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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Association between Pneumonia Development and Virulence Gene Expression in Carbapenem-Resistant Acinetobacter baumannii Isolated from Clinical Specimens

We investigated the virulence gene expression of carbapenem-resistant Acinetobacter baumanii (CRAB) isolated from the respiratory samples of patients with CRAB pneumonia and those with CRAB colonization to identify the virulence genes contributing to CRAB pneumonia's development and mortality. Patients with CRAB identified from respiratory specimens were screened at a tertiary university hospital between January 2018 and January 2019. Patients were classified into CRAB pneumonia or CRAB colonization groups according to predefined clinical criteria. A. baumannii isolated from respiratory specimens was examined for the expression levels of ompA, uspA, hfq, hisF, feoA, and bfnL by quantitative reverse-transcription polymerase chain reaction. Among 156 patients with CRAB from respiratory specimens, 17 and 24 met the criteria for inclusion in the pneumonia and colonization groups, respectively. The expression level of ompA was significantly higher in the pneumonia group than in the colonization group (1.45 vs. 0.63, P=0.03). The expression levels of ompA (1.97 vs. 0.86, P=0.02), hisF (1.06 vs. 0.10, P < 0.01), uspA (1.62 vs. 1.01, P < 0.01), and bfnL (3.14 vs. 2.14, P=0.03) were significantly higher in patients with 30-day mortality than in the surviving patients. Elevated expression of hisF (adjusted odds ratio = 5.93, P=0.03) and uspA (adjusted odds ratio = 7.36, P=0.02) were associated with 30-day mortality after adjusting for age and the Charlson score. uspA and hisF may serve as putative targets for novel therapeutic strategies.

Successful addition of topical antibiotic treatment after surgery in treatment-refractory nontuberculous mycobacterial skin and soft tissue infections

Treatment of skin and soft tissue infections with nontuberculous mycobacteria sometimes fails despite repeated debridements and long-term systemic antibiotic therapy. These treatment-refractory infections can cause significant morbidity and pose a treatment challenge. Following surgery, we treated three patients with negative pressure wound therapy with the instillation and dwell time of topical antibiotics, in addition to systemic antibiotic treatment. Treatment was successful and well tolerated, except for some local irritation.

Distribution and antimicrobial resistance analysis of gram-negative bacilli isolated from a tertiary hospital in Central China: a 10-year retrospective study from 2012 to 2021

Background

Gram-negative bacilli are one of the most common causes of various infections in clinical. The emergence and global spread of multi-drug resistant gram-negative bacilli has become a major challenge in the global public health field.

Methods

A total of 51,189 non-repetitive strains of gram-negative bacilli were isolated in clinical settings. The antimicrobial susceptibility testing was conducted by using the automated VITEK 2 compact system and the matched AST susceptibility test card, complemented by the disk diffusion method. The antimicrobial susceptibility results were interpreted by CLSI. Rates of MDR and XDR in Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa were investigated. Used the chi-square test to determine whether the antimicrobial resistance rates of four major gram-negative bacilli isolated from ICU and non-ICU department have statistical differences.

Results

Escherichia coli (31.4%), Klebsiella spp. (21.2%), Acinetobacter spp. (13.8%), and P. aeruginosa (11.0%) were the most frequently isolated gram-negative bacilli. Escherichia coli was the top one organism isolated from urinary tract (68.4%), bloodstream (39.9%), body fluid (33.2%), wound and pus (37%), except for respiratory tract (8.8%). Whereas Acinetobacter baumannii and K. pneumoniae were the major isolated organisms from respiratory tract. Acinetobacter baumannii showed high resistance to fluoroquinolones, β-lactam/β-lactamase inhibitor combinations class, ceftazidime, cefepime, imipenem, and meropenem, the resistance rates reached more than 70%. Ceftazidime showed a lower resistance rate to E. coli than ceftriaxone. For E. coli, fluoroquinolones showed a high resistance rate (ciprofloxacin 61.36% and levofloxacin 53.97%), whereas amikacin, carbapenems exhibited a lower resistance rate fluctuating at 2%. Acinetobacter baumannii and K. pneumoniae showed rapid increases in carbapenem resistance whereas E. coli had the lowest resistance rate and remain stable at 2%. Acinetobacter baumannii exhibited the highest rate of MDR and XDR, reaching 60-80 and 45-55%, respectively. Compared to non-ICU departments, the resistance rates of four major gram-negative bacilli in the ICU department were much higher and the differences were statistically significant (p < 0.05).

