Comparison of the efficacy of ramoplanin and vancomycin in both in vitro and in vivo models of clindamycin-induced Clostridium difficile infection.
OBJECTIVE
Treatment of Clostridium difficile infection (CDI) is limited primarily to either metronidazole or vancomycin. We compared vancomycin and a novel glycolipodepsipeptide, ramoplanin, in both hamster and in vitro gut models of clindamycin-induced CDI.


METHODS
We used an in vitro triple-stage chemostat model that simulates the human gut, and an in vivo hamster model, both primed with clindamycin.


RESULTS
Clindamycin exposure elicited symptomatic disease in the hamster model, and promoted C. difficile germination and toxin production in the gut model. C. difficile germination and toxin production were not associated with depletion of gut microflora in the gut model, but were temporarily associated with subinhibitory concentrations of clindamycin. Both ramoplanin and vancomycin were associated with rapid symptom resolution in the hamster model, and rapid toxin titre decrease in the in vitro gut model. In both models of CDI, vancomycin was associated with greater persistence of C. difficile spores. C. difficile spores were recovered significantly more often from the caecal contents of vancomycin-treated (n = 19/23) compared with ramoplanin-treated (n = 6/23) hamsters (P < 0.05).


CONCLUSIONS
Results from the in vitro gut and hamster models were concordant. Ramoplanin and vancomycin were similarly effective at reducing cytotoxin production in the gut CDI model and in resolving symptoms in the hamster model. Ramoplanin may be more effective than vancomycin at killing spores and preventing spore recrudescence. These findings suggest a potential therapeutic role for ramoplanin in CDI that requires further clinical investigation.
Freeman
Jane
J
Department of Microbiology, University of Leeds and The General Infirmary, Old Medical School, Leeds, LS1 3EX, UK.
Baines
Simon D
SD
Jabes
Daniela
D
Wilcox
Mark H
MH
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002432:Cecum / Q000382:microbiology; D002981:Clindamycin / Q000494:pharmacology*; D016360:Clostridioides difficile / Q000187:drug effects*; D006224:Cricetinae; D047630:Depsipeptides / Q000627:therapeutic use*; D004195:Disease Models, Animal; D004761:Enterocolitis, Pseudomembranous / Q000188:drug therapy* / Q000382:microbiology*; D005766:Gastrointestinal Contents / Q000382:microbiology; D008297:Male; D011897:Random Allocation; D013997:Time Factors; D014640:Vancomycin / Q000627:therapeutic use*
D000900:Anti-Bacterial Agents; D047630:Depsipeptides; C041438:ramoplanin; D002981:Clindamycin; D014640:Vancomycin