CHARACTERIZATION OF MYCOPLASMA STRAINS ISOLATED FROM HOUSE MUSK SHREWS (SUNCUS-MURINUS) AND THEIR INFECTIVITY IN MICE AND RATS

Five mycoplasma strains isolated from house musk shrews (Suncus murinu s) in the Central Institute for Experimental Animals were characterize d and compared with three murine mycoplasma strains, Mycoplasma pulmon is m 53, M. arthritidis PG6, and M. neurolyticum Type A, and with refe rence strain G3-5 previously isolated from a house musk shrew. These i solates fermented glucose, but did not hydrolyze urea and arginine, pa ssed through membrane filters of 450 nm pore size, were sensitive to d igitonin, and formed minute (115 to 231 mum in diameter) colonies on a gar medium. All the five unclassified house musk shrew mycoplasma stra ins and strain G3-5 used as a reference constituted a homogeneous grou p based on (i) their antigenic properties (determined using the metabo lism inhibition test), (ii) their polypeptide profiles (determined usi ng sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the W estern blotting assay), and (iii) their genomic properties (determined using DNA cleavage pattern analysis) , but were quite distinct from t he established murine mycoplasmas on the basis of these findings. In a survey of 56 house musk shrews aged 2 to 45 weeks in our colonies, my coplasmas were isolated from the oral cavities of all animals examined . No gross or microscopic lesions were observed in the five animals fr om which the mycoplasma strains were isolated. In experimental infecti on, the mycoplasma was not infective for mice and rats. The results su ggest that this group of mycoplasmas is a common inhabitant of house m usk shrews.