Conclusion

Amikacin, carbapenems, and piperacillin/tazobactam exhibited relatively high sensitivity, whereas fluoroquinolones showed high resistance rate whether they can be the first-line antimicrobials for empirical treatment of UTI should take more consideration. The gram-negative bacilli in ICU were more resistance than that in non-ICU. These findings are helpful for clinicians using antimicrobials reasonably.

Impact of clinical pharmacist's interventions on clinical outcomes in appropriate use of colistin: a prospective pre-post intervention study

This study aims to evaluate the clinical pharmacist's contribution impact on the appropriate use of colistin. Our study was conducted prospectively in patients in the Internal Diseases Intensive Care Unit of Gazi University Medical Faculty Hospital for eight months. The first four months of the study were with the observation group, while the next four months were with the intervention group. The study determined how the active participation of clinical pharmacists had affected the appropriateness of colistin use. The results showed that the appropriate use of colistin was higher in the intervention group than in the observational group; furthermore, incidence of nephrotoxicity was lower. The difference between both groups was statistically significant (p < 0.001, p < 0.05), respectively. This study showed that the clinical pharmacist's active intervention by following the patients increased the frequency and percentage of the appropriate use of colistin. This decreased the incidence of nephrotoxicity, colistin's most important side effect.

Carbapenemase genes distribution in clonal lineages of Acinetobacter baumannii: a comprehensive study on plasmids and chromosomes

Background

The global spread of plasmids carrying carbapenemase genes within carbapenem resistant Acinetobacter baumannii (CRAB) strains poses a worldwide public health issue. In this study, we conducted a comprehensive genetic analysis of plasmids and chromosomes harboring the major carbapenemase genes (bla NDM, bla KPC, bla VIM, bla IMP, bla GES, bla OXA-58-like, bla OXA-24/40-like, bla OXA-143-like, and bla OXA-23-like) in CRAB strains using bioinformatic tools.

Methods

We retrieved plasmids and chromosomes carrying the major carbapenemase genes from GenBank. The size, replicon type, and conjugal apparatus of the plasmids were also determined. Furthermore, allele types, co-existence of other antimicrobial resistance genes alongside carbapenemases in plasmids or chromosomes, co-occurrence of carbapenemase genes, gene repetition, and sequence types (ST) of whole genomes were characterized.

Results

The database contained 113 plasmids and 38 chromosomes harboring carbapenemase genes. This investigation revealed that bla NDM and bla OXA-58-like were the predominant allele types in both the plasmids and chromosomes. Nine (7.96%) plasmids with bla NDM-1 were potentially conjugative. The most common replicon types of the plasmids were R3-T1, R3-T8, R3-T2, R3-T23, and RP-T1. The analysis revealed that bla NDM-1 and bla OXA-58-like genes possessed the highest variety of co-existence with other antibiotic resistance genes. The co-occurrence of dual carbapenemases was identified in 12 plasmids and 19 chromosomes. Carbapenemase gene repetitions were identified in 10 plasmids and one chromosome. Circular alignment revealed that the plasmids carrying the co-occurrence of bla NDM-1 and bla OXA-58 were more homogeneous. However, there was heterogeneity in certain regions of these plasmids. According to the minimum spanning tree (MST) results, the majority of the plasmids belonged to the genomes of ST2Pas, ST1Pas, ST422Pas, ST622Pas, and ST85Pas.

