Why mycoplasma is called pplo that is pleuropneumonia like organism??

MycoplasmasThese smallest, independently replicating prokaryotes organisms were first discovered by Pasteur when he studied the causative agent of the a pulmonary disease of cattle which appeared in Germany and Switzerland in 1713 known as “Bovine pleuropneumonia”. Due to its resemblance with pneumonia symptoms this disease is called as Bovine Pleuropneumonia. However, extraction and culture of the causal organism wasn`t done at that time, but It was believed that the causal agent was Pleuropneumonia like organisms (PPLO) and after that when mycoplasms were discovered, due to aforementioned reason it is still known as PPLO.