Genomic signatures of human and animal disease in the zoonotic pathogen Streptococcus suis. Streptococcus suis genomes

Streptococcus suis causes disease in pigs worldwide and is increasingly implicated in zoonotic disease in East and South-East Asia. To understand the genetic basis of disease in S.treptococcus suis, we have studydied the genomes of 375 isolates with detailed clinical phenotypes from pigs and humans from the UK and Vietnam. Here, we show that Iisolates associated with disease contained substantially fewer genes than non-clinical isolates, but were are more likely to encode virulence factors. Human disease isolates were are limited to a single virulent population, originating in the 1920s when pig production was intensified, but no consistent genomic differences between pig and human isolates were are observed. There was is little geographical clustering of different S. suis sub-populations, and the bacterium undergoes high rates of recombination, implying that an increase in virulence anywhere in the world could have a global impact over a short timescale.