Water pouring out of a pipe, carrying viruses and bacteria, with the title "What's in our water?"
Written by: Christopher Albin-Brooks
Illustrated by: Hannah Kalas

show/hide words to know

Microbe: a living thing so tiny that you would need a microscope to see it... more

Microbiome: the community of microorganisms that live inside and/or on your body.

Pathogen: a virus, bacterium, fungus or parasite that infects and harms a living host.

Pneumonia: an infection of the lungs that often results in fluid building up in the air sacs making it difficult to breathe.

Polymerase Chain Reaction (PCR): a technique that makes makes thousands of copies of a single piece of DNA to make it easier to analyze... more

Illustration of microorganisms in a drop of water.

A drop of drinking water can have millions of microbes in them! Image credit Jean-Baptiste Raina via wikimedia commons.

Grab a cup and pour yourself a glass of water. If you look into it, you probably won’t see much of anything. While our water is usually crystal clear, there are actually countless microbes that live in it. Most of the time these microscopic organisms don’t cause much of a problem. In fact, we ingest microbes constantly–not just in our water, but through the food we eat and the air we breathe. Sometimes though, harmful microbes can grow in the water we drink. And when we drink them in, they can cause serious problems. Kerry Hamilton’s research focuses on this problem. She is working to find the bad bacteria in our water and to learn how we can manage these organisms.

Deep dives to look for bacteria

Bacteria make up the world around us, and sometimes these microorganisms are a lot closer than we think! We can’t escape them, and we often shouldn’t want to. You may have heard a bit of the microbiome, the name for the collection of microbes that live on and inside of us. Many of them help us process foods and create vital nutrients we need to live. Some of them live on our skin and give us smelly body odor. But not all of these organisms are helpful, or even a mere annoyance. Some are bad for us.

Pathogens are what we call such microbes that cause disease. These tiny organisms can’t be seen with just our eyes, and we may miss them when looking through a microscope. This can make them tough to identify. 

One of the ways that Hamilton finds pathogens is through their DNA. By using a tool called quantitative polymerase chain reaction (qPCR), she can tell which bacteria are in our water and get an idea of how many there are. qPCR is a technique used to tell if a gene is present by making many copies of it. When enough copies are made, scientists can then look for the genes of specific bacterial species.  In Hamilton’s case, she does this with water samples. If a specific type of bacteria was in the water, then PCR would let her detect some of its genes. If the gene isn’t there after PCR, then she knows the bacteria wasn’t in the water. 

We can also tell how many original copies of a gene there were. With that data we can estimate how many pathogens are in a water sample. Not only does this help Hamilton to identify the bacteria, but it can also help her learn how different bacteria interact and what their risks are. Knowing which genes are present can tell us a lot about the microbial community. 

Going where the data flows

Picture of Legionella bacteria on an agar plate with ultraviolet light.

Legionella bacteria can be identified with dyes that shine in ultraviolet light. James Gathany via wikimedia commons. Click to see larger image.

One of the pathogens that Hamilton’s lab works with are Legionella bacteria. This group of bacteria has over 50 species that can affect the respiratory system. One illness they cause is a unique type of pneumonia known as Legionnaire’s Disease. While this disease is treatable with antibiotics, it is nothing to take lightly. It is particularly deadly for people who have weakened immune systems. So one place that we have to watch out for is a hospital. If the drinking water isn’t properly treated it could lead to a disease outbreak. 

Hamilton uses the data her lab collects to understand when, where, and how to best prevent outbreaks. Lots of places in the world have water treatment plants or other barriers in place to manage water pathogens. However, these don’t catch all of the pathogens and in some areas water treatment may be lacking. Her research can help us understand what areas may be at risk for an outbreak. 

Picture of water treatment digestion towers in Germany.

Water treatment plants use bacteria to help break down waste. Click image for more detail.

Hamilton also wants to figure out how to reduce the cost of keeping pathogens in check. In some cases, people might clean their water systems by passing lots of water through it to remove pathogens, but this may not be the right option in water-scarce areas like deserts. Other places might heat up water tanks to kill the bacteria, but this can cost a lot of money and energy. Hamilton is learning how to be more efficient with how we treat our water. Using computer models, she can weigh the costs and benefits for different options.

One of the toughest challenges with this research is sifting through all of the data that’s out there. Over the past two decades scientists have analyzed the DNA of countless microbes. They’ve also learned about how individual pathogens cause disease. Hamilton sees that one big challenge is how to integrate all this information so we can make better sense of it. She works with scientists in many fields across the world to tackle this problem. Water is the basis for all life, so it’s all the more important that we work together to make it safe for everyone.

Ocean image credit Pexels on pixabay.

View Citation

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Bibliographic details:

  • Article: What's in Our Water?
  • Author(s): Christopher Albin-Brooks
  • Publisher: Arizona State University School of Life Sciences Ask A Biologist
  • Site name: ASU - Ask A Biologist
  • Date published: March 21, 2023
  • Date accessed: July 15, 2024
  • Link: https://askabiologist.asu.edu/explore/water-pathogens

APA Style

Christopher Albin-Brooks. (2023, March 21). What's in Our Water?. ASU - Ask A Biologist. Retrieved July 15, 2024 from https://askabiologist.asu.edu/explore/water-pathogens

American Psychological Association. For more info, see http://owl.english.purdue.edu/owl/resource/560/10/

Chicago Manual of Style

Christopher Albin-Brooks. "What's in Our Water?". ASU - Ask A Biologist. 21 March, 2023. https://askabiologist.asu.edu/explore/water-pathogens

MLA 2017 Style

Christopher Albin-Brooks. "What's in Our Water?". ASU - Ask A Biologist. 21 Mar 2023. ASU - Ask A Biologist, Web. 15 Jul 2024. https://askabiologist.asu.edu/explore/water-pathogens

Modern Language Association, 7th Ed. For more info, see http://owl.english.purdue.edu/owl/resource/747/08/
Picture of water waves at sunset.

Water is important for all life on the planet, and as such life can be found almost anywhere that there is water. The ocean is full of creatures both large and small.

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