Conclusion

A. baumannii appears to have a strong ability for genome plasticity to incorporate carbapenemase genes on its plasmids and chromosomes to develop resistance against carbapenems. Mobilizable plasmids harboring carbapenemases significantly contribute to the dissemination of these genes. The genetic structure of the plasmids revealed a strong associations of class I integrons, ISAba-like structures, Tn4401 elements, and aac (6')-Ib with carbapenemases. Furthermore, gene repetition may also be associated with carbapenem heteroresistance.

Linezolid dose adjustment according to therapeutic drug monitoring helps reach the goal concentration in severe patients, and the oldest seniors benefit more

BACKGROUND

The elderly with severe infection increased dramatically in intensive care unit (ICU). Proper antimicrobial therapy help improve the prognosis. Linezolid, as an antimicrobial drug, is commonly utilized to treat patients infected with methicillin-resistant S. aureus and vancomycin-resistant enterococci. Clinical evidence suggests elderly patients prone to linezolid overexposure. Here, we describe the results of three years' linezolid adjustment experiences according to therapeutic drug monitoring (TDM), especially in the oldest old.

METHODS

Linezolid therapeutic drug monitoring data were collected between January 2020 and November 2022 from patients who were admitted to ICU and treated with linezolid. All the patients started with a dosage of 600 mg, twice daily. The first TMD was carried out ten minutes before the seventh administration. The dosage adjustment was determined by the doctor according to the first TMD and patients' condition, and the repeated TDM was conducted as required. The dosage adjustment in different age group was recorded. Laboratory data were compared between the old and the oldest old. The high mortality risk of the oldest old was also explored.

RESULTS

Data of 556 linezolid TDM from 330 patients were collected. Among which, 31.6%, 54.8%, and 75% of patients had supra-therapeutic linezolid trough concentrations at the first TDM assessment in different age group, leading to the dosage adjustment rate of 31.0%, 40.3%, 68.8% respectively. The linezolid dosage adjustments according to TDM help to reach therapeutic concentration. The oldest old was in high risk of linezolid overexposure with lowercreatinine clearance. The norepinephrine maximum dosage but not linezolid Cmin was associated with 28-day mortality in the oldest old.

CONCLUSIONS

Elderly patients with linezolid conventional 600 mg twice-daily dose might be at a high risk of overexposure, especially in the oldest old. The linezolid dosage adjustments according to TDM help reach the therapeutic concentration. The high mortality of the oldest old was not related with initial linezolid overexposure.

Combination of AS101 and Mefloquine Inhibits Carbapenem-Resistant Pseudomonas aeruginosa in vitro and in vivo

Background

In recent years, carbapenem-resistant Pseudomonas aeruginosa (CRPA) has spread around the world, leading to a high mortality and close attention of medical community. In this study, we aim to find a new strategy of treatment for CRPA infections.

Methods

Eight strains of CRPA were collected, and PCR detected the multi-locus sequence typing (MLST). The antimicrobial susceptibility test was conducted using the VITEK@2 compact system. The minimum inhibitory concentration (MIC) for AS101 and mefloquine was determined using the broth dilution method. Antibacterial activity was tested in vitro and in vivo through the chessboard assay, time killing assay, and a mouse model. The mechanism of AS101 combined with mefloquine against CRPA was assessed through the biofilm formation inhibition assay, electron microscopy, and detection of reactive oxygen species (ROS).

Results

The results demonstrated that all tested CRPA strains exhibited multidrug resistance. Moreover, our investigation revealed a substantial synergistic antibacterial effect of AS101-mefloquine in vitro. The assay for inhibiting biofilm formation indicated that AS101-mefloquine effectively suppressed the biofilm formation of CRPA-5 and CRPA-6. Furthermore, AS101-mefloquine were observed to disrupt the bacterial cell wall and enhance the permeability of the cell membrane. This effect was achieved by stimulating the production of ROS, which in turn hindered the growth of CRPA-3. To evaluate the therapeutic potential, a murine model of CRPA-3 peritoneal infection was established. Notably, AS101-mefloquine administration resulted in a significant reduction in bacterial load within the liver, kidney, and spleen of mice after 72 hours of treatment.

