Background Information

WHY YOU SHOULD CARE ABOUT: Clean Water Crisis

Each year the world undergoes countless natural disasters from wildfires, to floods, to earthquakes and hurricanes (1). When disasters such as these sweep through towns and cities, they raze buildings to the ground and utterly destroy the infrastructure of electric lines, pipes and water mains. People lose access to necessities such as electricity and, more importantly, water and must find a way to pick up the remains and make do until emergency services can access them. However, sometimes, despite the best efforts of the government, nothing can be done and thousands of people remain without easy access to clean drinking water or electricity for weeks or even months, as evidenced by the situation in Puerto Rico since Hurricanes Irma and Maria (2). Instead, they are left with collapsed water systems that have accumulated debris and sewage and are likely teeming with thousands of bacteria and waterborne diseases.

This only begins to scratch the surface of the need for clean water in our world. Even without natural disasters leaving their mark, there are almost 1 billion people living in underdeveloped parts of the world who do not have access to basic, clean and safe drinking water (3,4). Of these people, 160 million are purely dependent on surface water, from sources such as lakes, rivers, and ponds, all of which are subject to runoff. Furthermore, over 2 billion people in the world use drinking water from sources contaminated with fecal matter and waterborne disease. Taking all these shocking and disturbing facts into account, it’s no wonder that many nonprofits and organizations have started pushing for clean water initiatives over the last few years.

Access OpenStax:
1.1 What Our Ancestors Knew
16.4 Global Public Health

History Connection

Clean drinking water, purifying water and deliberately contaminating water wells has been important to human culture for thousands of years. The “Medicine, Microbiology and Health” study abroad group from UF visited the London School of Hygiene and Tropical Medicine, where diseases and outbreaks are still studied today.

Check out the Cholera map in London

Virtual Lab Simulations

Activity: Water Sampling Interactive

Activity: Water Testing Interactive

Online Lab

ACTIVITY #1:

Look over the water born pathogens poster MCS_Water_Borne_Pathogens_Toxins_Poster_2022 –

For your ELN describe if you have encountered water born pathogens, means to avoid it. As it comes to drinking water explore what you are most concerned about.

ACTIVITY #2: Water Lab

EC blue tubes are prepared already

· Reagents to make 500 mL EC Blue media

• o Peptone (2.5 g)
• o Sodium chloride (2.5 g)
• o Monopotassium phosphate (0.5 g)
• o Dipotassium hydrogen phosphate (2 g)
• o Sodium lauryl sulfate (0.05 g)
• o Sodium pyruvate (0.5 g)
• o Potassium nitrate (0.5 g)
• o IPTG (0.05 g)
• o X-GAL (0.05 g)
• o 4-methylumbelliferyl-ß-D-glucuronide (0.05 g)
• o Approximately 500 mL DIW

Get a dirty water sample (pond, ocean or puddle)

Use

• · 2 tubes of EC Blue media
• · Micropipettes, tips
• · Syringe and syringe filter
• · Small beakers
• · Bleach or chemical water treatment tablets
• · UV light (for results)

Water lab overview

Lab Experiment

First Method- Sari Filtration

This is a simple method for filtering water to reduce the incidence of cholera. It requires using readily available sari cloth to filter pond and river water. This method successfully reduced the incidence of cholera by >70% in Bangladesh.

Per row:

· Label 6 EC/BLUE tubes as follows: – control, original water sample, sari filtrate, boiling, vacuum filter, chemical treatment/chlorine.

Sari filtration

· Sari Filtrate: filter 50mL of the water sample into a 50mL beaker with funnel, lined with sari (cotton) cloth (this is only done once for an entire row). You will use 4 layers of sari cloth to do this. You can pre-wet the cloth with water to facilitate water flow

· Take 1ml of your sari filtered water and add it to your Sari filtered EC/Blue tube.

Treatment Methods:

Filtration (syringe filtration)

· Suck up 2 ml of sari-filtered water into a syringe

· Attach a 0.22 μm syringe filter unit syringe

· Squeeze liquid through syringe and collect it in a clean Eppendorf tube

· Take 1ml of your filtered water and add it to your EC/Blue tube.

Boiling

· Boil ~25 ml sari filtered water for 10 minutes, cover it to prevent evaporation, do not dilute

· Add 1mL of boiled sample into the EC/Blue tube.

Chemical treatment (Traveller’s chlorine or iodine tablets or diluted bleach)

· Mix ~25 ml sari filtered water with 1 Chlorine tablet and incubate at room temperature for 30 min.

· Alternatively, ad 5 µl of household bleach to 25ml sari filtered water and incubate at room temperature for 30 min. (CDC Make water safe) -> 8 drops to 1 Gallon of water

· Add 1mL of boiled sample into the EC/Blue tube.

Once you have completed all treatments and added 1ml of each water sample into your EC/Blue Media, place tubes in the 370C incubator (or at room temperature if you do this experiment in the field) for 24-48h

Test results – shine your fluorescent light at the tubes and determine the results

· The leftmost tube has changed to blue and also fluoresces

indicating both coliforms and E. coli presence.

· The middle tube has only changed color and does not

fluoresce indicating coliforms but no E. coli.

· The rightmost tube has experienced no change and has

neither coliforms nor E. coli.

Did you get it?

1. When governments evaluate water quality, what are they looking for?

2. Does the presence of coliforms always indicate pathogenic bacteria?

3. How does EC Blue media work?

4. What are some alternate uses for EC Blue media and how might it be used in the future?

5. What are the advantages and disadvantages of this method?

In-Person Lab

Activity: Clean Water Crisis – The Global Traveler

Waterborne Pathogens & Toxins Poster:

Resources

Take a look at the appropriate module for the vocabulary that is being tested: Microbiology @ UF Lab Terminology Quizlet.

Use GIDEON to diagnose disease caused by contaminated water, learn about the diseases, get to know the different pathogens

See how the UN sustainable development goals (SDGs) relate to Microbiology.