Application of a diagnostic DNA probe for the differentiation of the two types of Mycoplasma mycoides subspecies mycoides.

Contagious bovine pleuropneumonia (CBPP), which is caused by Mycoplasma mycoides subspecies mycoides, is still a serious disease in some parts of the world. There is also a commonly occurring mycoplasma which is sufficiently related to the CBPP organism to bear the same name, even though this organism does not cause CBPP. Thus it is very important to be able to distinguish between these organisms and identify either with certainty. Fragments derived from M mycoides subspecies capri by restriction enzyme digestion of genomic DNA were cloned into the vector M13mp8. One resulting clone CAP-21, with a 1.5 kb insert was used as a probe in Southern hybridisation assays where genomic DNA was digested with the restriction endonuclease TaqI. This probe could differentiate a strain of M mycoides subspecies mycoides which does not cause CBPP. Subsequent tests on 14 other strains from cattle and goats showed that although they were isolated from diverse geographical areas, CAP-21 could clearly differentiate between these two types of M mycoides subspecies mycoides.