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Fitzpatrick F, Brennan R, van Prehn J, Skally M, Brady M, Burns K, Rooney C, Wilcox MH. European Practice for CDI Treatment. Adv Exp Med Biol 2024; 1435:57-84. [PMID: 38175471 DOI: 10.1007/978-3-031-42108-2_4] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Clostridioides difficile infection (CDI) remains a significant cause of morbidity and mortality worldwide. Historically, two antibiotics (metronidazole and vancomycin) and a recent third (fidaxomicin) have been used for CDI treatment; convincing data are now available showing that metronidazole is the least efficacious agent. The European Society of Clinical Microbiology and Infectious Diseases (ESCMID) management guidance for CDI were updated in 2021. This guidance document outlines the treatment options for a variety of CDI clinical scenarios and for non-antimicrobial management (e.g., faecal microbiota transplantation, FMT). One of the main changes is that metronidazole is no longer recommended as first-line CDI treatment. Rather, fidaxomicin is preferred on the basis of reduced recurrence rates with vancomycin as an acceptable alternative. Recommended options for recurrent CDI now include bezlotoxumab as well as FMT.A 2017 survey of 20 European countries highlighted variation internationally in CDI management strategies. A variety of restrictions were in place in 65% countries prior to use of new anti-CDI treatments, including committee/infection specialist approval or economic review/restrictions. This survey was repeated in November 2022 to assess the current landscape of CDI management practices in Europe. Of 64 respondents from 17 countries, national CDI guidelines existed in 14 countries, and 11 have already/plan to incorporate the ESCMID 2021 CDI guidance, though implementation has not been surveyed in 6. Vancomycin is the most commonly used first-line agent for the treatment of CDI (n = 42, 66%), followed by fidaxomicin (n = 30, 47%). Six (9%) respondents use metronidazole as first-line agent for CDI treatment, whereas 22 (34%) only in selected low-risk patient groups. Fidaxomicin is more likely to be used in high-risk patient groups. Availability of anti-CDI therapy influenced prescribing in six respondents (9%). Approval pre-prescription was required before vancomycin (n = 3, 5%), fidaxomicin (n = 10, 6%), bezlotoxumab (n = 11, 17%) and FMT (n = 10, 6%). Implementation of CDI guidelines is rarely audited.Novel anti-CDI agents are being evaluated; it is not yet clear what will be the roles of these agents. The treatment of recurrent CDI is particularly troublesome, and several different live biotherapeutics are being developed, in addition to FMT.
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Affiliation(s)
- Fidelma Fitzpatrick
- Department of Clinical Microbiology, The Royal College of Surgeons in Ireland, Dublin, Ireland.
- Department of Clinical Microbiology, Beaumont Hospital, Dublin, Ireland.
| | - Robert Brennan
- Department of Clinical Microbiology, The Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Joffrey van Prehn
- Department of Medical Microbiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Mairead Skally
- Department of Clinical Microbiology, The Royal College of Surgeons in Ireland, Dublin, Ireland
- Department of Clinical Microbiology, Beaumont Hospital, Dublin, Ireland
| | - Melissa Brady
- Health Protection Surveillance Centre (HPSC), Dublin, Ireland
| | - Karen Burns
- Department of Clinical Microbiology, Beaumont Hospital, Dublin, Ireland
| | - Christopher Rooney
- Microbiology, Leeds Teaching Hospitals, Leeds, UK
- University of Leeds, Leeds, UK
| | - Mark H Wilcox
- University of Leeds, Leeds, UK.
- Leeds Teaching Hospitals and Leeds Regional Public Health Laboratory, UK Health Security Agency (UKHSA), Leeds, UK.
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2
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Mason CS, Avis T, Hu C, Nagalingam N, Mudaliar M, Coward C, Begum K, Gajewski K, Alam MJ, Bassères E, Moss S, Reich S, Duperchy E, Fox KR, Garey KW, Powell DJ. The Novel DNA Binding Mechanism of Ridinilazole, a Precision Clostridiodes difficile Antibiotic. Antimicrob Agents Chemother 2023; 67:e0156322. [PMID: 37093023 DOI: 10.1128/aac.01563-22] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023] Open
Abstract
Clostridioides difficile infection (CDI) causes substantial morbidity and mortality worldwide with limited antibiotic treatment options. Ridinilazole is a precision bisbenzimidazole antibiotic being developed to treat CDI and reduce unacceptably high rates of infection recurrence in patients. Although in late clinical development, the precise mechanism of action by which ridinilazole elicits its bactericidal activity has remained elusive. Here, we present conclusive biochemical and structural data to demonstrate that ridinilazole has a primary DNA binding mechanism, with a co-complex structure confirming binding to the DNA minor groove. Additional RNA-seq data indicated early pleiotropic changes to transcription, with broad effects on multiple C. difficile compartments and significant effects on energy generation pathways particularly. DNA binding and genomic localization was confirmed through confocal microscopy utilizing the intrinsic fluorescence of ridinilazole upon DNA binding. As such, ridinilazole has the potential to be the first antibiotic approved with a DNA minor groove binding mechanism of action.
