Clinical Feature, Therapy, Antimicrobial Resistance Gene Distribution, and Outcome of Nosocomial Meningitis Induced by Multidrug-Resistant Enterobacteriaceae-A Longitudinal Cohort Study From Two Neurosurgical Centers in Northern China

Insights into biofilm-mediated mechanisms driving last-resort antibiotic resistance in clinical ESKAPE pathogens

The rise of antibiotic-resistant bacteria poses a grave threat to global health, with the ESKAPE pathogens, which comprise Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp. being among the most notorious. The World Health Organization has reserved a group of last-resort antibiotics for treating multidrug-resistant bacterial infections, including those caused by ESKAPE pathogens. This situation calls for a comprehensive understanding of the resistance mechanisms as it threatens public health and hinder progress toward the Sustainable Development Goal (SDG) 3: Good Health and Well-being. The present article reviews resistance mechanisms, focusing on emerging resistance mutations in multidrug-resistant ESKAPE pathogens, particularly against last-resort antibiotics, and describes the role of biofilm formation in multidrug-resistant ESKAPE pathogens. It discusses the latest therapeutic advances, including the use of antimicrobial peptides and CRISPR-Cas systems, and the modulation of quorum sensing and iron homeostasis, which offer promising strategies for countering resistance. The integration of CRISPR-based tools and biofilm-targeted approaches provides a potential framework for managing ESKAPE infections. By highlighting the spread of current resistance mutations and biofilm-targeted approaches, the review aims to contribute significantly to advancing our understanding and strategies in combatting this pressing global health challenge.

Diagnostic, monitoring, and prognostic value of combined detection of cerebrospinal fluid heparin-binding protein, interleukin-6, interleukin-10, and procalcitonin for post-neurosurgical intracranial infection

OBJECTIVE

Intracranial infection is a common complication after neurosurgery and can increase the length of hospital stay, affect patient prognosis, and increase mortality. We aimed to investigate the value of the combined detection of cerebrospinal fluid (CSF) heparin-binding protein (HBP), interleukin-6 (IL-6), interleukin-10 (IL-10), and procalcitonin (PCT) for post-neurosurgical intracranial infection.

METHODS

This study assessed the diagnostic values of CSF HBP, IL-6, IL-10, PCT levels, and combined assays for post-neurosurgical intracranial infection with the area under the receiver operating characteristic (ROC) curve by retrospectively analysing biomarkers of post-neurosurgical patients.

RESULTS

The CSF HBP, IL-6, IL-10, and PCT levels were significantly higher in the infected group than the uninfected group and the control group (P < 0.001). The indicators in the groups with severe intracranial infections were significantly higher than those in the groups with mild intracranial infections (P < 0.001), and the groups with poor prognoses had significantly higher indexes than the groups with good prognoses. According to the ROC curve display, the AUC values of CSF HBP, IL-6, IL-10, and PCT were 0.977 (95 % CI 0.952-1.000), 0.973 (95 % CI 0.949-0.998), 0.884 (95 % CI 0.823-0.946), and 0.819 (95 % CI 0.733-0.904), respectively. The AUC of the combined test was 0.996 (95 % CI 0.989-1.000), which was higher than those of the four indicators alone.

CONCLUSION

The combined detection can be an important indicator for the diagnosis and disease monitoring of post-neurosurgical intracranial infection.

Clinical distribution of carbapenem genotypes and resistance to ceftazidime-avibactam in Enterobacteriaceae bacteria

Introduction

Bacterial resistance is a major threat to public health worldwide. To gain an understanding of the clinical infection distribution, drug resistance information, and genotype of CRE in Dongguan, China, as well as the resistance of relevant genotypes to CAZ-AVI, this research aims to improve drug resistance monitoring information in Dongguan and provide a reliable basis for the clinical control and treatment of CRE infection.

Methods

VITEK-2 Compact automatic analyzer was utilized to identify 516 strains of CRE collected from January 2017 to June 2023. To determine drug sensitivity, the K-B method, E-test, and MIC methods were used. From June 2022 to June 2023, 80 CRE strains were selected, and GeneXpert Carba-R was used to detect and identify the genotype of the carbapenemase present in the collected CRE strains. An in-depth analysis was conducted on the CAZ-AVI in vitro drug sensitivity activity of various genotypes of CRE, and the results were statistically evaluated using SPSS 23.0 and WHONET 5.6 software.

