In vitro selection, via serial passage, of Clostridium difficile mutants with reduced susceptibility to fidaxomicin or vancomycin

Leeds, Jennifer A.; Sachdeva, Meena; Mullin, Steve; Barnes, S. Whitney; Ruzin, Alexey

doi:10.1093/jac/dkt302

Cited by 77 publications

(71 citation statements)

References 14 publications

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“…Serial passage experiments were conducted in 96-DeepWell plates (Thermo Scientific), essentially as described previously [15] except for the use of BHITY broth (1 mL) as the growth medium. Initially, compounds were two-fold serially diluted to yield antibiotic concentrations that were eight-fold above and four-fold below their MICs.…”

Section: Methodsmentioning

confidence: 99%

Action of nitroheterocyclic drugs against Clostridium difficile

Kumar

Adhikari

Hurdle

2014

International Journal of Antimicrobial Agents

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The nitroheterocyclic classes of drugs have a long history of use in treating anaerobic infections, as exemplified by metronidazole as a first-line treatment for mild-to-moderate Clostridium difficile infection (CDI). Since direct comparisons of the three major classes of nitroheterocyclic drugs (i.e. nitroimidazole, nitazoxanide and nitrofurans) and nitrosating agents against C. difficile are under-examined, in this study their actions against C. difficile were compared. Results show that whilst transient resistance occurs to metronidazole and nitazoxanide, stable resistance arises to nitrofurans upon serial passage. All compounds killed C. difficile at high concentrations in addition to the host defence nitrosating agent S-nitrosoglutathione (GSNO). This suggests that GSNO killing of C. difficile contributes to its efficacy in murine CDI. Although nitric oxide production could not be detected for the nitroheterocyclic drugs, the cellular response to metronidazole and nitrofurans has some overlap with the response to GSNO, causing significant upregulation of the hybrid-cluster protein Hcp that responds to nitrosative stress. These findings provide new insights into the action of nitroheterocyclic drugs against C. difficile.

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Section: Methodsmentioning

confidence: 99%

Action of nitroheterocyclic drugs against Clostridium difficile

Kumar

Adhikari

Hurdle

2014

International Journal of Antimicrobial Agents

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“…Point mutations conferring loss of susceptibility of Bacillus subtilis, Mycobacterium tuberculosis, Enterococcus faecalis, and C. difficile to FDX were typically selected in the genes encoding the b-and b 0 -subunits of RNAP (encoded by rpoB and rpoC, respectively) (Gualtieri et al 2006;Kurabachew et al 2008;Gualtieri et al 2009;Seddon et al 2011;Srivastava et al 2011;Seddon and Sears 2012;Babakhani et al 2014;Leeds et al 2014). Shortly after the mechanism of action of FDX was first reported, Sonenshein et al (1977) published the first report of B. subtilis mutants selected on superinhibitory concentrations of the compound that helped to validate RNAP as the target of the antibacterial activity.…”

Section: Frequencies and Mechanisms Of Reduced Susceptibility To Fdxmentioning

confidence: 99%

“…Leeds et al subjected C. difficile strain ATCC 43255 and three clinical isolates of C. difficile to 10 passages on a range of concentrations of FDX (Leeds et al 2014). The genomes of selected C. difficile mutants with reduced susceptibility to the selecting agents and their isogenic parental strains were fully sequenced to determine the single-nucleotide polymorphisms (SNPs) that were observed in the mutant background compared with the susceptible parent.…”

mentioning

confidence: 99%

Antibacterials Developed to Target a Single Organism: Mechanisms and Frequencies of Reduced Susceptibility to the Novel Anti-Clostridium difficileCompounds Fidaxomicin and LFF571

Leeds

2016

Cold Spring Harb Perspect Med

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Clostridium difficile is the most common cause of antibacterial-associated diarrhea. Clear clinical presentation and rapid diagnostics enable targeted therapy for C. difficile infection (CDI) to start quickly. CDI treatment includes metronidazole and vancomycin (VAN). Despite decades of use for CDI, no clinically meaningful resistance to either agent has emerged. Fidaxomicin (FDX), an RNA polymerase inhibitor, is also approved to treat CDI. Mutants with reduced susceptibility to FDX have been selected in vitro by single and multistep methods. Strains with elevated FDX minimum inhibitory concentrations (MICs) were also identified from FDX-treated patients in clinical trials. LFF571 is an exploratory agent that inhibits EF-Tu. In a proof-of-concept study, LFF571 was safe and effective for treating CDI. Spontaneous mutants with reduced susceptibility to LFF571 were selected in vitro in a single step, but not via serial passage. Although there are several agents in development for treatment of CDI, this review summarizes the frequencies and mechanisms of C. difficile mutants displaying reduced susceptibility to FDX or LFF71.

