Submitted to: Veterinary Microbiology
Publication Type: Other
Publication Acceptance Date: December 8, 1999
Publication Date: N/A
Technical Abstract: Escherichia coli bacteria are the most frequently identified cause of diarrhea in newborn and weaned pigs. E. coli cause diarrhea because they adhere in the small intestine, grow, and produce toxins. Several different toxins have been found in E. coli that are believed to be important in causing diarrhea. In an earlier publication (Casey et al. 1998; Infect. Immun. 66:1270-1272), we studied one of these toxins, called "heat-stable enterotoxin b" or STb and showed that it was not important for E. coli to cause severe diarrhea in piglets. In response to a letter to the editor criticizing our experiments, I pointed out that all of the objections in the letter were either discussed in our publication or were not relevant to our conclusions. Our work shows that the STb toxin produced by some E. coli is not sufficient for causing severe diarrhea in newborn pigs. This information is important because knowing the E. coli characteristics that are needed to cause diarrhea and those that are not needed can be used by diagnostic laboratories to accurately identify important E. coli that can cause diarrhea in pigs. This information is also an important step for designing effective vaccines and for identifying other ways for producers and veterinarians to prevent diarrhea in newborn pigs caused by E. coli.