A Mutant of Salmonella Possessing Straight Flagella

Abstract

SUMMARYA mutant of Salmonella typhimurium produced straight flagella in phase 2 (antigen-1,a) and normal flagella in phase I (antigen-i). The straight flagella were observed by light microscopy and electron microscopy either with or without formalin fixation. Flagellar bundles of the mutant bacteria prepared in 0.25 yo methylcellulose (w/v) and examined by dark-field microscopy were also found to be straight. It was shown by electron microscopy that the component flagella of the straight flagellar bundle were in most instances irregularly twisted about each other. Heteromorphous bacteria which had straight flagella and either normal or mini-small-amplitude flagella were seen at a frequency of 10-1 3 yo among the bacterial clones in phase 2. The bacteria with straight flagella were non-motile but they were sensitive to bacteriophage x, which is known to infect motile bacteria of Salmonella species. In transduction, using phage P 22 grown on a normal flagellar strain and the phase 2 straight strain as recipient, transductional clones with normal flagella in both phase I and phase 2 were obtained. The transductional clones showed theantigen of the recipient in phase I and that of the donor in phase 2. This indicated that the straight mutant originated by a mutation of the structural gene of phase 2 flagellin. In absorption-agglutination experiments with antisera prepared against flagella of either normal-r,a or straight-r,z no antigenic difference between normal and straight flagella could be detected.

Flagellar determinants of bacterial sensitivity to χ-phage

“…When it was realized that flagellar filaments rotate, the suggestion was made that a phage moves along the filament ''like a nut on a bolt'' (5). This observation was consistent with the finding that mutants with straight filaments, while nonmotile, remain fully sensitive to (6). Ravid and Eisenbach (7) found that the number of phage particles adsorbed by cells, i.e., removed from the supernatant fraction, correlated only with the fraction of the population of cells whose flagella rotated incessantly; it did not correlate with the direction of rotation.…”

The Role of Motility and Aerotaxis in the Selective Increase of Avirulent Bacteria in Still Broth Cultures of Pseudomonas solanacearum

“…I a) than those observed on motile avirulent bacteria. Other investigators have reported that bacteria with straight flagella were non-motile (Iino & Mitani, 1967;Iino, 1969).…”

Molecular and Cellular Characterization of a Salmonella enterica Serovar Paratyphi A Outbreak Strain and the Human Immune Response to Infection

“…5C and D). Salmonella mutants that produce irregular flagella were described more than 40 years ago and were shown to be impaired in their movement (22). Thus, it is very likely that the structural differences identified in the flagella of both strains affect the degree of their motility.…”