Clinical efficacy of ceftazidime/avibactam combination therapy for severe hospital-acquired pulmonary infections caused by carbapenem-resistant and difficult-to-treat Pseudomonas aeruginosa

Synergistic Effect of Ceftazidime-Avibactam with Aztreonam on Carbapenemase-Positive Klebsiella pneumoniae MBL+, NDM

Background

The difficulties in attaining effective antibiotic therapy arising from the multidrug resistance of Gram-negative bacilli compel the exploration of new possibilities for synergistic interactions among existing antibiotics.

Research Design and Methods

An analysis was conducted to assess the efficacy of two antibiotic therapy regimens in the treatment of infections caused by Klebsiella pneumoniae strains producing carbapenemases (MBL). Two patient groups were considered: Group A - individuals in whom the treatment of infection involved the application of ceftazidime-avibactam in combination with aztreonam. Group B comprised patients subjected to an alternative antibiotic therapy regimen.

Results

In the group subjected to the treatment regimen involving ceftazidime-avibactam and aztreonam, as compared to alternative antibiotic combinations, a statistically lower mortality rate during the course of treatment and a faster clinical response to the administered therapy were evident.

Conclusion

The results obtained may be applicable to routine in vitro assays performed and serve as valuable guidance for the potential utilization of the positive effect of antibiotic therapy through the synergy between ceftazidime-avibactam and aztreonam. The selection of antibiotics employed in the therapy of invasive infections caused by K. pneumoniae influences the ultimate treatment outcome.

Clinical outcomes and risk factors for mortality in recipients with carbapenem-resistant gram-negative bacilli infections after kidney transplantation treated with ceftazidime-avibactam: a retrospective study

Background

Ceftazidime-avibactam is a treatment option for carbapenem-resistant gram-negative bacilli (CR-GNB) infections. However, the risk factors associated with ceftazidime-avibactam (CAZ-AVI) treatment failure in kidney transplant (KT) recipients and the need for CAZ-AVI-based combination therapy remain unclear.

Methods

From June 2019 to December 2023, a retrospective observational study of KT recipients with CR-GNB infection treated with CAZ-AVI was conducted, with the primary outcome being 30-day mortality and secondary outcomes being clinical cure, microbiological cure, and safety. Risk factors for 30-day mortality and clinical failure were also investigated.

Results

A total of 81 KT recipients treated with CAZ-AVI were included in this study. Forty recipients (49.4%) received CAZ-AVI monotherapy, with a 30-day mortality of 22.2%. The clinical cure and microbiological cure rates of CAZ/AVI therapy were 72.8% and 66.7%, respectively. CAZ-AVI alone or in combination with other medications had no effect on clinical cure or 30-day mortality. Multivariate logistic regression analysis revealed that a higher Acute Physiology and Chronic Health Evaluation (APACHE) II score (odds ratio [OR]: 4.517; 95% confidence interval [CI]: 1.397-14.607; P = 0.012) was an independent risk factor for 30-day mortality. Clinical cure was positively associated with the administration of CAZ-AVI within 48 hours of infection onset (OR: 11.009; 95% CI: 1.344-90.197; P=0.025) and negatively associated with higher APACHE II scores (OR: 0.700; 95% CI: 0.555-0.882; P=0.002). Four (4.9%) recipients experienced recurrence within 90 days after the initial infection, 3 (3.7%) recipients experienced CAZ-AVI-related adverse events, and no CAZ-AVI resistance was identified.

Conclusion

CAZ-AVI is an effective medication for treating CR-GNB infections following kidney transplantation, even as monotherapy. Optimization of CAZ/AVI therapy (used within 48 hours of infection onset) is positively associated with potential clinical benefit. Further larger-scale studies are needed to validate these findings.

Antibiotics Usage in Special Clinical Situations

Medicine and the treatment of infectious diseases are increasingly focused on patient-tailored diagnostics and therapy [...].