Colonization With Fluoroquinolone-Resistant Enterobacterales Decreases the Effectiveness of Fluoroquinolone Prophylaxis in Hematopoietic Cell Transplant Recipients

Michael J. Satlin, Liang Chen, Claire Douglass, Michael Hovan, Emily Davidson, Rosemary Soave, Marisa La Spina, Alexandra Gomez-Arteaga, Koen van Besien, Sebastian Mayer, Adrienne Phillips, Jing Mei Hsu, Rianna Malherbe, Catherine B. Small, Stephen G. Jenkins, Lars F. Westblade, Barry N. Kreiswirth, Thomas J. Walsh

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


BACKGROUND: Levofloxacin prophylaxis is recommended to prevent gram-negative bloodstream infections (BSIs) in patients with prolonged chemotherapy-induced neutropenia. However, increasing fluoroquinolone resistance may decrease the effectiveness of this approach. METHODS: We assessed the prevalence of colonization with fluoroquinolone-resistant Enterobacterales (FQRE) among patients admitted for hematopoietic cell transplantation (HCT) from November 2016 to August 2019 and compared the risk of gram-negative BSI between FQRE-colonized and noncolonized patients. All patients received levofloxacin prophylaxis during neutropenia. Stool samples were collected upon admission for HCT and weekly thereafter until recovery from neutropenia, and underwent selective culture for FQRE. All isolates were identified and underwent antimicrobial susceptibility testing by broth microdilution. FQRE isolates also underwent whole-genome sequencing. RESULTS: Fifty-four of 234 (23%) patients were colonized with FQRE prior to HCT, including 30 of 119 (25%) allogeneic and 24 of 115 (21%) autologous HCT recipients. Recent antibacterial use was associated with FQRE colonization (P = .048). Ninety-one percent of colonizing FQRE isolates were Escherichia coli and 29% produced extended-spectrum β-lactamases. Seventeen (31%) FQRE-colonized patients developed gram-negative BSI despite levofloxacin prophylaxis, compared to only 2 of 180 (1.1%) patients who were not colonized with FQRE on admission (P < .001). Of the 17 gram-negative BSIs in FQRE-colonized patients, 15 (88%) were caused by FQRE isolates that were genetically identical to the colonizing strain. CONCLUSIONS: Nearly one-third of HCT recipients with pretransplant FQRE colonization developed gram-negative BSI while receiving levofloxacin prophylaxis, and infections were typically caused by their colonizing strains. In contrast, levofloxacin prophylaxis was highly effective in patients not initially colonized with FQRE.

Original languageEnglish (US)
Pages (from-to)1257-1265
Number of pages9
JournalClinical infectious diseases : an official publication of the Infectious Diseases Society of America
Issue number7
StatePublished - Oct 5 2021
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Microbiology (medical)
  • Infectious Diseases


  • fluoroquinolone resistance
  • hematopoietic cell transplant recipient
  • levofloxacin prophylaxis
  • neutropenia


Dive into the research topics of 'Colonization With Fluoroquinolone-Resistant Enterobacterales Decreases the Effectiveness of Fluoroquinolone Prophylaxis in Hematopoietic Cell Transplant Recipients'. Together they form a unique fingerprint.

Cite this