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Affiliation(s)
| | - Tim Avis
- Summit Therapeutics, Cambridge, United Kingdom
| | - Chenlin Hu
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | | | | | | | - Khurshida Begum
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | - Kathleen Gajewski
- Department of Biology & Biochemistry, University of Houston Colleges of Natural Sciences and Mathematics, Houston, Texas, USA
| | - M Jahangir Alam
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | - Eugenie Bassères
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
| | | | | | | | - Keith R Fox
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Kevin W Garey
- Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, Texas, USA
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3
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Collins DA, Riley TV. Ridinilazole: a novel, narrow-spectrum antimicrobial agent targeting Clostridium (Clostridioides) difficile. Lett Appl Microbiol 2022; 75:526-536. [PMID: 35119124 PMCID: PMC9541751 DOI: 10.1111/lam.13664] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 01/12/2022] [Accepted: 01/31/2022] [Indexed: 11/26/2022]
Abstract
Clostridium (Clostridioides) difficile infection (CDI) remains an urgent threat to patients in health systems worldwide. Recurrent CDI occurs in up to 30% of cases due to sustained dysbiosis of the gut microbiota which normally protects against CDI. Associated costs of initial and recurrent episodes of CDI impose heavy financial burdens on health systems. Vancomycin and metronidazole have been the mainstay of therapy for CDI for many years; however, these agents continue to cause significant disruption to the gut microbiota and thus carry a high risk of recurrence for CDI patients. Treatment regimens are now turning towards novel narrow spectrum antimicrobial agents which target C. difficile while conserving the commensal gut microbiota, thus significantly reducing risk of recurrence. One such agent, fidaxomicin, has been in therapeutic use for several years and is now recommended as a first-line treatment for CDI, as it is superior to vancomycin in reducing risk of recurrence. Another narrow spectrum agent, ridnilazole, was recently developed and is undergoing evaluation of its potential clinical utility. This review aimed to summarize experimental reports of ridinilazole and assess its potential as a first-line agent for treatment of CDI. Reported results from in vitro assessments, and from hamster models of CDI, show potent activity against C. difficile, non-inferiority to vancomycin for clinical cure and non-susceptibility among most gut commensal bacteria. Phase I and II clinical trials have been completed with ridinilazole showing high tolerability and efficacy in treatment of CDI, and superiority over vancomycin in reducing recurrence of CDI within 30 days of treatment completion. Phase III trials are currently underway, the results of which may prove its potential to reduce recurrent CDI and lessen the heavy health and financial burden C. difficile imposes on patients and healthcare systems.
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Affiliation(s)
- Deirdre A Collins
- School of Medical and Health SciencesEdith Cowan UniversityJoondalupWesternAustralia
| | - Thomas V. Riley
- School of Medical and Health SciencesEdith Cowan UniversityJoondalupWesternAustralia
- Department of MicrobiologyPathWest Laboratory MedicineNedlandsWesternAustralia
- Medical, Molecular and Forensic SciencesMurdoch UniversityMurdochWestern AustraliaAustralia
- School of Biomedical SciencesThe University of Western AustraliaQueen Elizabeth II Medical CentreNedlandsWAAustralia
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4
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Pal R, Seleem MN. Discovery of a novel natural product inhibitor of Clostridioides difficile with potent activity in vitro and in vivo. PLoS One 2022; 17:e0267859. [PMID: 35939437 PMCID: PMC9359557 DOI: 10.1371/journal.pone.0267859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 04/17/2022] [Indexed: 11/22/2022] Open
Abstract
Clostridioides difficile infection is a global health threat and remains the primary cause of hospital-acquired infections worldwide. The burgeoning incidence and severity of infections coupled with high rates of recurrence have created an urgent need for novel therapeutics. Here, we report a novel natural product scaffold as a potential anticlostridial lead with antivirulence properties and potent activity both in vitro and in vivo. A whole cell phenotypic screening of 1,000 purified natural products identified 6 compounds with potent activity against C. difficile (minimum inhibitory concentration (MIC) range from 0.03 to 2 μg/ml). All these 6 compounds were non-toxic to human colorectal cells. The natural product compounds also inhibited the production of key toxins, TcdA and TcdB, the key virulence determinants of C. difficile infection pathology. Additionally, the compounds exhibited rapid bactericidal activity and were superior to the standard-of-care antibiotic vancomycin, in reducing a high inoculum of C. difficile in vitro. Furthermore, a murine model of C. difficile infection revealed that compound NP-003875 conferred 100% protection to the infected mice from clinical manifestations of the disease. Collectively, the current study lays the foundation for further investigation of the natural product NP-003875 as a potential therapeutic choice for C. difficile infection.
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Affiliation(s)
- Rusha Pal
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, Indiana, United States of America
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - Mohamed N. Seleem
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, Indiana, United States of America
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
- Center for Emerging, Zoonotic and Arthropod-borne Pathogens, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
- * E-mail:
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Kullar R, Tran MCN, Goldstein EJC. Investigational Treatment Agents for Recurrent Clostridioides difficile Infection (rCDI). J Exp Pharmacol 2020; 12:371-384. [PMID: 33116952 PMCID: PMC7553590 DOI: 10.2147/jep.s242959] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 08/13/2020] [Indexed: 11/23/2022] Open
Abstract
Clostridioides difficile infection (CDI) is a major cause of nosocomial diarrhea that is deemed a global health threat. C. difficile strain BI/NAP1/027 has contributed to the increase in the mortality, severity of CDI outbreaks and recurrence rates (rCDI). Updated CDI treatment guidelines suggest vancomycin and fidaxomicin as initial first-line therapies that have initial clinical cure rates of over 80%. Unacceptably high recurrence rates of 15–30% in patients for the first episode and 40% for the second recurrent episode are reported. Alternative treatments for rCDI include fecal microbiota transplant and a human monoclonal antibody, bezlotoxumab, that can be used in patients with high risk of rCDI. Various emerging potential therapies with narrow spectrum of activity and little systemic absorption that are in development include 1) Ibezapolstat (formerly ACX-362E), MGB-BP-3, and DS-2969b-targeting bacterial DNA replication, 2) CRS3213 (REP3123)-inhibiting toxin production and spore formation, 3) ramizol and ramoplanin-affecting bacterial cell wall, 4) LFF-571-blocking protein synthesis, 5) Alanyl-L-Glutamine (alanylglutamine)-inhibiting damage caused by C. difficile by protecting intestinal mucosa, and 6) DNV3837 (MCB3681)-prodrug consisting of an oxazolidinone–quinolone combination that converts to the active form DNV3681 that has activity in vitro against C. difficile. This review article provides an overview of these developing drugs that can have potential role in the treatment of rCDI and in lowering recurrence rates.
