An emerging zoonotic clone in the Netherlands provides clues to virulence and zoonotic potential of Streptococcus suis.

Streptococcus suis is a zoonotic swine pathogen and a major public health concern in Asia, where it emerged as an important cause of bacterial meningitis in adults. While associated with food-borne transmission in Asia, zoonotic S. suis infections are mainly occupational hazards elsewhere. To identify genomic differences that can explain zoonotic potential, we compared whole genomes of 98 S. suis isolates from human patients and pigs with invasive disease in the Netherlands, and validated our observations with 18 complete and publicly available sequences. Zoonotic isolates have smaller genomes than non-zoonotic isolates, but contain more virulence factors. We identified a zoonotic S. suis clone that diverged from a non-zoonotic clone by means of gene loss, a capsule switch, and acquisition of a two-component signalling system in the late 19th century, when foreign pig breeds were introduced. Our results indicate that zoonotic potential of S. suis results from gene loss, recombination and horizontal gene transfer events.

Neurological Aspects of Stuttering : Summary Overview of Scientific Fingings

The aim of this article is to provide a summary overview of some of the more important scientific evidence of neurological differences between stutterers and non-stutterers. Stuttering is a complex disorder of speech fluency; the aetiology of which is still largely unclear. Although most of the knowledge about stuttering has been derived from clinical observations; essential information obtained through laboratory research delineated some important neurological differences between people with a stuttering problem and people who do not stutter. These differences are identified in terms of neuroimaging; speech production processes and even in terms of auditory perception and feedback mechanisms. The development of new and improved neuroimaging techniques has greatly enhanced the potential to investigate neurological correlates of stuttering. Current knowledge is indicative of a complex neurological basis for stuttering. However; on the basis of current scientific evidence any currently held theory cannot be conclusively substantiated

Gastro intestinal hyperpermeability: a review.

OBJECTIVE: To present a wide overview of the recent developments in the understanding of the aetiopathogenesis of gastrointestinal hyperpermeability. DATA SOURCES: Medline, from 1985, was sourced for relevant articles. Review articles were included in order to minimise the number of references in the reference list. STUDY SELECTION: Results from experiments and observations on humans and other mammalian species were studied. DATA SYNTHESIS: The major mechanisms elucidated in the aetiopathogenesis of the gastrointestinal hyperpermeability were integrated and consolidated into a flow diagram and the major factors responsible for normal permeability presented for comparison. CONCLUSION: The occurrence of increased gastrointestinal hyperpermeability is probably vastly underestimated. In addition to the hyperpermeability commonly associated with chronic gastro intestinal disorders, an increase in gastrointestinal permeability may occur in any condition of metabolic depletion, enterocyte ATP-depletion, stimulation of gastrointestinal pro-inflammatory cytokine production and disturbances of the normal gastrointestinal flora as with prolonged use of antibiotics.