidis.B. salamandrivorans Strain Isolation and Culture Conditions. Chytrid isolationon tryptone-gelatin hydrolysate-lactose (TGhL) agar plates containing penicillin/streptomycin(200 mg/L) at 20 °C was attempted from the dead S.salamandra as described previously for the isolation of B. dendrobatidis (7).Skin samples without contaminating bacterial or fungal growth weretransferred to TGhL broth once zoospores were seen on the agar plates. Theisolate was subsequently subcultured in TGhL broth in cell culture flasks at15–20 °C. A 10-d-old subculture was frozen in liquid nitrogen (20). To obtainzoospores, 1 mL of a culture growing in TGhL broth was transferred to a TGhLagar plate and incubated for 5–10 d at 15 °C. Zoospores were obtained bywashing the agar plate with 2 mL of 0.2-μm filtered pond water. The numberof zoospores in the suspension was determined using a hemocytometer.To determine thermal growth conditions, 200 μL of a 5-d-oldB. salamandrivorans culture in TGhL broth at 15 °C was transferred to the wellsof a 24-well plate, and 0.8 mL of TGhL broth was added. The plates were incubatedat 5 °C, 10 °C, 15 °C, 20 °C, 22 °C, 23 °C, 24 °C, 25 °C, and/or 30 °C ± 1 °Cfor 10 d. Growth was defined as a significant increase of the surface of thewell covered by the fungus compared with wells incubated at 30 °C (which isabove the lethal temperature for B. salamandrivorans) and the presence ofmotile zoospores. The surface coverage was determined by image analysis(GNU Image Manipulation Program) of pictures, taken through an invertedlight microscope (Nikon Eclipse ts100, 20× magnification). Each condition wastested in triplicate. If no growth was seen after 10 d of incubation, the plateswere further incubated at 15 °C. Cultures were considered dead if no growthoccurred within 10 d
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