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“…For example, the Tn6218 element of C. difficile contains a cfr-like gene that can confer resistance to peptidyl transferase inhibitors such as linezolid 255 and the Tn5397 element carries a tetracycline resistance determinant 256 . Reduced susceptibility or resistance to the commonly used antibiotics vancomycin, metronidazole and fidaxomicin has been noted [257][258][259][260] . Although this is cause for concern, the clinical relevance of resistance to these antibiotics so far is limited.…”

Section: Antibiotic Resistance Of Clostridium Difficilementioning

confidence: 99%

Clostridium difficile Infection

Wilcox¹,

Vehreschild²,

Nord³

2015

Annual Update in Intensive Care and Emergency Medicine

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Infection of the colon with the Gram-positive bacterium Clostridium difficile is potentially life threatening, especially in elderly people and in patients who have dysbiosis of the gut microbiota following antimicrobial drug exposure. C. difficile is the leading cause of health-care-associated infective diarrhoea. The life cycle of C. difficile is influenced by antimicrobial agents, the host immune system, and the host microbiota and its associated metabolites. The primary mediators of inflammation in C. difficile infection (CDI) are large clostridial toxins, toxin A (TcdA) and toxin B (TcdB), and, in some bacterial strains, the binary toxin CDT. The toxins trigger a complex cascade of host cellular responses to cause diarrhoea, inflammation and tissue necrosis -the major symptoms of CDI. The factors responsible for the epidemic of some C. difficile strains are poorly understood. Recurrent infections are common and can be debilitating. Toxin detection for diagnosis is important for accurate epidemiological study, and for optimal management and prevention strategies. Infections are commonly treated with specific antimicrobial agents, but faecal microbiota transplants have shown promise for recurrent infections. Future biotherapies for C. difficile infections are likely to involve defined combinations of key gut microbiota. Competing interests statement W.K.S. has performed research for Cubist. D.L. has performed research for Immuron and Adenium Biotech. D.B.L. has performed research for MedImmune and Merck. M.H.W. has received consulting fees from Abbott, Actelion Pharmaceuticals, Astellas, AstraZeneca, Bayer, Cerexa, Cubist, Durata, The European Tissue Symposium, The Medicines Company, MedImmune, Merck, Motif Biosciences, Nabriva, Optimer, Paratek, Pfizer, Roche, Sanofi Pasteur, Seres Therapeutics, Summit Pharmaceuticals, and Synthetic Biologics. M.H.W. has also received lecture fees from Abbott, Alere, Astellas, AstraZeneca, Pfizer and Hoffmann La Roche, and received grant support from Abbott, Actelion, Astellas, bioMérieux, Cubist, Da Volterra, The European Tissue Symposium, Merck and Summit Pharmaceuticals. E.J.K. has performed research for Cubist, Novartis and Qiagen, and has participated in advisory forums of Astellas, Optimer, Actelion, Pfizer, Sanofi Pasteur and Seres Therapeutics. These companies had no role in the writing of this Primer. HHS Public AccessAuthor manuscript Nat Rev Dis Primers. Author manuscript; available in PMC 2017 June 01. Published in final edited form as:Nat Rev Dis Primers. ; 2: 16020. doi:10.1038/nrdp.2016.20. Author Manuscript Author ManuscriptAuthor Manuscript Author ManuscriptClostridium difficile is a Gram-positive obligate anaerobic bacterium that was originally identified as part of the flora of healthy infants in 1935, described as an "actively motile, heavy-bodied rod with elongated subterminal or nearly terminal spores" (REF. 1) (FIG. 1). At that time, the strain was named Bacillus difficilis to reflect the difficulty experienced in isolating and culturing it. De...

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In vitro selection, via serial passage, of Clostridium difficile mutants with reduced susceptibility to fidaxomicin or vancomycin

Cited by 77 publications

References 14 publications

Action of nitroheterocyclic drugs against Clostridium difficile

Action of nitroheterocyclic drugs against Clostridium difficile

Antibacterials Developed to Target a Single Organism: Mechanisms and Frequencies of Reduced Susceptibility to the Novel Anti-Clostridium difficileCompounds Fidaxomicin and LFF571

Clostridium difficile Infection

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