Risk Factors for Infection and Mortality Associated With Stenotrophomonas maltophilia Bloodstream Infections in Children; Comparison With Pseudomonas aeruginosa Bloodstream Infections

Pharmacokinetics, Safety and Tolerability of Single-dose or Multiple-dose Cefiderocol in Hospitalized Pediatric Patients Three Months to Less Than Eighteen Years Old With Infections Treated With Standard-of-care Antibiotics in the PEDI-CEFI Phase 2 Study

BACKGROUND

Multidrug-resistant Gram-negative bacterial infections are increasing globally in neonates, infants and children; antibiotic options are limited.

METHODS

This international, multicenter, open-label phase 2 study, investigated the pharmacokinetics, safety and tolerability of single-dose and multiple-dose cefiderocol [as a 3-hour infusion (every 8 hours) dosed at 2000 mg for body weight ≥34 kg and at 60 mg/kg for body weight <34 kg], over a range of renal function, in hospitalized pediatric patients with aerobic Gram-negative bacterial infection; multiple-dose patients required standard-of-care systemic antibiotics for 5-14 days. Four cohorts of pediatric patients were enrolled (cohort 1: 12 to <18 years, cohort 2: 6 to <12 years, cohort 3: 2 to <6 years and cohort 4: 3 months to <2 years).

RESULTS

A total of 53 patients (median age: 73.5 months) were enrolled. Plasma concentration profiles were similar with single-dose (n = 24) and multiple-dose (n = 29) cefiderocol, irrespective of age and body weight in those with normal renal function or mild renal impairment. Geometric mean concentrations at the end of infusion ranged between 72.7 and 97.1 μg/mL for single-dose cefiderocol and between 88.8 and 106.0 μg/mL after multiple doses. At 8 hours, corresponding trough concentrations ranged from 7.86 to 10.8 μg/mL with single-dose cefiderocol and from 9.64 to 18.1 μg/mL with multiple doses. There were no deaths, no cefiderocol-related serious adverse events, significant related laboratory abnormalities or discontinuations.

CONCLUSIONS

Multiple-dose cefiderocol, administered for 5-14 days and according to body weight, achieved steady-state plasma concentrations that remained above the susceptibility breakpoints of Gram-negative bacteria throughout the dosing period. Cefiderocol was well tolerated.

Protective effect of San Huang Pill and its bioactive compounds against ulcerative colitis in Drosophila via modulation of JAK/STAT, apoptosis, Toll, and Nrf2/Keap1 pathways

ETHNOPHARMACOLOGICAL RELEVANCE

San Huang Pill (SHP) is a prescription in Dunhuang Ancient Medical Prescription, which has the efficacy of heat-clearing and dampness-drying, and is a traditional formula for the treatment of gastrointestinal diseases. However, its efficacy and mechanism in treating ulcerative colitis (UC) are still unclear.

AIM OF THE STUDY

To investigate the protective effects of SHP and its bioactive compounds against Dextran Sulfate Sodium (DSS)-induced intestinal damage using the Drosophila melanogaster model, and to detect the molecular mechanism of SHP in the treatment of UC.

METHODS

Survival rate, locomotion, feeding, and excretion were used to explore the anti-inflammatory effects of SHP. The pharmacotoxicity of SHP was measured using developmental analysis. Intestinal integrity, intestinal length, intestinal acid-base homeostasis, and Tepan blue assay were used to analyze the protective effect of SHP against DSS-induced intestinal damage. The molecular mechanism of SHP was detected using DHE staining, immunofluorescence, real-time PCR, 16 S rRNA gene sequencing, and network pharmacology analysis. Survival rate, intestinal length, and integrity analysis were used to detect the protective effect of bioactive compounds of SHP against intestinal damage.

