Evidence Hub

Association of minimum inhibitory concentration with outcome in patients with Stenotrophomonas maltophilia bacteraemia treated with empirical levofloxacin

Ngiam JN, Koh MCY, Allen DM, Chew KL

Pathology, 2026

79 participants

Abstract

Stenotrophomonas maltophilia is intrinsically resistant to carbapenems and most β-lactam antibiotics. Empiric therapy for bloodstream infections often includes either trimethoprim-sulfamethoxazole or levofloxacin. However, there are currently no European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints available for interpretation of susceptibility testing for levofloxacin. We examined the relationship between levofloxacin minimum inhibitory concentration (MIC) and clinical outcomes in S. maltophilia bacteraemia. We retrospectively examined 79 consecutive patients with S. maltophilia bacteraemia from a single centre who received empiric antibiotic therapy with levofloxacin from 1 January 2012 to 30 June 2024. Adverse outcomes were defined as all-cause in-hospital mortality and were compared against the levofloxacin MIC, as tested by ETEST. Of the 79 patients, 28 (35.4%) experienced in-hospital mortality. A majority of infections were central-line related, which had comparatively better outcomes than pneumonia or intra-abdominal infections. A majority of infections were acquired nosocomially, and patients often had exposure to carbapenems prior to presentation. The MIC ranged from 0.125 mg/L to ≥32 mg/L, with MIC50 and MIC90 of 1 mg/L and 2 mg/L, respectively. Increasing frequency of adverse outcomes was observed at higher MIC cut-offs. Mortality was 100% at an MIC ≥4 mg/L. Adverse outcomes were common in S. maltophilia bacteraemia. In patients treated…

How strong is the evidence?

Evidence Hub reads this as a cohort study, done in people. Its evidence level is 3 of 5 (Moderate · trial / cohort / secondary analysis). Trials without a large randomized design, cohorts and secondary analyses give moderate evidence. Reported size: 79 participants or records.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free