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Affiliation(s)
| | - Mai-Chi N Tran
- Pharmacy Department, Keck Medical Center of USC, Los Angeles, CA, USA.,Clinica Juan Pablo Medical Group, Los Angeles, CA, USA
| | - Ellie J C Goldstein
- R.M. Alden Research Laboratory, Santa Monica, CA, USA.,David Geffen School of Medicine, Los Angeles, CA, USA
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Abutaleb NS, Seleem MN. Repurposing the Antiamoebic Drug Diiodohydroxyquinoline for Treatment of Clostridioides difficile Infections. Antimicrob Agents Chemother 2020; 64:e02115-19. [PMID: 32253206 DOI: 10.1128/AAC.02115-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 03/27/2020] [Indexed: 12/15/2022] Open
Abstract
Clostridioides difficile, the leading cause of nosocomial infections, is an urgent health threat worldwide. The increased incidence and severity of disease, the high recurrence rates, and the dearth of effective anticlostridial drugs have created an urgent need for new therapeutic agents. In an effort to discover new drugs for the treatment of Clostridioides difficile infections (CDIs), we investigated a panel of FDA-approved antiparasitic drugs against C. difficile and identified diiodohydroxyquinoline (DIHQ), an FDA-approved oral antiamoebic drug. DIHQ exhibited potent activity against 39 C. difficile isolates, inhibiting growth of 50% and 90% of these isolates at concentrations of 0.5 μg/ml and 2 μg/ml, respectively. In a time-kill assay, DIHQ was superior to vancomycin and metronidazole, reducing a high bacterial inoculum by 3 log10 within 6 h. Furthermore, DIHQ reacted synergistically with vancomycin and metronidazole against C. difficile in vitro. Moreover, at subinhibitory concentrations, DIHQ was superior to vancomycin and metronidazole in inhibiting two key virulence factors of C. difficile, toxin production and spore formation. Additionally, DIHQ did not inhibit the growth of key species that compose the host intestinal microbiota, such as Bacteroides, Bifidobacterium, and Lactobacillus spp. Collectively, our results indicate that DIHQ is a promising anticlostridial drug that warrants further investigation as a new therapeutic for CDIs.
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7
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Prasetyoputri A, Jarrad AM, Cooper MA, Blaskovich MA. The Eagle Effect and Antibiotic-Induced Persistence: Two Sides of the Same Coin? Trends Microbiol 2019; 27:339-354. [DOI: 10.1016/j.tim.2018.10.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 09/21/2018] [Accepted: 10/18/2018] [Indexed: 12/21/2022]
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8
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Carlson TJ, Endres BT, Bassères E, Gonzales-Luna AJ, Garey KW. Ridinilazole for the treatment of Clostridioides difficile infection. Expert Opin Investig Drugs 2019; 28:303-310. [PMID: 30767587 DOI: 10.1080/13543784.2019.1582640] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 02/11/2019] [Indexed: 12/23/2022]
Abstract
INTRODUCTION Ridinilazole is a novel antibiotic being developed for the treatment of Clostridioides difficile infection (CDI). Ridinilazole has completed two phase II trials and phase III trials which are denoted Ri-CoDIFy 1 and 2, are planned (ClinicalTrials.gov identifiers: NCT03595553 and NCT03595566). Areas covered: This article covers the chemistry, mechanism of action, in vitro microbiology versus C. difficile and host microbiota, pre-clinical and clinical efficacy, pharmacokinetics, pharmacodynamics and safety and tolerability of ridinilazole. Expert opinion: Ridinilazole is a novel antibiotic with ideal properties for the treatment of CDI. Given the promising results from the phase II clinical trial, ridinilazole may have the capability to lower the risk for CDI recurrence thus improving sustained clinical response rates - a current unmet medical need. Assuming a positive phase III trial, ridinilazole will enter a market with heightened awareness on the importance of prevention of CDI. This along with further research into the economic consequences and decreased patient quality of life associated with recurrent CDI, should provide clinicians with further evidence for the need for therapy that limits CDI recurrence and improves sustained clinical cure.
