Identification of extracellular vesicles from J strain and wild isolate of Mycoplasma hyopneumoniae

Abstract

Respiratory diseases constitute a major health challenge for the worldwide pork industry. Porcine enzootic pneumonia (PES) is caused by Mycoplasma hyopneumoniae (Mhyo). Mycoplasmas have the ability to produce extracellular vesicles (EVs), which can be useful for pathogenicity studies and as delivery systems for vaccines. The aim of this study was to demonstrate and compare, under laboratory conditions, EVs produced by Mhyo strain J and wild isolate in stressed and non-stressed in vitro conditions. Using differential centrifugation, density gradient ultracentrifugation, and transmission electron microscopy, the ability of Mhyo strains to produce EVs was demonstrated under favorable and unfavorable conditions.

Keywords: Autogenous vaccine; Enzootic pneumonia; Extracellular vesicle.

Fig. 1

a: EV purification technique, 10-mL Friis medium non-inoculated, after early purification steps. Bar 500 nm. b: control of EV purification technique, 100-mL Friis medium non-inoculated, after early purification steps. Bar 100 nm. c: 100-mL Friis medium inoculated with J strain under normal growth conditions. Bar 200 nm. d: 100-mL Friis medium inoculated with wild isolate under normal growth conditions. Bar 500 nm. e: 10-mL Friis medium inoculated with strain J under normal growth conditions. Bar 100 nm. f: 10-mL Friis medium inoculated with J strain under oxidative stress, separated only by differential centrifugation (dC). Bar 100 nm. g, h: 10-mL Friis medium inoculated with J strain under oxidative stress, purified by dC and differential gradient ultracentrifugation. The arrows highlight the EVs. Bar 100 nm