Not all bacteria are harmful to humans. An example of beneficial bacteria is Lactobacillus GG. These are also known as probiotics, and aid in digestion by limiting the amount of bad bacteria in the colon. However, there are bad bacteria, found outside the body, that are not only harmful to humans, but also deadly. Some of these bacteria are found in river water.
Dr. Charles L. Stoltenow, an extension veterinarian at North Dakota State University, wrote an article on the cyanobacteria poisoning in animals that have drunk water that contains one or more species of cyanobacteria. According to Dr. Stoltenow, cyanobacteria, also known as blue-green algae, can cause convulsions, bloody diarrhoea and sudden death in affected animals. Cyanobacteria are photosynthetic bacteria, which mean they use the energy of the sun to produce organic material. Photosynthesis is also how they get their trademark, blue-green pigment. Cyanobacteria, which are found in many bodies of water, including river water, produce "taste-and-odour compounds." According to the USGS Kansas Algal Toxin Research Team these cyanobacteria compounds have been reported to cause illness and even death in humans and animals, in at least 35 U.S. states.
Yersinia enterocolitica Bacteria
Yersinia enterocolitica infection is normally attributed to the consumption of raw or undercooked pork, and pork products. However, the Yersinia enterocolitica can also be transmitted to animals and humans in heavily contaminated river water. Symptoms of infection include fever, abdominal pain, and bloody diarrhoea. According to a 1980 study published by the international iournal Current Microbiology, Vol. 4, 24 isolated strains of the Yersinia enterocolitica were identified from 46 water samples taken from small rivers throughout Belgium. These strains showed characteristics, which were biochemical and serological in nature, meaning the bacteria contamination was the direct result of biological matter.
Escherichia coli and Streptococci
Microorganisms, such as coliform bacteria Escherichia coli and streptococci, are found in river water for a number of reasons. Grazing animals can defecate in or near rivers, which can contribute to a high concentration of fecal bacteria. Other ways these bacteria can enter a river system or river water source is through storm drains and faulty sewage systems or receptacles, such as a public sewage overflow or a septic tank leakage. In humans, the streptococci bacteria can cause rheumatic fever; acute glomerulonephritis (kidney disease); scarlet fever; bacteria sepsis, called Bacteremia; and toxic-shock syndrome. Human coliform bacteria poisoning can cause cramps, diarrhoea, and in some cases other waterborne diseases.