Genetically related clostridium difficile from water sources and human CDI cases revealed by whole-genome sequencing
Abstract
Clostridium difficile isolates from the environment are closely related to those from humans, indicating a possible environmental transmission route for C. difficile infection (CDI). In this study, C. difficile was isolated from 47.3% (53/112) of lake/pond, 23.0% (14/61) of river, 20.0% (3/15) of estuary and 0.0% (0/89) of seawater samples. The most common toxigenic strain isolated was C. difficile PCR ribotype (RT) 014/020 (10.5%, 8/76). All water isolates were susceptible to fidaxomicin, metronidazole, rifaximin, amoxicillin/clavulanic acid, moxifloxacin and tetracycline. Resistance to vancomycin, clindamycin, erythromycin and meropenem was detected in 5.3% (4/76), 26.3% (20/76), 1.3% (1/76) and 6.6% (5/76) of isolates, respectively. High-resolution core-genome analysis was performed on RT 014/020 isolates of water origin and 26 clinical RT 014/020 isolates from the same year and geographical location. Notably, both human and water strains were intermixed across three sequence types (STs), 2, 13 and 49. Six closely related groups with ≤10 core-genome single nucleotide polymorphisms were identified, five of which comprised human and water strains. Overall, 19.2% (5/26) of human strains shared a recent genomic relationship with one or more water strains. This study supports the growing hypothesis that environmental contamination by C. difficile plays a role in CDI transmission.
Document Type
Journal Article
Date of Publication
3-1-2022
Volume
24
Issue
3
PubMed ID
34693624
Publication Title
Environmental Microbiology
Publisher
Wiley
School
School of Medical and Health Sciences
RAS ID
39862
Funders
Edith Cowan University
Grant Number
G1004458
Copyright
subscription content
First Page
1221
Last Page
1230
Comments
Lim, S. C., Hain‐Saunders, N. M., Imwattana, K., Putsathit, P., Collins, D. A., & Riley, T. V. (2022). Genetically related Clostridium difficile from water sources and human CDI cases revealed by whole‐genome sequencing. Environmental Microbiology, 24(3), 1221-1230. https://doi.org/10.1111/1462-2920.15821