Properties of Proteus mirabilis and Providence spheroplasts.

Susceptibility to polymyxin B in penicillin G-induced Proteus mirabilis L forms and spheroplasts.

A polymyxin B-resistant strain of Proteus mirabilis was converted into L forms and spheroplasts in the presence of penicillin G. This treatment caused a 400-fold increase in polymyxin B susceptibility. The acquired susceptibility was in the range of the natural susceptibility reported for susceptible gram-negative bacteria ( approximately 1 mug/ml). The high susceptibility to polymyxin B was lo...

Reversion of L forms and spheroplasts of Proteus mirabilis.

Altenbern, Robert A. (U.S. Army Chemical Corps, Fort Detrick, Frederick, Md.). Reversion of L forms and spheroplasts of Proteus mirabilis. J. Bacteriol. 85:269-272. 1963.-Spheroplasts or 3-B type L forms of Proteus mirabilis formed by growth in the presence of penicillin are able to revert to the bacillary form, as judged by regain of resistance to osmotic shock. Reversion takes place in the ab...

Deoxyribonucleic acid base composition of Proteus and Providence organisms.

Falkow, Stanley (Walter Reed Army Institute of Research, Washington D.C.), I. R. Ryman, and O. Washington. Deoxyribonucleic acid base composition of Proteus and Providence organisms. J. Bacteriol. 83:1318-1321. 1962.-Deoxyribonucleic acids (DNA) from various species of Proteus and of Providence bacteria have been examined for their guanine + cytosine (GC) content. P. vulgaris, P. mirabilis, and...

Critical factors influencing growth of L forms of Proteus mirabilis.

The observations, primarily by Dienes and associates, of L colonies arising spontaneously or by penicillin induction from species of Proteus or Salmonella led to the description of two morphologically distinct colonial forms, designated as the 3B type and the 3A type. It has been reported further that the viable elements of these two types exhibit markedly dissimilar properties such as size, nu...

Plasmids and Putative Virulence Characters in Proteus mirabilis