Difference in twitching motility between Neisseria meningitidis and Neisseria gonorrhoeae and its relation to pilus dynamics
(English)Manuscript (preprint) (Other academic)
Type IV pili of pathogenic Neisseria, i. e. Neisseria gonorrhoeae and Neisseria meningitidis, are essential for initial attachment to host cells, induction of signal transduction cascades and disease development. A characteristic feature of type IV pili is their ability to retract, which generates forces that move bacteria over surfaces. However, the relation between bacterial motility and pilus dynamics remains poorly understood. In this work we analyzed bacterial motility and monitored movement of fluorescently labeled pili by live cell imaging. We found that movement of N. meningitidis occurred at higher speed and with a larger number of retracting pili than for N. gonorrhoeae. Analysis of time-lapse images suggested that N. gonorrhoeae most often moved using one retracting pilus, whereas N. meningitidis most often used four pili. There were no differences in the membrane distribution of PilT among strains. However, we found significantly higher levels of PilT in N. gonorrhoeae than in N. meningitidis. This produces a higher retraction probability, which could contribute to explaining the lower number of pili observed in N. gonorrhoeae. Finally, we propose a mechanism for how the speed of bacterial movement on a surface depends on the number of retracting pili.
Type IV pili, twitching motility, PilT, Neisseria
Research subject Biophysics; Microbiology
IdentifiersURN: urn:nbn:se:su:diva-65804OAI: oai:DiVA.org:su-65804DiVA: diva2:464839