FIG. 1.
Diagram of STM. Mutant strains were pooled, and a mixed inoculum containing 105 CFU was injected into the dorsal muscle of four zebrafish. At 24 h, zebrafish were euthanized, and bacterial DNA was isolated from the homogenized spleens and muscles of three fish. Both input and output pools were subjected to PCR analysis with a specific primer for each of the 12 tags (lanes 1 to 12). The gel shows that the STM-2 clone was missing from the output pools of both organs of all three fish but was present in the input pool. Also missing were STM-9 and STM-11, but since they were also missing from the input (in vitro) pool, they were not considered further. Lanes L1 and L2, DNA ladder; lane C, positive control amplified from an STM plasmid. M, muscle; S, spleen.