Mycoplasma hyopneumoniae is a species of bacteria known to cause the disease porcine enzootic pneumonia, a highly contagious and chronic disease affecting pigs. As with other mollicutes, M. hyopneumoniae is small in size (400–1200 nm), has a small genome (893–920 kilo-base pairs (kb)) and lacks a cell wall. It is difficult to grow in laboratories due to its complex nutritional requirements and the high chances of contamination associated with mycoplasma culture. To successfully grow the bacterium, an environment of 5–10% carbon dioxide is required, and the medium should demonstrate an acid colour shift.