Nebulous Pathogen Identification
Consider the impact of nomenclatural status on pathogen identification. Where speciation is not well defined, can organisms be convicted of diseases they did not commit? What are the implications of false positives?Tell us what you think. Click on the 'Post Message' button below.
Speaking from experience, Tilletia controversa and T. caries are very
difficult to tell apart. In this case, if one were to call a
T. caries teliospore a T. controversa teliospore, then the whole
shipment of grain would be unable to be shipped to certain countries
that have zero tolerance for T. controversa. The economic loss
alone would be very great, as the grain would also be devalued. This
is not pleasant for me to think about while testing grain. I believe
that such a simple thing as mistaken identity becomes much more
complex when dealing with an export/import for an entire country.
To avoid these mistakes, people testing grain should, at the very
least have sample slides, clear pictures and someone else to confer
with about results of testing.
Hi Jennifer
You are correct about the consequences of a false positive - and that is why there are a number of steps in place to ensure that this does not happen. The protocol for the national survey includes the need for trained staff in each lab and reference slides as well as upcoming test slides. Additionally, any suspect positives must be sent to me for verification. At the same time extracted teliospores will be sent to Dr. Rob Meyer, who will be doing molecular testing with a probe specific for T. indica. Therefore, an identification will not be made until there is absolute certainty that the fungus is or isn't T. indica.
You bring up some very good points and I think that if all steps are followed we will be able to avoid any false positives (or negatives for that matter!). If you have any questions about the National Survey or about how to obtain sample slides you can contact Coanne O'Hern or Dave McNeal at 301-734-8247 or Arne Tschanz at 301-504-8141.
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