Fildes technique is used for the culture of? – Microbiology MCQ

Fildes technique is used for the culture of?
A. Clostridium perfringens
B. Clostridium tetani
C. Clostridium botulinum
D. Clostridium difficile

Correct answer : B. Clostridium tetani

Tennis racket appearance of Clostridium tetani

• Clostridium tetani grows on ordinary media.
• Growth can be improved by blood and serum.
• Because of marked tendency to swarm over the surface of the agar, surface colonies are difficult to obtain.
• After incubating anaerobically for 24 hours, if the water of condensation at the bottom of a slope of nutrient agar is inoculated with a mixed cell culture, subcultures from the top of the tube will yield a pure growth of tetanus bacillus.
• This is called Fildes technique.

Ref: Ananthanarayan and Paniker’s Textbook of Microbiology, 9th edition, p259, 260
Image credits: Centers for Disease Control and Prevention’s Public Health Image Library. http://phil.cdc.gov/phil/details.asp?pid=6372