Isolation and preliminary characterisation of mycoplasmavirus 20-P.

A mycoplasmavirus, MV 20-P, was isolated from the fastidious, slow-growing human mycoplasma 20-P, previously identified by the growth inhibition test as Mycoplasma hominis type 2. Its broth culture was ultracentrifuged into 35% saccharose, the pellet was resuspensed in buffer, and the suspension was dropped onto laws of the virus indicator Acholeplasma laidlawii BCL-13. The virus was washed off the plaque areas by buffer. MV 20-P appeared in electron microscopy as spherical, enveloped particles about 80 nm in diameter. It was sensitive to lipid solvents. These preliminary results indicate that MV 20-P is a MVL2 type mycoplasmavirus and possibly the first of human origin.