#06-156

Complete

Date Full Report Received

05/26/2009

Date Abstract Report Received

05/26/2009

Investigation

Institution: , ,
Primary Investigator:

In recent years, there has been increased incidence and severity of human disease associated with the bacterium Clostridium difficile (Cd). It appears that epidemic disease is being caused by newly emerging strains of Cd. No one knows where the new strains came from, but several human disease strains have been compared to strains found in swine. On that basis, some researchers speculate that the new strains may have come from pigs or could be food-associated (i.e., came from pork). We proposed this study to determine how frequently pigs (across production and age groups) are colonized by Cd and how pig isolates compare to other animal and human Cd isolates. We isolated 131 Cd from predominantly suckling piglets, but very few from finisher or adult swine. The majority of isolates occurred during the cold months. Our pig isolates did not appear to have as much resistance to antibiotics as human isolates do. We determined that our pig isolates are not the human epidemic strain. Although these pig strains can colonize humans and cause disease, they are not the most common strains seen in human disease. We found 4 isolates in pork trim used to make sausage and these strains were of the same type as found in our pigs and also the same as most commonly reported for meat. Because of the low carriage rate of Cd by market age pigs and the fact that Cd had a low frequency in meat, we conclude that pork is a low risk for transmission of Cd into the food chain.