1
|
Redding LE, Tu V, Abbas A, Alvarez M, Zackular JP, Gu C, Bushman FD, Kelly DJ, Barnhart D, Lee JJ, Bittinger KL. Genetic and phenotypic characteristics of Clostridium (Clostridioides) difficile from canine, bovine, and pediatric populations. Anaerobe 2022; 74:102539. [PMID: 35217150 PMCID: PMC9359814 DOI: 10.1016/j.anaerobe.2022.102539] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 02/02/2022] [Accepted: 02/17/2022] [Indexed: 12/15/2022]
Abstract
Objectives: Carriage of Clostridioides difficile by different species of animals has led to speculation that animals could represent a reservoir of this pathogen for human infections. The objective of this study was to compare C. difficile isolates from humans, dogs, and cattle from a restricted geographic area. Methods: C. difficile isolates from 36 dogs and 15 dairy calves underwent whole genome sequencing, and phenotypic assays assessing growth and virulence were performed. Genomes of animal-derived isolates were compared to 29 genomes of isolates from a pediatric population as well as 44 reference genomes. Results: Growth rates and relative cytotoxicity of isolates were significantly higher and lower, respectively, in bovine-derived isolates compared to pediatric- and canine-derived isolates. Analysis of core genes showed clustering by host species, though in a few cases, human strains co-clustered with canine or bovine strains, suggesting possible interspecies transmission. Geographic differences (e.g., farm, litter) were small compared to differences between species. In an analysis of accessory genes, the total number of genes in each genome varied between host species, with 6.7% of functional orthologs differentially present/absent between host species and bovine-derived strains having the lowest number of genes. Canine-derived isolates were most likely to be non-toxigenic and more likely to carry phages. A targeted study of episomes identified in local pediatric strains showed sharing of a methicillin-resistance plasmid with dogs, and historic sharing of a wide range of episomes across hosts. Bovine-derived isolates harbored the widest variety of antibiotic-resistance genes, followed by canine Conclusions: While C. difficile isolates mostly clustered by host species, occasional co-clustering of canine and pediatric-derived isolates suggests the possibility of interspecies transmission. The presence of a pool of resistance genes in animal-derived isolates with the potential to appear in humans given sufficient pressure from antibiotic use warrants concern.
Collapse
Affiliation(s)
- L E Redding
- Department of Clinical Studies-New Bolton Center, University of Pennsylvania, School of Veterinary Medicine, Kennett Square, PA, 19348, USA.
| | - V Tu
- Division of Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Philadelphia, PA, 19104, USA
| | - A Abbas
- Division of Protective Immunity, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - M Alvarez
- Division of Protective Immunity, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - J P Zackular
- Division of Protective Immunity, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA; Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - C Gu
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - F D Bushman
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - D J Kelly
- Department of Clinical Studies-New Bolton Center, University of Pennsylvania, School of Veterinary Medicine, Kennett Square, PA, 19348, USA
| | - D Barnhart
- Department of Clinical Studies-New Bolton Center, University of Pennsylvania, School of Veterinary Medicine, Kennett Square, PA, 19348, USA
| | - J J Lee
- Division of Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Philadelphia, PA, 19104, USA
| | - K L Bittinger
- Division of Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Philadelphia, PA, 19104, USA
| |
Collapse
|