@article{mbs:/content/journal/mgen/10.1099/mgen.0.000644, author = "Locke, Rebecca K. and Greig, David R. and Jenkins, Claire and Dallman, Tim J. and Cowley, Lauren A.", title = "Acquisition and loss of CTX-M plasmids in Shigella species associated with MSM transmission in the UK", journal= "Microbial Genomics", year = "2021", volume = "7", number = "8", pages = "", doi = "https://doi.org/10.1099/mgen.0.000644", url = "https://www.microbiologyresearch.org/content/journal/mgen/10.1099/mgen.0.000644", publisher = "Microbiology Society", issn = "2057-5858", type = "Journal Article", keywords = "antimicrobial resistance", keywords = "public health", keywords = "ESBL", keywords = "Shigella", keywords = "CTX-M", keywords = "MSM", eid = "000644", abstract = "Shigellosis in men who have sex with men (MSM) is caused by multidrug resistant Shigellae, exhibiting resistance to antimicrobials including azithromycin, ciprofloxacin and more recently the third-generation cephalosporins. We sequenced four bla CTX-M-27-positive MSM Shigella isolates (2018–20) using Oxford Nanopore Technologies; three S. sonnei (identified as two MSM clade 2, one MSM clade 5) and one S. flexneri 3a, to explore AMR context. All S. sonnei isolates harboured Tn7/Int2 chromosomal integrons, whereas S. flexneri 3a contained the Shigella Resistance Locus. All strains harboured IncFII pKSR100-like plasmids (67-83kbp); where present bla CTX-M-27 was located on these plasmids flanked by IS26 and IS903B, however bla CTX-M-27 was lost in S. flexneri 3a during storage between Illumina and Nanopore sequencing. IncFII AMR regions were mosaic and likely reorganised by IS26; three of the four plasmids contained azithromycin-resistance genes erm(B) and mph(A) and one harboured the pKSR100 integron. Additionally, all S. sonnei isolates possessed a large IncB/O/K/Z plasmid, two of which carried aph(3’)-Ib/aph(6)-Id/sul2 and tet(A). Monitoring the transmission of mobile genetic elements with co-located AMR determinants is necessary to inform empirical treatment guidance and clinical management of MSM-associated shigellosis.", }