Results

This study identified 516 CRE strains, with the majority (70.16%) being K.pneumoniae, followed by E.coli (18.99%). Respiratory specimens had highest detection rate with 53.77% identified, whereas urine specimens had the second highest detection rate with 17.99%. From June 2022 to June 2023, 95% of the strains tested using the CRE GeneXpert Carba-R assay possessed carbapenemase genes, of which 32.5% were blaNDM strains and 61.25% blaKPC strains. The results showed that CRE strains containing blaKPC had a significantly higher rate of resistance to amikacin, cefepime, and aztreonam than those harboring blaNDM.

Conclusions

The CRE strains isolated from Dongguan region demonstrated a high resistance rate to various antibiotics used in clinical practice but a low resistance rate to tigecycline. These strains produce Class A serine carbapenemases and Class B metals β-lactamases, with the majority of them carrying blaNDM and blaKPC. Notably, CRE strains with blaKPC and blaNDM had significantly lower resistance rates to tigecycline. CAZ-AVI showed a good sensitivity rate with no resistance to CRE strains carrying blaKPC. Therefore, CAZ-AVI and tigecycline should be used as a guide for rational use of antibiotics in clinical practice to effectively treat CRE.

Effect of antibiotic prophylaxis in the prognosis of Post-neurosurgical meningitis patients

AIMS

To evaluate the effect of antibiotic prophylaxis(AP) in the prognosis of Post-neurosurgical meningitis(PNM) patients.

METHODS

A cohort analysis was performed using the clinical database in Beijing Tiantan Hospital and Capital Medical University. Data were collected on patients with the diagnosis of PNM (n = 3931) during 2012.01 to 2022.04. The microbial distribution, types of AP, and 42 and 90 days survival analysis of AP patients were evaluated using probable statistical methods. Independent risk factors for mortality were established by constructing a logistic regression analysis.

RESULT

A total of 1,190 patients were included in this study, Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus occupied the highest proportion. Of them, 929 cases received AP, cefuroxime and ceftriaxone are the most frequent used antibiotics. In addition, We found that PNM patients without AP significantly increased the 42 days and 90 days all-cause mortality rates. The use of different levels of AP did not improve patient outcomes, and ICU admission and assisted mechanical ventilation (AMV) were identified as independent mortality risk factors for PNM patient received AP.

CONCLUSIONS

AP plays an important role in the prognosis of PNM patients and has a significant function in improving prognosis. The prevention of PNM with antibiotics prior to neurosurgery should be emphasized in clinical practice, and appropriate selection of antibiotics is necessary to prevent the occurrence of infection and inhibit the emergence of antibiotic-resistant bacteria.

Clinical presentations and microbiological analysis of cerebrospinal fluid samples in cases of suspected bacterial meningitis patients attending a 1600 bedded teaching hospital from 2019 to 2022: A retrospective study

Background

Meningitis can be attributed to bacterial, fungal, or viral agents. In this study, we demonstrate the common bacterial agents causing meningitis along with their antibiotics susceptibility pattern in patients of all age groups.

Material and Methods

This retrospective, observational study was carried out in the Department of Microbiology with cerebrospinal fluid (CSF) samples collected from November 2019 to May 2022. We collected 1986 nonrepeat CSF samples from clinically suspected patients of bacterial meningitis, and clinical information about the patients was extracted from the hospital information system.

Results

Out of the 1986 CSF samples included in our study, 150 (7.55%) were found to be positive on bacterial culture. Most of our patients were in the age group of 0-20 years. Common clinical manifestations observed in our patients were: high-grade fever, 87 patients (58%); severe headache, 126 patients (84%); neck rigidity, 47 patients (31.3%); altered mental status, 76 patients (50.7%) and photophobia, 83 patients (55.3%). The most commonly isolated bacteria was Acinetobacter species (30%). The mean length of hospitalization (37.76 ± 25.30), the mean total cell count, high levels of protein (mg/dl) and low levels of glucose (mg/dl) of CSF were statistically significant in meningitis caused by multidrug-resistant bacteria.

Conclusion

We recognized the spectrum of pathogens causing meningitis at our center along with the antibiotic resistance pattern to guide and facilitate early treatment by primary health care professionals and family medicine practitioners.

