Occurrence of Imipenem in natural water: Effect of dissolved organic matter and metals

The occurrence of trace antibiotic residues in the environment poses a threat by promoting antibiotic resistance and spreading resistant genes. Recent studies show that these residues interact with metals, forming toxic and persistent antibiotic-metal complexes (AMCs). Investigating the photodegradation of these contaminants in environmental waters is essential to understand their fate and ecotoxicological risk assessment in environmental waters. In this sense, the present work delineates the fate of IMP, a carbapenem antibiotic, in the environmental matrix and studies its interactions with humic acid and metals. The study established that the drug was labile and underwent degradation under light and ambient temperatures. Further, analytical studies with dissolved organic matter (DOM), such as humic acids, established an accelerating effect on antibiotic degradation via indirect photochemical pathways. For instance, for a concentration of 100 mg/L IMP mixed with 20 mg/L HA in volumetric ratios of IMP: HA 1:2, 1:1, and 2:1, the final concentrations of IMP after 24 h were 26.11 mg/L (-73.89 %), 34.44 mg/L (-65.56 %), and 44.22 mg/L (55.78 %), respectively. The higher the humic acid, the faster the degradation of IMP, thereby supporting the photochemical generation of reactive oxygen species (OH•) and subsequent oxidative degeneration of the drug. The interactions with metals, specifically copper, accelerated the degradation kinetics of the drug. The promotion effect was owed to the action of the OH• as the oxidizing agent. Based on the degradation products identified by LC-MS/MS, a scheme of the synergistic action of copper-redox coupling and imipenem, resulting in the oxidative degradation of the drug, was proposed. Understanding the photochemical behavior of antibiotics, and their behavior in the presence of DOM and metal is vital for unravelling their fate and complexity in wastewater.

Efficiency of combination therapy versus monotherapy for the treatment of infections due to carbapenem-resistant Gram-negative bacteria: a systematic review and meta-analysis

BACKGROUND

For resistant Gram-positive bacteria, evidence suggests that combination therapy is more effective. However, for resistant Gram-negative bacteria, no consensus has been reached. This study aims to comprehensively summarize the evidence and evaluate the impact of combination versus monotherapy on infections caused by carbapenem-resistant Gram-negative bacteria (CRGNB).

METHODS

A systematic search was conducted in PubMed, Cochrane library, Web of Science, and Embase up to June 15, 2024, to identify relevant studies. This study included comparisons of monotherapy and combination therapy for treating infections caused by CRGNB. Topical antibiotics (i.e., inhalational or intratracheal administration) and monotherapy with sulbactam/relebactam was excluded. The primary outcome was mortality, and the secondary outcomes were clinical success and microbiological eradication. Pooled odds ratios (OR) and 95% confidence intervals (CI) were calculated in order to systematically assess effect of treatment on mortality, clinical success and microbiological eradication. Subgroup analyses, publication bias tests, and sensitivity analyses were also performed.

RESULTS

A total of 62 studies, including 8342 participants, were analyzed, comprising 7 randomized controlled trials and 55 non-randomized studies. Monotherapy was associated with higher mortality (OR = 1.29, 95%CI: 1.11-1.51), lower clinical success (OR = 0.74, 95%CI: 0.56-0.98), and lower microbiological eradication (OR = 0.71, 95%CI: 0.55-0.91) compared to combination therapy for CRGNB infections. Specifically, patients with carbapenem-resistant Enterobacteriaceae (CRE) infections receiving monotherapy had higher mortality (OR = 1.50, 95%CI: 1.15-1.95), comparable clinical success (OR = 0.57,95%CI: 0.28-1.16), and lower microbiological eradication (OR = 0.48,95%CI:0.25-0.91) than those receiving combination therapy. For carbapenem-resistant Acinetobacter baumannii (CRAB) infections, no significant differences were observed in mortality (OR = 1.15.95%CI: 0.90-1.47), clinical success (OR = 0.95,95%CI: 0.74-1.24) and microbiological eradication (OR = 0.78,95%CI: 0.54-1.12).

CONCLUSIONS

Monotherapy or combination therapy is controversial. The systematic review and meta-analysis suggested that monotherapy is associated with higher mortality, lower clinical success, and lower microbiological eradication for treating infection caused by CRGNB. The available evidence suggests that treatment should be selected based on the specific bacteria and antibiotic used. Monotherapy for CRE infections may lead to adverse outcomes. For CRAB infections, no significant differences were found between combination therapy and monotherapy.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022331861.

Systematic review and meta-analysis of vancomycin therapeutic level for treatment of vancomycin-sensitive enterococcal infections

AIMS

Evidence on the optimal targets of vancomycin for treating other Gram-positive infections apart from methicillin-resistant Staphylococcus aureus (MRSA) is lacking. This review aims to identify the recommended vancomycin therapeutic level for favourable clinical outcomes among patients infected with vancomycin-sensitive enterococcal infections.

METHODS

Analytical studies describing the vancomycin levels of vancomycin-sensitive enterococcal infections among adult population were searched. The primary outcome was 30-day all-cause mortality, and the secondary outcomes were clinical failure and nephrotoxicity. Study characteristics were extracted and pooled using random-effects meta-analysis. The study quality was assessed using the Joanna Briggs Institute critical appraisal tool.

RESULTS

A total of nine retrospective cohorts studies involving 1013 patients with vancomycin-sensitive enterococci were included. The meta-analysis found that high area under the curve to minimum inhibitory concentration ratio (AUC/MIC) of vancomycin ≥ 389 mg*h/L significantly lowered the 30-day mortality (odds ratio [OR], 0.44, 95% confidence interval [CI], 0.26-0.75). Analysis of the target AUC/MIC showed that high vancomycin AUC/MIC (≥ 389-400 mg*h/L) significantly reduced clinical failure rate (OR 0.59, 95% CI 0.37-0.94). The mortality and treatment failure rates did not differ significantly between those with high or low trough levels. Higher vancomycin AUC/MIC and trough levels were significantly associated with increased nephrotoxicity (OR 3.11, 95% CI 1.65-5.89; OR 2.95, 95% CI 1.60-5.44, respectively).

CONCLUSIONS

The use of a higher vancomycin AUC/MIC concentration can be effective to reduce 30-day mortality and clinical failure but this needs to take into consideration the risk of nephrotoxicity. Well-conducted prospective studies are warranted due to the scarcity of evidence.

Arthrospira maxima and biosynthesized zinc oxide nanoparticles as antibacterials against carbapenem-resistant Klebsiella pneumoniae and Acinetobacter baumannii: a review article

Carbapenem resistance among bacteria, especially Klebsiella pneumoniae and Acinetobacter baumannii, constitutes a dreadful threat to public health all over the world that requires developing new medications urgently. Carbapenem resistance emerges as a serious problem as this class is used as a last-line option to clear the multidrug-resistant bacteria. Arthrospira maxima (Spirulina) is a well-known cyanobacterium used as a food supplement as it is rich in protein, essential minerals and vitamins and previous studies showed it may have some antimicrobial activity against different organisms. Biosynthesized (green) zinc oxide nanoparticles have been investigated by several researchers as antibacterials because of their safety in health. In this article, previous studies were analyzed to get to a conclusion about their activity as antibacterials.

The relation between inflammatory biomarkers and drug pharmacokinetics in the critically ill patients: a scoping review

BACKGROUND

The level of inflammation alters drug pharmacokinetics (PK) in critically ill patients. This might compromise treatment efficacy. Understanding the specific effects of inflammation, measured by biomarkers, on drug absorption, distribution, metabolism, and excretion is might help in optimizing dosing strategies.

OBJECTIVES

This review investigates the relationship between inflammatory biomarkers and PK parameters absorption, distribution, metabolism and excretion (ADME) in critically ill patients, providing insight in the complexity of dosing drugs in critically ill patients.

METHOD

Following PRISMA guidelines, we conducted a comprehensive search of Medline, Embase, Web of Science, and Cochrane databases (January 1946-November 2023). Studies examining inflammatory biomarkers, PK parameters, or drug exposure in critically ill patients were included. Records were screened by title, abstract, and full text, with any discrepancies resolved through discussion or consultation with a third reviewer.

RESULTS

Of the 4479 records screened, 31 met our inclusion criteria: 2 on absorption, 7 on distribution, 17 on metabolism, and 6 on excretion. In general, results are only available for a limited number of drugs, and most studies are done only looking at one of the components of ADME. Higher levels of inflammatory biomarkers may increase or decrease drug absorption depending on whether the drug undergoes hepatic first-pass elimination. For drug distribution, inflammation is negatively correlated with drug protein binding capacity, positively correlated with cerebrospinal fluid penetration, and negatively correlated with peritoneal penetration. Metabolizing capacity of most drugs was inversely correlated with inflammatory biomarkers. Regarding excretion, inflammation can lead to reduced drug clearance, except in the neonatal population.

CONCLUSION

Inflammatory biomarkers can offer valuable information regarding altered PK in critically ill patients. Our findings emphasize the need to consider inflammation-driven PK variability when individualizing drug therapy in this setting, at the same time research is limited to certain drugs and needs further research, also including pharmacodynamics.

Extended-spectrum β-lactamase and carbapenemase producing Enterobacteriaceae among patients suspected with surgical site infection at Hospitals in Southern Ethiopia

Background

Extended-spectrum β-lactamase and carbapenemase-producing Enterobacteriaceae are an increasing problem for patients today. Data on clinical samples for ESBL and carbapenemase-producing Enterobacteriaceae for surgical site infection patients in developing countries are limited, including Ethiopia, mainly due to resource constraints. Hence, this study aimed to determine the prevalence of extended-spectrum beta-lactamase- and carbapenemase-producing Enterobacteriaceae among patients suspected to have surgical site infection at Hospital in Southern Ethiopia.

Materials and methods

A hospital-based cross-sectional study was conducted on 422 suspected surgical site infections from June 1, 2022 to August 30, 2022 at Hospitals in Southern Ethiopia. Sociodemographic and clinical data were obtained by using a structured questionnaire. Clinical samples (pus, pus aspirates, and wound swabs) were collected aseptically and processed within 30 min by placing the swabs in sterile test tubes containing sterile normal saline (0.5 mL). Samples were cultured on blood and MacConkey agar plates. All positive cultures were characterized by colony morphology, Gram staining, and standard biochemical tests. Antimicrobial sensitivity tests were performed using Kirby Baur disk diffusion on Mueller-Hinton agar. ESBL production was confirmed using a double-disc synergy test (DDST) method. Carbapenemase production was assessed using the modified Hodge test. Logistic regression analysis was used to determine associated factors. A P-value < 0.05 were considered statistically significant.

