An association between swarming and hemolysin BL secretion was observed in a collection of 42 Bacillus cereus isolates (P=0.029). The highest levels of toxin were detected in swarmers along with swarm cell differentiation (P=0.021), suggesting that swarming B. cereus strains may have a higher virulence potential than nonswarming strains.

Most agent-based modeling techniques generate one trajectory per run, greatly under-sampling the space of possible trajectories. Swarming agents that interact through digital pheromones can explore many alternative futures in parallel, based on an interpretation of pheromone fields as probability fields that yields more information from them than swarming models usually yield, and also facilita...

Computer-based swarm systems, aiming to replicate the flocking behavior of birds, were first introduced by Reynolds in 1987. In his initial work, Reynolds noted that while it was difficult to quantify the dynamics of the behavior from the model, observers of his model immediately recognized them as a representation of a natural flock. Considerable analysis has been conducted since then on quant...

BACKGROUND Many investigators have recognised that a significant proportion of environmental bacteria exist in a viable but non-culturable state on agar plates, and some researchers have also noticed that some of such bacteria clearly recover their growth on matrices other than agar. However, the reason why agar is unsuitable for the growth of some bacteria has not been addressed. METHODOLOGY...

The use of swarming Tylenchorhynchus martini nematodes provided a rapid and efficient in vitro method for the study of nematode orientation mechanisms as affected by chemical stimuli. Orientation of the nematodes occurred in concentration gradients diffusing from agar discs containing 0.05, 0.1, 0.25 M of both AlCln and CdCL>, and 0.25 M of NH..C1. Attraction of the nematodes did not occur at t...

Salmonella enterica utilizes flagellar motility to swim through liquid environments and on surfaces. The biosynthesis of the flagellum is regulated on various levels, including transcriptional and posttranscriptional mechanisms. Here, we investigated the motility phenotype of 24 selected single gene deletions that were previously described to display swimming and swarming motility effects. Muta...

In this study, we describe wosA, a Proteus mirabilis gene identified by its ability to increase swarming motility when overexpressed. At various times during the swarming cycle, the increased expression of wosA resulted in a 4- to 16-fold upregulation of the transcription of flhDC, encoding the master regulator of the flagellar cascade. In turn, the expression of flaA, encoding flagellin, was s...

We report the complete genome sequence of two Pseudomonas aeruginosa phages MP29 and MP42. Their genomes are similar to those of P. aeruginosa temperate phages DMS3 and MP22, whose lysogens are impaired in swarming motilities, involving the host CRISPR loci. Both MP29 and MP42 lysogens, however, were proficient in swarming, suggesting the absence of the phage-host CRISPR interaction.