Types of Water Bacteria

Bacteria are the most abundant forms of life on Earth and an essential component of plant nutrient cycles, needing only water, nutrients and energy to thrive. Some types have evolved, however, making them resistant to antibiotics and disinfectants, which is of increasing concern to microbiologists and geneticists. Bacteria have been discovered living in temperatures ranging from 482 degrees Fahrenheit to below freezing. Despite this, water sanitation methods are generally effective, and most types of bacteria found in water no longer pose a threat to humans.

Aeromonas species

• Aeromonas are bacteria occurring in natural water systems that cause gastric illness in humans. No recent outbreaks have been documented in the United States; however, the bacteria are still considered an economic threat to aquaculture.

Campylobacter species

• These species normally occur in wild and domestic animals. Campylobacter bacteria commonly occur in birds, chickens, sheep and goats. From 1985 through 1994, the bacteria caused six reported U.S. outbreaks.

Francisella tularensis

• One of the most infectious forms of bacteria known, Francisella tularensis causes the disease tularemia. This type of bacteria is highly resistant to antibiotics and associated with high mortality rates. Infection in humans occurs through insect bites, food, drinking water, handling of dead animals or inhalation. It is most likely to occur in rural areas and has been reported across the continental United States.

Helicobacter pylori

• The Helicobacter pylori species of bacterial organism infects 90 percent of populations in developing countries and 60 percent of populations in developed nations. It is now known to be the primary cause of stomach ulcers.

Legionella pneumophila

• This bacteria infects humans with Legionnaires' disease and can also cause Pontiac fever. Symptoms can be mild, severe or fatal. Legionnaires' disease was named in 1976, when many people at an American Legion convention in Philadelphia came down with severe respiratory disease.

Leptospira species

• Leptospira causes widespread disease in wild and domestic animals, but humans are only susceptible as incidental hosts. This type is rare in temperate regions; nevertheless, infections can be fatal.

Mycobacterium avium

• The Mycobacterium avium bacteria has increased resistance to disinfectants because of its complex cell wall. It is widespread in nature and can cause chronic pulmonary disease. It is especially dangerous to people with compromised immune systems.

Salmonella

• Commonly associated with improper food preparation, salmonella also thrives in water, and it is found in low numbers in all environments. Infections cause diarrhea and high fever, but infections are rare; from 1985 through 1994, only two outbreaks of salmonella were reported in the United States.

Shigella

• The shigella bacteria is found in water, but it is commonly associated with food outbreaks in children. Shigella has a poor survival rate in the environment and is easily killed by disinfectants. A dozen outbreaks were reported in the United States from 1985 through 1994.

Toxigenic Escherichia coli

• Escherichia encompasses a vast genera that includes a great number of diverse species. A small number of infections can be fatal, and young children and the elderly are most at risk. Although some types cause diarrhea, others can cause urinary tract infections, pneumonia and other diseases. Still other types, though not dangerous themselves, are used to test for water contamination as they are typically present in contaminated water.

Vibrio cholerae

• Vibrio cholerae bacteria causes cholera, which is often fatal. Cholera is associated with poor sanitation methods and has been successfully eradicated in industrialized nations. It is still common in the Indian subcontinent and sub-Saharan Africa, making it a concern for travelers.

Yersinia enterocolitica

• Yersinia enterocolitica organisms are common in wild and domestic animals that live near natural water sources. They are a hardy cold water species. Sporadic U.S. infections have been reported.