An Outbreak of Clostridium (Clostridioides) difficile Infections within an Acute and Long-Term Care Wards Due to Moxifloxacin-Resistant PCR Ribotype 176 Genotyped as PCR Ribotype 027 by a Commercial Assay.

Elena Novakova,Mark Wilcox,Marcela Krutova,Nina Kotlebova,Anezka Gryndlerova,Michala Vladarova,Ed Kuijper,Martin Novak

doi:10.3390/jcm9113738

Abstract

We aimed to characterize Clostridioides difficile isolates cultured during a six-month single-center study from stool samples of patients with C. difficile infection (CDI) genotyped by the Xpert® C. difficile/Epi assay by polymerase chain reaction (PCR) ribotyping, toxin genes’ detection and multi-locus variable number tandem repeats analysis (MLVA). The susceptibility to metronidazole, vancomycin and moxifloxacin was determined by agar dilution. In addition, the presence of Thr82Ile in the GyrA and a single nucleotide deletion at position (Δ117) in the tcdC gene were investigated. Between January 1 and June 30, 2016, of 114 CDIs, 75 cases were genotyped as presumptive PCR ribotype (RT) 027 infections using a commercial assay. C. difficile isolates cultured from presumptive RT027 stool samples belonged to RT176. These isolates carried genes for toxin A (tcdA), B (tcdB), binary (cdtA/B) and had Δ117 in the tcdC gene. Using MLVA, the 71/75 isolates clustered into two clonal complexes (CCs). Of these, 39 isolates (54.9%) were from patients hospitalized in acute care and 32 isolates (45.1%) were isolated from patients hospitalized in the long-term care department. All isolates were susceptible to metronidazole and vancomycin, and 105 isolates were resistant to moxifloxacin (92%) carrying Thr83Ile in the GyrA. An outbreak of RT176 CDIs, suspected as RT027, was recognized in a Slovakian hospital. In order to monitor the emergence and spread of RT027-variants, the identification of a presumptive RT027 CDI should be confirmed at a strain level by PCR ribotyping.

Highlights

Clostridium difficile, recently reclassified as Clostridioides difficile, belongs to the most important healthcare-associated pathogens [1,2]
Unformed stool samples from patients with a suspected C. difficile infection (CDI) were tested for the presence of toxins A/B (CerTest Clostridium difficile GDH + Toxin A + B one-step combo card test, Zaragoza Spain)
Presumptive Ribotype 027 CDI Outbreak Was Identified from Stool Samples

Summary

Introduction

Clostridium difficile, recently reclassified as Clostridioides difficile, belongs to the most important healthcare-associated pathogens [1,2]. The major virulence factors in C. difficile are toxins TcdA and TcdB; some strains can produce a third toxin, C. difficile transferase (CDT) which is named binary toxin [1,3]. The tcdC gene, located in the pathogenicity locus (PaLoc), encodes one of the proteins involved in transcriptional regulation [4,5]. The epidemiological importance of RT027 led to the development of several commercial molecular assays for the differentiation of C. difficile RT027 from other ribotypes. The assays are based on the presence of toxin genes (toxin B, binary toxin) and the specific deletion at position 117 in the tcdC gene [9]

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