Carriage of a Single Strain of Nontoxigenic Corynebacterium diphtheriae bv. Belfanti ( Corynebacterium belfantii ) in Four Patients with Cystic Fibrosis

Diane Pivot (1) , Annlyse Fanton (2) , Edgar Badell-Ocando (3, 4) , Marion Benouachkou (1) , Karine Astruc (1) , Frederic Huet (2) , Lucie Amoureux (1) , Catherine Neuwirth (1) , Alexis Criscuolo (5, 6) , Serge Aho (1) , Julie Toubiana (3, 4) , Sylvain Brisse (3, 4)

1 CHU Dijon - Centre Hospitalier Universitaire de Dijon - Hôpital François Mitterrand
2 CRCM Toulouse - Centre de Ressources et de Compétences en Mucoviscidose [CHU Toulouse]
3 Biodiversité et Epidémiologie des Bactéries pathogènes - Biodiversity and Epidemiology of Bacterial Pathogens
4 CNR - Centre national de Référence des Corynebactéries du Complexe Diphtheriae - National Reference Center Corynebacteria of the diphtheriae complex
5 IP - Institut Pasteur [Paris]
6 Hub Bioinformatique et Biostatistique - Bioinformatics and Biostatistics HUB

Cystic fibrosis (CF) patients are commonly colonized by bacterial pathogens, which can induce persistent lung inflammation and may contribute to clinical deterioration. Colonization of CF patients and cross-transmission by Corynebacterium diphtheriae have not been reported so far. The aim of this article was to investigate the possibility of a cross-transmission of C. diphtheriae biovar Belfanti between four patients of a CF center. C. diphtheriae biovar Belfanti (now formally called C. belfantii) isolates were collected from four patients in a single CF care center over a period of 6 years and analyzed by microbiological methods and whole-genome sequencing. Epidemiological links among patients were investigated. Ten isolates were collected from 4 patients. Whole-genome sequencing of one isolate from each patient showed that a single strain was shared among them. In addition, one patient was found to have the same strain in two consecutive samplings performed 9 months apart. The strain was nontoxigenic and was susceptible to most antimicrobial agents. Ciprofloxacin resistance was observed in one patient. The idea of transmission of the strain among patients was supported by the occurrence of same-day visits to the CF center. This study demonstrated colonization of CF patients by C. diphtheriae biovar Belfanti (C. belfantii), and the data suggest persistence and transmission of a unique strain during at least 6 years in a single CF patient care center.

Keywords: Corynebacterium diphtheriae; colonization; cystic fibrosis; epidemiology; genomic sequencing; transmission

Domains: Life Sciences [q-bio]

Diane Pivot, Annlyse Fanton, Edgar Badell-Ocando, Marion Benouachkou, Karine Astruc, et al.. Carriage of a Single Strain of Nontoxigenic Corynebacterium diphtheriae bv. Belfanti ( Corynebacterium belfantii ) in Four Patients with Cystic Fibrosis. Journal of Clinical Microbiology, 2019, 57 (5), ⟨10.1128/JCM.00042-19⟩. ⟨pasteur-03265229⟩