“Ki kote twalet publik la, souple?”

     Last week, Meer and I went out looking for public toilets or more accurately places where people poop. Here is why:

Phages attached to a bacterium

One of the projects that I would like to do is to look for bacteriophages in different water sources in Haiti. Bacteriophages, or phages, are viruses that attack bacteria. They are everywhere in the environment and every species of bacteria has groups of phages that attack those bacteria. Most phages kill the bacteria that they attack.
A phage injects its DNA (or RNA) into the bacterium and takes over the biosynthetic machinery of the bacterium. Then the phage directs the bacterium to make more copies of the phage genome and the parts that go into making the phage capsid, its head and tail particles. At the end of this period of synthesis, the phage genomes are packaged into the head, and the head and tail are assembled into the phage capsids. In the final step, the phage produces an enzyme that breaks open (lyses) the bacterium, releasing the newly manufactured phages that go on to infect new bacteria. However, bacteriophages are specific for the bacteria that they attack. Phages that attack Escherichia coli will generally not attack Vibrio cholerae. Phages that attack Shigella will not attack Yersinia. This specificity is useful for classifying bacteria and also for doing genetics.

So why are we in pursuit of poop? We are studying the bacteria, like Vibrio cholerae, E. coli, Shigella, and Salmonella, that cause diarrheal diseases. These bacteria are found in large numbers in the feces of people who have diarrhea. Thus the risk of diseases like cholera increases when human waste is not treated but is dumped directly into the environment potentially contaminating water supplies on which people depend. Since I am interested in looking for the phages that attack these bacteria, the best place to start foraging for phages is in places where people, with or without diarrhea, defecate. That’s why we were out looking for “twalet publik”.

Small tent city in Gressier

Remember, don't poop in the river

We drove down a side road to an area where people are living in tents. Makende asked someone, “Ki kote twalet publik la, souple?” Then Makende explained to the person that he wasn’t looking for himself but that the “blan” (Haitian word for anyone who is not Haitian) in the truck were scientists who were looking for “kaka”, poop. That got a good laugh, a really good laugh. Oh, the Haitians were willing to show us where they go to defecate, they just thought it was funny that we wanted to see the poop (kaka).

I kept telling Makende that we were not interested in the poop itself. We just wanted to see where the water runs off the poop into whatever water source is near by. If the bacteria are there, there will be phages. Nancy and Rey back in my lab in Bethesda sent us the chemicals we need to isolate the phage. We should get the material we need in another two weeks. Then Meer and I can start hunting for phage. When we find the phages we are looking for, we can start studying how the presence of certain phages in the aquatic environment may correlate with the ebb and flow of diarrheal disease. That is, the phage might be a good indicator of the disease potential in the environment. The second project is another hunt for a certain phage that attacks Shigella. I will have more to report about that one after we find it. In the meantime, Meer and I are just a couple of “blan” looking for poop.

Animals (and people) living next to
stream running through tent city

Meer standing next to stream running in a channel
through a tent city