Result

Bacteria belonging to the order Enterobacterales were cultured in 23.7% out of 422 patients with suspected surgical wound infection. Of all the isolates, Enterobacteriaceae (69 isolates) were the most frequent, with E. coli (29/69) followed by K. pneumoniae (14/69). Of 69 Enterobacteriaceae isolates, 66.6 % (46/69) were positive for ESBL production, and 21.7 (15/69) were positive for carbapenemase-producing Enterobacteriaceae. The majority of Enterobacteriaceae isolates showed sensitivity to meropenem (72.1%); however revealed 63.9% and 70.5% were resistant to gentamicin and ciprofloxacin, respectively. Similarly, a higher resistance rate to cefepime (91.8%), amoxicillin-clavulanic acid (98.4%), ceftriaxone (95.1%), and ceftazidime (91.8%). MDR rate of Enterobacteriaceae isolates was 25/61 (41%) among patients suspected for surgical site infection. The Multivariable analysis revealed that length of hospital stay in hospital [AOR = 3.81 (95% CI 2.08-6.95)] remained statistically significant factor associated with surgical site infection due to ESBL producing Enterobacteriaceae.

Conclusion

Study results showed the severity of ESBL-producing Enterobacteriaceae is critical and CPE is alarming. Meropenem is the most effective antibiotic against the ESBL-producing Enterobacteriaceae. MDR rate of Enterobacteriaceae isolates was 61 (61%) among patients suspected for surgical site infection. Therefore, antibiotic selection should be based on the results of the culture and sensitivity tests.

Impact of nitric oxide donors on capsule, biofilm and resistance profiles of Klebsiella pneumoniae

Klebsiella pneumoniae is considered to be a critical public health threat due to its ability to cause fatal, multi-drug-resistant infections in the bloodstream and key organs. The polysaccharide-based capsule layer that shields K. pneumoniae from clearance via innate immunity is a prominent virulence factor. K. pneumoniae also forms biofilms on biotic and abiotic surfaces. These biofilms significantly reduce penetration by, and antibacterial activity from, traditional antibiotics. Nitric oxide (NO), an endogenous molecule involved in the innate immune system, is equally effective at eradicating bacteria but without engendering resistance. This study investigated the effects of NO-releasing small molecules capable of diverse release kinetics on the capsule and biofilm formation characteristics of multiple K. pneumoniae strains. The use of NO donors with moderate and extended NO-release properties (i.e., half-life >1.8 h) inhibited bacterial growth. Additionally, treatment with NO decreased capsule mucoviscosity in K. pneumoniae strains that normally exhibit hypermucoviscosity. The NO donors were also effective against K. pneumoniae biofilms at the same minimum biocidal concentrations that eliminated planktonic bacteria, while meropenem showed little antibacterial action in the same experiments. These results represent the first account of exogenous NO affecting biomarkers involved in K. pneumoniae infections, and may therefore inform future development of NO-based therapeutics for treating such infections.

A Rapid and Simple HPLC-MS/MS Method for the Quantitative Determination of Colistin for Therapeutic Drug Monitoring in Clinical Practice

Colistin is the last-line option for the treatment of multidrug-resistant gram-negative bacterial infections with narrow therapeutic window. It is essential to ensure its efficacy and safety by therapeutic drug monitoring (TDM). Quantitative determination of colistin is difficult due to its complex ingredients. Previous determination methods demand intricate sample pre-treatment which are not only time-consuming but also costly, and is difficult to apply in clinical practice. Therefore, in order to carry out quantitative determination of colistin accurately and quickly, we establish a rapid high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) with simple sample pre-treatment process. The sample was purified by acetonitrile to remove the plasma protein. Then purified colistin was effectively separated from terfenadine, an internal standard (IS) using Phenomenex Kinetex C18 column (50.0×2.1mm, 5µm) with acetonitrile and water mobile phase at a flow rate of 0.5 mL/min and 40°C column temperature. Colistin and IS were monitored in positive ion mode. Our method expressed good linearity in 50.0~6000 ng/mL of colistin B and 28.31~3397.51 ng/mL of colistin A in plasma. Methodology validations, including selectivity, precision, accuracy, recovery, stability, matrix effect, and dilution integrity met acceptance criteria of Bioanalytical Method Validation (M10) of the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH).

Outcomes of adult patients with multidrug-resistant Acinetobacter baumannii ventilator-associated pneumonia treated with monotherapy versus combination therapy in a tertiary hospital

We compared clinical outcomes of patients who received monotherapy and combination therapy for treatment of MDR A. baumannii VAP. 170 patients were included. Vasopressor use and mortality rate were higher for combination therapy (69.3% versus 28.6%, p=0.024; 67.5% versus 14.3%, p=0.007; respectively). Majority received polymyxin B-based combination therapy, with higher mortality than those without polymyxin B (80.2% versus 19.8%, p=0.043). After adjusting for vasopressor use, monotherapy, dual combination, and triple combination therapy were not associated with mortality (aHR 0.24, 95% CI 0.03 to 1.79, p=0.169; aHR 1.26, 95% CI 0.79 to 2.00, p=0.367; aHR 0.93, 95% CI 0.57 to 1.49, p=0.744; respectively). There was no difference in adverse effects and length of stay between the two groups. Mortality from MDR A. baumannii VAP was high and not associated with monotherapy or combination therapy after adjustment for vasopressor use. Antibiotic regimens other than those containing polymyxin are urgently needed for the treatment of these infections.

First case report of a vertebral osteomyelitis caused by carbapenem-resistant Enterobacter cloacae treated with imipenem/cilastatin/relebactam prolonged infusion then meropenem/vaborbactam in continuous infusion

Introduction

Bone and joint infections (BJIs) caused by multidrug-resistant bacteria are becoming more frequent. However, data on the use of novel β-lactam/β-lactamase inhibitors, such as imipenem/cilastatin/relebactam (I-R) and meropenem/vaborbactam (MVB), to treat BJIs is lacking. Furthermore, prolonged infusions of these β-lactams should theoretically optimize pharmacokinetic/pharmacodynamics target in these indications, but there are currently no reports on this type of infusions, especially in the setting of BJI.

Case Presentation

We report a case of a vertebral osteomyelitis caused by carbapenem-resistant Enterobacter cloacae successfully treated with extended-infusion of I-R (1.25 g q6h over 2 h), then with continuous infusion of MVB (2 g q4h as over 4 h). Therapeutic drug monitoring confirmed that extended-infusion of I-R and continuous infusion of MVB achieved serum concentrations up to 12 mg/L of imipenem and 19 mg/L of meropenem, respectively.

Conclusion

The favourable outcome of this patient treated for a vertebral osteomyelitis caused by carbapenem-resistant E. cloacae suggest that extended- and continuous infusions of I-R and MVB, are promising regimens for treatment of BJIs caused by carbapenem-resistant Enterobacterales.

Empyema Caused by Peptoniphilus asaccharolyticus and Complicated by Secondary Pulmonary Infection from Acinetobacter baumannii: A Case Report

Peptoniphilus asaccharolyticus is a gram-positive anaerobic coccus that can cause infections in immunocompromised individuals. P. asaccharolyticus causing empyema has not been reported earlier. Here, we present a novel case of empyema caused by P. asaccharolyticus. A 72-year-old male had a constant fever with difficulty breathing. A chest computed tomography scan revealed infiltration in the right lower lobe and pleural effusion. Following hospital admission, pleural fluid drainage was conducted, and the culture isolated P. asaccharolyticus. Initially treated with piperacillin/tazobactam, the patient experienced excessive thick sputum production, prompting a tracheostomy. Subsequent sputum cultures identified Acinetobacter baumannii. After transitioning to cefoperazone/sulbactam for antibiotic treatment and continued pleural effusion drainage, recovery was achieved. Empyema can be caused by P. asaccharolyticus and further complicated by a secondary infection with A. baumannii. Management should include appropriate antibiotic therapy, pleural drainage, vigilant monitoring, and supportive care. We aim to raise clinicians' awareness of the potential for P. asaccharolyticus to cause empyema in immunocompromised patients and to provide early treatments, thereby improving morbidity and mortality.

Evaluation of blaOXA-48-like point mutation carbapenemase-producing Enterobacterales in Prapokklao Hospital, Thailand

Carbapenemase-producing Enterobacterales (CPE) isolates increasingly carry oxacillinase-48 (OXA-48)-like enzymes encoded by blaOXA-48-like, which can confer high levels of carbapenem resistance. This aims to determine the prevalence of CPE and genetic variation among blaOXA-48-like-carrying isolates recovered from Prapokklao Hospital in Chanthaburi Province, Thailand in 2016-2017. In total, 122 carbapenem-resistant Enterobacterales (CRE) isolates were recovered from clinical samples. CRE were evaluated using standard biochemical tests and MIC test strips. Carbapenemase production was assessed through the modified Hodge test (MHT), modified carbapenem inactivation method (mCIM), and EDTA-modified carbapenem inactivation method (eCIM). Detection of blaOXA-48-like mutations was conducted via PCR and confirmed by Sanger sequencing. Among these CRE isolates, 72 (59.02%), 44 (36.07%), 3 (2.46%), and 3 (2.46%) were Klebsiella pneumoniae, Escherichia coli, Enterobacter aerogenes, and Enterobacter cloacae, respectively. The MHT identified carbapenemase production in 108 isolates (88.52%). Based on the mCIM, 81 isolates (66.39%) were carbapenemase producers. Seventy-three isolates (59.84%) were eCIM-positive, indicating metallo-β-lactamase production. Three distinct genetic variants of the blaOXA-48-like gene were identified among the isolates, including the wild-type and two point mutation types harboring the mutations E168Q and S171A (mutation type 1) and E168Q, S171A, and R214S (mutation type 2). Multiple-sequence alignment and in silico analysis revealed variation of R214 located in the β5-β6 loop. This study identified blaOXA-48-like point mutation groups and carbapenemase production, predominantly metallo-β-lactamases, among CRE isolates, especially K. pneumoniae and E. coli. These findings highlight the importance of implementing stringent infection control measures and active antimicrobial resistance surveillance to combat the spread of difficult-to-treat, metallo-β-lactamase-producing CRE in healthcare settings.

