Sequential intraventricular injection of tigecycline and polymyxin B in the treatment of intracranial Acinetobacter baumannii infection after trauma: a case report and review of the literature

Comparison of two minimally invasive surgical approaches for hypertensive intracerebral hemorrhage: a study based on postoperative intracranial pressure parameters

BACKGROUND

Increased intracranial pressure (ICP) in patients with hypertensive intracerebral hemorrhage (HICH) has been associated with poor prognosis. The transsylvian insular approach (TIA) and the transcortical (TCA) approach are applied for patients with HICH. We aimed to compare the postoperative ICP parameters of TIA and TCA to identify which procedure yields better short-term outcomes in patients with basal ganglia hematoma volumes ranging from 30 to 50 mL.

METHODS

Eighty patients with basal ganglia hematomas 30-50 mL were enrolled in this study. Patients were implanted with ICP probes and divided into TIA and TCA groups according to the procedure. The ICP values were continuously recorded for five days at four-hour intervals. Short-term outcomes were evaluated using the length of hospitalization and postoperative consciousness recovery time.

RESULTS

No statistically significant differences were found in age, sex, GCS score at admission, hematoma volume, and hematoma clearance rate (p > 0.05). The results showed that postoperative initial ICP, ICP on the first postoperative day, mean ICP, DICP20 mmHg × 4 h, postoperative consciousness recovery time, the length of hospitalization, mannitol utilization rate and the mannitol dosage were lower in the TIA group than in the TCA group (p < 0.05). Postoperative consciousness recovery time was positively correlated with ICP on the first postoperative day, and the length of hospitalization was positively correlated with mean ICP.

CONCLUSIONS

TIA is more effective than TCA in improving the short-term outcomes of patients with basal ganglia hematoma volumes ranging from 30 to 50 mL according to comparisons of postoperative ICP parameters.

Intrathecal tigecycline is a safe and effective treatment for central nervous system infections

Both the safety and effectiveness of intrathecal tigecycline (TGC) for treatment of infections of the central nervous system (CNS) are discussed using the clinical findings from a study of a recent patient who came to our attention, along with a literature review. Although penetration into the CNS is low (approximately 11%), intraventricular TGC could help treat patients with severe post- neurosurgical CNS infections. The use of multiple routes of TGC administration appears to be encouraging and should be considered in managing life-threatening intraventricular infections.

The Blood-Brain Barrier and Pharmacokinetic/Pharmacodynamic Optimization of Antibiotics for the Treatment of Central Nervous System Infections in Adults

Bacterial central nervous system (CNS) infections are serious and carry significant morbidity and mortality. They encompass many syndromes, the most common being meningitis, which may occur spontaneously or as a consequence of neurosurgical procedures. Many classes of antimicrobials are in clinical use for therapy of CNS infections, some with established roles and indications, others with experimental reporting based on case studies or small series. This review delves into the specifics of the commonly utilized antibacterial agents, updating their therapeutic use in CNS infections from the pharmacokinetic and pharmacodynamic perspectives, with a focus on the optimization of dosing and route of administration that have been described to achieve good clinical outcomes. We also provide a concise synopsis regarding the most focused, clinically relevant information as pertains to each class and subclass of antimicrobial therapeutics. CNS infection morbidity and mortality remain high, and aggressive management is critical in ensuring favorable patient outcomes while averting toxicity and upholding patient safety.

Intrathecal or Intraventricular Tigecycline Therapy for Central Nervous System Infection Associated with Carbapenem-Resistant Klebsiella pneumoniae

PURPOSE

Infection with carbapenem-resistant Klebsiella pneumoniae (CRKP) is a great challenge. Central nervous system (CNS) infection caused by CRKP is rarely reported, and effective treatment is limited. Thus, this study aimed to assess intrathecal (IT) or intraventricular (IVT) injection of tigecycline for clearing infection with CRKP in CNS.

PATIENTS AND METHODS

Two patients who had intracranial infection with CRKP after craniotomy were treated in our institution and analyzed retrospectively, summarizing their therapeutic schedules.

RESULTS

They all had a fever with the positive results of cerebrospinal fluid (CSF) test, and CSF culture showed positive for CPKP, which was sensitive only to tigecycline. In addition, the MIC of polymyxin B was not tested due to the limited laboratory conditions. After IT or IVT injection of tigecycline treatment, the temperature of the patients became normal in 3 days, with normal levels of white blood cells, protein, glucose and chlorine concentrations in the CSF. Crucially, twice CSF cultures also became negative with no clinical symptoms of intracranial infection after IT or IVT injection of tigecycline treatment. Moreover, there were no adverse drug reactions observed.