Clinical Experience with Off-Label Intrathecal Administration of Selected Antibiotics in Adults: An Overview with Pharmacometric Considerations

Drain-associated intracerebral infections are life-threatening emergencies. Their treatment is challenging due to the limited penetration of antibiotics to the site of infection, resulting in potentially inadequate exposure. The emergence of multidrug-resistant pathogens might force the use of off-label intrathecal (IT) doses of antibiotics. We reviewed the literature on general aspects determining intrathecal dosing regimen, using pharmacometric knowledge. We summarised clinical experience with IT doses of antibiotics that are usually not used intrathecally, as well as the outcome of the cases and concentrations reached in the cerebrospinal fluid (CSF). Factors determining the IT regimen are the size of the ventricle system and the CSF drainage volume. With regard to pharmacometrics, pharmacokinetic/pharmacodynamic indices are likely similar to those in non-cerebral infections. The following number (N) of cases were described: benzylpenicillin (>50), ampicillin (1), ceftazidime (2), cephaloridine (56), ceftriaxone (1), cefotiam (1), meropenem (57), linezolid (1), tigecycline (15), rifampicin (3), levofloxacin (2), chloramphenicol (3) and daptomycin (8). Many side effects were reported for benzylpenicillin in the 1940-50s, but for the other antibiotics, when administered correctly, all side effects were minor and reversible. These data might help when choosing an IT dosing regimen in case there is no alternative option due to antimicrobial resistance.

Development and Validation of a Nomograph Model for Post-Operative Central Nervous System Infection after Craniocerebral Surgery

PURPOSE

A nomograph model of predicting the risk of post-operative central nervous system infection (PCNSI) after craniocerebral surgery was established and validated.

METHODS

The clinical medical records of patients after cranial surgery in Renmin Hospital of Wuhan University from January 2020 to September 2022 were collected, of whom 998 patients admitted to Shouyi Hospital District were used as the training set and 866 patients admitted to Guanggu Hospital District were used as the validation set. Lasso regression was applied to screen the independent variables in the training set, and the model was externally validated in the validation set.

RESULTS

A total of 1864 patients after craniocerebral surgery were included in this study, of whom 219 (11.75%) had PCNSI. Multivariate logistic regression analysis showed that age > 70 years, a previous history of diabetes, emergency operation, an operation time ≥ 4 h, insertion of a lumbar cistern drainage tube ≥ 72 h, insertion of an intracranial drainage tube ≥ 72 h, intraoperative blood loss ≥ 400 mL, complicated with shock, postoperative albumin ≤ 30 g/L, and an ICU length of stay ≥ 3 days were independent risk factors for PCNSI. The area under the curve (AUC) of the training set was 0.816 (95% confidence interval (95%CI), 0.773-0.859, and the AUC of the validation set was 0.760 (95%CI, 0.715-0.805). The calibration curves of the training set and the validation set showed p-values of 0.439 and 0.561, respectively, with the Hosmer-Lemeshow test. The analysis of the clinical decision curve showed that the nomograph model had high clinical application value.

CONCLUSION

The nomograph model constructed in this study to predict the risk of PCNSI after craniocerebral surgery has a good predictive ability.

Treatment of Ventriculitis and Meningitis After Neurosurgery Caused by Carbapenem-Resistant Enterobacteriaceae (CRE): A Challenging Topic

Post-neurosurgical infection is a common complication of neurosurgery, and serious infection can threaten the life of patients. In recent years, the increase in multidrug-resistant bacteria, especially carbapenem-resistant Enterobacteriaceae (CRE), has proved fatal to patients. Although there are a few cases of CRE meningitis and few clinical trials have been carried out, it has attracted increasing attention with the increasing probability of its occurrence, especially considering that there are few successful cases. An increasing number of studies are also looking for the risk factors and clinical symptoms of CRE intracranial infection. In terms of treatment, some new antibiotics are gradually being used in the clinic, but due to the complicated drug-resistant mechanism of CRE and the obstruction of the blood‒brain barrier (BBB), the therapeutic effect is still very poor. In addition, obstructive hydrocephalus and brain abscess caused by CRE meningitis are still important causes of patient death and are also difficult to treat.

Mechanical filtration of the cerebrospinal fluid: procedures, systems, and applications

INTRODUCTION

Mechanical methods aimed at the filtration of the cerebrospinal fluid (CSF) are a group of therapies that have been proposed to treat neurological conditions where pathogens are present in the CSF. Even though the industry of medical devices has not been very active in this field, there is a lack of systematization of the different systems and procedures that can be applied.

AREAS COVERED

First, we systematize the classification and definitions of procedures and systems for mechanical filtration of the CSF. Then, we made a literature review in search of clinical or preclinical studies where any system of mechanical CSF clearance was proposed or applied.