IMPORTANCE

In this study, we aimed to investigate genetic variation and CPE among blaOXA-48-like carrying isolates recovered from Prapokklao Hospital, Chanthaburi Province, Thailand, during 2016-2017. A total of 122 carbapenem-resistant Enterobacterales (CRE) were recovered from clinical samples in Prapokklao Hospital. All CRE samples were confirmed by standard biochemical tests and minimum inhibitory concentration (MIC) test strips (E-test). The carbapenemase production was determined using the modified Hodge test (MHT), the modified carbapenem inactivation method (mCIM), and EDTA-CIM (eCIM). Three single mutations (E168Q, S171A, and R214S) were characterized in this study. This mutation might reflect the hydrolysis of the modified β-lactam spectrum, especially carbapenem, by OXA-48-like. Our report provides evidence of the blaOXA-48-like point mutation and carbapenemase-producing phenotype of CRE detected in this healthcare setting. Effective control measures and active surveillance of drug resistance in nosocomial pathogens are crucial for controlling diseases associated with difficult-to-treat bacteria.

Combined nephrotoxicity of Polymyxins and Vancomycin: a study on adverse event reporting for monotherapy versus combinations using the FDA adverse event reporting system (FAERS)

BACKGROUND

Multidrug-resistant (MDR) infections pose a global public health crisis with significant mortality and economic burdens. Combination of polymyxins and vancomycin has shown effectiveness against MDR infections. However, their combined nephrotoxicity complicates clinical use. Given these concerns, we conducted a pharmacovigilance analysis using the FDA Adverse Event Reporting System (FAERS) to assess the nephrotoxicity of combinations of polymyxins and vancomycin compared to monotherapy.

RESEARCH DESIGN AND METHODS

In this retrospective study, data from FAERS reports (2012 Q4 to 2023 Q2) were deduplicated and analyzed for adverse events (AEs) related to vancomycin, polymyxin B, and colistin. Disproportionality analyses were performed to evaluate the association between drugs and nephrotoxicity.

RESULTS

A total of 9,796,784 adverse event reports, including 73,009 reports associated with nephrotoxicity, were included. All three drugs showed significant associations with nephrotoxicity. In combination therapy, polymyxin B-vancomycin exhibited a stronger association with nephrotoxicity compared to monotherapy, whereas colistin-vancomycin demonstrated a lower association with nephrotoxicity than colistin monotherapy.

CONCLUSIONS

This study found that combining vancomycin with colistin alleviated colistin-induced nephrotoxicity, while combining vancomycin with polymyxin B worsened polymyxin B-induced nephrotoxicity.

Population Pharmacokinetics of Tigecycline for Critically Ill Patients Undergoing Continuous Renal Replacement Therapy

Background

Tigecycline is considered one of the last resorts for treating infections caused by multidrug-resistant bacteria. Continuous renal replacement therapy (CRRT) is widely used in critically ill patients, especially those with acute kidney injury or severe infections. However, pharmacokinetic data for tigecycline in patients receiving CRRT are limited.

Methods

This was a single-center prospective clinical study with intensive sampling that included critically ill patients who received tigecycline and CRRT. A population pharmacokinetic (PPK) model was developed and evaluated by goodness-of-fit plots, bootstrap analysis, visual predictive checks, and numerical predictive checks. Pharmacokinetic/pharmacodynamic target attainment and cumulative fraction of response analyses were performed to explore the potential need for dose adjustments of tigecycline in CRRT.

Results

In total, 21 patients with 167 concentrations were included. A two-compartment model adequately described the tigecycline concentration-time points, but no covariates were found to adequately explain the viability in the pharmacokinetic parameters of tigecycline. The typical values of CL, Q, V1 and V2 were 4.42 L/h, 34.8 L/h, 30.9 L and 98.7 L, respectively. For most infections, the standard regimen of 50 mg/12 h was deemed appropriate, expect for skin and soft skin tissue infections and community-acquired pneumonia caused by Acinetobacter baumannii and Klebsiella pneumoniae, which required a dosage regimen of 100 mg/12 h or higher.

Conclusion

A tigecycline PPK model describing critically ill patients undergoing CRRT was successfully developed. The optimized dosage regimens for various infections are recommended.

Antibiotics-associated pseudomembranous colitis: a disproportionality analysis of the US food and drug administration adverse event reporting system (FAERS) database

BACKGROUND

Evaluating antibiotics most commonly associated with pseudomembranous colitis (PMC) based on the real-world data is of great significance.

RESEARCH DESIGN AND METHODS

We used the data from FAERS to evaluate the potential association between antibiotics and PMC by disproportionality analyzes.

RESULTS

Eighty-one antibiotics which met the three algorithms simultaneously were enrolled. There were 1683 reports of PMC associated with the enrolled antibiotics. In the top 24 antibiotics, cefoxitin, streptomycin, fosfomycin, and micafungin had a high risk of PMC, but there were few reports in the literature.

CONCLUSIONS

This study was of great significance for healthcare professionals to realize the potential PMC risks of antibiotics.

Immunomodulator AS101 restores colistin susceptibility of clinical colistin-resistant Escherichia coli and Klebsiella pneumoniae in vitro and in vivo

OBJECTIVES

Colistin (COL) was once considered to be the last line of defence against multidrug-resistant bacteria belonging to the family Enterobacteriaceae. Due to the misuse of COL, COL-resistant (COL-R) Enterobacteriaceae have emerged. To address this clinical issue and combat COL resistance, novel approaches are urgently needed.

METHODS

In this study, the in vitro and in vivo antimicrobial and antibiofilm effects of the immunomodulator AS101 were investigated in combination with COL against COL-R Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae).

RESULTS

Checkerboard assay, time-kill assay, and scanning electron microscopy confirmed the in vitro antimicrobial phenotype, whereas, crystal violet staining and multidimensional confocal laser scanning microscopy with live/dead staining confirmed the antibiofilm capability of the combination therapy. Moreover, the Galleria mellonella infection model and the mouse infection model indicated the high in vivo efficacy of the combination therapy. Additionally, cytotoxicity experiments performed using human kidney-derived HK-2 cells and haemolysis assays performed using human erythrocytes collectively demonstrated safety at effective combination concentrations. Furthermore, quantification of the expression of inflammatory cytokines via enzyme-linked immunosorbent assay confirmed the anti-inflammatory advantage of combination therapy. At the mechanistic level, changes in outer and inner membrane permeability and accumulation of ROS levels, which might be potential mechanisms for synergistic antimicrobial effects.

CONCLUSIONS

This study found that AS101 can restore COL susceptibility in clinical COL-R E. coli and K. pneumoniae and also has synergistic antibiofilm and anti-inflammatory capabilities. This study provided a novel strategy to combat clinical infections caused by COL-R E. coli and K. pneumoniae.

Characteristic roadmap of linker governs the rational design of PROTACs

Proteolysis targeting chimera (PROTAC) technology represents a groundbreaking development in drug discovery, leveraging the ubiquitin‒proteasome system to specifically degrade proteins responsible for the disease. PROTAC is characterized by its unique heterobifunctional structure, which comprises two functional domains connected by a linker. The linker plays a pivotal role in determining PROTAC's biodegradative efficacy. Advanced and rationally designed functional linkers for PROTAC are under development. Nonetheless, the correlation between linker characteristics and PROTAC efficacy remains under-investigated. Consequently, this study will present a multidisciplinary analysis of PROTAC linkers and their impact on efficacy, thereby guiding the rational design of linkers. We will primarily discuss the structural types and characteristics of PROTAC linkers, and the optimization strategies used for their rational design. Furthermore, we will discuss how factors like linker length, group type, flexibility, and linkage site affect the biodegradation efficiency of PROTACs. We believe that this work will contribute towards the advancement of rational linker design in the PROTAC research area.

Risk-Adapted Use of Vancomycin in Secondary Scoliosis Surgery May Normalize SSI Risk in Surgical Correction of High-Risk Patients

Introduction: Intrawound application of vancomycin is becoming increasingly controversial for the prevention of surgical site infection (SSI). As children undergoing spinal fusion for secondary scoliosis are at high risk for SSIs, evidence regarding the impact of intraoperative vancomycin installation on SSI rates in these patients is of utmost importance. Methodology: A single surgeon cohort of patients under 18 years of age undergoing surgery for secondary scoliosis in 2017 was analyzed with regard to the development of SSIs requiring surgical revision and adverse events. Use of vancomycin was restricted to cases with higher risk of infection. Patients undergoing distraction surgery for growing devices were excluded. Results: After exclusions, 64 patients remained (vancomycin n = 39, control n = 25). The SSI rates were 12.8% in patients receiving vancomycin (n = 5/39) and 4% in the control group (n = 1/25, p = 0.785). None of the patients suffered from adverse events. Univariable logistic regression revealed younger age (p = 0.03) and meningomyelocele as predictors for SSI (p = 0.006), while the high-risk group receiving vancomycin was not at higher odds for SSI, also after adjustment for possible confounders such as age or MMC (p = 0.031; p = 0.009). Discussion: SSI rates were comparable between groups, suggesting a normalization of SSI risk in the vancomycin-treated patients with a preoperatively increased risk of SSI. Future, larger studies in these rare diseases are needed to confirm these results.

Antibiotic-Polyphosphate Nanocomplexes: A Promising System for Effective Biofilm Eradication

Purpose

The eradication of bacterial biofilms poses an enormous challenge owing to the inherently low antibiotic susceptibility of the resident microbiota. The complexation of antibiotics with polyphosphate can substantially improve antimicrobial performance.

Methods

Nanoparticular complexes of the model drug colistin and polyphosphate (CP-NPs) were developed and characterized in terms of their particle size and morphology, polydispersity index (PDI), zeta potential, and cytotoxicity. Enzyme-triggered monophosphate and colistin release from the CP-NPs was evaluated in the presence of alkaline phosphatase (AP). Subsequently, antimicrobial efficacy was assessed by inhibition experiments on planktonic cultures, as well as time-kill assays on biofilms formed by the model organism Micrococcus luteus.

Results

The CP-NPs exhibited a spherical morphology with particle sizes <200 nm, PDI <0.25, and negative zeta potential. They showed reduced cytotoxicity toward two human cell lines and significantly decreased hemotoxicity compared with native colistin. Release experiments with AP verified the enzymatic cleavage of polyphosphate and subsequent release of monophosphate and colistin from CP-NPs. Although CP-NPs were ineffective against planktonic M. luteus cultures, they showed major activity against bacterial biofilms, outperforming native colistin treatment. Strongly elevated AP levels in the biofilm state were identified as a potential key factor for the observed findings.

Conclusion

Accordingly, polyphosphate-based nanocomplexes represent a promising tool to tackle bacterial biofilm.

Risk factors for mortality in Acinetobacter baumannii bloodstream infections and development of a predictive mortality model

OBJECTIVES

Acinetobacter baumannii (A. baumannii) nosocomial infections represent a serious hazard to public health, given high mortality rates and rapid spread of multidrug-resistance. The primary outcome of this study was to evaluate predictors of 14- and 30-d mortality in bloodstream infections (BSIs) due to both carbapenem-resistant and carbapenem-sensitive Acinetobacter. Secondary end points were to identify risk factors for BSIs due to carbapenem-resistant A. baumannii (CRAB) and to develop a predictive model for mortality in CRAB-related BSIs.

