Alpacas are susceptible to mycobacterial infections causing Johne's disease. Affected alpacas can gradually lose weight despite a good appetite. The affected animal can become so weak it cannot rise. These mycobacterial infections localize in the intestinal tract to reduce nutrient absorption due to a thickened intestinal lining resulting in hypoproteinemia (low blood protein). 

Many of these mycobacteria are difficult to grow in the laboratory. If they do grow it can take weeks or months to be able to identify them. This research project aims to develop a PCR-DNA based test to detect these types of bacteria in a few days. 

One of the major obstacles in developing these tests has been the presence of PCR (test) inhibitors in fecal samples that prevent the detection of mycobacteria. Our laboratory has developed a technique to counteract these inhibitors and allows the detection of the mycobacteria present in the fecal sample. At the present time the PCR test is less sensitive than the fecal cultures. By using methods to concentrate the mycobacteria, we are hopeful to have a PCR test that is more sensitive than the most sensitive fecal culture method now available. 

During the development of this new molecular diagnostic test if veterinarians or alpaca owners suspect Johne's disease, or other mycobacterial diseases in alpacas, they may submit samples to our laboratory for diagnostic testing at substantially reduced cost. These samples will help in the test development. For more information aboutmycobacterial disease or Johne's disease call (610) 444-5800 ext.2321 (Dr. Whitlock's office) or Terry Fyock at (610) 444-5800 ext. 2245 or contact Dr. Robert Whitlock by email at: whitlock@vet.upenn.edu.