Conclusion

The present study showed that the combination of AS101 and mefloquine yielded a notable synergistic bacteriostatic effect both in vitro and in vivo, suggesting a potential clinical application of this combination in the treatment of CRPA.

Colistin treatment in older adults: why should we know more?

OBJECTIVES

We aimed to investigate the risk factors of colistin-associated nephrotoxicity in patients older than 65 years treated in the palliative care unit.

METHODS

119 palliative care patients who received intravenous colistimethate for at least 7 days were included in the study. The estimated glomerular filtration rate (GFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) 2021 equation. Data were obtained from the hospital information system.

RESULTS

The mean age of the participants was 76.7 ± 9.9 years and 49.4% were female. Of the 119 patients, 57 had colistin-induced nephropathy (CIN) according to Kidney Disease: Improving Global Outcomes (KDIGO) criteria. The rate of CIN was higher in women than in men. The baseline phosphate level was higher in the CIN (+) group than in the CIN (-) group. The lower GFR values in patients with pneumonia persisted at days 14 and 30, whereas the lower GFR in patients without pneumonia did not. According to multivariate logistic regression, female gender and baseline phosphate level ≥ 4.5 mg/dl were found as independent variables for the development of nephropathy.

CONCLUSIONS

The creatinine levels of the patients with pneumonia and CIN did not improve after nephrotoxicity, whereas the creatinine levels of the other patients without pneumonia and CIN did. Female gender and baseline phosphate were independent risk factors for CIN. Prolonged kidney failure may lead to a more difficult clinical follow-up process for clinicians. Therefore, clinicians should be aware of persistent renal insufficiency in older patients with pneumonia receiving colistimethate.

Population Pharmacokinetic Analysis of Vancomycin in Patients with Solid or Hematological Malignancy in Relation to the Quick Sequential Organ Failure Assessment Scores

BACKGROUND AND OBJECTIVE

It remains unclear whether sepsis in patients with malignancy interferes with the predictive performance of the dose-estimation formulas. The quick sequential organ failure assessment (qSOFA) score can help identify patients with poor outcomes because of sepsis-associated organ damage. Vancomycin, an important antibiotic, treats systemic infections (sepsis) caused by methicillin-resistant Staphylococcus aureus. We aimed to clarify whether including the qSOFA score in a standard population pharmacokinetic (PopPK) assessment may improve the predictive performance of vancomycin doses in patients with malignancy.

METHODS

This was a retrospective, observational study. Serum vancomycin concentration-time datasets were obtained from the therapeutic drug monitoring records of St. Luke's International Hospital (Tokyo, Japan) from January 2011 to August 2016. Clinical and laboratory data of the relevant patients were retrieved from electronic health records. PopPK analysis was performed using the NONMEM program, which includes creatinine clearance (CLCr), blood neutrophil counts, qSOFA scores, and type of malignancy as covariates. We examined the validity of the final PopPK model using bootstrapping, goodness-of-fit plots, and prediction-corrected visual predictive checks.

RESULTS

Six hundred and eight blood samples were obtained from 325 patients. In the final PopPK model, the CLCr and qSOFA scores were selected as covariates of systemic vancomycin clearance (p < 0.05): the population mean value was 2.8 (L/h). Regardless of the CLCr, a qSOFA score of greater than 1 was associated with an approximately 10% reduction in vancomycin clearance.

CONCLUSIONS

qSOFA scores might be an additional covariate to CLCr for estimating vancomycin concentrations with a PopPK model in patients with malignancy.