METHODS

Between 2019 and 2023, all consecutive hospitalized adult patients with bacteraemia due to A. baumannii were retrospectively enrolled at a single-centre.

RESULTS

One hundred twenty-six episodes of BSI caused by A. baumannii were recorded, 89.7% of which were due to CRAB. Recent burn injuries, older age, previous CRAB colonization, and antibiotics exposure were identified as risk factors for acquiring CRAB BSI. Overall, 14-d mortality was observed in 26.1% of the patients and 30-d mortality in 30.9% of the patients. On multivariate analysis, the Sequential Organ Failure Assessment (SOFA) score was associated with both 14- and 30-d mortality, whereas burn injuries correlated with 30-d survival. Concurrent coronavirus disease (COVID) was associated with mortality, although not reaching statistical figures. No major impact of receiving appropriate treatment was observed. Based on these findings, a multivariable model to predict mortality among patients with CRAB BSI was built and internally validated.

CONCLUSIONS

A. baumannii BSIs are characterized by poor outcomes and limited therapeutic options. This study aimed to assist physicians in prompt identification of patients who are at greater risk of death, contributing to more informed clinical decision making.

Development and validation of a nomogram to predict the risk of vancomycin-related acute kidney injury in critical care patients

Background

Vancomycin-associated acute kidney injury (AKI) leads to underestimated morbidity in the intensive care unit (ICU). It is significantly important to predict its occurrence in advance. However, risk factors and nomograms to predict this AKI are limited.

Methods

This was a retrospective analysis of two databases. A total of 1,959 patients diagnosed with AKI and treated with vancomycin were enrolled from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. According to the 7:3 ratio, the training set (n = 1,372) and the internal validation set (n = 587) were randomly allocated. The external validation set included 211 patients from the eICU Collaborative Research Database (eICU). Next, to screen potential variables, the least absolute shrinkage and selection operator (LASSO) regression was utilized. Subsequently, the nomogram was developed by the variables of the selected results in the multivariable logistic regression. Finally, discrimination, calibration, and clinical utility were evaluated to validate the nomogram.

Results

The constructed nomogram showed fine discrimination in the training set (area under the receiver operator characteristic curve [AUC] = 0.791; 95% confidence interval [CI]: 0.758-0.823), internal validation set (AUC = 0.793; 95% CI: 0.742-0.844), and external validation set (AUC = 0.755; 95% CI: 0.663-0.847). Moreover, it also well demonstrated calibration and clinical utility. The significant improvement (P < 0.001) in net reclassification improvement (NRI) and integrated differentiation improvement (IDI) confirmed that the predictive model outperformed others.

Conclusion

This established nomogram indicated promising performance in determining individual AKI risk of vancomycin-treated critical care patients, which will be beneficial in making clinical decisions.

Carbapenem-resistant Enterobacterales sepsis following endoscopic retrograde cholangiopancreatography: risk factors for 30-day all-cause mortality and the development of a nomogram based on a retrospective cohort

BACKGROUND

Endoscopic retrograde cholangiopancreatography (ERCP) has become a routine endoscopic procedure that is essential for diagnosing and managing various conditions, including gallstone extraction and the treatment of bile duct and pancreatic tumors. Despite its efficacy, post-ERCP infections - particularly those caused by carbapenem-resistant Enterobacterales (CRE) - present significant risks. These risks highlight the need for accurate predictive models to enhance postprocedural care, reduce the mortality risk associated with post-ERCP CRE sepsis, and improve patient outcomes in the context of increasing antibiotic resistance.

OBJECTIVE

This study aimed to examine the risk factors for 30-day mortality in patients with CRE sepsis following ERCP and to develop a nomogram for accurately predicting 30-day mortality risk.

METHODS

Data from 195 patients who experienced post-ERCP CRE sepsis between January 2010 and December 2022 were analyzed. Variable selection was optimized via the least absolute shrinkage and selection operator (LASSO) regression model. Multivariate logistic regression analysis was then employed to develop a predictive model, which was evaluated in terms of discrimination, calibration, and clinical utility. Internal validation was achieved through bootstrapping.

RESULTS

The nomogram included the following predictors: age > 80 years (hazard ratio [HR] 2.61), intensive care unit (ICU) admission within 90 days prior to ERCP (HR 2.64), hypoproteinemia (HR 4.55), quick Pitt bacteremia score ≥ 2 (HR 2.61), post-ERCP pancreatitis (HR 2.52), inappropriate empirical therapy (HR 3.48), delayed definitive therapy (HR 2.64), and short treatment duration (< 10 days) (HR 5.03). The model demonstrated strong discrimination and calibration.

CONCLUSIONS

This study identified significant risk factors associated with 30-day mortality in patients with post-ERCP CRE sepsis and developed a nomogram to accurately predict this risk. This tool enables healthcare practitioners to provide personalized risk assessments and promptly administer appropriate therapies against CRE, thereby reducing mortality rates.

A pilot clinical risk model to predict polymyxin-induced nephrotoxicity: a real-world, retrospective cohort study

OBJECTIVES

Polymyxin-induced nephrotoxicity (PIN) is a major safety concern and challenge in clinical practice, which limits the clinical use of polymyxins. This study aims to investigate the risk factors and to develop a scoring tool for the early prediction of PIN.

METHODS

Data on critically ill patients who received intravenous polymyxin B or colistin sulfate for over 24 h were collected. Logistic regression with the least absolute shrinkage and selection operator (LASSO) was used to identify variables that are associated with outcomes. The eXtreme Gradient Boosting (XGB) classifier algorithm was used to further visualize factors with significant differences. A prediction model for PIN was developed through binary logistic regression analysis and the model was assessed by temporal validation and external validation. Finally, a risk-scoring system was developed based on the prediction model.

RESULTS

Of 508 patients, 161 (31.6%) patients developed PIN. Polymyxin type, loading dose, septic shock, concomitant vasopressors and baseline blood urea nitrogen (BUN) level were identified as significant predictors of PIN. All validation exhibited great discrimination, with the AUC of 0.742 (95% CI: 0.696-0.787) for internal validation, of 0.708 (95% CI: 0.605-0.810) for temporal validation and of 0.874 (95% CI: 0.759-0.989) for external validation, respectively. A simple risk-scoring tool was developed with a total risk score ranging from -3 to 4, corresponding to a risk of PIN from 0.79% to 81.24%.

CONCLUSIONS

This study established a prediction model for PIN. Before using polymyxins, the simple risk-scoring tool can effectively identify patients at risk of developing PIN within a range of 7% to 65%.

Association of Vancomycin AUC/MIC and Trough Concentration With Early Clinical Response in Enterococcus or Coagulase-Negative Staphylococcus Infection: A Prospective Study

This study was condcuted to examine the association of area under the curve (AUC)/minimum inhibitory concentration (MIC) and trough concentration (Ctrough) of vancomycin with treatment outcome and nephrotoxicity in infections caused by Enterococcus spp. and coagulase-negative Staphylococci (CoNS). Peak and trough concentrations were used to calculate AUC in 89 patients receiving vancomycin for infections with Enterococcus spp. (n = 65) or CoNS (n = 24). Correlations between Ctrough, AUC/MIC, early clinical response (ECR), and nephrotoxicity were assessed and cutoff values were determined. Sixty-three (70.8%) patients showed improvement in ECR and 10 (11.2%) experienced nephrotoxicity. Enterococcus spp. infections displayed correlations between AUC/MIC and ECR for AUC0-24 h/MIC (r2 = 0.27, P ≤ .05) and AUC24-48 h/MIC (r2 = 0.28, P ≤ .05), but not for Ctrough (r2 = 0.21, P > .05). There were no correlations between Ctrough (r2 = 0.26, P > .05), AUC0-24 h/MIC (r2 = -0.12, P > .05), AUC24-48 h/MIC (r2 = 0.01, P > .05) and ECR for CoNS. In the CoNS group, a moderate correlation was found between ECR and Ctrough at a cutoff value of 6.9 μg/mL. In addition, nephrotoxicity is also moderately associated with AUC0-24 h and AUC24-48 h at 505.7 and 667.1 μg•h/mL, respectively. A strong correlation between nephrotoxicity and Ctrough was observed when the cutoff value was 18.9 μg/mL. AUC/MIC during the first 48 h was a determinant of vancomycin efficacy in Enterococcus infections but not for CoNS. Ctrough was not correlated with clinical outcome. Nephrotoxicity could be predicted using Ctrough and AUC for infections with both pathogens.

Treatment of infections caused by carbapenem-resistant Acinetobacter baumannii

Patients with severe carbapenem-resistant Acinetobacter baumannii (CRAB) infections currently face significant treatment challenges. When patients display signs of infection and the clinical suspicion of CRAB infections is high, appropriate treatment should be immediately provided. However, current treatment plans and clinical data for CRAB are limited. Inherent and acquired resistance mechanisms, as well as host factors, significantly restrict options for empirical medication. Moreover, inappropriate drug coverage can have detrimental effects on patients. Most existing studies have limitations, such as a restricted sample size, and are predominantly observational or non-randomized, which report significant variability in patient infection severity and comorbidities. Therefore, a gold-standard therapy remains lacking. Current and future treatment options of infections due to CRAB were described in this review. The dose and considerable side effects restrict treatment options for polymyxins, and high doses of ampicillin-sulbactam or tigecycline appear to be the best option at the time of initial treatment. Moreover, new drugs such as durlobactam and cefiderocol have substantial therapeutic capabilities and may be effective salvage treatments. Bacteriophages and antimicrobial peptides may serve as alternative treatment options in the near future. The advantages of a combination antimicrobial regimen appear to predominate those of a single regimen. Despite its significant nephrotoxicity, colistin is considered a primary treatment and is often used in combination with antimicrobials, such as tigecycline, ampicillin-sulbactam, meropenem, or fosfomycin. The Infectious Diseases Society of America (IDSA) has deemed high-dose ampicillin-sulbactam, which is typically combined with high-dose tigecycline, polymyxin, and other antibacterial agents, the best option for treating serious CRAB infections. A rational combination of drug use and the exploration of new therapeutic drugs can alleviate or prevent the effects of CRAB infections, shorten hospital stays, and reduce patient mortality.

