Question

Bacteriological examination of drinking water for Escherischia Coliforms (E.Coli) is performed because

• A. they are pathogens causing intestinal diseases
• B. their presence indicates viral contamination of water
• C. they represent unique indicator organism for sewage pollution.
• D. they are used as indicator organisms for probable presence of pathogens

Answer 1

The correct option is D they are used as indicator organisms for probable presence of pathogens

Pathogenic bacteria are tested and counted with great difficulty in laboratory. Hence, coliform bacteria or Escherischia Coliform are tested and counted which themselves are harmless aerobic lactose fermenters but their presence or absence indicates the presence or absence of pathogenic bacteria.