CONCLUSION

IT or IVT injection of tigecycline may be a bright choice to control intracranial infection with CRKP.

Silver Carboxylate-Eluting Titanium-Dioxide Polydimethylsiloxane Coating Inhibits Multi-Drug-Resistant Acinetobacterium baumannii and Vancomycin-Resistant Enterococcus faecalis Adherence and Proliferation on Orthopedic Trauma Fixation and Spinal Fusion Materials

Background: Vancomycin-resistant Enterococcus faecalis and multi-drug-resistant (MDR) Acinetobacter baumannii are rising contributors to spinal fusion and fracture-associated infections (FAI), respectively. These MDR bacteria can form protective biofilms, complicating traditional antibiotic treatment. This study explores the effects of the antibiotic-independent antimicrobial silver carboxylate (AgCar)-doped coating on the adherence sand proliferation of these pathogens on orthopedic implant materials utilized in spinal fusion and orthopedic trauma fixation. Methods: Multi-drug-resistant Acinetobacter baumannii and vancomycin-resistant Enterococcus faecalis were inoculated on five common implant materials: cobalt chromium, titanium, titanium alloy, polyether ether ketone, and stainless steel. Dose response curves were generated to assess antimicrobial potency. Scanning electron microscopy and confocal laser scanning microscopy were utilized to characterize and quantify growth and adherence on each material. Results: The optimal AgCar concentration was a 95% titanium dioxide (TiO₂)-5% polydimethylsiloxane (PDMS) matrix combined with 10 × silver carboxylate, which inhibited bacterial proliferation by 89.40% (p = 0.001) for MDR Acinetobacter baumannii and 84.02% (p = 0.001) for vancomycin-resistant Enterococcus faecalis compared with uncoated implants. A 95% TiO₂-5% PDMS matrix combined with 10 × AgCar was equally effective at inhibiting bacterial proliferation across all implant materials for MDR Acinetobacter baumannii (p = 0.19) and vancomycin-resistant Enterococcus faecalis (p = 0.07). A 95% TiO2-5% PDMS matrix with 10 × AgCar is effective at decreasing bacterial adherence of both MDR Acinetobacter baumannii and vancomycin-resistant Enterococcus faecalis on implant materials. Conclusions: Application of this antibiotic-independent coating for surgery in which these implant materials might be used may prevent adherence, biofilm formation, spinal infections, and FAI by MDR Acinetobacter baumannii and vancomycin-resistant Enterococcus faecalis.

Outcome of Using Intraventricular Plus Intravenous Polymyxin B in Post-neurosurgical Patients With Multi/Extensively Drug-Resistant Gram-Negative Bacteria-Induced Intracranial Infection

Introduction

Post-neurosurgical central nervous system (CNS) infection caused by multidrug-resistant (MDR)/extensively drug-resistant (XDR) Gram-negative bacteria remains a major clinical challenge. This study describes our experience of treating such patients with combined intraventricular (IVT) and intravenous (IV) polymyxin B administration.

Methods

This retrospective study included six patients with post-neurosurgical CNS infections of carbapenem-resistant Acinetobacter baumannii (CRAB) or carbapenem-resistant Klebsiella pneumoniae (CRKP). All patients were treated in the intensive care unit (ICU) of First Affiliated Hospital, Zhejiang University School of Medicine (Hangzhou, China) between November 2020 and November 2021, and all received IVT plus IV polymyxin B. Data including patients' characteristics, therapeutic process, symptoms, cerebrospinal fluid (CSF) examination, laboratory tests, and complications were collected.

Results

Six patients with post-neurosurgical CNS infection were enrolled in the study. The patients comprised five males and one female, and the average age was 58 years (range, 38–73 years). Four out of the six cases were CRAB-positive in CSF culture, while two cases were CRKP-positive. The mean duration of polymyxin B administration was 14 ± 5.69 days (range, 6–20 days). The average period of patients reaching CSF sterilization was 10.33 ± 3.67 days (range, 5–14 days). All six cases were cured without acute kidney injury or epilepsy.

Conclusion

IVT plus IV polymyxin B is a safe and effective treatment for post-neurosurgical patients with intracranial infection caused by MDR/XDR Gram-negative bacteria.

Polymyxin B, Cefoperazone Sodium-Sulbactam Sodium, and Tigecycline against Multidrug-Resistant Acinetobacter baumannii Pneumonia

Purpose

The purpose of this study is to investigate the significance of polymyxin B in combination with cefoperazone sodium-sulbactam sodium (CSSS) and tigecycline for the treatment of multidrug-resistant Acinetobacter baumannii- (MDRAB-) induced pneumonia on the levels of white blood cell (WBC) count, serum C-reactive protein (CRP), and procalcitonin (PCT).

