#04-005

Complete

Date Full Report Received

06/15/2005

Date Abstract Report Received

12/20/2006

Investigation

Institution:
Primary Investigator:

The swine industry is of significant importance in the North American economy. Streptococcus suis serotype 2, a bacterium colonizing the upper respiratory tract of the pig, is responsible for many cases of septicaemias, meningitis and endocarditis in pig herds. Treatments by antibiotics can be effective to control S. suis infections if they are administrated early. However, the literature indicates the frequent isolation of S. suis strains resistant to penicillin. Therefore, studies aiming to develop alternative methods for the prevention and control of S. suis infections are essential. In this project, we investigated the ability of S. suis to produce antibacterial substances, called bacteriocins. Our results indicated that the non-pathogenic isolate S. suis 94-623 produces a bacteriocin having a low molecular and a great stability to heat and pH. The conditions for optimal production of the bacteriocin by S. suis 94-623 were determined and a partially purified fraction of the bacteriocin was obtained. The logical extension of the project will be to evaluate the potential of a theraby based on bacterial interference, in which piglets would be inoculated with the bacteriocin-producing non-pathogenic S. suis strain. Once established, this bacterium would confer protection against colonization by pathogenic isolates of S. suis, thus having a positive impact on the animal and public health.