Development and validation of a prognostic nomogram to predict 30-day all-cause mortality in patients with CRO infection treated with colistin sulfate

Background

Carbapenem-resistant Gram-negative organism (CRO) infection is a critical clinical disease with high mortality rates. The 30-day mortality rate following antibiotic treatment serves as a benchmark for assessing the quality of care. Colistin sulfate is currently considered the last resort therapy against infections caused by CRO. Nevertheless, there is a scarcity of reliable tools for personalized prognosis of CRO infections. This study aimed to develop and validate a nomogram to predict the 30-day all-cause mortality in patients with CRO infection who underwent colistin sulfate treatment.

Methods

A prediction model was developed and preliminarily validated using CRO-infected patients treated with colistin sulfate at Tongji Hospital in Wuhan, China, who were hospitalized between May 2018 and May 2023, forming the study cohort. Patients admitted to Xianning Central Hospital in Xianning, China, between May 2018 and May 2023 were considered for external validation. Multivariate logistic regression was performed to identify independent predictors and establish a nomogram to predict the occurrence of 30-day all-cause mortality. The receiver operating characteristic (ROC) curve, the area under the ROC curve (AUC), and the calibration curve were used to evaluate model performance. The decision curve analysis (DCA) was used to assess the model clinical utility.

Results

A total of 170 patients in the study cohort and 65 patients in the external validation cohort were included. Factors such as age, duration of combination therapy, nasogastric tube placement, history of previous surgery, presence of polymicrobial infections, and occurrence of septic shock were independently associated with 30-day all-cause mortality and were used to construct the nomogram. The AUC of the nomogram constructed from the above six factors was 0.888 in the training set. The Hosmer-Lemeshow test showed that the model was a good fit (p = 0.944). The calibration curve of the nomogram was close to the ideal diagonal line. Furthermore, the decision curve analysis demonstrated significantly better net benefit in the model. The external validation proved the reliability of the prediction nomogram.

Conclusion

A nomogram was developed and validated to predict the occurrence of 30-day all-cause mortality in patients with CRO infection treated with colistin sulfate. This nomogram offers healthcare providers a precise and efficient means for early prediction, treatment management, and patient notification in cases of CRO infection treated with colistin sulfate.

Metabolomics highlights biochemical perturbations occurring in the kidney and liver of mice administered a human dose of colistin

Introduction: Colistin (CMS) is used for the curation of infections caused by multidrug-resistant bacteria. CMS is constrained by toxicity, particularly in kidney and neuronal cells. The recommended human doses are 2.5-5 mg/kg/day, and the toxicity is linked to higher doses. So far, the in vivo toxicity studies have used doses even 10-fold higher than human doses. It is essential to investigate the impact of metabolic response of doses, that are comparable to human doses, to identify biomarkers of latent toxicity. The innovation of the current study is the in vivo stimulation of CMS's impact using a range of CMS doses that have never been investigated before, i.e., 1 and 1.5 mg/kg. The 1 and 1.5 mg/kg, administered in mice, correspond to the therapeutic and toxic human doses, based on previous expertise of our team, regarding the human exposure. The study mainly focused on the biochemical impact of CMS on the metabolome, and on the alterations provoked by 50%-fold of dose increase. The main objectives were i) the comprehension of the biochemical changes resulting after CMS administration and ii) from its dose increase; and iii) the determination of dose-related metabolites that could be considered as toxicity monitoring biomarkers. Methods: The in vivo experiment employed two doses of CMS versus a control group treated with normal saline, and samples of plasma, kidney, and liver were analysed with a UPLC-MS-based metabolomics protocol. Both univariate and multivariate statistical approaches (PCA, OPLS-DA, PLS regression, ROC) and pathway analysis were combined for the data interpretation. Results: The results pointed out six dose-responding metabolites (PAA, DA4S, 2,8-DHA, etc.), dysregulation of renal dopamine, and extended perturbations in renal purine metabolism. Also, the study determined altered levels of liver suberylglycine, a metabolite linked to hepatic steatosis. One of the most intriguing findings was the detection of elevated levels of renal xanthine and uric acid, that act as AChE activators, leading to the rapid degradation of acetylcholine. This evidence provides a naïve hypothesis, for the potential association between the CMS induced nephrotoxicity and CMS induced 39 neurotoxicity, that should be further investigated.

Comparing prolonged infusion to intermittent infusion strategies for beta-lactam antibiotics in patients with gram-negative bacterial infections: a systematic review and meta-analysis

INTRODUCTION

Our objective is to determine whether prolonged infusion (PI) of beta-lactam antibiotics yields superior outcomes compared to intermittent infusion (II) in patients with Gram-Negative Bacterial (GNB) infections.

METHODS

We systematically searched papers from PubMed, the Cochrane Library, Embase, and Clinicaltrials.gov, targeting mortality as the primary outcome and looking at the clinical cure rate, hospital and intensive care unit (ICU) stay lengths, antibiotic treatment duration, and mechanical ventilation (MV) duration as secondary outcomes.

RESULTS

Our meta-analysis of 18 studies, including 5 randomized control trials and 13 observational studies, with a total of 3,035 patients-1,510 in the PI group and 1,525 in the II group, revealed significant findings. PI was associated with reduced mortality (RR, 0.67; 95% CI, 0.55-0.81; p = 0.001; I2 = 4.52%) and a shorter MV duration (SMD, -0.76; 95% CI, -1.37 to -0.16; p = 0.01; I2 = 87.81%) compared to II. However, no differences were found in clinical cure rates, antibiotic treatment duration, length of hospital stay, or length of ICU stay.

CONCLUSIONS

The PI approach for administering beta-lactam antibiotics in patients with suspected or confirmed GNB infections may be advantageous in reducing mortality rates and the duration of MV when compared to the II strategy.

Population pharmacokinetic analysis for dose regimen optimization of vancomycin in Southern Chinese children

Changes in physiological factors may result in large pharmacokinetic variability of vancomycin in pediatric patients, thereby leading to either supratherapeutic or subtherapeutic exposure and potentially affecting clinical outcomes. This study set out to characterize the disposition of vancomycin, quantify the exposure target and establish an optimal dosage regimen among the Southern Chinese pediatric population. Routine therapeutic drug monitoring data of 453 patients were available. We performed a retrospective population pharmacokinetic analysis of hospitalized children prescribed intravenous vancomycin using NONMEM® software. A one-compartment PPK model of vancomycin with body weight and renal functions as covariates based on a cutoff of 2 years old children was proposed in this study. Both internal and external validation showing acceptable and robust predictive performance of the model to estimate PK parameters. The value of area under the curve over 24 h to minimum inhibitory concentration ratio (AUC0-24/MIC) ≥ 260 was a significant predictor for therapeutic efficacy. Monte Carlo simulations served as a model-informed precision dosing approach and suggested that different optimal dose regimens in various scenarios should be considered rather than flat dosing. The evaluation of vancomycin exposure-efficacy relationship indicated that lower target level of AUC0-24/MIC may be needed to achieve clinical effectiveness in children, which was used to derive the recommended dosing regimen. Further prospective studies will be needed to corroborate and elucidate these results.

Usefulness of vancomycin treatment individualization via Bayesian algorithms: a 5-year study in critical patients

Aim: Compare two vancomycin dosing strategies in critical patients with methicillin-resistant Staphylococcus aureus (MRSA) infections, considering the heterogeneity of the dosing regimens administered and their implications for toxicity and efficacy. Materials & methods: Longitudinal retrospective observational study in two patient cohorts (standard dosing vs dosing via Bayesian algorithms). Results: The group of Bayesian algorithms received substantially higher and significantly heterogeneous doses, with an absence of nephrotoxicity. The speed of decrease observed in CRP and PCT was greater for the Bayesian strategy (p = 0.045 and 0.0009, respectively). Conclusion: Applying Bayesian algorithms to vancomycin dosage individualization allows for administering much higher doses than with standard regimens, facilitating a quicker clinical response in the absence of nephrotoxicity.

Clinical Characteristics and Risk Factors for Infection and Death in Critically Ill Patients with Pulmonary Infection with Elizabethkingia Spp

Purpose

Elizabethkingia spp. infections have recently increased, and they are difficult to treat because of intrinsic antimicrobial resistance. This study aimed to investigate the clinical characteristics of patients with pulmonary infection with Elizabethkingia spp. and reveal the risk factors for infection and death.

Patients and Methods

In this retrospective case-control study, patients were divided into infection and control groups based on the bacterial identification results. Patients in the infection group were further divided into survival and death groups according to their hospital outcomes. Clinical characteristics between different groups were compared. We further analyzed antimicrobial susceptibility testing results of the isolated strains.

Results

A total of the 316 patients were divided into infection (n = 79), 23 of whom died, and control (n = 237) groups. Multivariate logistic regression analysis showed that glucocorticoid consumption (OR: 2.35; 95% CI: 1.14-4.81; P = 0.02), endotracheal intubation (OR: 3.74; 95% CI: 1.62-8.64; P = 0.002), and colistin exposure (OR: 2.50; 95% CI: 1.01-6.29; P = 0.046) were significantly associated with pulmonary infection with Elizabethkingia spp. Advanced age (OR: 1.07, 95% CI: 1.00-1.15; P = 0.046), high acute physiology and chronic health evaluation (APACHE) II score (OR: 1.21; 95% CI: 1.01-1.45; P = 0.037), and low albumin level (OR: 0.73, 95% CI: 0.56-0.96; P = 0.025) were significantly associated with in-hospital mortality of infected patients. Elizabethkingia spp. was highly resistant to cephalosporins, carbapenems, macrolides, and aminoglycoside, and was sensitive to fluoroquinolones, minocycline, and co-trimoxazole in vitro.

Conclusion

Glucocorticoid consumption, tracheal intubation, and colistin exposure were associated with pulmonary infection with Elizabethkingia spp. for critically ill patients. Patients with advanced age, high APACHE II score, and low albumin level had higher risk of death from infection.

Physical compatibility of colistin with analgesics during simulated Y-site administration

PURPOSE

Special consideration is needed when intravenous drugs are administered simultaneously using a Y-site connector. This study aimed to investigate the physical compatibility of colistin with 6 analgesics at concentrations commonly used in clinical practice.

METHODS

A pharmaceutical preparation of colistin was dissolved according to the manufacturer's instructions and diluted to a concentration of 1.5 mg/mL or 0.67 mg/mL (of colistin base). Simulated administration via Y-site infusion set was performed by mixing 5 mL of colistin solution with an equal volume of a solution of one of 6 intravenous analgesics. Infusion solutions of ibuprofen, ketoprofen, metamizole sodium, morphine sulfate, paracetamol, and tramadol hydrochloride were studied. For each analgesic tested, concentrates for injection were diluted with 2 solvents, resulting in 11 different combinations with each concentration of the colistin solution. The mixtures were visually inspected, and their turbidity was measured directly after mixing and at 3 consecutive time points (30, 60, and 120 minutes). Additionally, the pH of the mixtures was measured after 120 minutes and compared with the pH of the analgesic and the colistin solutions.

