| The mycoplasmas belong to the class Mollicutes. They are evolutionary descendants of the gram-positive bacteria and, through chromosome reduction, represent the smallest self-replicating life forms. Their streamlined genome size imposes complex nutritional requirements, such as dependence on external supplies of biosynthetic precursors. Pathogenic mycoplasmas are among the most difficult microorganisms to grow from clinical specimens. Therefore, to manage to grow the mycoplasmas independently, we have to take into account their difficult nature and the intimate dependence with the host.;This thesis was focused on the study of mycoplasma culture media. In a first part, a semidefined medium (MWS) without animal serum and beef serum albumin was developed to be used in vaccines production against mycoplasmosis. Later the adaptation to grow in this media, the replication of different strains of Mycoplasma mycoides subsp. mycoides LC type, M. m. subsp. capri, M. capricolum subsp. capricolum, M. agalactiae and M. arginini was managed.;For the present, no culture media has been appropriated for all the mycoplasma species for reasons that are still not clear. Knowing the inconvenience of having different formulations for a mycoplasma heterogeneous group (porcine, bovine, caprine, ovine and avian mycoplasmas), in a second part of this study, an isolating medium, the SP4-II, was developed with this purpose in mind. This medium has given such satisfactory results, that it can be recommended as general isolation medium for classic mycoplasmas species (Mycoplasma and Acholeplasma). |
