Journal: Environmental Microbiology

Article Title: The Coral Host Microbiome Modulates the Virulence of the Bacterial Pathogen Vibrio coralliilyticus

doi: 10.1111/1462-2920.70224

Figure Lengend Snippet: Representative photos of diseased M. capitata and a comparison of the orange and red colour morph susceptibility to V. coralliilyticus . Representative photos of (A) a healthy orange M. capitata fragment, (B) the same orange fragment with progressive acute tissue loss, (C) a healthy red fragment, and (D) the same red fragment with progressive acute tissue loss. The black scale bars represent 1.5 cm. Potential differences observed in image clarity between panels A & C and B & D are likely due to dead coral tissue floating in the aquarium water as infection proceeds in panels B & D. (E) Kaplan–Meier survival curve of red and orange M. capitata fragments exposed to V. coralliilyticus OCN008 or OCN014 ( n = 12 for each treatment). The dotted line with open squares represents control orange and red fragments exposed to FSW, A. macleodii OCN004, or V. cyclitrophicus HMSC5 ( n = 12 for each treatment). Black lines with solid circles represent orange fragments exposed to OCN008, grey lines with open circles represent red fragments exposed to OCN008, dashed black lines with solid triangles represent orange fragments exposed to OCN014, and dashed grey lines with open triangles represent red fragments exposed to OCN014.

Article Snippet: AphA and VcpR represent the V. coralliilyticus “low” and “high” cell density quorum sensing regulators (Hasegawa and Häse ; Van Kessel et al. ; Ushijima et al. ; Lydick et al. ), respectively, which suggests that distinct virulence factors may be expressed at different cell densities.

Techniques: Comparison, Infection, Control

Journal: Environmental Microbiology

Article Title: The Coral Host Microbiome Modulates the Virulence of the Bacterial Pathogen Vibrio coralliilyticus

doi: 10.1111/1462-2920.70224

Figure Lengend Snippet: The effect of antibiotic pre‐treatment on M. capitata susceptibility to infection by various V. coralliilyticus strains. Kaplan–Meier survival curves of (A) M. capitata fragments pre‐treated with FSW prior to exposure to six Vibrio strains with control fragments and (B) fragments pre‐treated with ampicillin and spectinomycin before exposure to the same seven treatments. These were paired experiments organised into experimental blocks (i.e., each replicate) consisting of fragments from the same colony (genets) to account for intraspecific differences. The black dotted lines with open squares represent control fragments were exposed to FSW ( n = 10); pink solid lines with closed squares represent fragments exposed to HMSC5 ( n = 10); solid teal likes with closed hexagons represent fragments exposed to H1 ( n = 10); solid purple lines with closed nabla represent fragments exposed to RE22 ( n = 10); solid light blue lines with closed circles represent fragments exposed to BAA‐450 ( n = 10); solid purple lines with closed diamonds represent fragments exposed to RE98 ( n = 10); and solid black lines with closed circles represent fragments exposed to OCN008 ( n = 10). Labels are localised near their represented line on each graph.

Article Snippet: AphA and VcpR represent the V. coralliilyticus “low” and “high” cell density quorum sensing regulators (Hasegawa and Häse ; Van Kessel et al. ; Ushijima et al. ; Lydick et al. ), respectively, which suggests that distinct virulence factors may be expressed at different cell densities.

Techniques: Infection, Control

Journal: Environmental Microbiology

Article Title: The Coral Host Microbiome Modulates the Virulence of the Bacterial Pathogen Vibrio coralliilyticus

doi: 10.1111/1462-2920.70224

Figure Lengend Snippet: Effect of antibiotic pre‐treatment on the virulence of different V. coralliilyticus mutants. Kaplan–Meier survival curves of (A) M. capitata fragments pre‐treated with FSW prior to exposure to OCN008 and OCN014‐derived strains and (B) fragments pre‐treated with ampicillin and spectinomycin before exposure to OCN008 or OCN014‐derived strains. These were paired experiments organised into experimental blocks (i.e., each replicate) consisting of fragments from the same colony (genets) to account for intraspecific differences. Dotted lines with open squares represent controls, which were either exposed to FSW or V. cyclitrophicus HMSC5 ( n = 10 for each treatment). Solid black lines with closed circles represent corals treated with OCN008 ( n = 10). Solid black lines with closed triangles represent corals treated with OCN008 Δ vcpR ( n = 10). Solid black lines with closed diamonds represent corals treated with OCN008 Δ aphA ( n = 10). Dashed blue lines with open circles represent corals treated with OCN014 ( n = 10). Dashed blue lines with open triangles represent corals treated with OCN014 Δ vcpR ( n = 10). Dashed blue lines with open diamonds represent corals treated with OCN014 Δ aphA ( n = 10). Labels are localised near their represented line on each graph.