RESULTS

SHP supplementation significantly increased the survival rate, restored locomotion, increased metabolic rate, maintained intestinal morphological integrity and intestinal homeostasis, protected intestinal epithelial cells, and alleviated intestinal oxidative damage in adult flies under DSS stimulation. Besides, administration of SHP had no toxic effect on flies. Moreover, SHP supplementation remarkably decreased the expression levels of genes related to JAK/STAT, apoptosis, and Toll signaling pathways, increased the gene expressions of the Nrf2/Keap1 pathway, and also reduced the relative abundance of harmful bacteria in DSS-treated flies. Additionally, the ingredients in SHP (palmatine, berberine, baicalein, wogonin, rhein, and aloeemodin) had protection against DSS-induced intestinal injury, such as prolonging survival rate, increasing intestinal length, and maintaining intestinal barrier integrity.

CONCLUSION

SHP had a strong anti-inflammatory function, and remarkably alleviated DSS-induced intestinal morphological damage and intestinal homeostatic imbalance in adult flies by regulating JAK/STAT, apoptosis, Toll and Nrf2/Keap1 signaling pathways, and also gut microbial homeostasis. This suggests that SHP may be a potential complementary and alternative medicine herb therapy for UC, which provides a basis for modern pharmacodynamic evaluation of other prescriptions in Dunhuang ancient medical prescription.

Current viewpoint on the epidemiology of nonfermenting Gram-negative bacterial strains

PURPOSE OF REVIEW

This article aims to review the epidemiology of nonfermenting Gram-negative bacilli (NFGNB) based on recent literature reports, particularly, of the less common, but with emerging clinical significance species.

RECENT FINDINGS

The reported frequency of multidrug-resistant Acinetobacter baumannii and Pseudomonas aeruginosa is increasing, with very significant variability, however, between different countries. Apart from the major NFGNB, that is, A. baumannii and P. aeruginosa, already recognized as of critical importance healthcare risks, several other NFGNB genera have been increasingly associated with diverse severe infections, such as Stenotrophomonas maltophilia, Burkholderia spp., Elizabethkingia spp., Chryseobacterium spp., Achromobacter spp., Alcaligenes spp., Sphingomonas spp., Shewanella spp. and Ralstonia spp., among others.

SUMMARY

The exploration of the epidemiology, as well as the pathogenic potential of the of the less frequent, but emerging and increasingly reported NFGNB, is crucial, not only for immunocompromised patients, but also for critically ill patients without overt immunosuppression. As we are heading fast towards a postantibiotic era, such information would contribute to the optimal antimicrobial management, that is, providing prompt, appropriate antimicrobial coverage when needed and, at the same time, avoiding overuse and/or inappropriate use of antimicrobial therapy. Also, it would help to better understand their transmission dynamics and to develop effective prevention strategies.

Global impact of antibacterial resistance in patients with hematologic malignancies and hematopoietic cell transplant recipients

Patients with hematologic malignancies and hematopoietic cell transplant (HCT) recipients are at high risk of developing bacterial infections. These patients may suffer severe consequences from these infections if they do not receive immediate effective therapies, and thus are uniquely threatened by antimicrobial-resistant bacteria. Here, we outline how the emergence of specific resistant bacteria threatens the effectiveness of established approaches to prevent and treat infections in this population. The emergence of fluoroquinolone resistance among Enterobacterales and viridans group streptococci may decrease the effectiveness of fluoroquinolone prophylaxis during neutropenia. The emergence of Enterobacterales that produce extended-spectrum β-lactamases or carbapenemases and of increasingly resistant Pseudomonas aeruginosa may result in neutropenic patients experiencing delayed time to active antibacterial therapy, and consequently worse clinical outcomes. The ability to select targeted antibacterial therapies after the availability of susceptibility data may be limited in patients infected with metallo-β-lactamase-producing Enterobacterales and difficult-to-treat P. aeruginosa. Vancomycin-resistant enterococci and Stenotrophomonas maltophilia can cause breakthrough infections in patients already being treated with broad-spectrum β-lactam antibiotics. Resistance can also limit the ability to provide oral stepdown antibacterial therapy for patients who could otherwise be discharged from hospitalization. We also outline strategies that have the potential to mitigate the negative impact of antimicrobial resistance, including interventions based on active screening for colonization with resistant bacteria and the use of novel rapid diagnostic assays. Additional research is needed to better understand how these strategies can be leveraged to combat the emerging crisis of antimicrobial resistance in patients with hematologic malignancies and HCT recipients.

