Genetic Characterization of Extensively Drug-Resistant Shigella sonnei Infections, Spain, 2021-2022

Area of Science:

• Microbiology
• Infectious Diseases
• Genomics

Background:

• The United Kingdom observed a rise in drug resistance among Shigella sonnei isolates in 2022.
• Shigella sonnei is a significant cause of bacterial dysentery, posing public health challenges globally.
• Antimicrobial resistance in bacterial pathogens is a growing concern, necessitating continuous surveillance.

Purpose of the Study:

• To investigate the genetic relationship and antimicrobial resistance profiles of Shigella sonnei isolates in Spain.
• To determine if Spanish cases are linked to the increased drug resistance reported in the UK.
• To identify the genetic diversity and resistance patterns of circulating Shigella sonnei strains in Spain.

Main Methods:

• WGS sequencing was performed on Shigella sonnei isolates from Spain.
• Phylogenetic analysis was used to compare Spanish isolates with international strains, including those from the UK.
• Antimicrobial susceptibility testing was conducted to assess resistance profiles.

Main Results:

• Thirty-three cases in Spain were genetically related to the UK outbreak strains.
• An additional four cases in Spain exhibited similar antimicrobial resistance profiles but were infected with genetically distinct strains.
• The findings indicate the presence of multiple, diverse genetic clusters of multidrug-resistant Shigella sonnei circulating within Spain.

Conclusions:

• Spain is experiencing the circulation of multidrug-resistant Shigella sonnei, with connections to international outbreaks.
• The emergence of genetically distinct resistant strains highlights the complex epidemiology of Shigella sonnei.
• Enhanced surveillance and molecular typing are crucial for controlling the spread of antimicrobial resistance.