A 3 yr old boy fell down and injured his leg while he was playing on ground. After a few days, there are crepitations felt from injured area, what could be the probable causative organism?

Ans. (d) Clostridium WelchiiRef: Microbiology by Ananthanarayan and Paniker 8th ed. /643, 655, 249-54* Clostridium Welchii is also known as Clostridium perfringens.* It is the most common bacterial agent which causes gas gangrene.* Gas gangrene results in tissue necrosis, putrefaction of tissues, and gas production.* It is caused primarily by Clostridium perfringens alpha toxin, usually after a injury or trauma.* These gases form bubbles in muscle and produce characteristic smell of decomposing tissue.* The local spread of gases under tissue produces Crepitations when pressed on it.* Crepitations: sound of snow crushing* After rapid and destructive local spread (which can take hours), systemic spread of bacteria and bacterial toxins may result in death.