Question

Which organism is used as a common indicator of water pollution?
A)Coliform
B)Mycobacterium spp
C)Helicobacter pylori
D)All of the above

Answer 1

Hint: Indicator bacteria are those which can detect the level of fecal contamination of water. They are not harmful to human health and are indicators of the presence of a health risk.

Complete answer:
Water pollution is the contamination of water bodies mostly by human activities. Illness can be contracted from activities in water that are contaminated by fecal pollution. They may contain pathogenic viruses, protozoa, and parasites. Fecal matter can enter the environment from sources like wastewater treatment plants, sanitary landfills, septic systems, sewage sludge, pets, livestock, wildlife, etc. If a sufficient amount of the fecal pathogens are ingested, they can cause disease. Risk of human exposure requires: Pathogens to be present and to survive; their ability to multiply on the water surface; individuals to come in contact with water for sufficient time or ingest enough volume of water that can cause the infection.
Indicator bacteria can be cultured on the media that are created to allow the growth of the species we want and to inhibit the growth of other organisms.

Commonly used indicators are coliforms. These are rod-shaped, Gram-negative, non-spore-forming, motile, or non-motile bacteria. They are identified on the fact that they can ferment lactose with the production of acid and gas when incubated at 35- 37 degrees Celsius. Coliforms can be found in aquatic environments, soil, on vegetation and the fecal coliforms are found in the intestinal tracts of warm-blooded animals. Total coliforms are used as indicator bacteria for a long time. Typical genera include citrobacter, enterobacter, klebsiella, escherichia, etc.

Non-coliform bacteria are also used for measuring fecal contamination, such as Streptococcus bovis, some clostridia, etc.

Hence, the correct answer is option (A)

Note: Some coliform bacteria cannot ferment lactose, so the definition has changed to the bacteria containing the enzyme beta-galactosidase. Species of mycobacterium are the causative agents of tuberculosis. Helicobacter pylori are germs that can enter the stomach and cause infection.