Mycoplasma hyopneumoniae is the etiological agent of swine mycoplasmal pneumonia (also called enzootic pneumonia (EP)). It is one of the most common and economically significant respiratory diseases affecting swine production worldwide. The disease is associated with secondary infections, high-morbidity and low-mortality rates, low feed conversion and can be attributed to global economic losses estimated at about $1 billion per year.
In EP, Mycoplasma hyopneumoniae bacteria attach to the cilia of epithelial cells in the lungs of swine destroying healthy normal cilia allowing for opportunistic organisms to establish themselves into the respiratory tissue causing disease. Once established, M. hyopneumoniae causes lesions in the lungs of pigs.
The disease is highly contagious and transmission is usually through direct contact with infected respiratory tract secretions, for example droplets ejected from the snout or mouth on sneezing or coughing.
Several vaccines against M. hyopneumoniae currently exist. Most current vaccines are provided by about 10 companies with 22 vaccine brands registered as either single or bi/multivalent. All are killed or inactivated M. hyopneumoniae preparations.
Examples of whole cell inactivated M. hyopneumoniae vaccines include RESPISURE™ and STELLAMUNE™ (Pfizer), SUVAXYN M. HYO™ (Fort Dodge), HYORESP™ (Meriel), M+PAC™ (Schering-Plough) and PORCILIS™ (Intervet).
While some vaccines can reduce the severity of EP, none of the available whole cell killed or inactivated vaccines provide full protection from M. hyopneumoniae infection. Accordingly there is a need for a more effective vaccine.
It is an aim of a preferred embodiment of the present invention to provide a live strain of Mycoplasma pneumoniae suitable for use in vaccination to prevent enzootic pneumonia.
All references, including any patents or patent applications, cited in this specification are hereby incorporated by reference. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents forms part of the common general knowledge in the art.