Reproductive Processes in Proteus Cultures.

Abstract

The complex reproductive processes formerly observed in other Gram-negative bacteria have also been observed in Proteus. The bacilli are transformed into large round bodies and these reproduce either the usual bacteria or a growth similar to pleuropneumonia-like organisms. In Proteus this process presents several distinctive characteristics. The large round bodies are not produced by swelling of the bacilli as in other spp., but by a process known as ''plasmoptysis''[long dash]an outflow of the content of the bacillary filaments from their membrane. The bacilli show this phenomenon only in a special phase of their development when they grow out into long filaments actively motile on solid media. The spreading filaments show a tendency to ''plasmoptysis'' under various adverse conditions, e.g., when they are subjected to refrigeration or when they are transferred into tapwater or into broth containing HgCl2. Transformation of the filament into large bodies occurs also when the spreading halo of one strain meets the spreading halo of another appropriate strain. The large bodies so produced are fully viable; they return within a few hrs. into regular bacillary forms and continue to multiply. Rarely they produce a tiny pleuropneumonia-like colony. Large bodies produced by refrigeration are also viable. Large bodies produced in tapwater are only slightly viable and if they grow they produce pleuropneumonia-like colonies. Those produced by HgCl2 or by other toxic influences such as penicillin are not viable. The meeting of 2 appropriate strains induces a complex reproductive process consisting of several consecutive steps. It is not likely that this process is simply degenerative. The observations at present do not support the supposition that the interaction between the strains is sexual because it involves no union of cells.