Multidrug-resistant Enterobacterales infections in abdominal solid organ transplantation

Deciphering the impact of Acinetobacter baumannii on human health, and exploration of natural compounds as efflux pump inhibitors to treat multidrug resistance

Acinetobacter baumannii is an ESKAPE pathogen and threatens human health by generating infections with high fatality rates. A. baumannii leads to a spectrum of infections such as skin and wound infections, endocarditis, meningitis pneumonia, septicaemia and urinary tract infections. Recently, strains of A. baumannii have emerged as multidrug-resistant (MDR), meaning they are resistant to at least three different classes of antibiotics. MDR development is primarily intensified by widespread antibiotic misuse and inadequate stewardship. The World Health Organization (WHO) declared A. baumannii a precarious MDR species. A. baumannii maintains the MDR phenotype via a diverse array of antimicrobial metabolite-hydrolysing enzymes, efflux of antibiotics, impermeability and antibiotic target modification, thereby complicating treatment. Hence, a deeper understanding of the resistance mechanisms employed by MDR A. baumannii can give possible approaches to treat antimicrobial resistance. Resistance-nodulation-cell division (RND) efflux pumps have been identified as the key contributors to MDR determinants, owing to their capacity to force a broad spectrum of chemical substances out of the bacterial cell. Though synthetic inhibitors have been reported previously, their efficacy and safety are of debate. As resistance-modifying agents, phytochemicals are ideal choices. These natural compounds could eliminate the bacteria or interact with pathogenicity events and reduce the bacteria's ability to evolve resistance. This review aims to highlight the mechanism behind the multidrug resistance in A. baumannii and elucidate the utility of natural compounds as efflux pump inhibitors to deal with the infections caused by A. baumannii.

Intra-abdominal infections survival guide: a position statement by the Global Alliance For Infections In Surgery

Intra-abdominal infections (IAIs) are an important cause of morbidity and mortality in hospital settings worldwide. The cornerstones of IAI management include rapid, accurate diagnostics; timely, adequate source control; appropriate, short-duration antimicrobial therapy administered according to the principles of pharmacokinetics/pharmacodynamics and antimicrobial stewardship; and hemodynamic and organ functional support with intravenous fluid and adjunctive vasopressor agents for critical illness (sepsis/organ dysfunction or septic shock after correction of hypovolemia). In patients with IAIs, a personalized approach is crucial to optimize outcomes and should be based on multiple aspects that require careful clinical assessment. The anatomic extent of infection, the presumed pathogens involved and risk factors for antimicrobial resistance, the origin and extent of the infection, the patient's clinical condition, and the host's immune status should be assessed continuously to optimize the management of patients with complicated IAIs.

New Antibiotics Against Multidrug-Resistant Gram-Negative Bacteria in Liver Transplantation: Clinical Perspectives, Toxicity, and PK/PD Properties

Antimicrobial resistance is a growing global health problem, and it is especially relevant among liver transplant recipients where infections, particularly when caused by microorganisms with a difficult-to-treat profile, are a significant cause of morbidity and mortality. We provide here a complete dissection of the antibiotics active against multidrug-resistant Gram-negative bacteria approved over the last years, focusing on their activity spectrum, toxicity profile and PK/PD properties, including therapeutic drug monitoring, in the setting of liver transplantation. Specifically, the following drugs are presented: ceftolozane/tazobactam, ceftazidime/avibactam, meropenem/vaborbactam, imipenem/relebactam, cefiderocol, and eravacycline. Overall, studies on the safety and optimal employment of these drugs in liver transplant recipients are limited and especially needed. Nevertheless, these pharmaceuticals have undeniably enhanced therapeutic options for infected liver transplant recipients.

Update on Epidemiology and Outcomes of Infection in Pediatric Organ Transplant Recipients

Pediatric solid organ transplant (SOT) recipients are at risk for infection following transplantation. Data from adult SOT recipients are often used to guide prevention and treatment of infections associated with organ transplantation in children. This article highlights key recent pediatric SOT-specific publications for an array of infectious complications of organ transplantation. Attention is given to areas of need for future study.

Establishment of a risk prediction model for multidrug-resistant bacteria in deceased organ donors: a retrospective cohort study in China

Background

Multidrug resistance in bacteria is a serious problem in organ transplantations. This study aimed to identify risk factors and establish a predictive model for screening deceased organ donors for multidrug-resistant (MDR) bacteria.

Methods

A retrospective cohort study was conducted at the First Affiliated Hospital of Zhejiang University School of Medicine from July 1, 2019 to December 31, 2022. The univariate and multivariate logistic regression analysis was used to determine independent risk factors associated with MDR bacteria in organ donors. A nomogram was established based on these risk factors. A calibration plot, receiver operating characteristic (ROC) curve, and decision curve analysis (DCA) were used to estimated the model.

Results

In 164 organ donors, the incidence of MDR bacteria in culture was 29.9%. The duration of antibiotic use ≥3 days (odds ratio [OR] 3.78, 95% confidence interval [CI] 1.62-8.81, p=0.002), length of intensive care unit (ICU) stay per day(OR 1.06, 95% CI 1.02-1.11, p=0.005) and neurosurgery (OR 3.31, 95% CI 1.44-7.58, p=0.005) were significant independent predictive factors for MDR bacteria. The nomogram constructed using these three predictors displayed good predictive ability, with an area under the ROC curve value of 0.79. The calibration curve showed a high consistency between the probabilities and observed values. DCA also revealed the potential clinical usefulness of this nomogram.

Conclusions

The duration of antibiotic use ≥3 days, length of ICU stay and neurosurgery are independent risk factors for MDR bacteria in organ donors. The nomogram can be used to monitor MDR bacteria acquisition risk in organ donors.