Emerging <i>Clostridioides difficile</i> strains belonging to PCR ribotype 955 in Serbia are distinct from metronidazole-resistant RT955 outbreak isolates from the UK
End 2023, the UK Health Security Agency sent an alert about a new hypervirulent <i>Clostridioides difficile</i> PCR ribotype, ribotype 955 (RT955), causing slowly progressing infection clusters in hospitals in the Midlands. Between March 2018 and February 2022, surveillance of <i>Clostridioides difficile</i> infections (CDI) was performed in southern Serbia with centres providing medical services for approximately 750,000 inhabitants. Using the ECDC recommended protocol, clinical, epidemiological and microbiological data were collected. <i>C. difficile</i> RT955 was identified in 27 (7%) of 383 surveyed patients with CDI. Of 27 patients, 16 (59%) was older than 60 years and 19 (70%) were male. CDI was always associated with previous antibiotic therapy and had a hospital onset in 23 (85%) patients. The clinical presentation was milder than reported in UK. All sequenced strains belonged to multilocus sequence type (ST) 1 and were highly similar, with 0-1 alleles differences in a core genome multilocus sequence typing analysis. The strains differed clearly from the UK RT955 outbreak strain by whole genome sequencing and phenotypic susceptibility to metronidazole, lincosamides and rifampicin. Interestingly, a high-level erythromycin resistance was observed associated with the presence of the <i>mrmA</i> gene. Both the UK and Serbian RT955 strains contained <i>gyrA</i>_p.T82I associated with resistance to fluoroquinolone antimicrobials and carried the PnimBG promoter mutation, suggestive for haem-dependent metronidazole resistance. We conclude that <i>C. difficile</i> RT955 is present in southern Serbia since 2018. The Serbian RT955 strains differed clearly from a representative UK cluster strain.
Authors
- Predrag Stojanović (ORCID: https://orcid.org/0000-0001-7209-6660)
- Daan W. Notermans (ORCID: https://orcid.org/0000-0002-9494-0989)
- James A. Groot (ORCID: https://orcid.org/0000-0003-1630-1652)
- Mark H. Wilcox (ORCID: https://orcid.org/0000-0002-4565-2868)
- Céline Harmanus (ORCID: https://orcid.org/0000-0002-5328-3273)
- Margriet E. M. Kraakman (ORCID: https://orcid.org/0000-0002-1723-4570)
- Wiep Klaas Smits (ORCID: https://orcid.org/0000-0002-7409-2847)
- Ed J. Kuijper (ORCID: https://orcid.org/0000-0001-5726-2405)
- Joffrey van Prehn (ORCID: https://orcid.org/0000-0002-4544-4807)
Institutions
- University of Leeds (GB)
- Leeds Teaching Hospitals NHS Trust (GB)
- Leiden University Medical Center (NL)
- National Institute for Public Health and the Environment (NL)
- Public Health Institute (US)
Publication Details
- Journal
- Emerging Microbes & Infections
- Published
- 2025-08-12
- DOI
- https://doi.org/10.1080/22221751.2025.2544733
- Citations
- 2
- Primary Topic
- Clostridium difficile and Clostridium perfringens research
- Type
- article
- Field-Weighted Citation Impact
- 2.79