FIG. 1.
Individual and age-related patterns of stx-positive fecal cultures from calves between birth and the 24th week of age and from their dams before or after parturition. White boxes depict fecal cultures analyzed by stx1-type/stx2-type multiplex PCR. Detection of the stx1 type and the stx2 type is marked in gray and black, respectively. Cultures testing stx2-type positive were further analyzed for the presence of stx2 subtypes: stx2, stx2c, and stx2 plus stx2c were detected in individual cultures, but the results were omitted from the figure for ease of reading. p.n., first sample after birth; 24 h, second sample, taken within first 24 h after birth and after colostrum uptake; a.p., before parturition; p.p., sample taken subsequent to parturition. Arrowhead, dam 15 is listed twice because this dam delivered twin calves (15a and 15b).