RESULTS

During visual inspection with the unaided eye, no precipitate formation or gas evolution was observed in any of the tested analgesics except for sodium metamizole, where the yellow color of the solutions was observed. For samples containing the mixture of ibuprofen and colistin, the turbidity measurements revealed the presence of turbidity in the studied mixtures. The greatest change in pH relative to the value immediately after preparation was noted for combinations of ketoprofen and morphine sulfate with the tested antibiotic.

CONCLUSION

Colistin was found to be incompatible with ibuprofen and metamizole sodium formulations. It should also not be combined with morphine sulfate due to the significant differences in the pH value of the preparations. The colistin 0.67 mg/mL and 1.5 mg/mL infusion solutions were physically compatible with ketoprofen, tramadol hydrochloride, and paracetamol.

Spectrum and antimicrobial resistance in acute exacerbation of chronic obstructive pulmonary disease with pneumonia: a cross-sectional prospective study from Vietnam

BACKGROUND

Respiratory infections have long been recognized as a primary cause of acute exacerbation of chronic obstructive pulmonary disease (AE-COPD). Additionally, the emergence of antimicrobial resistance has led to an urgent and critical situation in developing countries, including Vietnam. This study aimed to investigate the distribution and antimicrobial resistance of bacteria in patients with AE-COPD using both conventional culture and multiplex real-time PCR. Additionally, associations between clinical characteristics and indicators of pneumonia in these patients were examined.

METHODS

This cross-sectional prospective study included 92 AE-COPD patients with pneumonia and 46 without pneumonia. Sputum specimens were cultured and examined for bacterial identification, and antimicrobial susceptibility was determined for each isolate. Multiplex real-time PCR was also performed to detect ten bacteria and seven viruses.

RESULTS

The detection rates of pathogens in AE-COPD patients with pneumonia were 92.39%, compared to 86.96% in those without pneumonia. A total of 26 pathogenic species were identified, showing no significant difference in distribution between the two groups. The predominant bacteria included Klebsiella pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae, followed by Acinetobacter baumannii and Streptococcus mitis. There was a slight difference in antibiotic resistance between bacteria isolated from two groups. The frequency of H. influenzae was notably greater in AE-COPD patients who experienced respiratory failure (21.92%) than in those who did not (9.23%). S. pneumoniae was more common in patients with stage I (44.44%) or IV (36.36%) COPD than in patients with stage II (17.39%) or III (9.72%) disease. ROC curve analysis revealed that C-reactive protein (CRP) levels could distinguish patients with AE-COPD with and without pneumonia (AUC = 0.78).

CONCLUSION

Gram-negative bacteria still play a key role in the etiology of AE-COPD patients, regardless of the presence of pneumonia. This study provides updated evidence for the epidemiology of AE-COPD pathogens and the appropriate selection of antimicrobial agents in Vietnam.

Antibiotic Resistance Profiles and MLST Typing of Staphylococcus Aureus Clone Associated with Skin and Soft Tissue Infections in a Hospital of China

Objective

To analyze the antibiotic resistance profile, virulence genes, and molecular typing of Staphylococcus aureus (S. aureus) strains isolated in skin and soft tissue infections at the First Affiliated Hospital, Gannan Medical University, to better understand the molecular epidemiological characteristics of S. aureus.

Methods

In 2023, 65 S. aureus strains were isolated from patients with skin and soft tissue infections. Strain identification and susceptibility tests were performed using VITEK 2 and gram-positive bacteria identification cards. DNA was extracted using a DNA extraction kit, and all genes were amplified using polymerase chain reaction. Multilocus sequence typing (MLST) was used for molecular typing.

Results

In this study, of the 65 S. aureus strains were tested for their susceptibility to 16 antibiotics, the highest resistance rate to penicillin G was 95.4%. None of the staphylococcal isolates showed resistance to ceftaroline, daptomycin, linezolid, tigecycline, teicoplanin, or vancomycin. fnbA was the most prevalent virulence gene (100%) in S. aureus strains isolated in skin and soft tissue infections, followed by arcA (98.5%). Statistical analyses showed that the resistance rates of methicillin-resistant S. aureus isolates to various antibiotics were significantly higher than those of methicillin-susceptible S. aureus isolates. Fifty sequence types (STs), including 44 new ones, were identified by MLST.

Conclusion

In this study, the high resistance rate to penicillin G and the high carrying rate of virulence gene fnbA and arcA of S.aureus were determine, and 44 new STs were identified, which may be associated with the geographical location of southern Jiangxi and local trends in antibiotic use. The study of the clonal lineage and evolutionary relationships of S. aureus in these regions may help in understanding the molecular epidemiology and provide the experimental basis for pathogenic bacteria prevention and treatment.

Molecular Epidemiological Characteristics of Carbapenem Resistant Aeromonas from Hospital Wastewater

Background

Hospital wastewater (HWW) promotes the spread of carbapenem resistance genes (CRGs). Aeromonas carry a large number of CRGs in HWW, they may play a role as a suitable reservoir for CRGs, while resistomes in HWW are still poorly characterized regarding carbapenem resistant Aeromonas. Thus, the aim of the study was to evaluate the molecular epidemiological characteristics of carbapenem resistant Aeromonas in HWW.

Methods

A total of 33 carbapenem resistant Aeromonas were isolated from HWW. Antimicrobial susceptibility testing and polymerase chain reaction (PCR) were used to assess the antimicrobial resistance profiles. Molecular typing was performed using enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) and multilocus sequence typing (MLST). The horizontal transmission mode of bla KPC was explored through conjugation and transformation experiments. The stability of bla KPC-IncP-6 plasmids was assessed through plasmid stability and in vitro competition test. The PCR mapping method was used to investigate the structural diversity of bla KPC.

Results

The detection rates of bla KPC and cphA in Aeromonas were 97.0% and 39.4% respectively. Aeromonas caviae were grouped into 13 clusters by ERIC-PCR and 12 STs by MLST. Aeromonas veronii were grouped into 11 clusters by ERIC-PCR and 4 STs by MLST. 56.3% bla KPC were located on mobilizable IncP-6 plasmids. bla KPC-IncP-6 plasmid showed high stability and low cost fitness.

Conclusion

Carbapenem resistant Aeromonas from HWW mainly carried bla KPC, which exhibited great structural diversity. Aeromonas might serve as reservoirs for bla KPC and bla KPC might spread mainly through transformation in HWW.

Evaluating Thromboprophylaxis Strategies for High-Risk Pregnancy: A Current Perspective

Venous thromboembolism (VTE) represents one of the leading causes of death during pregnancy. The greatest risk for it is the presence of medical or family history of VTE, stillbirth, cesarean section and selected thrombophilia. Appropriate thromboprophylaxis has the potential to decrease the risk of VTE in at-risk pregnant patients by 60-70%. Based on this, the authors reviewed the PubMed, Web of Science and Scopus databases to identify the possibilities of thromboprophylaxis in pregnant patients with a high risk of VTE. Moreover, they summarized its management in specific situations, such as cesarean delivery or neuraxial blockade. Currently, low-molecular-weight heparins (LMWH) are the preferred drugs for anticoagulant thromboprophylaxis in the course of pregnancy and postpartum due to easy administration and a lower rate of adverse events.

Carbapenem-resistant Acinetobacter baumannii Outbreak in a COVID-19 Isolation Ward and Successful Outbreak Control with Infection Control Measures

BACKGROUND

Even amid the coronavirus disease-19 (COVID-19) pandemic, the spread of multidrug-resistant bacteria and infection control are still important tasks. After recognizing the carbapenem-resistant Acinetobacter baumannii (CRAB) outbreak that occurred in the isolation room for COVID-19, we would like to introduce what infection control measures were implemented to eradicate it.

MATERIALS AND METHODS

All COVID-19 patients with CRAB in any specimen admitted to the COVID-19 isolation ward of the tertiary hospital in Korea from October to November 2021 were analyzed.

RESULTS

During the outbreak, 23 patients with COVID-19 and CRAB infections were identified. The index case was an 85-year-old female referred from a long-term care facility. CRAB was identified in sputum culture in most patients (91.3%). The CRAB outbreak occurred mainly in the rooms around the index case. Environmental cultures on the floor, air inlet, air outlet, and window frame of the rooms were performed. The antimicrobial resistance patterns of CRAB from patients and the environment were identical; whole-genome sequencing analyses revealed isolated clonality. Infection control measures with enhanced environmental cleaning using 1,000 ppm sodium hypochlorite and phenolic compounds, enhanced hand hygiene, additional education, and mandatory additional gowning and gloving of COVID-19 personal protective equipment (PPE) were applied on 29 October. No CRAB infection cases occurred from 2 November for two weeks.

CONCLUSION

In addition to applying PPE and COVID-19 precautions in COVID-19 isolation wards, adhering to strict contact precautions along with environmental control can help prevent the spread of multidrug-resistant bacteria.

Combination Therapy for OXA-48 Carbapenemase-Producing Klebsiella Pneumoniae Bloodstream Infections in Premature Infant: A Case Report and Literature Review

The prevalence of carbapenem-resistant Klebsiella pneumoniae (CRKP) has been increasing in recent years. Chinese Infectious Disease Surveillance of Pediatrics (ISPED) showed that in 2022, its resistance rate to meropenem was 18.5%. However, there is limited data available on the treatment of CRKP infection in neonates. In this study, we present a case involving a premature infant infected with OXA-48-producing Klebsiella pneumoniae. The combined susceptibility test revealed a significant synergistic effect between ceftazidime-avibactam(CAZ-AVI), and aztreonam(ATM). The infection was successfully treated with a combination of CAZ-AVI, ATM, and fosfomycin. This case represents the first reported instance of sepsis in a premature infant caused by OXA-48-producing Klebsiella pneumoniae in China. The objective of our study is to evaluate the effectiveness and safety of combination therapy in treating CRKP infections in premature infants. We hope that the findings of this study will provide valuable insights for clinicians in their treatment approach.

Knowledge, Attitude, and Practices of Mothers Working as Nurses Toward Multidrug-Resistant: Impact of an Educational Program in Neonatal Intensive Care Unit

Objective

This study seeks to assess the influence of an educational program on enhancing the knowledge, attitudes, and practices of NICU nurses regarding MDROs.

Methodology

Quasi-experimental design that investigated the efficacy of an educational intervention in shaping the knowledge, attitudes, and practices of mothers working as nurses in NICU toward MDROs was used. A total of 168 nurses participated, divided into 84 intervention groups and 84 non-educational groups.