Ceftazidime/avibactam combined with colistin: a novel attempt to treat carbapenem-resistant Gram-negative bacilli infection

BACKGROUND

The rapid global emergence and spread of carbapenem-resistant Gram-negative bacilli (CR-GNB) is recognized as a major public health concern, and there are currently few effective treatments for CR-GNB infection. The aim of this study was to investigate the clinical characteristics and outcomes of patients with CR-GNB infections treated with ceftazidime/avibactam (CAZ/AVI) combined with colistin from October 2019 to February 2023 in China.

METHODS

A total of 31 patients with CR-GNB infections were retrospectively identified using the electronic medical record system of Zhejiang Provincial People's Hospital.

RESULTS

Thirty-one patients were treated with CAZ/AVI combined with colistin. Respiratory tract infections (87%) were most common. The common drug-resistant bacteria encompass Klebsiella pneumonia (54.8%), Acinetobacter baumannii (29.0%), and Pseudomonas aeruginosa (16.1%). The 30-day mortality rate was 29.0%, and the 7-day microbial clearance rate was 64.5%. The inflammatory marker CRP changes, but not PCT and WBC, were statistically significant on days 7 and 14 after combination therapy. There were seven patients developing acute renal injury (AKI) after combination therapy and treating with continuous renal replacement therapy (CRRT). Two patients developed diarrhea.

CONCLUSION

The combination of CAZ/AVI and colistin has potential efficacy in patients with CR-GNB infection, but more studies are needed to determine whether it can reduce 30-day mortality rates and increase 7-day microbial clearance. At the same time, the adverse reactions of combination therapy should not be ignored.

Emergence of ST1193 Clone in Maternal and Neonatal ESBL-Producing E. coli Isolates

Objective

The emerging epidemic of extended-spectrum β-lactamase-producing E. coli (ESBL-EC) is a global public health crisis. ESBL-EC infections are increasing worldwide and contribute to morbidity and mortality among newborn infants. However, the antimicrobial resistance characteristics and clonal transmission of maternal and neonatal ESBL-EC isolates need to be further deciphered.

Materials and Methods

We performed phenotypic and genotypic characterization of 33 ESBL-EC isolates from pregnant women and newborn during 2019-2020.

Results

Minimum inhibitory concentrations of 17 antimicrobial agents showed that all isolates were multidrug-resistant (MDR) and had a resistance rate of 100% to ampicillin, and mild resistance to florfenicol, gentamicin, ceftazidime, and amoxicillin-clavulanate. Additionally, imipenem, meropenem, polymyxin, and tigecycline exhibited good activity against the tested ESBL-EC isolates with low MIC50 (0.06-1 μg/mL) and MIC90 (0.06-1 μg/mL). Whole genome sequencing indicated that ESBL-EC isolates contained diverse antimicrobial resistant genes (blaCTX-M, blaTEM, blaSHV, tetA, etc.) and toxin genes (ompA, csg, fimH, hybtA, etc.). blaCTX-M genes were the main ESBL genotype. ST1193 (18.2%) was the second most abundant ST among the ESBL-EC isolates (ST131 was the most common, with 30.3%), and this is the first report of its mother-to-infant colonization transmission in China.

Conclusion

These findings revealed the occurrence of high-risk ST1193 clone among ESBL-EC isolates from pregnant women and newborn colonization in China. Further national or regional multicenter studies are needed to assess the dissemination and evolution of ESBL-EC ST1193 clone as a nosocomial pathogen in China.

