It is important for us to learn not just about the organisms we like to study as parasitologists, but also about the history of our chosen profession. The field of parasitology has a rich and colorful history full of people who make it such. Today, I’ve decided to post not about a parasite, but about one of the many parasitophiliacs who contributed to what we know about parasites today.
|Gottlieb Heinrich Friedrich Küchenmeister|
Today’s parasitophiliac of interest: Gottlieb Heinrich Friedrich Küchenmeister (No, not the alcoholic cake, silly pants! The person!)
Can you guess where Dr. Küchenmeister hailed from? That’s right! He was born in Germany in 1821. After studying medicine in Leipzig and Prague he became a general practitioner in Zittau. In 1856, he and his wife moved to Dresden where he began his research on parasites such as Trichinella spiralis and various tapeworms. In 1852, he came up with a theory that would lead him down a controversial path as a parasitologist.
Parasitology After Steenstrup
To tell his story, let’s back up just a tad. A Danish zoologist named Johann Steenstrup made some great contributions to the field of parasitology in the 1830s by discovering that flukes had various life cycle stages that were morphologically different. This researcher proved that the eggs, rediae, cercariae, and adults were all different parts of the life cycle for a single species rather than being four distinct species as had been believed previously by science. These were the days when people believed that parasites were spontaneously generated by the body because they didn’t understand how parasites worked.
After his ground-breaking work, Steenstrup decided to do some work with “bladder worms”, which lived in mammalian muscles. He thought these worms might actually be juvenile stages of some other unknown worm. Other scientists began postulating that these little worms that ended up in the tongues of sheep and pigs were baby tapeworms that somehow screwed up their life cycle and were malformed pockets of babies that would eventually die because they were in the wrong host.
When Küchenmeister heard about this in the 1840s, he was more than a little upset. Küchenmeister was a very religious man, and he refused to accept the idea that God could screw up so badly and sentence his own creations to such an awful, and frequently occurring, dead end. So, in the interest of biological science as well as proving that ALL of God’s creatures had a purpose, this man set out to unlock the mystery of the “bladder worms”. Küchenmeister believed that the “bladder worm” stage was a very much natural and integral part of the tapeworm life cycle.
By 1851, Küchenmeister was busy conducting experiments to prove his theory. He harvested bladder worms from rabbits and fed them to foxes. A few weeks later he would cut open the foxes to find adult tapeworms. He did the same thing with mice and cats using a different species of tapeworm. He eventually moved on to harvesting from a sheep and infecting a dog. This time, when the dog began to pass proglottids in its feces, Küchenmeister fed the proglottids back to a healthy sheep. After 16 days the sheep became ill, and after it died Küchenmeister gazed inside its skull. He found little bladder worms resting atop the brain of the recently deceased sheep.
When he reported his findings, an uproar ensued amongst the biological community. This guy was a general physician who played with parasites for fun and was uber-pro-cremation. He wasn’t a serious researcher like so many others who had not been able to unlock such mysteries on their own. He couldn’t possibly be taken seriously. Established scientists worked hard to poke holes in the good doctor’s theories, but none of them managed to do so. Why? Because he was RIGHT!
Dr. Küchenmeister did manage a few little slip ups with his research. Apparently he sometimes lost parasites because he fed them to the wrong hosts and failed to get the next life-cycle stage. But this negative data wasn’t really wrong…it just proved that tapeworms were species-specific. So his theory still stood.
Bladder Worm Soup with a Side of Blood Sausage
So what’s the big deal? They guy fed some tapeworms to some animals and figured some stuff out? What should we care? Küchenmeister wasn’t done with his research yet. Hang in there people, this is where it gets interesting!
To further prove his theory, the good doctor began experimentally infecting humans with tapeworms. That’s right, HUMANS! He started feeding bladder worms to prisoners with the permission of the prisons, but not with the knowledge of the prisoners themselves. He found prisoners nearing their execution dates and fed them delicious meals full of little parasites. After the prisoners were executed, he would cut them open like one of his foxes to find fully-grown adult tapeworms in their intestines.
Interesting sidenote: He cooled a noodle soup to body temperature and added some bladder worms for his first prisoner, who liked the soup so much that he asked for seconds. Küchenmeister, being the nice guy he was, gave the prisoner seconds AND gave him a nice bladder worm-spiked blood sausage to go with it.
The first prisoner was executed three days after eating Küchenmeister’s special meal and upon dissection, Küchenmeister found tapeworms belonging to the genus Taenia. His second prisoner was fed four months before his execution and his corpse revealed a nice five-foot tapeworm.
Küchenmeister’s experiments were looked on as barbaric by most of his colleagues. However barbaric it was, his work helped to establish the life cycle of these tapeworms. His work was also very important because he was the first person to demonstrate that not all parasites had to spend part of their lives out in the environment. Küchenmeister proved that some parasites could be transmitted from host to host simply by being eaten.
|Life Cycle of Taenia from the CDC|
Moral of the Story
|Taenia solium scolex|
Sometimes it takes someone who isn’t an “expert” to make remarkable discoveries. Sometimes we need to look at a problem with fresh eyes and open minds if we want to figure out how things work. The beauty of biology is that what we KNOW today may or may not be the great truth of tomorrow. There is constant change and adaptation in the field just as there is constant change and adaptation in nature. It’s amazing how even the history of our field reflects the very essence of life as we understand it! So remember to always question even the most well-established principles for yourself. And if you can develop an experiment to test your hypothesis, it’s always nice to be able to test it out on
prisoners lab rats.