Results

The analysis of overall knowledge scores before and after the educational interventions revealed a significant improvement in post-education knowledge scores (Mean = 16.94) compared to pre-education scores (Mean = 12.9929; t(83) = 40.119, p < 0.001). Attitude scores exhibited a notable improvement post-education, with mean scores increasing from 46.64 in the pretest to 58.45 in the posttest. The total attitude shift was statistically significant (t(83) = 104.23, p < 0.001 0). Regarding overall practice, the data suggests a positive impact of education on neonatal nurses' practices related to antibiotic usage (t(3) = 149.31, p < 0.001). A significant positive correlation was found between post-knowledge and post-attitude (r = 0.251, p = 0.021).

Conclusion

Based on the study findings, the MDROs educational program demonstrated its effectiveness in improving nurses' knowledge and attitudes toward MDROs, serving as a valuable educational resource for nurses. Given the increasing demand for nurses with MDROs knowledge, attitude, and practice in NICU, and considering the documented positive impact on protecting neonates from fatal infections, enhancing nurses' knowledge, attitudes, and practices toward MDROs has become imperative.

A novel multivariate logistic model for predicting risk factors of failed treatment with carbapenem-resistant Acinetobacter baumannii ventilator-associated pneumonia

Background

This study aimed to explore the risk factors for failed treatment of carbapenem-resistant Acinetobacter baumannii ventilator-associated pneumonia (CRAB-VAP) with tigecycline and to establish a predictive model to predict the incidence of failed treatment and the prognosis of CRAB-VAP.

Methods

A total of 189 CRAB-VAP patients were included in the safety analysis set from two Grade 3 A national-level hospitals between 1 January 2022 and 31 December 2022. The risk factors for failed treatment with CRAB-VAP were identified using univariate analysis, multivariate logistic analysis, and an independent nomogram to show the results.

Results

Of the 189 patients, 106 (56.1%) patients were in the successful treatment group, and 83 (43.9%) patients were in the failed treatment group. The multivariate logistic model analysis showed that age (OR = 1.04, 95% CI: 1.02, 1.07, p = 0.001), yes. of hypoproteinemia (OR = 2.43, 95% CI: 1.20, 4.90, p = 0.013), the daily dose of 200 mg (OR = 2.31, 95% CI: 1.07, 5.00, p = 0.034), yes. of medication within 14 days prior to surgical intervention (OR = 2.98, 95% CI: 1.19, 7.44, p = 0.019), and no. of microbial clearance (OR = 0.31, 95% CI: 0.14, 0.70, p = 0.005) were risk factors for the failure of tigecycline treatment. Receiver operating characteristic (ROC) analysis showed that the AUC area of the prediction model was 0.745 (0.675-0.815), and the decision curve analysis (DCA) showed that the model was effective in clinical practice.

Conclusion

Age, hypoproteinemia, daily dose, medication within 14 days prior to surgical intervention, and microbial clearance are all significant risk factors for failed treatment with CRAB-VAP, with the nomogram model indicating that high age was the most important factor. Because the failure rate of CRAB-VAP treatment with tigecycline was high, this prediction model can help doctors correct or avoid risk factors during clinical treatment.

A pharmacovigilance study of adverse events associated with polymyxins based on the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS) database

BACKGROUND

Polymyxins have been regarded as last-line treatment for multidrug-resistant gram-negative bacterial infections. Nonetheless, concerns regarding toxicity persist. This study aimed to explore and compare potential adverse events (AEs) between colistin and polymyxin B (PMB).

METHODS

Polymyxins-related AEs were retrieved from the U.S. Food and Drug Administration Adverse Event Reporting System between 2004 and 2022. Potential signals were estimated by the reporting odds ratio (ROR), and subgroup analyses were preformed to adjust for potential factors in AEs with significant disproportionality.

RESULTS

Analysis of 3,915 records involving 718 patients revealed a higher disproportionality of renal and urinary disorders (ROR 1.62, 95% CI 1.01-2.59) and acute kidney injury (ROR 1.75, 95% CI 1.07-2.87) with colistin treatment. Conversely, colistin exhibited a lower risk for neurotoxicity (ROR 0.47, 95% CI 0.30-0.73). Seven cases of skin hyperpigmentation were reported with PMB, whereas none were reported with colistin. Over 80% of cases involving polymyxin-related AEs occurred during the first two weeks of therapies, with a median onset time of 4.5 days.

CONCLUSIONS

Patients received colistin displayed a higher potential risk of nephrotoxicity but a lower risk of neurotoxicity. Clinicians should be vigilant in monitoring the AEs of hyperpigmentation disorders induced by PMB.

Ineffectiveness of colistin monotherapy in treating carbapenem-resistant Acinetobacter baumannii Pneumonia: A retrospective single-center cohort study

BACKGROUND

Acinetobacter baumannii, a common carbapenem-resistant gram-negative bacillus, usually causes nosocomial infections. Colistin has been used for carbapenem-resistant A. baumannii (CRAB) infections; however, only a few studies have evaluated colistin as a treatment option compared to appropriate controls. We investigated the effectiveness of colistin monotherapy in treating CRAB pneumonia compared to those treated without an active drug.

METHODS

Adult patients (≥ 18 years) with CRAB isolated from respiratory specimens were screened from September 2017 to August 2022. Only patients with pneumonia treated with colistin monotherapy (colistin group) were included and compared to those without any active antibiotics (no active antibiotics [NAA] group). The primary and secondary outcomes were 30-day all-cause mortality and acute kidney injury within 30 days. The inverse probability of the treatment-weighted Cox proportional hazard model was used to compare mortality between groups.

RESULTS

Among the 826 adult patients with CRAB in their respiratory specimens, 45 and 123 patients were included in the colistin and NAA groups, respectively. Most of the CRAB pneumonia (91.1%) cases were hospital-acquired pneumonia. The 30-day all-cause mortality rates in the colistin and NAA groups were 58.3% and 56.1%, respectively, and no difference was observed after adjustments (adjusted hazard ratio, 0.74; 95% CI, 0.47-1.17). The incidence of acute kidney injury was higher in the colistin group (65.3%) compared to the NAA group (39.0%) (P = 0.143).

CONCLUSIONS

Colistin monotherapy did not significantly improve treatment outcomes for CRAB pneumonia. The development and evaluation of new antimicrobials for CRAB pneumonia should be advocated in clinical practice.

Risk factors for bacteremic pneumonia and mortality (28-day mortality) in patients with Acinetobacter baumannii bacteremia

BACKGROUND

Patients infected with Acinetobacter baumannii (AB) bacteremia in hospital have high morbidity and mortality. We analyzed the clinical characteristics of pneumonia and nonpneumonia-related AB bloodstream infections (AB BSIs) and explored the possible independent risk factors for the incidence and prognosis of pneumonia-related AB BSIs.

METHODS

A retrospective monocentric observational study was performed. All 117 episodes of hospital-acquired AB bacteremia sorted into groups of pneumonia-related AB BSIs (n = 45) and nonpneumonia-related AB BSIs (n = 72) were eligible. Univariate/multivariate logistic regression analysis was used to explore the independent risk factors. The primary outcome was the antibiotic susceptibility in vitro of pneumonia-related AB BSIs group. The secondary outcome was the independent risk factor for the pneumonia-related AB BSIs group.

RESULTS

Among 117 patients with AB BSIs, the pneumonia-related group had a greater risk of multidrug resistant A. baumannii (MDRAB) infection (84.44%) and carbapenem-resistant A. baumannii (CRAB) infection (80%). Polymyxin, minocycline and amikacin had relatively high susceptibility rates (> 80%) in the nonpneumonia-related group. However, in the pneumonia-related group, only polymyxin had a drug susceptibility rate of over 80%. Univariate analysis showed that survival time (day), CRAB, MDRAB, length of hospital stay prior to culture, length of ICU stay prior to culture, immunocompromised status, antibiotics used prior to culture (n > = 3 types), endotracheal tube, fiberoptic bronchoscopy, PITT, SOFA and invasive interventions (n > = 3 types) were associated with pneumonia-related AB bacteremia. The multivariate logistic regression analysis revealed that recent surgery (within 1 mo) [P = 0.043; 0.306 (0.098-0.962)] and invasive interventions (n > = 3 types) [P = 0.021; 0.072 (0.008-0.671)] were independent risk factors related to pneumonia-related AB bacteremia. Multivariate logistic regression analysis revealed that length of ICU stay prior to culture [P = 0.009; 0.959 (0.930-0.990)] and recent surgery (within 1 mo) [P = 0.004; 0.260 (0.105-0.646)] were independent risk factors for mortality in patients with pneumonia-related AB bacteremia. The Kaplan‒Meier curve and the timing test showed that patients with pneumonia-related AB bacteremia had shorter survival time compared to those with nonpneumonia-related AB bacteremia.

CONCLUSIONS

Our study found that A. baumannii had a high rate of antibiotic resistance in vitro in the pneumonia-related bacteremia group, and was only sensitive to polymyxin. Recent surgery was a significantly independent predictor in patients with pneumonia-related AB bacteremia.

Clinical characteristics and antimicrobial therapy of healthcare-associated carbapenem-non-susceptible gram-negative bacterial meningitis: a 16-year retrospective cohort study

OBJECTIVE

Healthcare-associated Gram-negative bacterial meningitis is a substantial clinical issue with poor outcomes, especially for neurosurgical patients. Here, we aimed to study the characteristics and treatment options of patients with healthcare-associated carbapenem-non-susceptible (Carba-NS) Gram-negative bacterial meningitis.

METHODS

This observational cohort study was conducted at a teaching hospital from 2004 to 2019. The clinical characteristics of patients with meningitis with Carba-NS and carbapenem-susceptible (Carba-S) bacilli were compared, and the antimicrobial chemotherapy regimens and outcomes for Carba-NS Gram-negative bacterial meningitis were analyzed.

RESULTS

A total of 505 patients were included, of whom 83.8% were post-neurosurgical patients. The most common isolates were Acinetobacter spp. and Klebsiella spp., which had meropenem-resistance rates of 50.6% and 42.5%, respectively, and showed a markedly growing carbapenem-resistance trend. Kaplan-Meier curve analysis revealed that Carba-NS Gram-negative bacilli were associated with a significantly higher in-hospital mortality rate (18.8%, 35/186) compared to the Carba-S group (7.4%, 9/122; P = 0.001). For Carba-NS Enterobacterales meningitis, aminoglycoside-based and trimethoprim-sulfamethoxazole-based regimens yielded significantly higher clinical efficacy rates than non-aminoglycoside-based and non-trimethoprim-sulfamethoxazole-based regimens (69.0% vs. 38.7%, P = 0.019 and 81.8% vs. 46.9%, P = 0.036, respectively). For Carba-NS A. baumannii complex meningitis, tetracycline-based (including doxycycline, minocycline, or tigecycline) therapy achieved a significantly higher clinical efficacy rate (62.9%, 22/35) than the non-tetracycline-based therapy group (40.4%, 19/47; P = 0.044).