Carbapenem-Resistant Acinetobacter baumannii Bloodstream Infection in a Ghanaian Patient with Unilateral Diaphragmatic Eventration and HIV Type 1 Infection

Carbapenem-resistant Acinetobacter baumannii infection is a critically prioritized pathogen by the World Health Organization and a cause for growing concern due to increased mortality among hospitalised patients. Phrenic nerve palsy is a rare complication of herpes zoster infection of the C3, C4, and C5 nerve roots. We present a case of bloodstream carbapenem-resistant A. baumannii infection in a Ghanaian patient with HIV type 1 infection and multiple risk factors, including unilateral diaphragmatic eventration with compression atelectasis likely secondary to phrenic nerve palsy due to herpes zoster infection, consequently leading to recurrent hospital and ICU admission. In this case, we emphasize the need for clinicians in LMICs to be aware of CRAB, in order to advocate for the availability of evidence-based medicines in resource-limited settings for appropriate treatment. In addition, we illustrate the importance of a high index of suspicion for infection with carbapenem-resistant organisms such as A. baumannii and highlight a rare and severe complication of herpes zoster infection in the form of phrenic nerve palsy and consequent diaphragmatic eventration.

Use of a common spreadsheet program to demonstrate the ability of Bayesian forecasting to estimate the pharmacokinetic parameters of antibiotics

OBJECTIVES

Recent guidelines for vancomycin have incorporated the use of Bayesian forecasting, reinforcing the need to inform students in pharmacy and clinical pharmacology of its use in therapeutic drug monitoring. The goal was to devise a PharmD research project that could demonstrate to students through simulation and data generation the utility of the Bayesian approach in estimating the pharmacokinetics of gentamicin and vancomycin.

METHODS

A series of steps were devised using Microsoft Excel to simulate patient data based on study-derived means and variances, pharmacokinetic modelling, random selection of sparse blood samples, introduce random error into the selected concentrations based on assay variability measure, and finally, inputting of the information into an add-in computer program to find the pharmacokinetic estimates using Bayesian forecasting.

KEY FINDINGS

Excellent correlations were seen between Bayesian estimates and true clearances. Lower assay variability tended to provide better estimates than larger assay variability for gentamicin, and for vancomycin, selecting a sample during the distribution phase and near the trough values tended to provide estimates with less bias and greater precision.

CONCLUSIONS

The approach used was able to demonstrate all aspects involved in Bayesian forecasting, and the results supported its use for these antibiotics.

Association between vancomycin therapeutic drug monitoring and clinical outcomes in treating neonatal sepsis

BACKGROUND

Neonatal sepsis is commonly treated with vancomycin in the neonatal intensive care unit. Therapeutic drug monitoring of vancomycin is routinely used to personalise dosing to optimise effectiveness and avoid toxicity.

OBJECTIVES

This study aimed to define a target range by evaluating associations between vancomycin trough concentrations or area under the concentration time curve over 24 hours (AUC24h) and clinical outcomes in neonates.

METHODS

Neonates, who were admitted to the neonatal intensive care unit and received intravenous vancomycin, were included in this retrospective cohort study. For evaluating effectiveness, patients who received vancomycin for < 5 days were excluded. The AUC24h was estimated based on a study-derived population pharmacokinetic model. Primary outcomes were persistent/recurrent infections and mortality within 30 days. Secondary outcomes, including acute kidney injury (AKI), were also assessed. Logistic regression and classification and regression tree analyses were performed.

RESULTS

A total of 448 patients (123 patients for effectiveness analysis) were included. A vancomycin trough > 10 mg/L was associated with 70% lower odds of persistent/recurrent infections (adjusted OR 0.30, 95% CI 0.09-0.86; P = 0.023). Patients who took more than a day to reach target range had 1.4 times higher odds of persistent/recurrent infections or death (P = 0.04). A vancomycin trough > 15 mg/L was associated with a three times higher risk of AKI (P = 0.003). An AUC24h of 420-650 mg*h/L was also associated with the lowest risk of composite outcomes (adjusted OR 0.29, 95% CI 0.08-0.86; P = 0.025).

CONCLUSION

A vancomycin trough target range of 10-15 mg/L and achievement of this target within a day of treatment initiation were associated with the most optimal clinical outcomes in treating neonatal sepsis.

