An Unexpected Finding
Some of science’s most interesting stories arise from accidents or unexpected results. Sir Alexander Fleming’s discovery of penicillin is probably the most famous example, but a more recent discovery could lead to a way to block disease transmission between insects and, ultimately, lead to healthier humans and less crop damage. But before we get to the implications, let’s start at the beginning.
Two years ago, Thomas Fritz, 71, cut down and removed a dead crab apple tree from his yard. While clearing the debris, he fell, and a limb impaled his right hand between his thumb and index finger. Fritz, a former EMT, cleaned and dressed the wound and waited to visit his doctor a few days later. By the time of the doctor’s visit, a cyst had formed. Fritz was given an antibiotic and a sample of the cyst was sent to a lab. Five weeks later, the wound began to heal after bits of tree bark were removed.
Identifying the bacterium also proved problematic and involved multiple labs. Results finally arrived and showed that Fritz’s wound was infected by a previously unknown bacterium that has since been named human Soldalis (HS).
“We had close matches for it, but none were validly described species,” says Mark Fisher of the ARUP Institute for Clinical and Experimental Pathology and a co-author of a paper appearing in PLoS Genetics. “It caught my eye because I knew Colin Dale worked on Sodalis.” Dale, a biologist at the University of Utah and senior author of the paper, discovered and named Sodalis in 1999. According to him, the findings represent "a missing link in our understanding of how beneficial insect-bacteria relationships originate. They show that these relationships arise independently in each insect."
Here’s why this discovery is an important one. It may point the way for scientists to genetically alter the new bacterium to block disease transmission by insects and prevent crop damage by insect-borne viruses.
Here are two examples. Tsetse flies and aphids carry symbiotic Sodalis bacteria related to strain HS. It may be possible to insert genes in HS and then place the bacteria in tsetse flies to kill the protozoan parasites that live in the flies and cause sleeping sickness. Aphids transmit many plant viruses that attack crops. Replacing normal symbiotic bacteria with a genetically engineered strain of HS could interfere with disease transmission.
And these are just two potential examples. While this discovery might not become as famous as Fleming’s, it does have an incredible back story and could create a significant impact. All arising from an accident.