Article Snippet: AphA and VcpR represent the V. coralliilyticus “low” and “high” cell density quorum sensing regulators (Hasegawa and Häse ; Van Kessel et al. ; Ushijima et al. ; Lydick et al. ), respectively, which suggests that distinct virulence factors may be expressed at different cell densities.

Techniques: Derivative Assay

Journal: iScience

Article Title: A coral peptide with bactericidal activity against a global marine pathogen, Vibrio coralliilyticus

doi: 10.1016/j.isci.2025.113286

Figure Lengend Snippet: Measurements of antimicrobial activity against coral-pathogenic bacteria in low-salt conditions (A–C) In 1% (w/v) NaCl medium, the antimicrobial assay was performed by exposing bacteria to 10 μM digitiferin. Antimicrobial activity was evaluated by plating all wells onto 1/10 strength ZoBell’s 2216E plates, and CFU counts after incubation at 25°C for 24 h. (D–F) In PB-mannitol medium, antimicrobial activity was determined by testing various concentrations of digitiferin. Antimicrobial activity was evaluated by plating all wells onto Marine Agar plates, and CFU counts after incubation at 30°C for 24 h. (A–F) All data are given as means ± standard error of the mean, n = 3. Statistical analysis between each sample and the negative control (0 μM digitiferin) was conducted using t test. p values less than 0.05 were considered statistically significant (ns, non-significant; p > 0.05). Significant differences are indicated by asterisks. (A and D) V. coralliilyticus P1, (B and E) V. coralliilyticus YB1, and (C and F) V. shiloi AK1.

Article Snippet: Using a liquid growth inhibition assay, antibacterial activity was assayed against Gram-negative bacteria ( E. coli [NBRC 102203 T ], P. aeruginosa [NBRC 12689 T ], and S. marcescens [ATCC BAA-632]), Gram-positive bacteria ( B. subtilis [NBRC 13719 T ] and S. aureus [NBRC 100910 T ]) and coral-pathogenic bacteria ( V. coralliilyticus P1 [LMG23696], V. coralliilyticus YB1 [ATCC BAA-450 T ], V. shiloi AK1 [ATCC BAA-91 T ] and S . marcescens [ATCC BAA-632]).

Techniques: Activity Assay, Bacteria, Incubation, Negative Control

Journal: iScience

Article Title: A coral peptide with bactericidal activity against a global marine pathogen, Vibrio coralliilyticus

doi: 10.1016/j.isci.2025.113286

Figure Lengend Snippet: Measurements of antimicrobial activity against coral-pathogenic bacteria in low-salt conditions (A–C) In 1% (w/v) NaCl medium, the antimicrobial assay was performed by exposing bacteria to 10 μM digitiferin. Antimicrobial activity was evaluated by plating all wells onto 1/10 strength ZoBell’s 2216E plates, and CFU counts after incubation at 25°C for 24 h. (D–F) In PB-mannitol medium, antimicrobial activity was determined by testing various concentrations of digitiferin. Antimicrobial activity was evaluated by plating all wells onto Marine Agar plates, and CFU counts after incubation at 30°C for 24 h. (A–F) All data are given as means ± standard error of the mean, n = 3. Statistical analysis between each sample and the negative control (0 μM digitiferin) was conducted using t test. p values less than 0.05 were considered statistically significant (ns, non-significant; p > 0.05). Significant differences are indicated by asterisks. (A and D) V. coralliilyticus P1, (B and E) V. coralliilyticus YB1, and (C and F) V. shiloi AK1.

Article Snippet: To explore the antibacterial spectrum of digitiferin, we evaluated its activity according to MBC, MIC, and MAC definitions against Gram-positive bacteria: ( Bacillus subtilis [NBRC 13719 T ] and Staphylococcus aureus [NBRC 100910 T ]); Gram-negative bacteria: ( E. coli [NBRC 102203 T ], Pseudomonas aeruginosa [NBRC 12689 T ], and Serratia marcescens [ATCC BAA-632]); and coral pathogens: ( V. coralliilyticus P1 [LMG23696], V. coralliilyticus YB1 [ATCC BAA-450 T ], Vibrio shiloi AK1 [ATCC BAA-91 T ], and S. marcescens [ATCC BAA-632]).

Techniques: Activity Assay, Bacteria, Incubation, Negative Control