BACTERIA GENERALLY RECEIVE BAD PRESS, such as when the news reports,

It's true that disease bacteria sometimes negatively impact Florida's waters. However, many bacterium organisms are beneficial to animal and plant life and serve many different purposes, having been around for three or four billion years. The truth is bacteria have always been and will always be an essential part of everyday life.

BACTERIA are...
Bacteria are perhaps the simplest and oldest form of life, found throughout nature in the soil, in the water and riding on dust in the air. Bacteria are so unlike plants and animals - they're just DNA/RNA encased in a hard cover - that they get their own category. They are able to reproduce, but they are extremely small, none bigger than the smallest cell. There are thousands of species of bacteria, in all sizes and shapes such as cones, spirals, rods... A gram of soil contains about 2.5 billion bacteria.

BACTERIA BENEFITS
Scientists consider most bacteria to be harmless and some to be beneficial. Many bacteria species are found naturally in the human body, and in all other animal bodies. These symbiotic (mutually beneficial) bacteria are instrumental in digestion, vitamin production, and other good work. When you are sick and take antibiotics, the goal is to kill the "bad" bacteria that have caused the disease. However, the antibiotics also kill the "good" bacteria that your body relies on. When you have been treated for a bacterial disease, you are not truly "cured" until the "good" bacteria have recolonized your body to do their work.

Scientists believe that bacteria helped create the earth's atmosphere. By producing so much life-producing oxygen, bacteria eventually made the atmosphere habitable for all creatures, including humans.

Bacteria are beneficial in other ways. Bacteria are what decompose and use up dead plant and animal matter. With no bacteria, the planet would be covered with dead plants and animals. Certain species of bacteria that live on the roots of plants actually "fix" nitrogen from the air, convert it to plant food, and feed the plants with essential plant nutrients. Some bacteria species have been harnessed to process foods such as cheese, yogurt and sour cream. Another bacterium, Bacillus thuringiensis(Bt), has insecticidal properties and is used to control plant pests.

Though bacteria are quite small and serve many beneficial functions, some of them do cause serious problems including diseases.

Tuberculosis R.W. Smithwick, CDC	Chelonea J. Carr, CDC	Plague CDC	Lyme disease CDC	Staphylococcus Carr, CDC

"BAD" BACTERIA
Still other bacteria are well known for the diseases they cause. These bacteria release toxins which cause the symptoms of strep throat, cholera, pneumonia and whooping cough. Another bacterium, Bacillus anthracis, is the agent of anthrax.

BACTERIAL CONTAMINATION and HEALTH STANDARDS
There are standards that governmental health agencies have set for acceptable levels of bacteria allowed in public waters. These standards were derived from years of experience and the knowledge of how much bacteria in the water is enough to get people sick.

As one may imagine, detecting any disease-causing bacteria in water can be very difficult. It is also an expensive proposition to isolate specific organisms found in a large surface area of water. There are many, many kinds of bacteria, including thousands of strains of E. coli in just that one group. The main bacteria that people are concerned about, which have caused much human misery throughout history, are enteric bacteria; these are organisms from the intestines of warm-blooded animals, including humans.

Because of the challenges of trying to isolate and identify all of the different types of bacteria one may find in water, health officials rely on only a handful of different types of bacteria. They use these as "indicator" organisms; if they are present in a water sample, it's thought that more harmful types of bacteria will be present. This practice was introduced as far back as 1892, and continues to be one of the more reliable tests for water contamination today.

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WHAT is E. coli ?
Another bacterium, E. coli, is becoming more well known in the public lexicon for "bad bacteria". (E. coli is the popular way of referring to the common bacterium, Escherichia coli.) The irony is that E. coli itself is not toxic - it is one of the required inhabitants of man and beast, as noted above - E. coli is simply an "indicator" of the possible presence of other, toxic, bacteria. The reasoning is that if there is increased levels of E. coli in local waters, and E. coli is relatively easy and cheap for health departments to test for, then there are likely to be increased levels of toxic, disease-causing bacteria, which are less easy and more expensive to test for.