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Affiliation(s)
- Travis J Carlson
- a Department of Pharmacy Practice and Translational Research , University of Houston College of Pharmacy , Houston , TX , USA
| | - Bradley T Endres
- a Department of Pharmacy Practice and Translational Research , University of Houston College of Pharmacy , Houston , TX , USA
| | - Eugénie Bassères
- a Department of Pharmacy Practice and Translational Research , University of Houston College of Pharmacy , Houston , TX , USA
| | - Anne J Gonzales-Luna
- a Department of Pharmacy Practice and Translational Research , University of Houston College of Pharmacy , Houston , TX , USA
| | - Kevin W Garey
- a Department of Pharmacy Practice and Translational Research , University of Houston College of Pharmacy , Houston , TX , USA
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9
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Tran MCN, Kullar R, Goldstein EJC. Investigational drug therapies currently in early-stage clinical development for the treatment of clostridioides (clostridium) difficile infection. Expert Opin Investig Drugs 2019; 28:323-335. [DOI: 10.1080/13543784.2019.1581763] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Mai-Chi N. Tran
- Department of Pharmacy, Providence St. John’s Health Center, Santa Monica,
CA, USA
- Department of Pharmacy, Clinica Juan Pablo Medical Group, Los Angeles,
CA, USA
| | | | - Ellie J. C. Goldstein
- R M Alden Research Laboratory, Santa Monica,
CA, USA
- David Geffen School of Medicine, Los Angeles,
CA, USA
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10
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Roshan N, Riley TV, Knight DR, Steer JH, Hammer KA. Natural products show diverse mechanisms of action against Clostridium difficile. J Appl Microbiol 2018; 126:468-479. [PMID: 30412324 DOI: 10.1111/jam.14152] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 10/11/2018] [Accepted: 10/23/2018] [Indexed: 12/13/2022]
Abstract
AIMS To investigate the mechanisms of action of natural products with bactericidal (cinnamon root powder, peppermint oil, trans-cinnamaldehyde, menthol and zingerone) or bacteriostatic (fresh garlic bulb extract, garlic clove powder, Leptospermum honey and allicin) activity against two Clostridium difficile strains. METHODS AND RESULTS Bactericidal products significantly reduced intracellular ATP after 1 h (P ≤ 0·01), quantified using the BacTiter-Glo reagent, and damaged the cell membrane, shown by the leakage of both 260-nm-absorbing materials and protein, and the uptake of propidium iodide. Bacteriolysis was not observed, determined by measuring optical density of treated cell suspensions at 620-nm. The effect of three bacteriostatic products on protein synthesis was quantified using an Escherichia coli S30 extract system, with Leptospermum honey (16% w/v) showing significant inhibition (P < 0·01). Lastly, no products showed elevated minimum inhibitory concentrations against antimicrobial-resistant C. difficile, determined by broth microdilution. CONCLUSIONS Cytoplasmic membrane damage was identified as a mechanism of action that may contribute to the activity of several natural products against C. difficile. SIGNIFICANCE AND IMPACT OF THE STUDY This study describes the possible mechanisms of action of natural products against C. difficile, yet the efficacy in vivo to be determined.
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Affiliation(s)
- N Roshan
- School of Biomedical Sciences (M504), The University of Western Australia, Crawley, WA, Australia
| | - T V Riley
- School of Biomedical Sciences (M504), The University of Western Australia, Crawley, WA, Australia.,Department of Microbiology, PathWest Laboratory Medicine, Queen Elizabeth II Medical Centre, Nedlands, WA, Australia.,School of Veterinary & Life Sciences, Murdoch University, Murdoch, WA, Australia.,School of Medical & Health Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - D R Knight
- School of Veterinary & Life Sciences, Murdoch University, Murdoch, WA, Australia
| | - J H Steer
- School of Biomedical Sciences (M504), The University of Western Australia, Crawley, WA, Australia
| | - K A Hammer
- School of Biomedical Sciences (M504), The University of Western Australia, Crawley, WA, Australia
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Abstract
Clostridium difficile (C. difficile) infection remains a global healthcare threat worldwide and the limited options available for its treatment are of particular concern. Ridinilazole is one potential future agent, as it demonstrates rapid bactericidal activity against C. difficile. Current studies show that ridinilazole has a lower propensity for collateral damage to the gut microbiome and appears to diminish the production of C. difficile toxins. Results from phase II studies demonstrate that patients receiving ridinilazole had a higher sustained clinical response compared with patients receiving vancomycin (66.7% vs. 42.4%; P=0.0004). Adverse reactions were similar between ridinilazole and vancomycin (40% vs. 56%, respectively), with most being gastrointestinal-related. Nausea (20%) and abdominal pain (12%) were the most commonly reported adverse reactions associated with ridinilazole. Phase II study results are promising and future availability of phase III trial results will help further delineate the role and value of ridinilazole.
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Affiliation(s)
- Jonathan C Cho
- College of Pharmacy, The University of Texas at Tyler, Tyler, TX (Jonathan C. Cho), USA
| | - Matthew P Crotty
- Department of Pharmacy, Methodist Dallas Medical Center, Dallas, TX (Matthew P. Crotty), USA
| | - Joe Pardo
- Department of Pharmacy, North FL/South GA Veterans Health System, Gainesville, FL (Joe Pardo), USA
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12
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Skinner K, Birchall S, Corbett D, Thommes P, Locher HH. Time-kill kinetics of cadazolid and comparator antibacterial agents against different ribotypes of Clostridium difficile. J Med Microbiol 2018; 67:1402-1409. [DOI: 10.1099/jmm.0.000808] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
| | | | - David Corbett
- 1Evotec (UK), Alderley Park, Cheshire, SK10 4TG, UK
| | - Pia Thommes
- 1Evotec (UK), Alderley Park, Cheshire, SK10 4TG, UK
| | - Hans H. Locher
- 2Actelion Pharmaceuticals Ltd, Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
- †Present address: Idorsia Pharmaceuticals Ltd., Hegenheimermattweg 91, CH-4123 Allschwil, Switzerland
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13
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Snydman DR, McDermott LA, Thorpe CM, Chang J, Wick J, Walk ST, Vickers RJ. Antimicrobial susceptibility and ribotypes of Clostridium difficile isolates from a Phase 2 clinical trial of ridinilazole (SMT19969) and vancomycin. J Antimicrob Chemother 2018; 73:2078-2084. [PMID: 29718329 PMCID: PMC6054158 DOI: 10.1093/jac/dky135] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 02/22/2018] [Accepted: 03/20/2018] [Indexed: 12/18/2022] Open
Abstract
Objectives We evaluated the antimicrobial susceptibility and ribotypes of Clostridium difficile isolates from participants in a Phase 2 study of ridinilazole, a novel targeted-spectrum agent for treatment of C. difficile infection. Methods Participants received ridinilazole (200 mg twice daily) or vancomycin (125 mg four times daily) for 10 days (ClinicalTrials.gov: NCT02092935). The MICs of ridinilazole and comparators for C. difficile isolates from stool samples were determined by agar dilution. Toxin gene profiling was performed by multiplex PCR and ribotype identification by capillary electrophoresis. Results Eighty-nine isolates were recovered from 88/100 participants (one participant had two strains at baseline). The median colony count (cfu/g stool) was 1.9 × 104 (range: 2.5 × 102-7.0 × 106). Twelve participants (three received ridinilazole and nine received vancomycin) experienced recurrence, confirmed by immunoassays for free toxin in stool samples. The ribotype of eight out of nine isolates obtained at recurrence matched those of the initial isolates. All isolates, including those obtained at recurrence, were susceptible to ridinilazole within the expected range [median (range) MIC: 0.12 (0.06-0.5) mg/L]. The median (range) vancomycin MIC was 1 (0.5-4.0) mg/L. At baseline, 13.6% and 13.3% of samples in the ridinilazole and vancomycin groups were positive for VRE, increasing to 23.7% and 29.7% by day 40, respectively. Common ribotypes included 014-20 (14 isolates), 027 (13), 106 (7), 002 (7), 078-126 (4), 001 (4), 087 (3) and 198 (3). Toxin gene profiling of nearly all baseline isolates (98.9%) revealed a binary toxin gene (cdtA/cdtB) prevalence of 35%. Conclusions Ridinilazole potently inhibited recovered C. difficile isolates. Recurrence was not associated with altered susceptibility.
