Brief Communication RESISTANCE OF PORCINE MYCOPLASMAS TO DRYING The survival time of porcine mycoplasmas outside their natural habitat is of considerable interest, especially with regard to the question of preventive measures to be taken in order to avoid the introduction of such organisms in pig herds established under SPF-programrnes. In a study on this problem Goodwin (1972) recorded a survival time of 1 month for Mycoplasma suipneumoniae stored in liquid medium at room temperature. Survival

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... for 100 days was reported for storage in refrigerator. The work here reported deals with experiments on the survival of porcine mycoplasmas after drying in air at room temperature. Strains of all the known porcine mycoplasma species, cloned 3 times on solid medium, were included in the study. The strains were : a reference strain" and 2 Danish isolates (M98 and M99) of Mycoplasma hyorhinis (M. hyor.) : a reference strain?" and 2 Danish isolates (Ms5 and Ms6) of Mycoplasma suipneumoniae (M. suip.); a reference strain""" (S39) of Acholeplasma granularum (A. gran.) ; a Danish isolate (M60) of Mycoplasma hyosynoviae (M. hyosyn.); a strain of Mycoplasma Ilocculare (M. f'loc.) designated Ms42 (Meyling & Friis 1972) . By the growth and metabolic inhibition tests (Friis 1971a) M98, M99, Ms5, and Ms6 were indislJinguishable f.rom the respective reference strains, and M60 from the reference strain of M. hyosyn. (S16, Ross & Karmon 1970) . Media previously described by Friis (1970 Friis ( , 1971b) ) were used for cultivation. Well-growing broth cultures in the final stage of the logarithmic growth phase were diluted about 10 bimes in pure broth, and from each strain 1 drop was deposited