Extracellular Vesicles Derived fromAcholeplasma laidlawiiPG8

Abstract

Extracellular vesicle production is believed to be a ubiquitous process in bacteria, but the data on such a process in Mollicutes are absent. We report the isolation of ultramicroforms – extracellular vesicles from supernatants ofAcholeplasma laidlawiiPG8 (ubiquitous mycoplasma; the main contaminant of cell culture). Considering sizes, morphology, and ultrastructural organization, the ultramicroforms ofA. laidlawiiPG8 are similar to membrane vesicles of Gram-positive and Gram-negative bacteria. We demonstrate thatA. laidlawiiPG8 vesicles contain genetic material and proteins, and are mutagenic to lymphocytes of human peripheral blood. We show thatMycoplasma gallisepticumS6, the other mycoplasma, also produce similar structures, which suggests that shedding of the vesicles might be the common phenomenon in Mollicutes. We found that the action of stress conditions results in the intensive formation of ultramicroforms in mycoplasmas. The role of vesicular formation in mycoplasmas remains to be studied.