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Affiliation(s)
- David R Snydman
- Division of Geographic Medicine and Infectious Diseases and Department of Medicine, Tufts Medical Center, Boston, MA, USA
- Tufts University School of Medicine, Boston, MA, USA
| | - Laura A McDermott
- Division of Geographic Medicine and Infectious Diseases and Department of Medicine, Tufts Medical Center, Boston, MA, USA
| | - Cheleste M Thorpe
- Division of Geographic Medicine and Infectious Diseases and Department of Medicine, Tufts Medical Center, Boston, MA, USA
- Tufts University School of Medicine, Boston, MA, USA
| | - Justin Chang
- Division of Geographic Medicine and Infectious Diseases and Department of Medicine, Tufts Medical Center, Boston, MA, USA
| | - Jenna Wick
- Division of Geographic Medicine and Infectious Diseases and Department of Medicine, Tufts Medical Center, Boston, MA, USA
| | - Seth T Walk
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
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14
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Jarrad AM, Blaskovich MAT, Prasetyoputri A, Karoli T, Hansford KA, Cooper MA. Detection and Investigation of Eagle Effect Resistance to Vancomycin in Clostridium difficile With an ATP-Bioluminescence Assay. Front Microbiol 2018; 9:1420. [PMID: 30013531 PMCID: PMC6036128 DOI: 10.3389/fmicb.2018.01420] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [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: 11/20/2017] [Accepted: 06/11/2018] [Indexed: 11/24/2022] Open
Abstract
Vancomycin was bactericidal against Clostridium difficile at eightfold the minimum inhibitory concentration (MIC) using a traditional minimum bactericidal concentration (MBC) assay. However, at higher concentrations up to 64 × MIC, vancomycin displayed a paradoxical “more-drug-kills-less” Eagle effect against C. difficile. To overcome challenges associated with performing the labor-intensive agar-based MBC method under anaerobic growth conditions, we investigated an alternative more convenient ATP-bioluminescence assay to assess the Eagle effect in C. difficile. The commercial BacTiter-GloTM assay is a homogenous method to determine bacterial viability based on quantification of bacterial ATP as a marker for metabolic activity. The ATP-bioluminescence assay was advantageous over the traditional MBC-type assay in detecting the Eagle effect because it reduced assay time and was simple to perform; measurement of viability could be performed in less than 10 min outside of the anaerobic chamber. Using this method, we found C. difficile survived clinically relevant, high concentrations of vancomycin (up to 2048 μg/mL). In contrast, C. difficile did not survive high concentrations of metronidazole or fidaxomicin. The Eagle effect was also detected for telavancin, but not for teicoplanin, dalbavancin, oritavancin, or ramoplanin. All four pathogenic strains of C. difficile tested consistently displayed Eagle effect resistance to vancomycin, but not metronidazole or fidaxomicin. These results suggest that Eagle effect resistance to vancomycin in C. difficile could be more prevalent than previously appreciated, with potential clinical implications. The ATP-Bioluminescence assay can thus be used as an alternative to the agar-based MBC assay to characterize the Eagle effect against a variety of antibiotics, at a wide-range of concentrations, with much greater throughput. This may facilitate improved understanding of Eagle effect resistance and promote further research to understand potential clinical relevance.
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Affiliation(s)
- Angie M Jarrad
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD, Australia
| | - Mark A T Blaskovich
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD, Australia
| | - Anggia Prasetyoputri
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD, Australia
| | - Tomislav Karoli
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD, Australia
| | - Karl A Hansford
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD, Australia
| | - Matthew A Cooper
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD, Australia
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Ooijevaar R, van Beurden Y, Terveer E, Goorhuis A, Bauer M, Keller J, Mulder C, Kuijper E. Update of treatment algorithms for Clostridium difficile infection. Clin Microbiol Infect 2018; 24:452-462. [DOI: 10.1016/j.cmi.2017.12.022] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 12/29/2017] [Accepted: 12/31/2017] [Indexed: 12/11/2022]
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Abstract
Clostridium difficile infection (CDI) remains a significant cause of morbidity and mortality worldwide. Historically, two antibiotics (metronidazole and vancomycin) and a recent third (fidaxomicin) have been used routinely for CDI treatment; convincing data are now available showing that metronidazole is the least efficacious agent. The European Society of Clinical Microbiology and Infectious Diseases CDI treatment guidelines outline the treatment options for a variety of CDI clinical scenarios, including use of the more traditional anti-CDI therapies (e.g., metronidazole, vancomycin), the role of newer anti-CDI agents (e.g., fidaxomicin), indications for surgical intervention and for non-antimicrobial management (e.g., faecal microbiota transplantation, FMT). A 2017 survey of 20 European countries found that while the majority (n = 14) have national CDI guidelines that provide a variety of recommendations for CDI treatment, only five have audited guideline implementation. A variety of restrictions are in place in 13 (65%) countries prior to use of new anti-CDI treatments, including committee/infection specialist approval or economic review/restrictions. Novel anti-CDI agents are being evaluated in Phase III trials; it is not yet clear what will be the roles of these agents. Prophylaxis is an optimum approach to reduce the impact of CDI especially in high-risk populations; monoclonal antibodies, antibiotic blocking approaches and multiple vaccines are currently in advanced clinical trials. The treatment of recurrent CDI is particularly troublesome, and several different live bio therapeutics are being developed, in addition to FMT.
