title: Outcome of relapsing Clostridium difficile infections do not correlate with virulence-, spore- and vegetative cell-associated phenotypes.
abstract: One of the main clinical challenges of Clostridium difficile infections (CDI) is the high rate of relapse episodes. The main determinants involved in relapse of CDI include the presence of antibiotic-resistant C. difficile spores in the colonic environment and a permanent state of dysbiosis of the microbiota caused by antibiotic therapy. A possible scenario is that phenotypes related to the persistence of C. difficile spores might contribute to relapsing infections. In this study, 8 C. difficile isolates recovered from 4 cases with relapsing infection, and 9 isolates recovered from single infection cases were analyzed for PCR ribotyping and the presence of tcdA, tcdB and cdtAB genes. Factors associated to spore persistence, sporulation, spore adherence and biofilm formation and sporulation during biofilm formation were characterized. We also evaluated motility and cytotoxicity. However, we observed no significant difference in the analyzed phenotypes among the different clinical outcomes, most likely due to the high variability observed among strains within clinical backgrounds in each phenotype and the small sample size. It is noteworthy that C. difficile spores adhered to similar extents to undifferentiated and differentiated Caco-2 cells. By contrast, spores of all clinical isolates tested had increased germination efficiency in presence of taurocholate, while decreased sporulation rate during biofilm development in the presence of glucose. In conclusion, these results show that, at least in this cohort of patients, the described phenotypes are not detrimental in the clinical outcome of the disease.
authors.affiliation: Gut Microbiota and Clostridia Research Group, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: Ángela
authors.initials: Á
authors.lastname: Plaza-Garrido
authors.affiliation: Gut Microbiota and Clostridia Research Group, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: Camila
authors.initials: C
authors.lastname: Miranda-Cárdenas
authors.affiliation: Gut Microbiota and Clostridia Research Group, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: Pablo
authors.initials: P
authors.lastname: Castro-Córdova
authors.affiliation: Gut Microbiota and Clostridia Research Group, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: Valeria
authors.initials: V
authors.lastname: Olguín-Araneda
authors.affiliation: Gut Microbiota and Clostridia Research Group, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: Glenda
authors.initials: G
authors.lastname: Cofré-Araneda
authors.affiliation: Departamento de Gastroenterología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Cristian
authors.initials: C
authors.lastname: Hernández-Rocha
authors.affiliation: Techlab, Inc, Blacksburg, VA, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Carman
authors.affiliation: Departamento de Gastroenterología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Patricio
authors.initials: P
authors.lastname: Ibáñez
authors.affiliation: Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom.
authors.forename: Warren N
authors.initials: WN
authors.lastname: Fawley
authors.affiliation: Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom; Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds, United Kingdom.
authors.forename: Mark H
authors.initials: MH
authors.lastname: Wilcox
authors.affiliation: Laboratorio de Genética y Patogénesis Bacteriana, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: Fernando
authors.initials: F
authors.lastname: Gil
authors.affiliation: Laboratorio de Genética y Patogénesis Bacteriana, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: Iván L
authors.initials: IL
authors.lastname: Calderón
authors.affiliation: Laboratorio de Genética y Patogénesis Bacteriana, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: Juan A
authors.initials: JA
authors.lastname: Fuentes
authors.affiliation: Laboratorio de Microbiología, Departamento de Laboratorio Clínico, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Ana María
authors.initials: AM
authors.lastname: Guzmán-Durán
authors.affiliation: Departamento de Gastroenterología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Manuel
authors.initials: M
authors.lastname: Alvarez-Lobos
authors.affiliation: Gut Microbiota and Clostridia Research Group, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile. Electronic address: daniel.paredes.sabja@gmail.com.
authors.forename: Daniel
authors.initials: D
authors.lastname: Paredes-Sabja
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D018441:Biofilms; D018938:Caco-2 Cells; D016360:Clostridioides difficile / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity* / Q000502:physiology; D003015:Clostridium Infections / Q000382:microbiology* / Q000473:pathology; D015331:Cohort Studies; D024881:Drug Resistance, Bacterial; D006801:Humans; D010641:Phenotype; D012008:Recurrence; D013171:Spores, Bacterial / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism / Q000472:pathogenicity; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins
keywords: Biofilm; Clostridium difficile; Recurrent CDI; Relapse; Relapsing CDI; Spore adherence; Spore germination; Sporulation