Timing in antibiotic therapy: when and how to start, de-escalate and stop antibiotic therapy. Proposals from a stablished antimicrobial stewardship program

The antibiotic de-escalation strategy in patients with multidrug-resistant bacterial colonization after allogeneic stem cell transplantation

Colonization by multidrug-resistant (MDR) bacteria and related bloodstream infections (BSI) are associated with a high rate of mortality in patients with hematological malignancies after intensive chemotherapy and allogeneic stem cell transplantation (allo-SCT). In this retrospective study, we analyzed the outcomes of patients colonized with MDR bacteria (primarily carbapenem-resistant klebsiella pneumoniae, KPC), before allo-SCT. We also investigated the feasibility and safety of an antimicrobial de-escalating approach in these patients. Since 2021, 106 patients have been undergoing allo-SCT in our department, and 34 (32%) of them were colonized by MDR bacteria before allo-SCT. In the pre-engraftment period, 84% received an empiric antibiotic therapy (EAT) active against MDR bacteria and 16% were treated with a conventional EAT. The MDR translocation rate was null, and the overall de-escalation rate was 79%, with 75% in patients with fever of unknown origin (FUO). Among the cohort of patients with MDR-positive rectal swabs just before allo-SCT (n = 18), the de-escalation rate was 100%. The all-cause mortality rates at 30 and 100 days for the whole MDR patient population were 6% (2/34) and 12% (4/34), respectively. Day +30 infection-related mortality rate was 3%. In this study, we confirm the safety of the de-escalation approach in patients with previous MDR infection after allo-SCT. This could reduce the exposure time to EAT antibiotics, reducing the selective pressure.

The importance of antibiotic treatment duration in antimicrobial resistance

Antimicrobial resistance (AMR) poses a significant threat to global health, leading to increased deaths from drug-resistant infections and escalates healthcare costs. Often termed a "silent pandemic," AMR occurs when pathogens become resistant to antimicrobial drugs, enabling their proliferation and spread. Inappropriate antibiotic usage is a major contributor to this phenomenon, which also extends to fungal infections. In particular, the duration of antibiotic therapy is a crucial aspect, with evidence suggesting that prolonged use can heighten bacterial resistance and harm the human microbiota. In fact, studies comparing short-term versus long-term antibiotic therapies show no significant difference in traditional treatments. In addition, therapeutic drug monitoring allows personalized antibiotic regimens, optimizing dosage and duration to minimize resistance and adverse effects. As a result, clinicians should regularly reassess treatment effectiveness, utilizing techniques like antibiotic timeout and de-escalation therapy to avoid prolonged antibiotic use and mitigate resistance. All these strategies are crucial to prevent and counter the phenomenon of antimicrobial resistance.

Efficacy of cefoperazone/sulbactam for ESBL-producing Escherichia coli and Klebsiella pneumoniae bacteraemia and the factors associated with poor outcomes

OBJECTIVE

We aimed to assess the efficacy of cefoperazone/sulbactam (CPZ/SUL) in extended-spectrum β-lactamase (ESBL)-producing Enterobacterales infections and identify factors influencing outcomes.

METHODS

This retrospective multicentre study was conducted in Taiwan (January 2015 to December 2020) and examined the efficacy of CPZ/SUL treatment in ESBL-producing Enterobacterales bacteraemia. The minimum inhibitory concentrations (MICs) were determined using agar dilution; ESBL/AmpC genes were detected using polymerase chain reaction. The primary outcome was clinical success, whereas the secondary outcome was 30-day mortality. Clinical success was defined as the complete resolution of clinical signs and symptoms of K. pneumoniae or E. coli infection, with no evidence of persistent or recurrent bacteraemia. The factors influencing outcomes were identified using a multivariate analysis.

RESULTS

CPZ/SUL demonstrated a clinical success rate of 82.7% (91/110) in treating ESBL-producing Enterobacterales bacteraemia, with a 30-day mortality rate of 9.1% (10/110). Among 110 ESBL-producing isolates, a high clinical success rate was observed at an MIC of ≤32/32 mg/L. Multivariate analysis revealed that a Charlson comorbidity index (CCI) of ≥6 was associated with lower clinical success [odds ratio (OR): 5.80, 95% confidence interval (CI): 1.15-29.14, P = 0.033]. High Sequential Organ Failure Assessment scores (≥6) were significantly associated with increased 30-day mortality (OR: 14.34, 95% CI: 1.45-141.82, P = 0.023).

DISCUSSION

CPZ/SUL demonstrated a clinical success rate of 82.7% (91/110) in treating ESBL-producing Enterobacterales bacteraemia. Treatment success was evident when the CPZ and SUL MIC was ≤32/32 mg/L. Comorbidities (CCI ≥6) were associated with lower clinical success, while disease severity (Sequential Organ Failure Assessment score ≥6) correlated with higher mortality.

Impact of Antimicrobial Stewardship on Reducing Antimicrobial Resistance

Antimicrobial resistance has become a serious global issue, posing a significant threat to public health and healthcare professionals. Since the advent of penicillin, many antibiotics have lost their effectiveness in combating microbes simply due to inappropriate, irrational, unnecessary, and unrestricted use. The ineffectiveness of an increasing number of antibiotics necessitates the utilization of more potent antimicrobial agents for combatting uncomplicated infections. In response to the escalating prevalence of multidrug-resistant pathogens and the imperative to curtail the demand for novel antibiotics, the Antimicrobial Stewardship Program was conceived and implemented. This initiative is characterized by a lead physician, ideally possessing expertise in infectious diseases, alongside a pharmacist serving as a secondary leader and a microbiologist with defined responsibilities to achieve several objectives. These objectives include reducing indiscriminate usage of antimicrobial agents, promoting selective antimicrobial utilization based on culture results, de-escalating therapy from broad-spectrum to targeted antimicrobial agents, and transitioning from parenteral to oral administration when feasible. These objectives are pursued through a combination of pre-prescription and post-prescription strategies. While the Antimicrobial Stewardship Program is widely established in developed nations, a pressing need exists for its more comprehensive implementation in less developed regions. This review aims to examine the strategies used in antimicrobial stewardship programs to evaluate their effectiveness in preventing the development of multidrug-resistant organisms (MDROs) based on existing research studies. Under the Antimicrobial Stewardship Program, education of healthcare professionals and continuous disposal of information about antimicrobial resistance have helped to restrict the emergence of multidrug-resistant organisms.

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.