Risk predict model using multi-drug resistant organism infection from Neuro-ICU patients: a retrospective cohort study

The aim of this study was to analyze the current situation and risk factors of multi-drug-resistant organism (MDRO) infection in Neuro-intensive care unit (ICU) patients, and to develop the risk predict model. The data was collected from the patients discharged from Neuro-ICU of grade-A tertiary hospital at Guizhou province from January 2018 to April 2020. Binary Logistics regression was used to analyze the data. The model was examined by receiver operating characteristic curve (ROC). The grouped data was used to verify the sensitivity and specificity of the model. A total of 297 patients were included, 131 patients infected with MDRO. The infection rate was 44.11%. The results of binary Logistics regression showed that tracheal intubation, artery blood pressure monitoring, fever, antibiotics, pneumonia were independent risk factors for MDRO infection in Neuro-ICU (P < 0.05), AUC = 0.887. The sensitivity and specificity of ROC curve was 86.3% and 76.9%. The risk prediction model had a good predictive effect on the risk of MDRO infection in Neuro ICU, which can evaluate the risk and provide reference for preventive treatment and nursing intervention.

Antimicrobial Resistance Patterns of Staphylococcus aureus and Enterococcus Species at the Ethiopian Public Health Institute, Ethiopia: A Five-Year Retrospective Analysis

Purpose

The study aimed to investigate the antimicrobial resistance patterns of Staphylococcus aureus and Enterococcus species isolated from clinical specimens over a period of five years, including resistance to methicillin and vancomycin.

Patients and Methods

Bacterial identification and antimicrobial susceptibility testing reports from 2017 to 2021 at the Ethiopian Public Health Institute were used for this retrospective study. The organisms were identified using either BD Phoenix M50, Vitek 2 compact, or conventional biochemical methods, whichever was available at the time of testing. The antimicrobial susceptibility profiles of the isolates were determined using either Kirby-Bauer disc diffusion, BD phoenix M50, or Vitek 2 compact. WHONET software was used to analyze the antimicrobial resistance patterns of both organisms. The p-values of ≤0.05 were considered statistically significant.

Results

During the study period, a total of 315 Staphylococcus aureus and 92 Enterococcus species were isolated. Out of 315 Staphylococcus aureus isolates, 27% and 5.1% were methicillin and vancomycin resistant, respectively. Staphylococcus aureus showed very high resistance to Penicillin G (86.7%). Out of 92 Enterococcus species recovered, 8.7% were vancomycin-resistant. Enterococcus species showed very high resistance to Penicillin G (71.4%) and tetracyclines (83.3%). Methicillin-resistant Staphylococcus aureus shows 100% resistance to penicillin followed by ciprofloxacin (50%), erythromycin (45.6%), and tetracycline (44.2%) and lower resistance to vancomycin (18.8%). All vancomycin-resistant isolates of both organisms were fully resistant (100%) to all antibiotics tested, except for linezolid and daptomycin, to which they were susceptible.

Conclusion

This study found a high prevalence of methicillin and vancomycin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus species between 2017 and 2021. However, there were no statistically significant changes in the prevalence of these organisms during the study period. This suggests that larger and more representative nationwide data is needed to show trends of these pathogens.

In vitro Activity of Cefepime/Avibactam Against Carbapenem Resistant Klebsiella pneumoniae and Integrative Metabolomics-Proteomics Approach for Resistance Mechanism: A Single-Center Study

Purpose

We aimed to evaluate the in vitro antibacterial effects of combination of cefepime/avibactam against carbapenem-resistant Klebsiella pneumonia (CRKP) and explore the resistance mechanism of FEP/AVI.

Patients and Methods

This study explored the in vitro antibacterial activities of ceftazidime/avibactam (CAZ/AVI) and cefepime/avibactam (FEP/AVI) against 40 and 76 CRKP clinical isolates. Proteomics and metabolomics were employed to investigate the resistance mechanisms of CRKP to FEP/AVI.