CONCLUSIONS

Our findings revealed that Carba-NS Gram-negative bacilli are associated with higher in-hospital mortality in patients with healthcare-associated meningitis. The combination therapies involving particular old antibiotics may improve patients' outcome.

TRIAL REGISTRATION

This study was registered on the Chinese Clinical Trial Register under ChiCTR2000036572 (08/2020).

A cohort study of the risk factors and the target AUC to avoid vancomycin-associated acute kidney injury in pediatric patients

OBJECTIVES

In recent years, Vancomycin (VCM) dosing design using area under the concentration-time curve (AUC) has been recommended as a measure of efficacy and safety, but there are fewer reports on pediatric patients than on adults. In this study, we evaluated the threshold of AUC for AKI occurrence in pediatric patients and investigated the factors that contribute to the occurrence of AKI.

METHODS

Pediatric patients aged 1-15 years on VCM treatment who underwent TDM at Kagoshima University Hospital from April 2016 to March 2022 were included in the computation of AUC using pediatric population pharmacokinetic parameters.

RESULTS

The ROC curve showed that the AUC threshold for the risk of developing AKI was 583.0 μg・h/mL, and the AUC-ROC curve was 0.873 (sensitivity 0.930, specificity 0.750). Univariate analysis showed that factors associated with AKI incidence were the duration of VCM administration, ICU admission, and AUCSS. Concomitant medications identified as risk factors for AKI incidence were tazobactam/piperacillin, liposomal amphotericin B, calcineurin inhibitors, contrast agents, and H2-receptor blockers. The multivariate analysis showed that AUC ≧ 583.0 μg・h/mL (odds ratio 20.14, 95% CI 3.52-115.22, p < 0.001) and H2-receptor blockers (odds ratio 8.70, 95% confidence interval = 1.38-54.87, p = 0.02) were independent factors for AKI incidence.

CONCLUSIONS

We showed that in pediatric patients receiving VCM, the risk of AKI increases as AUC increases. The findings imply that concurrent use of VCM and H2-receptor blockers may increase the risk of AKI.

Association between trough serum vancomycin concentration and vancomycin-associated acute kidney injury and 30-day mortality in critically ill elderly adults

BACKGROUND

Vancomycin-associated acute kidney injury (VA-AKI) is the most clinically relevant side effect of vancomycin. The objective of this study was to investigate the association between VTC and VA-AKI as well as 30-day mortality in critically ill elderly adults.

METHOD

Elderly patients with trough serum vancomycin concentration records(VTC) in the Medical Information Mart-IV (MIMIC-IV) and eICU databases were retrospectively studied.

RESULTS

A total of 3,146 critically ill elderly adults were finally enrolled. The incidence of VA-AKI in the elderly population was 76.5%. Logistic regression analysis revealed significant relationships between VA-AKI and various factors, including VTC, comorbidities, and laboratory indicators, and SOFA, and GCS score. For each mg/L increase, the OR for VA-AKI increased by 2.5%. The association between VTC and 30-day mortality was found to be statistically significant (odds ratio (OR): 1.021, 95% CI: 1.010-1.031), P < 0.001). The Restricted cubic splines (RCS) curves revealed that VTC ranged of 19.67 to 35.72 mg/l for AKI and 19.17 to 42.86 mg/l for 30-day mortality exhibit OR with 95% CI above 1, indicating statistically significant associations with an increased risk of AKI and 30-day mortality, respectively. In the subgroup analysis, VTC was identified as a risk factor for VA-AKI in specific patient groups, including white individuals, female patients, those with shock, patients with SOFA > 6, patients with baseline creatinine > 1.2 mg/dl and patients with or without exposed to other nephrotoxic medications.

CONCLUSION

This study found the significant association between VTC and the incidence of VA-AKI and 30-day mortality in critically ill elderly adults. The RCS curves indicated concentration ranges for AKI (19.67-35.72 mg/L) and 30-day mortality (19.17-42.86 mg/L), signifying increased risk.

Assessment of Knowledge, Attitude and Practice (KAP) Regarding Antimicrobial Usage and Resistance Among Animal Health Professionals of East Wallaga Zone, Oromiya, Ethiopia

Background

Antimicrobial resistance (AMR) is one of the top global public health and economic threats. The use of antimicrobials (AMs) in animal production is a major contributor to the development of AMR globally. Animal health professionals (AHPs) play a key role in ensuring judicious use of AMs.

Objective

To assess the knowledge, attitude and practice (KAP) of antimicrobial usage (AMU) and AMR among healthcare professionals in Nekemte town, Leka Dulecha and Sibu Sire districts.

Methods

A cross-sectional study was conducted with 120 purposively chosen AHPs residing in the districts and the town. A semi-structured questionnaire consisting of 49 questions was used to ascertain the KAP. The chi-square test (X2) was used to analyze the association between the knowledge score and demographic profile of the study participants.

Results

In the study the overall knowledge of the participants was moderately appreciable, and all participants had positive attitudes toward AMR and appropriate usage. In terms of knowledge of antibiotic use, the majority (93.33%) of the participants correctly answered the statement that antibiotics can kill viruses. About 84.17% of the participants correctly knew that antibiotics killed or stopped the growth of both bad and good bacteria. The majority of the participants (74.17%) always or (25.83%) sometimes rely on usage of antibiotics without a doctor's prescription. It was shown that comparing respondents from Sibu Sire, Leka Dulecha and Nekemte town, the scores of knowledge of AMU were significantly (X2=14.13, p=0.007) different. Most animal healthcare professionals from the Sibu sire have a good knowledge of AMU, and contribute to AMR development.

Conclusion

The study revealed that there was moderate knowledge and positive attitude toward AMU and resistance. This warrants continuing capacity building programs for the professionals on AM usage and resistance, and development of field-friendly disease diagnosis and management tools is essential in the need to reduce AMR.

Clinical success of anti-infective combination therapy compare to monotherapy in patients with carbapenem-resistant Pseudomonas aeruginosa infection: a 10-years retrospective study

BACKGROUND

Carbapenem-resistant Pseudomonas aeruginosa (CRPA) infection has become a major public health concern. The recommendations for monotherapy and combination therapy in the current guidelines lack sufficient evidence to support them. The primary objective of this study is to determine the effectiveness of anti-Infective combination therapy compared to monotherapy in achieving clinical success in patients with CRPA infection and risk factors of clinical failure of monotherapy.

METHODS

A retrospective study from Medical Information Mart for Intensive Care IV (MIMIC-IV) was conducted. We included adults with infections caused by CRPA. The outcomes of this study were clinical success, complete clinical success, and 28-day all-cause mortality.

RESULTS

A total of 279 subjects were finally enrolled. The rate of clinical success for combination therapy was higher than that for monotherapy (73.1% versus 60.4%, p=0.028). Compared to clinical failure patients, patients in the clinical success group were more likely to die within 28 days after CRPA was found (48.3% versus 3.6%, p<0.001). In a multivariate logistic regression analysis, monotherapy was found to be significantly correlated with clinical success (OR, 0.559, 95% CI, 0.321-0.976; p = 0.041).

CONCLUSION

Combination therapy is more effective for CRPA infection patients, especially those whose SOFA score is ≥ 2 or whose Charlson comorbidity index is ≥ 6.

Atwill E, Jeamsripong S. Antimicrobial resistance, virulence profile, and genetic analysis of ESBL-producing Escherichia coli isolated from Nile tilapia in fresh markets and supermarkets in Thailand

This study investigated the prevalence and antimicrobial resistance (AMR) of Escherichia coli (E. coli) in Nile tilapia from fresh markets and supermarkets. A total of samples (n = 828) were collected from Nile tilapia including fish flesh (n = 276), liver and kidney (n = 276), and intestine (n = 276). Overall prevalence of fecal coliforms (61.6%) and E. coli (53.0%) were observed. High prevalence of E. coli was found in the intestine (71.4%), followed by the liver and kidney (45.7%). The highest prevalence of resistance was commonly found against tetracycline (78.5%), ampicillin (72.8%), and sulfamethoxazole (45.6%) with resistance to only tetracycline (15.2%) as the most common antibiogram. The prevalence of multidrug resistance (MDR) (54.4%) and Extended-spectrum beta-lactamases (ESBLs) (5.7%) were examined. The predominant virulence genes (n = 158) were st (14.6%), followed by eaeA (0.6%). The blaTEM (73.4%), tetA (65.2%), and qnrS (57.6%). There is statistical significance between Nile tilapia from fresh markets and supermarkets. Based on logistic regression analysis, ampicillin-resistant E. coli was statistically associated with the phenotypic resistance to tetracycline and trimethoprim, and the presence of blaTEM and tetA (p < 0.05). Further investigation of AMR transference and their mechanisms is needed for AMR control.

Optimal Blood Sampling Time for Area under the Concentration-Time Curve Estimation of Vancomycin by Assessing the Accuracy of Four Bayesian Software

Effective blood sampling times, beyond trough and peak levels, have not been determined for estimating vancomycin's area under the concentration-time curve (AUC) using the Bayesian software. The aim of this study was to evaluate the accuracy of AUC estimation at different blood sampling times during the same dosing interval at steady state utilizing data from a prior phase I trial of vancomycin. Six healthy adult participants were sampled following intravenous administration of 1 g vancomycin for 1.5 h every 12 h. The AUC was estimated using four software packages and four population pharmacokinetic models. Accuracy was assessed using bias (difference between the estimated and reference AUC) and imprecision (absolute percentage difference between the estimated and reference AUC). The accuracy varied with the sampling time. The optimal two-point sampling times were determined to be 2.5 and 5.5 h post-injection using software packages for EasyTDM, Practical AUC-guided therapeutic drug monitoring (TDM), and Anti-MRSA Agents TDM Analysis Software (incorporating Rodvold, Yamamoto, and Yasuhara models). In these estimations, the mean bias (range, -1.7 to 9.5 µg·h/mL) was unbiased and the mean imprecision (range, -3.0% to 5.0%) was precise. The optimal one-point sampling time was 5.5 h post-injection for Anti-MRSA Agents TDM Analysis Software, which incorporated the Yamamoto and Yasuhara models. In conclusion, optimal blood sampling times may vary depending on the software and model used. Our findings suggest that identifying specific sampling times could improve the efficacy of TDM in clinical practice.