A large number of Salmonella typhimurium strains was classified according to sensitivities to bacteriophages. From this, 22 different type strains were classified and one strain of each type was selected and named as LT1, LT2, etc (meaning Lilleengen Type 1, etc) (Lilleengen, K. 1948. Acta. Pathol. Microbiol. Scand. Suppl. 77: 11-125). This set of strains was provided to J. Lederberg, and was used in the studies of Zinder and Lederberg (J. Bacteriol. 1952. 64:679-699) which led to the recognition of bacteriophage P22-mediated generalized transduction. Strain LT2 has been the most heavily analyzed; strain LT7 has also been used; strain LT22 was lysogeneic for the phage originally called PLT22, now called P22. These strains were provided by J. Lederberg to M. Demerec at Cold Spring Harbour Laboratory, LI., NY, and served as the starting point for the extensive genetic work in the Demerec lab. This work provided the basis for the establishment of the SGSC. The strains of the Lilleengen set were maintained in lyophils by the Lederberg lab; in the late 1970s these lyophils were made available to the SGSC, and the kit of Lilleengen strains in the SGSC were established from these lyophils. The strain of LT2 which was sequenced at the Genome Sequencing Center at Washington University is SGSC1412, which is the LT2 strain which came to the SGSC via J. Lederberg.
Strains which are included with Kit 14D:
Strain Designation SGSC Number Species Genotype LT1 SGSC1411 S. typhimurium LT1 prototrophic LT2 SGSC1412 S. typhimurium LT2 prototrophic LT3 SGSC1413 S. typhimurium LT3 prototrophic LT4 SGSC1414 S. typhimurium LT4 prototrophic LT5 SGSC1415 S. typhimurium LT5 prototrophic LT6 SGSC1416 S. typhimurium LT6 prototrophic LT7 SGSC1417 S. typhimurium LT7 prototrophic LT8 SGSC1418 S. typhimurium LT8 prototrophic LT9 SGSC1419 S. typhimurium LT9 prototrophic LT10 SGSC1420 S. typhimurium LT10 prototrophic LT11 SGSC1421 S. typhimurium LT11 prototrophic LT12 SGSC1422 S. typhimurium LT12 prototrophic LT13 SGSC1423 S. typhimurium LT13 prototrophic LT14 SGSC1424 S. typhimurium LT14 prototrophic LT15 SGSC1425 S. typhimurium LT15 prototrophic LT16 SGSC1426 S. typhimurium LT16 prototrophic LT18 SGSC1427 S. typhimurium LT18 prototrophic LT19 SGSC1428 S. typhimurium LT19 prototrophic LT20 SGSC1429 S. typhimurium LT20 prototrophic LT21 SGSC1430 S. typhimurium LT21 prototrophic LT22 SGSC1431 S. typhimurium LT22 prototrophic