1
|
Snydman DR, McDermott LA, Thorpe CM, Goldstein EJC, Schuetz AN, Johnson S, Gerding DN, Gluck L, Bourdas D, Carroll KC, Lancaster CK, Garey KW, Wang Q, Walk ST, Duperchy E. A US-based national surveillance study for the susceptibility and epidemiology of Clostridioides difficile isolates with special reference to ridinilazole: 2020-2021. Antimicrob Agents Chemother 2023; 67:e0034923. [PMID: 37728368 PMCID: PMC10583687 DOI: 10.1128/aac.00349-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 07/04/2023] [Indexed: 09/21/2023] Open
Abstract
We have previously reported on the susceptibility and epidemiology of Clostridioides difficile isolates from six geographically dispersed medical centers in the United States. This current survey was conducted with isolates collected in 2020-2021 from six geographically dispersed medical centers in the United States, with specific attention to susceptibility to ridinilazole as well as nine comparators. C. difficile isolates or stools from patients with C. difficile antibiotic-associated diarrhea were collected and referred to a central laboratory. After species confirmation of 300 isolates at the central laboratory, antibiotic susceptibilities were determined by the agar dilution method [M11-A9, Clinical and Laboratory Standards Institute (CLSI)] against the 10 agents. Ribotyping was performed by PCR capillary gel electrophoresis on all isolates. Ridinilazole had a minimum inhibitory concentration (MIC) 90 of 0.25 mcg/mL, and no isolate had an MIC greater than 0.5 mcg/mL. In comparison, fidaxomicin had an MIC 90 of 0.5 mcg/mL. The vancomycin MIC 90 was 2 mcg/mL with a 0.7% resistance rate [both CLSI and European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria]. The metronidazole MIC 90 was 1 mcg/mL, with none resistant by CLSI criteria, and a 0.3% resistance rate by EUCAST criteria. Among the 50 different ribotypes isolated in the survey, the most common ribotype was 014-020 (14.0%) followed by 106 (10.3%), 027 (10%), 002 (8%), and 078-126 (4.3%). Ridinilazole maintained activity against all ribotypes and all strains resistant to any other agent tested. Ridinilazole showed excellent in vitro activity against C. difficile isolates collected between 2020 and 2021 in the United States, independent of ribotype.
Collapse
Affiliation(s)
- D. R. Snydman
- Tufts Medical Center, Boston, Massachusetts, USA
- Tufts University School of Medicine and the Stuart B. Levy Center for the Integrated Management of Antimicrobial Resistance, Boston, Massachusetts, USA
| | - L. A. McDermott
- Tufts Medical Center, Boston, Massachusetts, USA
- Tufts University School of Medicine and the Stuart B. Levy Center for the Integrated Management of Antimicrobial Resistance, Boston, Massachusetts, USA
| | - C. M. Thorpe
- Tufts Medical Center, Boston, Massachusetts, USA
- Tufts University School of Medicine and the Stuart B. Levy Center for the Integrated Management of Antimicrobial Resistance, Boston, Massachusetts, USA
| | | | - A. N. Schuetz
- Mayo Clinic School of Medicine and Science, Rochester, Minnesota, USA
| | - S. Johnson
- Edward Hines, Jr. VA Hospital, Hines, Illinois, USA
- Loyola University Medical Center, Maywood, Illinois, USA
| | | | - L. Gluck
- Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - D. Bourdas
- Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - K. C. Carroll
- University of Houston College of Pharmacy, Houston, Texas, USA
| | | | - K. W. Garey
- Summit (Oxford) Ltd, Abingdon, United Kingdom
| | - Q. Wang
- Montana State University, Bozeman, Montana, USA
| | - S. T. Walk
- Montana State University, Bozeman, Montana, USA
| | - E. Duperchy
- Johns Hopkins Hospital, Baltimore, Maryland, USA
| |
Collapse
|
2
|
Schneider D, Duperchy E, Coursange E, Lenski RE, Blot M. Long-term experimental evolution in Escherichia coli. IX. Characterization of insertion sequence-mediated mutations and rearrangements. Genetics 2000; 156:477-88. [PMID: 11014799 PMCID: PMC1461276 DOI: 10.1093/genetics/156.2.477] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
As part of a long-term evolution experiment, two populations of Escherichia coli B adapted to a glucose minimal medium for 10,000 generations. In both populations, multiple IS-associated mutations arose that then went to fixation. We identify the affected genetic loci and characterize the molecular events that produced nine of these mutations. All nine were IS-mediated events, including simple insertions as well as recombination between homologous elements that generated inversions and deletions. Sequencing DNA adjacent to the insertions indicates that the affected genes are involved in central metabolism (knockouts of pykF and nadR), cell wall synthesis (adjacent to the promoter of pbpA-rodA), and ill-defined functions (knockouts of hokB-sokB and yfcU). These genes are candidates for manipulation and competition experiments to determine whether the mutations were beneficial or merely hitchhiked to fixation.
Collapse
Affiliation(s)
- D Schneider
- Laboratoire Plasticité et Expression des Génomes Microbiens, Université Joseph Fourier, 38041 Grenoble Cedex 9, France.
| | | | | | | | | |
Collapse
|