Mycoplasmas and related bacteria in the class Mollicutes are parasitic organisms found not only on the external surfaces of a wide range of eukaryotic host cells, but also intracellularly. They are characterized by small size and lack of a rigid cell wall, which gives them resistance to β-lactam antibiotics and the ability to pass through 0.2-µm filters (1,2). Contamination by Mollicutes is a common problem for cell cultures that is not easily detected because it usually does not produce turbidity…