In vitro activity of delafloxacin against anaerobic bacteria compared with other antimicrobials.

The aim of this study was to describe the in vitro activity of delafloxacin against 230 anaerobic isolates and compare it with the activity of other antimicrobials used against infections caused by anaerobic microorganisms. Minimal inhibitory concentrations (MICs) were lower for delafloxacin than for all other antibiotics tested with the exception of piperacillin-tazobactam and meropenem against Gram-positive anaerobic cocci. Only two (0.8 %) isolates of Bacteroides spp. showed a MIC ≥4 µg/mL. With some exceptions, the present results show lower MICs for delafloxacin in comparison to the other antibiotics used against anaerobes.

The Challenge of Bacteremia Treatment due to Non-Fermenting Gram-Negative Bacteria.

Nosocomial infections caused by non-fermenting Gram-negative bacteria are a real challenge for clinicians, especially concerning the accuracy of empirical treatment. This study aimed to describe the clinical characteristic, empirical antibiotic therapy, accuracy of these prescriptions for appropriate coverage and risk factor for clinical failure of bloodstream infections due to non-fermenting Gram-negative bacilli. This retrospective, observational cohort study was conducted between January 2016 and June 2022. Data were collected from the hospital's electronic record. The statistic tests corresponding to each objective were applied. A multivariate logistic regression was performed. Among the total 120 patients included in the study, the median age was 63.7 years, and 79.2% were men. Considering the appropriate empirical treatment rate by species, inappropriate treatment for S. maltophilia was 72.4% (p = 0.088), for A. baumanii 67.6% and 45.6% for P. aeruginosa. Clinical success was achieved in 53.3%, and overall, 28-day mortality was 45.8%. ICU admission, sepsis or shock septic, age, previous antibiotic treatment and contact with healthcare facilities were independently associated with clinical failure. In conclusion, bloodstream infection produced by multidrug-resistant non-fermenting Gram-negative bacteria is a significant therapeutic management challenge for clinicians. The accuracy of empirical treatment is low due to the fact that it is not recommended to cover these microorganisms empirically, especially S. maltophilia and A. baumanii.