Mycoplasma - First Isolation

First Isolation

In 1898 Nocard and Roux reported the cultivation of the causative agent of CBPP, which was at that time a grave and widespread disease in cattle herds. The disease is caused by M. mycoides subsp. mycoides SC (small-colony type), and the work of Nocard and Roux represented the first isolation of a mycoplasma species. Cultivation was, and still is difficult because of the complex growth requirements.

These researchers succeeded by inoculating a semi-permeable pouch of sterile medium with pulmonary fluid from an infected animal and depositing this pouch intraperitoneally into a live rabbit. After fifteen to twenty days, the fluid inside of the recovered pouch was opaque, indicating the growth of a microorganism. Opacity of the fluid was not seen in the control. This turbid broth could then be used to inoculate a second and third round and subsequently introduced into a healthy animal, causing disease. However, this did not work if the material was heated, indicating a biological agent at work. Uninoculated media in the pouch, after removal from the rabbit, could be used to grow the organism in vitro, demonstrating the possibility of cell-free cultivation and ruling out viral causes, although this was not fully appreciated at the time .