On Dec. 23, 2016, researchers at University of California (UC) Davis and California Department of Public Health (CDPH) announced they had sequenced and analyzed genomes from Shigella sonnei (S. sonnei) bacteria associated with major shigellosis outbreaks in California in 2014 and 2015. Shigella infection (shigellosis) is an intestinal infection caused by a family of bacteria known as shigella.

The results offered new insights into how the bacteria acquired virulence and antibiotic resistance genes, as well as the California strains’ relationships to other strains around the world. This was the first major, whole-genome study of S. sonnei strains found in North America. The research was published in the journal mSphere.

S. sonnei is responsible for most shigellosis outbreaks throughout the world. The team from the Microbial Diseases Laboratory at CDPH sequenced the genomes of 68 isolates, including samples from the California outbreaks and historical strains from California, Asia and elsewhere.