FIG 4.

Bioluminescence imaging of organs of soft-shelled turtles intravenously infected with bioluminescence-labeled V. cholerae strains. Six groups of soft-shelled turtles (three turtles per group) were intravenously infected with bioluminescence-labeled serogroup O1 strain VC1898, serogroup O139 strain VC4251, and VC4251-derived gene mutant bioluminescent strains. The negative control was injected with sterile PBS. All soft-shelled turtles were euthanized at 72 h, and internal organs, including the hearts, livers, lungs, spleens, kidneys, and digestive tracts, were separated and scanned. The experiments were repeated three times, and this figure shows one representative test. The color bar on the right shows bioluminescence intensity, representing increasing densities of bacteria. Anatomical structures are labeled in each picture.