Emergence of extensively drug-resistant and multidrug-resistant Shigella flexneri serotype 2a associated with sexual transmission among gay, bisexual, and other men who have sex with men, in England: a descriptive epidemiological study

Thorley, Katie, Charles, Hannah, Greig, David R, Prochazka, Mateo, Mason, Lewis CE ORCID: 0000-0001-5049-1352, Baker, Kate S ORCID: 0000-0001-5850-1949, Godbole, Gauri, Sinka, Katy and Jenkins, Claire (2023) Emergence of extensively drug-resistant and multidrug-resistant Shigella flexneri serotype 2a associated with sexual transmission among gay, bisexual, and other men who have sex with men, in England: a descriptive epidemiological study. LANCET INFECTIOUS DISEASES, 23 (6). pp. 732-739.

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Official URL: http://dx.doi.org/10.1016/s1473-3099(22)00807-6

Abstract

<h4>Background</h4>Shigellosis, also known as bacillary dysentery, is caused by Shigella spp that spread through fecal-oral contact and was traditionally associated with international travel in England. However, sexual transmission of Shigella flexneri and Shigella sonnei among gay, bisexual, and other men who have sex with men (MSM) is now common. In September, 2021, emergence of extensively drug-resistant (XDR) S sonnei harbouring plasmid-encoded bla<sub>CTX-M-27</sub> raised concerns over further spread of this extended-spectrum β-lactamase-producing gene. Using national surveillance in England, we identified and characterised isolates of S flexneri harbouring bla<sub>CTX-M-27</sub>.<h4>Methods</h4>In this epidemiological study, we identified and phylogenetically characterised S flexneri isolates harbouring bla<sub>CTX-M-27</sub> that were referred to the Gastrointestinal Bacterial Reference Unit (GBRU) at the UK Health Security Agency. All isolates referred to the GBRU undergo whole-genome sequencing, enabling antimicrobial resistance determination using genetic markers. Cases were defined as individuals diagnosed with S flexneri harbouring bla<sub>CTX-M-27</sub> in England, with a specimen date between Sept 1, 2015, and June 12, 2022, who were phylogenetically confirmed as part of two t10 (approximately ten single nucleotide polymorphisms) clusters. Long-read sequencing elucidated the genomic location of bla<sub>CTX-M-27</sub>. Laboratory data, integrated with available demographic and clinical information from patient questionnaires, were summarised using descriptive statistics.<h4>Findings</h4>A sustained increase in cases of S flexneri harbouring bla<sub>CTX-M-27</sub> (n=26) occurred from September, 2021, having been sporadically reported (n=11) in the preceding 6 years. bla<sub>CTX-M-27</sub> acquisition events within S flexneri 2a established an XDR paraphyletic (n=8) cluster and a multidrug-resistant monophyletic (n=18) cluster. Cases were among adult male individuals (median age 37 years [IQR 31-46]) and, of the 13 individuals who completed a patient questionnaire, ten (77%) identified as MSM. Antimicrobial treatment was received by seven (54%) of 13 individuals, and four (31%) individuals were admitted to hospital. The IncFII plasmids harbouring bla<sub>CTX-M-27</sub> showed high similarity to the XDR S sonnei outbreak plasmid, with 82% and 99% nucleotide similarity between the cluster plasmids and the XDR S sonnei outbreak plasmid.<h4>Interpretation</h4>We report emergence of XDR and multidrug-resistant S flexneri 2a harbouring bla<sub>CTX-M-27</sub> among MSM in England. Epidemiological and plasmid similarities with the XDR S sonnei outbreak support horizontal acquisition events, emphasising the importance of mobilisable antimicrobial resistance and the need for genomic-based surveillance.<h4>Funding</h4>National Institute for Health and Care Research Health Protection Research Unit in Gastrointestinal Infections at the University of Liverpool in partnership with the UK Health Security Agency.

Item Type:	Article
Uncontrolled Keywords:	Humans, Shigella flexneri, Dysentery, Bacillary, Anti-Bacterial Agents, Microbial Sensitivity Tests, Epidemiologic Studies, Homosexuality, Male, Adult, England, Male, Serogroup, Sexual and Gender Minorities
Divisions:	Faculty of Health and Life Sciences Faculty of Health and Life Sciences > Institute of Infection, Veterinary and Ecological Sciences Faculty of Health and Life Sciences > Institute of Systems, Molecular and Integrative Biology Faculty of Health and Life Sciences > Institute of Systems, Molecular and Integrative Biology > School of Life Sciences
Depositing User:	Symplectic Admin
Date Deposited:	19 Apr 2023 16:51
Last Modified:	08 Aug 2023 09:08
DOI:	10.1016/S1473-3099(22)00807-6
Open Access URL:	https://doi.org/10.1016/S1473-3099(22)00807-6
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3169779