Treatment efficacy of Ampicillin/Sulbactam in comparison to alternative beta-lactams for severe Acinetobacter baumannii infections

Therapeutic options for difficult-to-treat Acinetobacter baumannii infections: a 2020 perspective

INTRODUCTION

Treatment of severe infections due to Acinetobacter baumannii with difficult-to-treat resistance (DTR-AB), which exhibits resistance to all β-lactams, β-lactam/β-lactamases inhibitor combinations, and fluoroquinolones, remains a challenge for clinicians.

AREAS COVERED

The present perspective provides a personal view on both current and future agents for the treatment of severe DTR-AB infections.

EXPERT OPINION

We currently are in a transition era for the treatment of DTR-AB infections, where in the past 20 years, polymyxin-based regimens have become the most used approach (although possibly suboptimal, there were few or no alternatives) and where in the next 20 years, polymyxins will likely be replaced by less toxic novel agents as first-line choices. Two novel antimicrobial agents have been recently approved that show activity against DTR-AB, cefiderocol and eravacycline, while durlobactam/sulbactam is in phase-3 of clinical development. In the near future, these agents could become important first-line choices for the treatment of DTR-AB within approved indications, or for off-label indications in the absence of dependable alternatives. Good-quality post-marketing experiences remain necessary for arising clinically relevant questions and guiding the design of further dedicated randomized controlled trials to stably optimize the use of novel agents for DTR-AB infections in the next decades.

Challenges in the Diagnosis and Management of Bacterial Lung Infections in Solid Organ Recipients: A Narrative Review

Respiratory infections pose a significant threat to the success of solid organ transplantation, and the diagnosis and management of these infections are challenging. The current narrative review addressed some of these challenges, based on evidence from the literature published in the last 20 years. Specifically, we focused our attention on (i) the obstacles to an etiologic diagnosis of respiratory infections among solid organ transplant recipients, (ii) the management of bacterial respiratory infections in an era characterized by increased antimicrobial resistance, and (iii) the development of antimicrobial stewardship programs dedicated to solid organ transplant recipients.

Antimicrobials for the treatment of drug-resistant Acinetobacter baumannii pneumonia in critically ill patients: a systemic review and Bayesian network meta-analysis

BACKGROUND

An optimal therapy for the treatment of pneumonia caused by drug-resistant Acinetobacter baumannii remains unclear. This study aims to compare various antimicrobial strategies and to determine the most effective therapy for pneumonia using a network meta-analysis.

METHODS

Systematic search and quality assessment were performed to select eligible studies reporting one of the following outcomes: all-cause mortality, clinical cure, and microbiological eradication. The primary outcome was all-cause mortality. A network meta-analysis was conducted with a Bayesian approach. Antimicrobial treatments were ranked based on surface under the cumulative ranking curve (SUCRA) value along with estimated median outcome rate and corresponding 95% credible intervals (CrIs). Two treatments were considered significantly different if a posterior probability of superiority (P) was greater than 97.5%.

RESULTS

Twenty-three studies evaluating 15 antimicrobial treatments were included. Intravenous colistin monotherapy (IV COL) was selected as a common comparator, serving as a bridge for developing the network. Five treatments ranked higher than IV COL (SUCRA, 57.1%; median all-cause mortality 0.45, 95% CrI 0.41-0.48) for reducing all-cause mortality: sulbactam monotherapy (SUL, 100.0%; 0.18, 0.04-0.42), high-dose SUL (HD SUL, 85.7%; 0.31, 0.07-0.71), fosfomycin plus IV COL (FOS + IV COL, 78.6%; 0.34, 0.19-0.54), inhaled COL plus IV COL (IH COL + IV COL, 71.4%; 0.39, 0.32-0.46), and high-dose tigecycline (HD TIG, 71.4%; 0.39, 0.16-0.67). Those five treatments also ranked higher than IV COL (SUCRA, 45.5%) for improving clinical cure (72.7%, 72.7%, 63.6%, 81.8%, and 90.9%, respectively). Among the five treatments, SUL (P = 98.1%) and IH COL + IV COL (P = 99.9%) were significantly superior to IV COL for patient survival and clinical cure, respectively. In terms of microbiological eradication, FOS + IV COL (P = 99.8%) and SUL (P = 98.9%) were significantly superior to IV COL.

CONCLUSIONS

This Bayesian network meta-analysis demonstrated the comparative effectiveness of fifteen antimicrobial treatments for drug-resistant A. baumannii pneumonia in critically ill patients. For survival benefit, SUL appears to be the best treatment followed by HD SUL, FOS + IV COL, IH COL + IV COL, HD TIG, and IV COL therapy, in numerical order.

Anticipating the Unpredictable: A Review of Antimicrobial Stewardship and Acinetobacter Infections

Acinetobacter remains one of the most challenging pathogens in the field of infectious diseases owing primarily to the uniqueness and multiplicity of its resistance mechanisms. This resistance often leads to devastatingly long delays in time to appropriate therapy and increased mortality for patients afflicted with Acinetobacter infections. Selecting appropriate empiric and definitive antibacterial therapy for Acinetobacter is further complicated by the lack of reliability in commercial antimicrobial susceptibility testing devices and limited breakpoint interpretations for available agents. Existing treatment options for infections due to Acinetobacter are limited by a lack of robust efficacy and safety data along with concerns regarding appropriate dosing, pharmacokinetic/pharmacodynamic targets, and toxicity. Antimicrobial stewardship programs are essential to combat this unpredictable pathogen through use of infection prevention, rapid diagnostics, antibiogram-optimized treatment regimens, and avoidance of overuse of antimicrobials. The drug development pipeline includes several agents with encouraging in vitro activity against Acinetobacter, but their place in therapy and contribution to the armamentarium against this pathogen remain to be defined. The objective of this review is to highlight the unique challenge of treating infections due to Acinetobacter and summarize recent literature regarding optimal antimicrobial treatment for this pathogen. The drug development pipeline is also explored for future potentially effective treatment options.