Isolation and characterization of nonspreading mutants of the gliding bacterium Cytophaga johnsonae

Abstract

Three approaches were taken to isolate a total of 153 nonspreading mutants derived from our laboratory strain of Cytophagajohnsonae, UW101, or from its auxotrophic derivative, UW10538. Characterization of 109 of these mutants led to their placement in five general categories: (i) motile, nonspreading (MNS) mutants whose cells are motile to various degrees but whose colonies fail to spread on agar gels under any conditions of incubation; (ii) conditional nonspreading (CNS) mutants with motile cells whose colonies require more moisture to spread on agar gels than do those of wild-type cells; (iii) filamentous conditional motility (FCM) mutants whose cells grow aS nonmotile filaments or as motile cells with wild-type morphology, depending on conditions of incubation; (iv) short, tumbling, nonspreading (STN) mutants with short cells that tumble constantly; and (v) truly nonmotile (TNM) mutants whose cells never move and whose colonies never spread under any conditions tested. All TNM mutants exhibited a remarkable pleiotropy not seen in the other four classes of mutants: all were resistant to 39 phages to which wild-type cells are sensitive, and all were unable to digest chitin, which is digested by wild-type cells. The correlation between ability to move and phage sensitivity was strengthened further by showing that 150 additional TNM mutants derived from UW101 and 43 TNM mutants derived from 29 independent isolates of C. johnsonae were resistant to all phages to which their parents were sensitive. Furthermore, motile revertants of TNM nmutants became phage sensitive, and temperature-sensitive mutants were motile and phage sensitive at 25°C and nonmotile and phage resistant at 32°C. Evidence supports the conclusion that any mutation rendering cells truly nonmotile invariably alters cell surface-associated properties such as phage sensitivity and chitin digestion merely as a consequence of changing a moving cell surface to a static surface.

Virulent and nonvirulent Flavobacterium columnare colony morphologies: characterization of chondroitin AC lyase activity and adhesion to polystyrene

“…Rhizoid colonies or spreading growth is an indication of gliding motility of flavobacteria (Chang et al 1984;Bernardet and Keroault 1989;Bernardet et al 1996;Staroscik and Nelson 2008). In Fl.…”

“…columnare, but rhizoid colony morphology may also be connected to virulence (Kunttu et al 2009a). Gliding motility of flavobacteria is indicated by rhizoid colony morphology (Chang et al 1984;Bernardet and Kerouault 1989;Bernardet et al 1996;Staroscik and Nelson 2008), and it has been shown that loss of motility results also in loss in virulence of Fl. psychrophilum (Á lvarez et al 2006).…”

Bacterial predation: 75 years and counting!

“…Recently, it has been reported that M. xanthus and Flavobacterium johnsoniae glide using proteins that move in helical tracks, albeit with significantly different motility mechanisms, suggesting that these systems may have evolved independently (Nan et al ., ). It is interesting to note that F. johnsoniae non‐motile mutants fail to utilize chitin (Chang et al ., ). These results suggest that gliding motility might have evolved from a polysaccharide utilization system (McBride et al ., ).…”

Three-Dimensional Observations of an Aperiodic Oscillatory Gliding Behavior in Myxococcus xanthus Using Confocal Interference Reflection Microscopy

“…extracellular appendages for motility. The phenomenon of gliding motility has been identified in a diverse range of bacterial species spanning various phyla (3)(4)(5)(6)(7)(8). The deltaproteobacterium Myxococcus xanthus displays two different modes of gliding motility, adventurous motility and social motility, to seek out nutrients or prey as part of its complex life cycle (4,(9)(10)(11)(12)(13)(14)(15).…”