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Affiliation(s)
- Fidelma Fitzpatrick
- Department of Clinical Microbiology, The Royal College of Surgeons in Ireland, Dublin, Ireland.
- Department of Clinical Microbiology, Beaumont Hospital, Dublin, Ireland.
| | - Mairead Skally
- Department of Clinical Microbiology, Beaumont Hospital, Dublin, Ireland
| | - Melissa Brady
- Department of Clinical Microbiology, Beaumont Hospital, Dublin, Ireland
| | - Karen Burns
- Department of Clinical Microbiology, Beaumont Hospital, Dublin, Ireland
- Health Protection Surveillance Centre, Dublin, Ireland
| | - Christopher Rooney
- Microbiology, Leeds Teaching Hospitals and University of Leeds, Leeds, UK
| | - Mark H Wilcox
- Microbiology, Leeds Teaching Hospitals and University of Leeds, Leeds, UK.
- Leeds Teaching Hospitals and University of Leeds, Leeds, UK.
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Maxwell-Scott HG, Goldenberg SD. Existing and investigational therapies for the treatment of Clostridium difficile infection: A focus on narrow spectrum, microbiota-sparing agents. Med Mal Infect 2017; 48:1-9. [PMID: 29169816 DOI: 10.1016/j.medmal.2017.10.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 10/23/2017] [Indexed: 12/16/2022]
Abstract
Despite intense international attention and efforts to reduce its incidence, Clostridium difficile infection (CDI) remains a significant concern for patients, clinicians, and healthcare organizations. It is costly for payers and disabling for patients. Furthermore, recurrent CDI is particularly difficult to manage, resulting in excess mortality, hospital length of stay, and other healthcare resource use. A greater understanding of the role of the gut microbiome has emphasized the importance of this diverse community in providing colonization resistance against CDI. The introduction of fidaxomicin, which has limited effect on the microflora has improved clinical outcomes in relation to disease recurrence. There are a number of other new agents in development, which appear to have a narrow spectrum of activity whilst exerting minimal effect on the microflora. Whilst the role of these emerging agents in the treatment of CDI is presently unclear, they appear to be promising candidates.
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Affiliation(s)
- H G Maxwell-Scott
- London and Guy's and St Thomas' NHS Foundation Trust, Centre for Clinical Infection and Diagnostics Research, King's College, London, United Kingdom
| | - S D Goldenberg
- London and Guy's and St Thomas' NHS Foundation Trust, Centre for Clinical Infection and Diagnostics Research, King's College, London, United Kingdom.
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Vickers RJ, Tillotson GS, Nathan R, Hazan S, Pullman J, Lucasti C, Deck K, Yacyshyn B, Maliakkal B, Pesant Y, Tejura B, Roblin D, Gerding DN, Wilcox MH. Efficacy and safety of ridinilazole compared with vancomycin for the treatment of Clostridium difficile infection: a phase 2, randomised, double-blind, active-controlled, non-inferiority study. Lancet Infect Dis 2017; 17:735-744. [PMID: 28461207 PMCID: PMC5483507 DOI: 10.1016/s1473-3099(17)30235-9] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 02/21/2017] [Accepted: 03/02/2017] [Indexed: 12/17/2022]
Abstract
BACKGROUND Clostridium difficile infection is the most common health-care-associated infection in the USA. We assessed the safety and efficacy of ridinilazole versus vancomycin for treatment of C difficile infection. METHODS We did a phase 2, randomised, double-blind, active-controlled, non-inferiority study. Participants with signs and symptoms of C difficile infection and a positive diagnostic test result were recruited from 33 centres in the USA and Canada and randomly assigned (1:1) to receive oral ridinilazole (200 mg every 12 h) or oral vancomycin (125 mg every 6 h) for 10 days. The primary endpoint was achievement of a sustained clinical response, defined as clinical cure at the end of treatment and no recurrence within 30 days, which was used to establish non-inferiority (15% margin) of ridinilazole versus vancomycin. The primary efficacy analysis was done on a modified intention-to-treat population comprising all individuals with C difficile infection confirmed by the presence of free toxin in stool who were randomly assigned to receive one or more doses of the study drug. The study is registered with ClinicalTrials.gov, number NCT02092935. FINDINGS Between June 26, 2014, and August 31, 2015, 100 patients were recruited; 50 were randomly assigned to receive ridinilazole and 50 to vancomycin. 16 patients did not complete the study, and 11 discontinued treatment early. The primary efficacy analysis included 69 patients (n=36 in the ridinilazole group; n=33 in the vancomycin group). 24 of 36 (66·7%) patients in the ridinilazole group versus 14 of 33 (42·4%) of those in the vancomycin group had a sustained clinical response (treatment difference 21·1%, 90% CI 3·1-39·1, p=0·0004), establishing the non-inferiority of ridinilazole and also showing statistical superiority at the 10% level. Ridinilazole was well tolerated, with an adverse event profile similar to that of vancomycin: 82% (41 of 50) of participants reported adverse events in the ridinilazole group and 80% (40 of 50) in the vancomycin group. There were no adverse events related to ridinilazole that led to discontinuation. INTERPRETATION Ridinilazole is a targeted-spectrum antimicrobial that shows potential in treatment of initial C difficile infection and in providing sustained benefit through reduction in disease recurrence. Further clinical development is warranted. FUNDING Wellcome Trust and Summit Therapeutics.
