Table 1.

Association of Y. pseudotuberculosis wild-type and inv mutant strains with Peyer’s patch M cells after 60 min of incubation in mouse gut loops

StrainPhenotypeNo. of M-cell-associated bacteria/1,000 μm2a
TotalAdherentInvaded
YPIII/pIB1Wild type8.06 ± 4.722.58 ± 0.965.48 ± 3.80
SF104Invasin-defective mutant0.72 ± 0.17*b 0.54 ± 0.16*0.18 ± 0.06*
  • a All values are expressed as means ± standard errors (n = 7 Peyer’s patches).

  • b *, Significantly different (P< 0.05; Mann-Whitney U test) from wild-type values.