Supporting Clinical Decisions with Rapid Molecular Diagnostic Pneumonia Panel in Pediatric Intensive Care Unit: Single Center Experience in Turkiye

INTRODUCTION

Lower respiratory tract infections are the leading cause of morbidity and mortality in children worldwide. It is crucial to promptly conduct diagnostic investigations in order to determine the microbiological cause of pneumonia, since this is necessary to ensure the appropriate delivery of antibiotic therapy to each individual patient. We evaluated the results of a rapid molecular diagnostic pneumonia panel in children with LRTI in a pediatric intensive care unit (PICU).

PATIENTS AND METHODS

Rapid molecular diagnostic pneumonia panel (BioFire®, FilmArray Pneumonia Panel plus; FA-PP) findings (71 results from 46 children) in a tertiary care PICU between 2019 and 2023 were retrospectively reviewed.

RESULTS

At least one bacterial pathogen was detected in 57 cases. A total of 77% of children had underlying conditions. A total of 70.4% of children needed invasive mechanical ventilation and 54.4% had ventilator-associated pneumonia. Pseudomonas aeruginosa (50.8%), Acinetobacter calcoaceticus baumannii complex (42%), and Klebsiella pneumoniae (38.6%) were the most common pathogens detected with the FA-PP. Of the 33 cases diagnosed with VAP, more than one pathogen was identified in 65.9% of cases, with the most commonly identified bacteria being K. pneumoniae (43.1%), P. aeruginosa (38.6%), and Acinetobacter calcoaceticus baumannii complex (31.8%). According to the FA-PP results, the same antibiotic therapy was continued in 39.4% of cases, escalated in 54.5%, and de-escalated in 6.1%.

CONCLUSIONS

The utilization of the FA-PP has some beneficial effects, including more prompt delivery of findings compared to conventional approaches. Additionally, this approach enables the identification of resistance profiles in children diagnosed with pneumonia in the PICU. Consequently, these test results facilitate the organization of antibiotic treatment strategies, including escalation and de-escalation approaches. The detection of resistance patterns was exclusively determined via the implementation of molecular testing, prompting a reevaluation of the isolation technique in accordance with the obtained data.

The Prognosis of Patients Tested Positive for Stenotrophomonas maltophilia from Different Sources

Purpose

The purpose of this study was to analyze the prognosis of patients tested positive for Stenotrophomonas maltophilia (SMA) from different sources.

Methods

A retrospective study was conducted among 651 patients tested positive for SMA from January 2020 to October 2022 in the First Affiliated Hospital of Anhui Medical University. The patients were divided into seven groups by the source of SMA. Univariate and multivariate analyses were used to identify risk factors for mortality in patients tested positive for SMA from different sources.

Results

A total of 651 SMA isolates were collected from various sources, including sputum (348 isolates, 53%), bronchoalveolar lavage fluid (52, 8%), abdominal drainage fluid (76, 12%), wound secretion (66, 10%), blood (62, 10%), urine (41, 6%) and cerebrospinal fluid (6, 1%). Compared with other groups, the mortality of the patients in the bronchoalveolar lavage fluid culture group, blood culture group, and abdominal drainage fluid culture group was higher, at 40.38%, 32.26%, and 26.32%, respectively. Multivariate analysis showed that continuous renal replacement therapy was an independent risk factor for mortality in patients with SMA bloodstream infection (P=0.020, OR=6.86), and effective antimicrobial therapy after being positive for S. maltophilia isolates (P=0.002, OR=0.10) was negatively correlated with the death of patients with SMA bloodstream infection. Age ≥65 years (P= 0.043, OR=4.96), kidney disease (P=0.045, OR=4.62) and antifungal agent exposure (P=0.036, OR=5.13) were independent risk factors for mortality in patients with SMA intra-abdominal infection. Antifungal agent exposure (P=0.024, OR=0.51) and glycopeptide exposure (P=0.045, OR=0.53) were independent risk factors for mortality in patients in the sputum culture group.

Conclusion

SMA has a high rate of antimicrobial resistance and can cause multisite infection. Pulmonary infections, bloodstream infections and abdominal infections caused by SMA have high mortality, and timely standardized treatment can reduce mortality.