Abstract
Ledingham 1 indicated the presence of “nucleus like” chromatin bodies in the large swollen forms of the organism of bovine pleuropneumonia. Klieneberger and Smiles 2 and Klieneberger 3 studying the mode of reproduction in the pleuropneumonia group observed that the chromatin divides and is distributed into the new cells. This chromatin gives the Fuelgen reaction indicating the presence of nucleic acid and Klieneberger attributes nuclear character to this material.
We have seen exactly similar chromatin material in the large bodies of various bacterial species. 4 We have been able to study it best in 3 strains of Bacteroides funduliformis because of the regularity with which these strains produce large bodies 5 and because of the excellent staining of their chromatin material. Pleuropneumonia-like (L) colonies frequently appeared among the ordinary bacterial colonies of 2 of these strains.
The present report deals with studies made on 1 of these strains which we have designated as Strain No. 132. This strain has been carried through more than 50 subcultures and continues to produce L variants in abundance. These L variants have been isolated in pure culture. They did not revert to their parent bacterial form throughout 30 subcultures on agar. They were strictly anaerobic, just as their parent bacterial forms.
The chromatin in the bacilli and in the L forms is best seen in preparations made by a modification of Klieneberger's agar fixation technic. 2 Agar blocks bearing the organisms are inverted onto cover slips and fixed for several days with Bourn's solution. The agar is then peeled away and the cover slip rinsed, stained with Giemsa, differentiated with ascitic fluid and mounted in balsam. The cover slip should never be allowed to dry until just before mounting.
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