In doubtful cases, the presence of which organism confirms the fecal contamination of water-
Protozoa
Yeast
Clostridium perfringes
Fungi
Park's textbook of preventive and social medicine 23rd edition. the presence of spores of Cl. perfringens in a natural water suggest that fecal contamination has occurred and their presence in the absence of coliform group suggest fecal contamination occurred at some remote time.
Environment and health