title: Clostridium difficile carriage in adult cystic fibrosis (CF); implications for patients with CF and the potential for transmission of nosocomial infection.
abstract: Clostridium difficile is an anaerobic Gram-positive, spore-forming, toxin-producing bacillus transmitted among humans through the faecal-oral route. Despite increasing carriage rates and the presence of C. difficile toxin in stool, patients with CF rarely appear to develop typical manifestations of C. difficile infection (CDI). In this study, we examined the carriage, toxin production, ribotype distribution and antibiotic susceptibility of C. difficile in a cohort of 60 adult patients with CF who were pre-lung transplant. C. difficile was detected in 50% (30/60) of patients with CF by culturing for the bacteria. C. difficile toxin was detected in 63% (19/30) of C. difficile-positive stool samples. All toxin-positive stool samples contained toxigenic C. difficile strains harbouring toxin genes, tcdA and tcdB. Despite the presence of C. difficile and its toxin in patient stool, no acute gastrointestinal symptoms were reported. Ribotyping of C. difficile strains revealed 16 distinct ribotypes (RT), 11 of which are known to be disease-causing including the hyper-virulent RT078. Additionally, strains RT002, RT014, and RT015, which are common in non-CF nosocomial infection were described. All strains were susceptible to vancomycin, metronidazole, fusidic acid and rifampicin. No correlation was observed between carriage of C. difficile or any characteristics of isolated strains and any recorded clinical parameters or treatment received. We demonstrate a high prevalence of hypervirulent, toxigenic strains of C. difficile in asymptomatic patients with CF. This highlights the potential role of asymptomatic patients with CF in nosocomial transmission of C. difficile.
authors.affiliation: APC Microbiome Institute, University College Cork, Ireland.
authors.forename: D G
authors.initials: DG
authors.lastname: Burke
authors.affiliation: Cork Adult CF Centre, Dept. of Respiratory Medicine, Cork University Hospital, University College Cork, Ireland.
authors.forename: M J
authors.initials: MJ
authors.lastname: Harrison
authors.affiliation: Cork Adult CF Centre, Dept. of Respiratory Medicine, Cork University Hospital, University College Cork, Ireland.
authors.forename: C
authors.initials: C
authors.lastname: Fleming
authors.affiliation: Cork Adult CF Centre, Dept. of Respiratory Medicine, Cork University Hospital, University College Cork, Ireland.
authors.forename: M
authors.initials: M
authors.lastname: McCarthy
authors.affiliation: Cork Adult CF Centre, Dept. of Respiratory Medicine, Cork University Hospital, University College Cork, Ireland.
authors.forename: C
authors.initials: C
authors.lastname: Shortt
authors.affiliation: Dept. of Respiratory Medicine, Cork University Hospital, University College Cork, Ireland.
authors.forename: I
authors.initials: I
authors.lastname: Sulaiman
authors.affiliation: Cork Adult CF Centre, Dept. of Respiratory Medicine, Cork University Hospital, University College Cork, Ireland.
authors.forename: D M
authors.initials: DM
authors.lastname: Murphy
authors.affiliation: Health Research Board, Clinical Research Facility, University College Cork, Ireland.
authors.forename: J A
authors.initials: JA
authors.lastname: Eustace
authors.affiliation: APC Microbiome Institute, University College Cork, Ireland.
authors.forename: F
authors.initials: F
authors.lastname: Shanahan
authors.affiliation: School of Microbiology, University College Cork, Ireland.
authors.forename: C
authors.initials: C
authors.lastname: Hill
authors.affiliation: Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland.
authors.forename: C
authors.initials: C
authors.lastname: Stanton
authors.affiliation: Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland.
authors.forename: M C
authors.initials: MC
authors.lastname: Rea
authors.affiliation: APC Microbiome Institute, University College Cork, Ireland.
authors.forename: R P
authors.initials: RP
authors.lastname: Ross
authors.affiliation: Cork Adult CF Centre, Dept. of Medicine, Cork University Hospital, University College Cork, Ireland. Electronic address: b.plant@ucc.ie.
authors.forename: B J
authors.initials: BJ
authors.lastname: Plant
mesh_terms: D000328:Adult; D015373:Bacterial Typing Techniques / Q000379:methods; D002353:Carrier State / Q000175:diagnosis / Q000453:epidemiology; D016360:Clostridioides difficile / Q000302:isolation & purification*; D015331:Cohort Studies; D003428:Cross Infection / Q000175:diagnosis / Q000382:microbiology; D003550:Cystic Fibrosis / Q000453:epidemiology / Q000382:microbiology; D004761:Enterocolitis, Pseudomembranous / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D006801:Humans; D007494:Ireland / Q000453:epidemiology; D008297:Male; D008826:Microbial Sensitivity Tests / Q000379:methods; D015995:Prevalence
keywords: Clostridium difficile; Cystic fibrosis; Nosocomial infection; Transmission