SBIR-STTR Award

Swine Dysentery (SD) has been estimated to cost swine producers in excess of 130 million dollars annually, sad is quarantinable in most states. Confirmation of the disease is based on the detection of the bacteria, TreDonema hvodvsenteriae, from the feces of infected pigs. The currently available assay is time consuming, lacks sensitivity, and in many cases requires an experienced technician for an accurate diagnosis. Our goal is to develop an easily interpreted, rapid and sensitive assay to detect the organism from fecal samples. Recombinant DNA probes can be used for the rapid and sensitive indentification of the genome of any organism. Two probes for I. hvodvsenteriae will be tcsted in feces from both experimental and commercial pigs with SD to determine the feasibility of developing a gene probe assay for the diagnosis of this disease. Experiments are designed which address the specific detection of I hvodvsenteriae in feces and among other enteric flora, the sensitivity of the DNA probe or its ability to detect the asymptomatic "carrier" animal, and the comparison of the DNA probe to the currently available selective culture technique.Applications:It is anticipated that the information obtained from these studies will allow us to ultimately design and market a diagnostic test kit for swine dysentery. The development of such an assay would not only help producers and practitioners reduce SD related costs in their operations, but would eventually allow for the complete eradication of this disease from U.S. swine herds. An essential ingedien: to the successful completion of any eradication program is a diagnostic test that has the ability to detect the spirochete at low levels in "carrierw swine, and to differentiate between infected and vaccinated animals. If we are able to show our test has these qualities, we may have a widely marketable product.

Swine dysentery (SD) has been estimated to cost swine producers 180 million dollars annually, and is quarantinable in most states. Confirmation of the disease is based on the detection of the bacteria, TreDonema hvodvsenteriae. from the feces of infected pigs. The currently available assay lacks both specificity and sensitivity, and is often difficult to interpret. Results from our Phase I studies demonstrated that our diagnostic test, employing a nucleic acid probe, is completely specific for I. hvodvsenteriac and is easily interpreted. Our goal during Phase II is to increase the sensitivity of the nucleic acid probe in order to detect asymptomatic animals. The polymerase chain reaction (PCR) represents a powerful technique to increase sensitivity in the detection and identification of nucleic acids. The PCR technique will be evaluated for its ability to increase the sensitivity of our nucleic acid probe test for swine dysentery. Experiments are designed which address the specific amplification of I. hvodvsenteriae DNA in feces and among DNA from other enteric bacteria, the sensitivity of the nucleic acid probe test after gene amplification, and the comparison of the nucleic acid probe test with and without PCR to selective culture isolation.Applications:It is anticipated that the information obtained from these studies will result in the commercialization of a highly sensitive diagnostic assay for swine dysentery. The development of such an assay would not only help producers and practitioners reduce SD related costs, but would also allow for the complete eradication of this disease from U.S. swine herds. An essential ingredient to the successful completion of any eradication program is a diagnostic test which is sensitive enough to detect asymtomatic Zcarrierz animals. Through the use of PCR we feel we can increase the sensitivity of our nucleic acid probe test and thereby develop a widely marketable product.