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Affiliation(s)
| | | | | | | | | | | | - Kenneth Deck
- Alliance Research Centers, Laguna Hills, CA, USA
| | | | | | - Yves Pesant
- St-Jerome Medical Research, St-Jérôme, QC, Canada
| | | | | | - Dale N Gerding
- Edward Hines Jr Veterans Administration Hospital and Loyola University Chicago, Stritch School of Medicine, Maywood, IL, USA
| | - Mark H Wilcox
- Microbiology, Leeds Teaching Hospitals and University of Leeds, Leeds, UK
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Beran V, Kuijper EJ, Harmanus C, Sanders IM, van Dorp SM, Knetsch CW, Janeckova J, Seidelova A, Barekova L, Tvrdik J, Chmelar D, Ciznar I. Molecular typing and antimicrobial susceptibility testing to six antimicrobials of Clostridium difficile isolates from three Czech hospitals in Eastern Bohemia in 2011–2012. Folia Microbiol (Praha) 2017; 62:445-51. [DOI: 10.1007/s12223-017-0515-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 03/06/2017] [Indexed: 01/05/2023]
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Abstract
PURPOSE OF REVIEW Clostridium difficile infections (CDI) remain a challenge to treat clinically due primarily to limited number of antibiotics available and unacceptably high recurrence rates. Because of this, there has been significant demand for creating innovative therapeutics, which has resulted in the development of several novel antibiotics. RECENT FINDINGS This review updates seven different antibiotics that are currently in development to treat CDI including fidaxomicin, surotomycin, ridinilazole, ramoplanin, cadazolid, LFF571, and CRS3123. Available preclinical and clinical data are compared between these antibiotics. SUMMARY Many of these new antibiotics display almost ideal properties for antibiotics directed against CDI. Despite these properties, not all clinical development of these compounds has been successful. These studies have provided key insights into the pathogenesis of CDI and will continue to inform future drug development. Successful phase III clinical trials should result in several new and novel antibiotics to treat CDI.
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Endres BT, Bassères E, Memariani A, Chang L, Alam MJ, Vickers RJ, Kakadiaris IA, Garey KW. A novel method for imaging the pharmacological effects of antibiotic treatment on Clostridium difficile. Anaerobe 2016; 40:10-4. [DOI: 10.1016/j.anaerobe.2016.04.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 04/18/2016] [Accepted: 04/19/2016] [Indexed: 12/22/2022]
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Vickers RJ, Tillotson G, Goldstein EJC, Citron DM, Garey KW, Wilcox MH. Ridinilazole: a novel therapy for Clostridium difficile infection. Int J Antimicrob Agents 2016; 48:137-43. [PMID: 27283730 DOI: 10.1016/j.ijantimicag.2016.04.026] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [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: 03/23/2016] [Revised: 04/22/2016] [Accepted: 04/23/2016] [Indexed: 12/15/2022]
Abstract
Clostridium difficile infection (CDI) is the leading cause of infectious healthcare-associated diarrhoea. Recurrent CDI increases disease morbidity and mortality, posing a high burden to patients and a growing economic burden to the healthcare system. Thus, there exists a significant unmet and increasing medical need for new therapies for CDI. This review aims to provide a concise summary of CDI in general and a specific update on ridinilazole (formerly SMT19969), a novel antibacterial currently under development for the treatment of CDI. Owing to its highly targeted spectrum of activity and ability to spare the normal gut microbiota, ridinilazole provides significant advantages over metronidazole and vancomycin, the mainstay antibiotics for CDI. Ridinilazole is bactericidal against C. difficile and exhibits a prolonged post-antibiotic effect. Furthermore, treatment with ridinilazole results in decreased toxin production. A phase 1 trial demonstrated that oral ridinilazole is well tolerated and specifically targets clostridia whilst sparing other faecal bacteria. Phase 2 and 3 trials will hopefully further our understanding of the clinical utility of ridinilazole for the treatment of CDI.
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Affiliation(s)
- Richard J Vickers
- Summit Therapeutics plc, 85b Park Drive, Milton Park, Abingdon, Oxford OX14 4RY, UK.
| | | | - Ellie J C Goldstein
- R.M. Alden Research Laboratory, Culver City, CA, USA; David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | | | - Kevin W Garey
- University of Houston College of Pharmacy, Houston, TX, USA
| | - Mark H Wilcox
- Microbiology, Leeds Teaching Hospitals and University of Leeds, Old Medical School, Leeds General Infirmary, Leeds, UK
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Abstract
INTRODUCTION There are limited number of approved therapies for C. difficile infections (CDIs) and new treatments are needed to decrease recurrence rates. Over the past 5 years, four novel antibiotics have been evaluated in clinical trials that offer distinct advantages over existing therapies for the treatment of CDI. AREAS COVERED This article reviews the preclinical and clinical studies of cadazolid, LFF571, ridinilazole, and surotomycin. The advantages that these antibiotics may have in the treatment of CDI is compared with current therapies metronidazole, vancomycin, and fidaxomicin. Expert commentary: The antibiotics examined have the potential to improve rates of CDI treatment without recurrence. We anticipate that one or more of these medications will be approved within five years.
