Colonization With Fluoroquinolone-Resistant Enterobacterales Prior to HCT Increases Risk for Blood Stream Infection

Bacterial blood infection
Bacterial blood infection
Investigators conducted a prospective cohort study to determine the prevalence of and outcomes associated with fluoroquinolone-resistant Enterobacterales in patients undergoing hematopoietic cell transplantation for a hematologic malignancy.

Levofloxacin prophylaxis was found to be effective at preventing bloodstream infections among patients undergoing hematopoietic cell transplantation (HCT) for a hematologic malignancy who were not colonized with fluoroquinolone-resistant Enterobacterales (FQRE). These findings — from a prospective cohort study — were published in Clinical Infections Diseases.

Patients (N=234) undergoing autologous or allogeneic HCT between 2016 and 2019 at Weill Cornell Medicine in New York City were assessed for FQRE colonization and blood stream infections. Patients received prophylactic treatment with levofloxacin 500 mg on the day prior to HCT, with treatment continuing until neutropenia recovery.

The median age of study participants was 61 years; 44% were women, and 51% underwent allogeneic HCT. Patients were undergoing HCT for acute myeloid leukemia/myelodysplastic syndrome (31%), multiple myeloma (30%), and non-Hodgkin lymphoma (19%).

Before HCT, 23% of participants were colonized with FQRE. Compared with patients who were not colonized with FQRE, those who were colonized with FQRE were more likely to receive antibiotic treatment during the previous 90 days (78% vs 63%; P =.048), specifically trimethoprim-sulfamethoxazole (41% vs 24%; P =.015).

Among positive samples, 89% of isolates were dominated by Escherichia coli, 5% by Klebsiella pneumoniae, 2% by Citrobacter freundii, and 2% by Enterobacter cloacae. All isolates were susceptible to amoxicillin-clavulanate, aztreonam, ceftriaxone, ceftazidime, and cefepime.

A total of 11 patients (6.5%) were found to be colonized with FQRE a median of 2 days after undergoing HCT. These isolates were dominated by E coli (n=8), K pneumoniae (n=1), C freundii (n=1), and E cloacae (n=1).

Rates of 100-day mortality (9% vs 7%; P =.55) and graft-vs-host disease (allogeneic: 20% vs 27%; P =.45) did not differ between patients colonized with FQRE and those not colonized with FQRE, respectively.

More patients colonized with FQRE developed FQRE blood stream infections (29.6% vs 0.6%; P <.001), gram-negative blood stream infections (31.5% vs 1.1%; P <.001), and any blood stream infection (31.5% vs 14.4%; P =.005). Status of FQRE colonization did not have an effect on gram-positive blood stream infections (13.0% vs 13.9%; P =.86).

A limitation of this study is that these data were sourced from a single center and may have some institutional bias; external validation is therefore required.

These data suggest that levofloxacin prophylaxis was less effective among patients who were colonized with FQRE prior to undergoing HCT. Patients with FQRE were found to be at increased risk of developing FQRE blood stream infections and gram-negative blood stream infections. Additional studies are needed to determine optimal prophylaxis for this patient population.

Disclosure: Some authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please refer to the original article for a full list of authors’ disclosures.


Satlin MJ, Chen L, Douglass C, et al. Colonization with fluoroquinolone-resistant Enterobacterales decreases the effectiveness of fluoroquinolone prophylaxis in hematopoietic cell transplant recipients. Clin Infect Dis. Published online May 6, 2021. doi:10.1093/cid/ciab404