EXPERT OPINION

We found mechanical filtration of the CSF has been explored in subarachnoid hemorrhage, CNS infections (bacterial, viral, and fungal), meningeal carcinomatosis, multiple sclerosis, autoimmune encephalitis, and polyradiculomyelitis. Brain aging and neurodegenerative diseases are additional potential conditions of interest. While there is some preliminary positive evidence for many of these conditions, more advanced systems, detailed descriptions of procedures, and rigorous validations are needed to make these therapies a reality in the next decades.

The application of targeted nanopore sequencing for the identification of pathogens and resistance genes in lower respiratory tract infections

Objectives

Lower respiratory tract infections (LRTIs) are one of the causes of mortality among infectious diseases. Microbial cultures commonly used in clinical practice are time-consuming, have poor sensitivity to unculturable and polymicrobial patterns, and are inadequate to guide timely and accurate antibiotic therapy. We investigated the feasibility of targeted nanopore sequencing (TNPseq) for the identification of pathogen and antimicrobial resistance (AMR) genes across suspected patients with LRTIs. TNPseq is a novel approach, which was improved based on nanopore sequencing for the identification of bacterial and fungal infections of clinical relevance.

Methods

This prospective study recruited 146 patients suspected of having LRTIs and with a median age of 61 years. The potential pathogens in these patients were detected by both TNPseq and the traditional culture workups. We compared the performance between the two methods among 146 LRTIs-related specimens. AMR genes were also detected by TNPseq to prompt the proper utilization of antibiotics.

Results

At least one pathogen was detected in 133 (91.1%) samples by TNPseq, but only 37 (25.3%) samples contained positive isolates among 146 cultured specimens. TNPseq possessed higher sensitivity than the conventional culture method (91.1 vs. 25.3%, P < 0.001) in identifying pathogens. It detected more samples with bacterial infections (P < 0.001) and mixed infections (P < 0.001) compared with the clinical culture tests. The most frequent AMR gene identified by TNPseq was bla _TEM (n = 29), followed by bla _SHV (n = 4), bla _KPC (n = 2), bla _CTX-M (n = 2), and mecA (n = 2). Furthermore, TNPseq discovered five possible multi-drug resistance specimens.

Conclusion

TNPseq is efficient to identify pathogens early, thus assisting physicians to conduct timely and precise treatment for patients with suspected LRTIs.

Mortality Risk Factors and Prognostic Analysis of Patients with Multi-Drug Resistant Enterobacterales Infection

Background

The data from the China Network Antibacterial Surveillance Center (http://www.chinets.com) showed that the prevalence of Escherichia coli (E. coli), Klebsiella pneumoniae (KP), and Enterobacter cloacae (ecl), was 18.96%, 14.12%, and 2.74% in 2022, respectively. The resistance rates of E. coli and KP to 3rd or 4th generation cephalosporins were 51.7% and 22.1%, to carbapenems was 1.7% and 3.9%, to quinolones was 55.9% in Shanxi. The generation of extended-spectrum beta-lactamases (ESBLs) is a major mechanism resulting in drug resistance in Enterobacterales. To determine the mortality risk factors of multi-drug resistant Enterobacterales (MDRE) and multi-drug resistant Klebsiella pneumoniae (MDR-KP) infection.

Methods

91 MDR strains from 91 patients were collected from 2015 to 2019 in the second hospital of Shanxi Medical University. The mortality risk factors for the MDRE infections and clinical outcomes were analyzed by univariable and multivariable analysis. The independent predictors of 30-day mortality were analyzed through the Cox regression analysis including the variables with a value <0.2.

Results

The majority of patients were admitted to ICUs. Pulmonary infection was a major infection (43.96%, 40/91). Thirty-three (36.26%, 33/91) strains of MDR-KP were only detected in 2018. The proportion of multi-drug resistant Escherichia coli (MDR E. coli) and multi-drug resistant Enterobacter cloacae (MDR ecl) were 16.48% (15/91) and 17.58% (16/91), respectively. The presence of cerebrovascular diseases (OR, 4.046; 95%Cl, 1.434–11.418; P=0.008) and central venous catheterization (OR, 4.543; 95%Cl, 1.338–15.425; P=0.015) were associated with mortality in patients with MDRE infections. Endotracheal intubation (OR, 4.654; 95%Cl, 1.5–14.438; P=0.008) was an independent mortality risk factor for patients infected with MDR-KP strains. Patients who received aminoglycoside antibiotics (P=0.057) had a higher 30-day survival rate. The β-lactam antibiotics were the major agent in the clinic.

Conclusion

This study implies that patients with cerebrovascular diseases, central venous catheterization, and endotracheal intubation are at risk of carrying MDR isolates.