Ever wonder why you should wash your hands? Little animalcules..

In a recent trip in Cameroon; I was taking a car ride back from Douala to Buea (home of the Mount Cameroon) when I struck a conversation with a passenger/guide about what he thinks about modern medicine. After beating the bush for some point; I realized that he did not believe in germ theory. I had a hard time – on the very spot – trying to convince him that “invisible” germs cause diseases. He had never seen any of these germs; and yes he knew of stories of people getting better when they went to a doctor – but so he had also heard of stories when people went to a traditional healer. Although, in the end I was able to provide enough indirect evidence in that conversation; it has stuck with me as a challenge. How do we bring germ theory to people around the world; as an experience – not just a piece of information to know.

So today morning, I woke up and on my normal routine of Foldscoping whatever I can find around me – I choose a sample of rotting sea water. I intended to image some surface fungi that I could see growing on the water – but what I saw was quiet remarkable. It was a sea of little “animalcules” – swimming life forms teaming in the drop of water. The density of life forms in this single drop was so high that almost the entire droplet was churning due to the activity of the microbial life forms. I can not wait to share this video with you all. Accidentally – we also caught in audio a lesson associated with this post; “wash your hands often enough.”

What I find remarkable in this video – is the density of life forms. Looking closely, the diversity of swimming life forms is incredible. I am transported to a moment in the history of science – when Leeuwenhoek might have laid sight to a moment like this. What was going through his mind to find something like this under his investigative eyes. I could not help but wonder the power of microbial life forms; we so often ignore – displayed in it’s strongest form. Once they find a niche; they really go to town. It was an incredible display of complexity and I was just looking for words to explain what I saw.

Next time I am out in the field; and I have a conversation about the validity of germ theory – I will start by bringing animalcules right under my foldscope. Anyone who is reading this; a lesson to learn is – always wash your hands before eating 🙂 Hopefully this makes your conversation with your four year old a little bit easier.


3 Comments Add yours

  1. laksiyer says:

    @Manu: This is really great. In one video you can see so many different types of motility. Wonder how this would look in the dark field/phase contrast.

  2. Manu Prakash says:

    I am about to test that right now – both the dark field and side illumination. I am also trying to figure out if I can identify different motility motifs from a video like this. Finally; one idea is to actually see collective motion of the entire fluid because of the density of bacteria in the sample..

    See this video for example: http://phys.org/news/2014-06-emergence-bacterial-vortex.html


  3. laksiyer says:

    @Manu that would be great, cant wait to see how it goes. A long time back, I had bumped into a type of group dynamic of bacterial motility, where I felt there were pushing the edge of the droplet; or at least it appeared so. Perhaps because they were aerobic they organized along the interface of the water and air, but then there was this coordinated movement that was unforgettable. In light of the link you sent, I am curious if bacteria will form predictable patterns of collective motion depending on the flagellar distribution and affinity for molecular oxygen. I am surveying ponds locally and hope to find something similar again.

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