Controlling intestinal colonization of high-risk haematology patients with ESBL-producing Enterobacteriaceae: a randomized, placebo-controlled, multicentre, Phase II trial (CLEAR)

  • Vassiliki Dimitriou
  • Lena M Biehl
  • Axel Hamprecht
  • Wichard Vogel
  • Daniela Dörfel
  • Silke Peter
  • Philippe Schafhausen
  • Holger Rohde
  • Marie von Lilienfeld-Toal
  • Tilman E Klassert
  • Peter Slickers
  • Ralf Ehricht
  • Hortense Slevogt
  • Hildegard Christ
  • Martin Hellmich
  • Fedja Farowski
  • Anastasia Tsakmaklis
  • Paul G Higgins
  • Harald Seifert
  • Maria J G T Vehreschild


OBJECTIVES: We assessed the efficacy and safety of an oral antimicrobial regimen for short- and long-term intestinal eradication of ESBL-producing Escherichia coli and Klebsiella pneumoniae (ESBL-EC/KP) in immunocompromised patients.

METHODS: We performed a randomized (2:1), double-blind multicentre Phase II study in four haematology-oncology departments. Patients colonized with ESBL-EC/KP received a 7 day antimicrobial regimen of oral colistin (2 × 106 IU 4×/day), gentamicin (80 mg 4×/day) and fosfomycin (three administrations of 3 g every 72 h), or placebo. Faecal, throat and urine specimens were collected on day 0, 6 ± 2, 11 ± 2, 28 ± 4 and 42 ± 4 after treatment initiation, and the quantitative burden of ESBL-EC/KP, resistance genes and changes in intestinal microbiota were analysed. NCT01931592.

RESULTS: As the manufacture of colistin powder was suspended worldwide, the study was terminated prematurely. Overall, 29 (18 verum/11 placebo) out of 47 patients were enrolled. The short-term intestinal eradication was marginal at day 6 (verum group 15/18, 83.3% versus placebo 2/11, 18.2%; relative risk 4.58, 95% CI 1.29-16.33; Fisher's exact test P = 0.001) and not evident at later timepoints. Quantitative analysis showed a significant decrease of intestinal ESBL-EC/KP burden on day 6. Sustained intestinal eradication (day 28 + 42) was not achieved (verum, 38.9% versus placebo, 27.3%; P = 0.299). In the verum group, mcr-1 genes were detected in two faecal samples collected after treatment. Microbiome analysis showed a significant decrease in alpha diversity and a shift in beta diversity.

CONCLUSIONS: In this prematurely terminated study of a 7 day oral antimicrobial eradication regimen, short-term ESBL-EC/KP suppression was marginal, while an altered intestinal microbiota composition was clearly apparent.

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StatusVeröffentlicht - 01.07.2019

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© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email:

PubMed 31220256