The majority of human health agencies that test for bacteria depend on using three indicator bacterial types. They are the total coliform group, the fecal coliform group, and E. coli. There are a couple of new bacteria groups that biologists are considering using in tests to determine bacterial contamination, such as the enterocoxi test.

Read "UF/IFAS Graduate Student Studies Bacteria in Lakes" (PDF 416 KB), a Florida LAKEWATCH article.

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HOME TESTING KITS
There are companies that sell home testing kits, which are available through the Internet, if you suspect you have problems with local waters. Private labs will also test water samples. One should be cautioned that even positive results of a bacteria test, showing levels that surpass certain health levels, doesn't necessarily mean an entire waterbody is contaminated. Florida LAKEWATCH recommends that people conduct a series of tests to make an accurate assessment of bacterial levels. A three-step approach to this is described on pages 31-40 of Circular #106 (a link to this circular is at the bottom of this page).

SEPTIC TANKS and SEWER SYSTEMS
Due to advances in microbiology, bacterial contamination of food is fairly easy to trace back to its origin, even right back to certain food packages or particular farms in other countries. In water, this process is far more difficult. Contamination in water only occurs when natural dilution is no longer effective: that is when people run the risk of getting sick from swimming in the water, drinking it or eating certain kinds of food from it, such as shellfish in saltwater.

Not to mention produce vegetables in other countries. Tourists who have suffered ill effects, often nicknamed Montezuma's revenge, after eating vegetable salads in Third World countries or drinking the local water, have had a close encounter with what is very likely enteric bacteria. Such occurrences are fairly rare in the United States, with our improved water treatment and health education, and more stringent rules for septic tanks when people build homes. The old-fashioned outhouse is no longer acceptable; we have septic tanks and sewer systems.

CAUSES or the BLAME GAME?
It is important to realize that even though faulty septic tanks are often considered to be the reason for bacterial contamination of local waters, and may be blamed by the media, it's not always that simple. In fact, the larger municipal water treatment plants with their miles and miles of sewage pipes can be just as problematic, if not more so, than septic tanks: Water treatment plants and their sewer systems are just as prone as septic tanks to aging, cracking and releasing untreated sewage into the environment, including our waterways - either through stormwater runoff or contamination of groundwater. When a municipal sewage pipe leaks or breaks, it may release far more volume than a single home's aging septic tank.

For more information on the wastewater treatment debate, the pros and cons of septic tanks versus wastewater treatment plants, link to pages 12-15 in the Bacterial Circular #106 (a link to this circular is at the bottom of this page).

When bacterial contamination is discovered, the public often wants to point a finger at one easy source of contamination. But sources for contamination come from many places, such as human or animal waste, which might originate from agriculture farms as easily as from faulty septic systems. Or, too many seagulls feeding at the local landfill may be roosting at night on a town's reservoir. There are also sources for domestic animal waste, such as cats and dogs. Wash it from the lawns during a heavy rain, and problems may develop in smaller ponds. Too many wild deer can do the same.

NEVER ASSUME
The most important thing to keep in mind when looking for sources of contamination is that bacterial testing must be done before assumptions can be made. More often than not, bacterial contamination isn't all coming from just one source, but a combination of sources. Sometimes it originates from a source that no one has considered or imagined.

For more information about bacteria in water,

go to this University of California at Davis article

Read "A Beginner's Guide to Water Management - Bacteria" a circular published by Florida LAKEWATCH

 

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The Creators

This page was authored by Joe Richard.
Data is from the APIRS database.
This page was designed and is managed by Becca Hassell.
Photography and graphics are by Ann Murray and Vic Ramey.

Vic Ramey is the editor.

DEP review is by Jeff Schardt and Judy Ludlow

MAIN INDEX

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A collaboration of the Center for Aquatic and Invasive Plants, University of Florida, and the Invasive Plant Management Section of the Florida Fish and Wildlife Conservation Commission.

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