Results

FEP/AVI (MIC50/MIC90 0.5/4-64/4 μg/mL, resistance rate 17.1%) showed better antibacterial activity against CRKP than CAZ/AVI (MIC50/MIC90 4/4-128/4 μg/mL, resistance rate 20%) in vitro. Bioinformatics analysis showed that the differentially expressed proteins (DEPs) were enriched in alanine, aspartate and glutamate metabolism, and ribosome. Remarkably, transcriptional and translational activity-related pathways were inhibited in FEP/AVI resistant CRKP. Overlap analysis suggested that H-NS might play an important role in resistance to FEP/AVI in CRKP. The mRNA levels of DEPs-related genes (adhE, gltB, purA, ftsI and hns) showed the same trends as DEPs in FEP/AVI susceptible and resistant strains. FEP/AVI resistant isolates demonstrated stronger biofilm formation capacity than susceptible isolates. Metabolomics results showed that disturbed metabolites were mainly lipids, and adenine was decreased in FEP/AVI resistant CRKP.

Conclusion

These results indicated that H-NS, GltB and SpoT may directly or indirectly promote biofilm formation of CRKP and led to FEP/AVI resistance, but inhibited ribosomal function. Our study provides a mechanistic insight into the acquisition of resistance to FEP/AVI in Klebsiella pneumoniae.

Antibiotic-Resistant ESKAPE Pathogens and COVID-19: The Pandemic beyond the Pandemic

Antibacterial resistance is a renewed public health plague in modern times, and the COVID-19 pandemic has rekindled this problem. Changes in antibiotic prescribing behavior, misinformation, financial hardship, environmental impact, and governance gaps have generally enhanced the misuse and improper access to antibiotics during the COVID-19 pandemic. These determinants, intersected with antibacterial resistance in the current pandemic, may amplify the potential for a future antibacterial resistance pandemic. The occurrence of infections with multidrug-resistant (MDR), extensively drug-resistant (XDR), difficult-to-treat drug-resistant (DTR), carbapenem-resistant (CR), and pan-drug-resistant (PDR) bacteria is still increasing. The aim of this review is to highlight the state of the art of antibacterial resistance worldwide, focusing on the most important pathogens, namely Enterobacterales, Acinetobacter baumannii, and Klebsiella pneumoniae, and their resistance to the most common antibiotics.

Comparative Genomics Identified PenR E151V Substitution Associated with Carbapenem-Resistance Burkholderia cepacia Complex and a Novel Burkholderia cepacia Complex Specific OXA-1043 Subgroup

Purpose

Burkholderia cepacia complex (Bcc) is a known significant opportunistic pathogen causing morbidity and mortality, particularly in those with cystic fibrosis, chronic granulomatous disease, or immunocompromising host. Mortality of Bcc bloodstream infections among non-cystic fibrosis patients remained high. The antibiotic treatment for Bcc infection is quite challenging due to its intrinsic resistance to most antibiotics, and the resistance to carbapenems was the biggest concern among them. We aimed to realize the mechanism of carbapenem resistance in Bcc.

Patients and Methods

Ten strains of Bcc were identified by the MALDI-TOF MS, and the drug susceptibility test was using VITEK 2 system. The Burkholderia cepacia complex genomes were sequenced via Nanopore GridIon. We also downloaded another ninety-five strains of Bcc from the National Center for Biotechnology Information database to evaluate the divergence between carbapenem-resistance and carbapenem-sensitive strains.

Results

The genetic organization between carbapenem-sensitive and carbapenem-resistant strains of Bcc showed no difference. However, in the carbapenem-sensitive strain, E151V substitution in PenR was detected. In addition, a novel specific OXA family subgroup, blaOXA-1043 in Burkholderia cenocepacia was discovered.

Conclusion

The E151V substitution in PenR may be associated with carbapenem-sensitive in Bcc. Moreover, the V151E mutation in PenR may be related to the activation of PenB, leading to Bcc resistance to carbapenems. Besides, a novel OXA family subgroup, blaOXA-1043, was found in Burkholderia cenocepacia, which differs from the previous OXA family.