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Affiliation(s)
- Eric T Slayton
- a Department of Pharmaceutical Science and Research, School of Pharmacy , Marshall University , Huntington , WV , USA
| | - Abigail S Hay
- b Department of Pharmacy Practice, Administration, and Research, School of Pharmacy , Marshall University , Huntington , WV , USA.,c Department of Pharmacy , St. Mary's Medical Center , Huntington , WV , USA
| | - Charles K Babcock
- b Department of Pharmacy Practice, Administration, and Research, School of Pharmacy , Marshall University , Huntington , WV , USA
| | - Timothy E Long
- a Department of Pharmaceutical Science and Research, School of Pharmacy , Marshall University , Huntington , WV , USA.,d Department of Biochemistry and Microbiology, Joan C. Edwards School of Medicine , Marshall University , Huntington , WV , USA
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Bassères E, Endres BT, Khaleduzzaman M, Miraftabi F, Alam MJ, Vickers RJ, Garey KW. Impact on toxin production and cell morphology in Clostridium difficile by ridinilazole (SMT19969), a novel treatment for C. difficile infection. J Antimicrob Chemother 2016; 71:1245-51. [PMID: 26895772 PMCID: PMC4830417 DOI: 10.1093/jac/dkv498] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 12/15/2015] [Accepted: 12/21/2015] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVES Ridinilazole (SMT19969) is a narrow-spectrum, non-absorbable antimicrobial with activity against Clostridium difficile undergoing clinical trials. The purpose of this study was to assess the pharmacological activity of ridinilazole and assess the effects on cell morphology. METHODS Antibiotic killing curves were performed using the epidemic C. difficile ribotype 027 strain, R20291, using supra-MIC (4× and 40×) and sub-MIC (0.125×, 0.25× and 0.5×) concentrations of ridinilazole. Following exposure, C. difficile cells were collected for cfu counts, toxin A and B production, and morphological changes using scanning electron and fluorescence microscopy. Human intestinal cells (Caco-2) were co-incubated with ridinilazole-treated C. difficile growth medium to determine the effects on host inflammatory response (IL-8). RESULTS Treatment at supra-MIC concentrations (4× and 40× MIC) of ridinilazole resulted in a significant reduction in vegetative cells over 72 h (4 log difference, P < 0.01) compared with controls without inducing spore formation. These results correlated with a 75% decrease in toxin A production (P < 0.05) and a 96% decrease in toxin B production (P < 0.05). At sub-MIC levels (0.5× MIC), toxin A production was reduced by 91% (P < 0.01) and toxin B production was reduced by 100% (P < 0.001), which resulted in a 74% reduction in IL-8 release compared with controls (P < 0.05). Sub-MIC (0.5×)-treated cells formed filamentous structures ∼10-fold longer than control cells. Following fluorescence labelling, the cell septum was not forming in sub-MIC-treated cells, yet the DNA was dividing. CONCLUSIONS Ridinilazole had robust killing effects on C. difficile that significantly reduced toxin production and attenuated the inflammatory response. Ridinilazole also elicited significant cell division effects suggesting a potential mechanism of action.
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Affiliation(s)
- Eugénie Bassères
- University of Houston College of Pharmacy, 1441 Moursund Street, Houston, TX 77030, USA
| | - Bradley T Endres
- University of Houston College of Pharmacy, 1441 Moursund Street, Houston, TX 77030, USA
| | | | - Faranak Miraftabi
- University of Houston College of Pharmacy, 1441 Moursund Street, Houston, TX 77030, USA
| | - M Jahangir Alam
- University of Houston College of Pharmacy, 1441 Moursund Street, Houston, TX 77030, USA
| | - Richard J Vickers
- Summit Therapeutics, 85b Park Drive, Milton Park, Abingdon, Oxfordshire OX14 4RY, UK
| | - Kevin W Garey
- University of Houston College of Pharmacy, 1441 Moursund Street, Houston, TX 77030, USA
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Freeman J, Vernon J, Vickers R, Wilcox MH. Susceptibility of Clostridium difficile Isolates of Varying Antimicrobial Resistance Phenotypes to SMT19969 and 11 Comparators. Antimicrob Agents Chemother 2016; 60:689-92. [PMID: 26552981 PMCID: PMC4704187 DOI: 10.1128/aac.02000-15] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 11/04/2015] [Indexed: 12/27/2022] Open
Abstract
We determined the in vitro activity of SMT19969 and 11 comparators, including metronidazole, vancomycin, and fidaxomicin, against 107 C. difficile isolates of different antimicrobial resistance phenotypes. Fidaxomicin and SMT19969 were the most active. The fidaxomicin and SMT19969 geometric mean MICs were highest in ribotypes known to show multiple resistance. Coresistance to linezolid and moxifloxacin was evident in ribotypes 001, 017, 027, and 356. The high-level ceftriaxone resistance in ribotypes 356 and 018 was location linked.
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Affiliation(s)
- Jane Freeman
- Microbiology, Leeds Teaching Hospitals Trust, University of Leeds, Leeds, United Kingdom Healthcare Associated Infections Research Group, Leeds Institute for Biomedical and Clinical Sciences, University of Leeds, Leeds, United Kingdom
| | - Jonathan Vernon
- Healthcare Associated Infections Research Group, Leeds Institute for Biomedical and Clinical Sciences, University of Leeds, Leeds, United Kingdom
| | | | - Mark H Wilcox
- Microbiology, Leeds Teaching Hospitals Trust, University of Leeds, Leeds, United Kingdom Healthcare Associated Infections Research Group, Leeds Institute for Biomedical and Clinical Sciences, University of Leeds, Leeds, United Kingdom
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