Calcium Increases Xylella fastidiosa Surface Attachment, Biofilm Formation, and Twitching Motility

Calcium increases surface attachment, biofilm formation, and twitching motility in Xylella

Surface motility of Xylella fastidiosa visualized by oblique illumination.

Stereomicroscopic observations using oblique illuminations revealed the presence of two types of movement trails by Xylella fastidiosa strains (A- and G-genotypes) isolated from almond-leaf scorch samples on the surface of PW and PD3 culture media. The A-genotype strains showed curved motility trails, and the G-genotype strains showed straight motility trails. Haloes were found around some G-ge...

EFFECTS OF CHEMICAL MILIEU ON ATTACHMENT, AGGREGATION, BIOFILM FORMATION, AND VECTOR TRANSMISSION OF XYLELLA FASTIDIOSA STRAINS Project Leader:

We have begun work on the effects of chemical and physical factors, including type of media, pH, media volume, and vessel on the in vitro survival, growth and substrate-attachment of a wild-type and mutant strain of Xylella fastidiosa (Xf). The volume of media in which Xf is incubated appears to override the importance of other variables, including any strain differences. Xf populations incubat...

Mutations in type I and type IV pilus biosynthetic genes affect twitching motility rates in Xylella fastidiosa.

Xylella fastidiosa possesses both type I and type IV pili at the same cell pole. By use of a microfluidic device, the speed of twitching movement by wild-type cells on a glass surface against the flow direction of media was measured as 0.86 (standard error [SE], 0.04) microm min(-1). A type I pilus mutant (fimA) moved six times faster (4.85 [SE, 0.27] microm min(-1)) and a pilY1 mutant moved th...

EXPLOITING A CHEMOSENSORY SIGNAL TRANSDUCTION SYSTEM THAT CONTROLS TWITCHING MOTILITY AND VIRULENCE IN XYLELLA FASTIDIOSA Principal Investigator:

Previously we demonstrated that twitching motility in Xylella fastidiosa is dependent on an operon, named Pil-Chp, encoding signal transduction pathway proteins (PilG, PilI, PilJ, PilL, ChpB and ChpC), which is related to the system that controls flagella movement in Escherichia coli. We report three advances in examining this chemotaxis system. First, we have examined the operon genes more clo...