Adherence of Yersinia enterocolitica to Mammalian Epithelial Cell Lines

Yersinia enterocolitica RIMD 2501003 grown at 25 C avidly adhered to various kinds of cultured epithelial cell lines (HeLa, FL, Y-1 adrenal, human intestine, human conjunctiva) but the bacteria grown at 37 C did not adhere. This phenomenon paralleled the temperature-dependent motility of the bacteria. To clarify the adherence mechanism, we obtained two kinds of mutants, an im-mobile mutant and a nonadherent mutant, by treatment with N-methyl-N′-nitro-N-nitrosoguanidine. The immobile mutant did not move on soft agar but retained the capacity to adhere to cultured epithelial cells when grown at 25 C. The nonadherent mutant did not adhere to cultured epithelial cells but retained the ability to move on soft agar when grown at 25 C. When the bacteria were killed by heat, ultraviolet light irradiation or formal-dehyde they lost their capacity to adhere to the cultured epithelial cells. Antiserum against Y. enterocolitica RIMD 2501003 grown at 25 C was absorbed with the bacteria grown at 37 C, with the bacteria grown at 25 C, with the nonadherent mutant grown at 25 C and with the bacteria killed by various means. Only the antiserum absorbed with bacteria grown at 37 C inhibited the adherence of bacteria. These data indicate that motility does not correlate with adherence of Y. enterocolitica. It appears that the adherence factor involves both a temperature-dependent surface factor and a factor synthesized de novo during the interaction of susceptible cells with the bacteria.