Dominance of toxigenic Clostridioides difficile strains and the appearance of the emerging PCR ribotype 955 in hospitals in Silesia, Poland

Klaudia Szarek; Natalia Frankowska; Monika Kabała; Wiep Klaas Smits; Dorota Wultańska; Piotr Lalowski; Hanna Pituch; Adam Iwanicki; Krzysztof Hinc; Céline Harmanus; Ingrid M J G Sanders; Robert Wojtyczka; Tomasz J Wąsik

doi:10.3389/fmicb.2025.1644051

Dominance of toxigenic Clostridioides difficile strains and the appearance of the emerging PCR ribotype 955 in hospitals in Silesia, Poland

Front Microbiol. 2025 Aug 11:16:1644051. doi: 10.3389/fmicb.2025.1644051. eCollection 2025.

Authors

Affiliations

¹ Department of Medical Microbiology, Faculty of Medical Science in Katowice, Medical University of Silesia, Katowice, Poland.
² Division of Molecular Bacteriology, Medical University of Gdańsk, Gdańsk, Poland.
³ Intercollegiate Faculty of Biotechnology, University of Gdańsk, Gdańsk, Poland.
⁴ Leiden University Center for Infectious Diseases and Dutch National Expertise Center for Clostridioides difficile, Leiden University Medical Center, Leiden, Netherlands.
⁵ Department of Medical Microbiology, Medical University of Warsaw, Warsaw, Poland.
⁶ Department of Medical Microbiology, Faculty of Pharmaceutical Sciences in Sosnowiec, Medical University of Silesia, Katowice, Poland.

^# Contributed equally.

Abstract

Introduction: Toxigenic strains of Clostridioides difficile are the leading cause of healthcare-associated bacterial infections in Poland. In the Silesian Voivodeship, with 4.5 million inhabitants, the incidence of C. difficile infection (CDI) in 2023 reached 65.1/100,000, slightly down from 70.0/100,000 in 2022. This study aimed to investigate the occurrence of toxigenic C. difficile ribotypes in hospitalized patients in Silesia.

Materials and methods: A total of 130 stool samples from patients with confirmed antibiotic-associated diarrhea were tested. Multiplex PCR detected genes for GDH, toxins A/B, binary toxin CDT, and 16S rDNA. Ribotyping was performed by capillary PCR, and antibiotic susceptibility was tested with ETEST for 10 antibiotics.

Results: Multiplex PCR confirmed the presence of all toxins (A⁺B⁺CDT⁺) in 97 isolates. Six strains (6%) represented ribotype 955 (RT955), first reported in Poland in 2023. RT027 remained dominant (60%, n = 78). All isolates were susceptible to vancomycin, while 4% (5/130) showed metronidazole resistance.

Conclusion: RT027 remains prevalent among CDI cases in Silesia. The emergence of RT955, closely related to a UK epidemic strain, suggests a possible shared origin and epidemiological link.

Keywords: Clostridioides difficile; Clostridioides difficile infection; health care-associated CDI; hospital-acquired infection; ribotypes; toxigenic strains.