Among the minimal bacteria belonging to the genus Mycoplasma, several of them are recognized pathogens for a wide diversity of animals. Mycoplasma bovis is one of the most significant species infecting dairy and fattening cows, causing mastitis and pneumonia, respectively. Attempts to control the disease has led to mass culling and costs of hundreds of millions in treatments and compensation worldwide as current vaccines are still considered poorly effective. Our objective is to develop efficient genetic tools for M. bovis genome engineering tools to gain knowledge on the pathogen and pave the way for the development of rationally designed synthetic vaccines. We are currently developing CRISPR-based and synthetic biology tools to target virulence factors and optimize antigenic presentation. Such tools will be useful to build a vaccine chassis that would allow presentation of selected epitopes at the cell surface, leading to an improved immune response. Here we report the inactivation of the recombinase implicated in the highly frequent variation of surface proteins expressed by M. bovis that allow this pathogen to remain elusive. By neutralizing one of the main weapons in the M. bovis arsenal, this result is a main step toward the stabilization of the bacterial surfaceome and the development of an effective vaccine chassis.< Leer menos