Morin, C. | bioRxiv Science

bioRxiv2022

Diffusion MR imaging in the corticospinal tract of idiopathic scoliosis

Many studies have shown that idiopathic scoliosis is not only a deformity of the spine. It is often associated with neurological impairment without any macroscopic abnormality in the brain. In our previous diffusion MRI study, we demonstrated that children with right-thoracic idiopathic scoliosis had abnormal white matter microstructure of the crossing premotor fibres in the corpus callosum. Based on this, we hypothesized that similar microstructural changes could affect the main descending white matter tracts, the corticospinal tract. We compared the fractional anisotropy values along the corticospinal tracts in ten patients with right-thoracic and ten patients with left-thoracic idiopathic scoliosis to 49 healthy controls. We found abnormal left-right asymmetry of the fractional anisotropy values in scoliosis patients at the level of the pons. Whereas at upper levels the values were similar across all groups. Our results suggest that abnormal sensorimotor integration at the level of the pons is associated with the development of idiopathic scoliosis.

neuroscience↗

bioRxiv2022

Surface motility favors co-dependent interaction between Pseudomonas aeruginosa and Burkholderia cenocepacia

Interactions between different bacterial species shape bacterial communities and their environments. The opportunistic pathogens Pseudomonas aeruginosa and Burkholderia cenocepacia both can colonize the lungs of individuals affected by cystic fibrosis. Using the social surface behavior called swarming motility as a study model of interactions, we noticed intricate interactions between B. cenocepacia K56-2 and P. aeruginosa PA14. While strain K56-2 does not swarm under P. aeruginosa favorable swarming conditions, co-inoculation with a non-motile PA14 flagellum-less {Delta}fliC mutant restored spreading for both strains. We show that P. aeruginosa provides the wetting agent rhamnolipids allowing K56-2 to perform swarming motility, while aflagellated PA14 seems able to < > along with K56-2 cells in the swarming colony. ImportancePseudomonas aeruginosa and Burkholderia cenocepacia are important opportunistic pathogens often found together in the airways of persons with cystic fibrosis. Laboratory co-culture of both species often ends with one taking over the other. We used a surface motility assay to study the social interactions between population of these bacterial species. Under our conditions, B. cenocepacia cannot swarm without supplementation of the wetting agent produced by P. aeruginosa. In a mixed colony of both species, an aflagellated mutant of P. aeruginosa provides the necessary wetting agent to B. cenocepacia, allowing both bacteria to swarm and colonize a surface. We highlight this peculiar interaction where both bacteria set aside their antagonistic tendencies to cooperate.

microbiology↗