LAUSR

BACKGROUND In high-income countries shigellosis is mainly found in travellers to high-risk regions or among men who have sex with men (MSM). Here we investigated the genomic characteristics and the features of antimicrobial resistance of MSM-associated Shigella flexneri and Shigella sonnei circulating in Barcelona (Spain), elucidating their connectivity with contemporaneous Shigella from other countries. METHODS Antimicrobial susceptibility, WGS, genomic characterization and phylogenetic analysis was performed in MSM-associated Shigella recovered from 2015 to 2019. Reference genomes of MSM-associated Shigella were included for contextualization and determining their connection with international outbreaks. RESULTS We identified 44 S. flexneri and 26 S. sonnei among MSM. Overall, 80% showed resistance to azithromycin, 65.7% to trimethoprim-sulphamethoxazole and 32.8% to ciprofloxacin, and 27.1% were simultaneously resistant to these three antimicrobials. mphA and/or ermB as well as qnrS and mutations in the QRDR were found in the azithromycin- and ciprofloxacin-resistant isolates, respectively. Additionally, two isolates carried blaCTX-M-27. SNP-based analysis revealed that the isolates were organized into different lineages most of which were closely related to dominant MSM-associated lineages previously described in the UK and Australia. CONCLUSIONS We describe the circulation of lineages of S. flexneri and S. sonnei among MSM in Spain that are mostly resistant to first/second line oral treatments and closely related to dominant MSM-associated lineages previously described in the UK and Australia. These data reinforce the urgent need for the implementation of public health measures focused on the early detection and prevention of the transmission of this emerging pathogen that contributes to the crisis of antimicrobial resistance in sexually transmitted infections.