Methods

Fifty-six patients with MDRAB pneumonia admitted to the Fifth People's Hospital of Wuhu from February 2019 to December 2021 were randomized into the observation group (n = 28) and the experimental group (n = 28) by the random table method. The observation group received intravenous infusion of CSSS and tigecycline. The experimental group received intravenous infusion of polymyxin B sulfate plus CSSS and tigecycline. All patients were treated for 14 days.

Results

There was no significant difference in the overall response rate between the two groups; the bacterial clearance of the experimental group was significantly higher than that of the observation group; there was no significant difference in the WBC, CRP, and PCT levels between the two groups prior to the treatment; but after treatment, while the WBC, CRP, and PCT levels of the two groups decreased, the WBC count, CRP, and PCT levels of the experimental group were significantly lower than those of the observation group; no significant difference was found in adverse reactions.

Conclusion

Polymyxin B-CSSS-tigecycline has good clinical efficacy in the treatment of MDRAB pneumonia. It not only improves the patients' bacterial clearance rate and effectively reduces the levels of WBC count, serum CRP, and PCT, but also raises no risk of adverse reactions. Therefore, it is worthy of clinical promotion.

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

Objectives

This is a comparative cohort study aiming to evaluate the mortality risk factors for patients with nosocomial meningitis (NM) induced by multidrug-resistant Enterobacteriaceae (MDRE) in China. The clinical features and therapies of patients and the resistance mechanisms of MDRE pathogens were also assessed.

Methods

MDRE-NM patients from two neurosurgical centers in China from 2014 to 2019 were included in this study. Clinical features were extracted from the medical record databases of the two centers. The molecular mechanisms underlying the microbiological resistance mechanisms of each MDRE pathogen were determined, Kaplan-Meier survival analysis was conducted, and multivariable analyses were performed using a Cox proportional hazard model.

Results

Ninety MDRE-NM patients were included in this study. Klebsiella pneumoniae accounted for the highest proportion of causative pathogens (46/90, 51.1%), and 40 causative pathogens (44.4%) were meropenem-resistant. blaKPC (27/40, 67.5%) was the predominant carbapenem resistance gene. Multivariate Cox analysis showed that external ventricular drainage (EVD) [hazard ratio (HR) = 2.524, 95% confidence interval (CI) = 1.101-5.787, p = 0.029] and a Glasgow Coma Scale (GCS) score ≤;8 (HR = 4.033, 95% CI = 1.526-10.645, p = 0.005) were mortality risk factors for patients with MDRE-NM. A total of 90.0%, 94.4%, and 97.8% of MDRE-NM patients received antibiotic prophylaxis (AP), antibiotic empirical therapy (AET), and antibiotic definitive therapy (ADT), respectively.

Conclusions

NM caused by MDRE is an important sign of the failure of neurosurgery. MDRE possesses multiple drug resistance genotypes, and EVD and a GCS score ≤;8 are independent mortality risk factors for patients with MDRE-NM, which deserve the attention of microbiologists and neurosurgical clinicians.

Intraventricular Drug Delivery and Sampling for Pharmacokinetics and Pharmacodynamics Study

Although the blood-brain barrier (BBB) protects the brain from foreign entities, it also prevents some therapeutics from crossing into the central nervous system (CNS) to ameliorate diseases or infections. Drugs are administered directly into the CNS in animals and humans to circumvent the BBB. The present protocol describes a unique way of treating brain infections through intraventricular delivery of antibiotics, i.e., polymyxins, the last-line antibiotics to treat multi-drug resistant Gram-negative bacteria. A straightforward stereotaxic surgery protocol was developed to implant a guide cannula reaching into the lateral ventricle in rats. After a recovery period of 24 h, rats can be injected consciously and repeatedly through a cannula that is fitted to the guide. Injections can be delivered manually as a bolus or infusion using a microinjection pump to obtain a slow and controlled flow rate. The intraventricular injection was successfully confirmed with Evans Blue dye. Cerebrospinal fluid (CSF) can be drained, and the brain and other organs can be collected. This approach is highly amenable for studies involving drug delivery to the CNS and subsequent assessment of pharmacokinetic and pharmacodynamic activity.

Intrathecal Injection of Tigecycline and Polymyxin B in the Treatment of Extensively Drug-Resistant Intracranial Acinetobacter baumannii Infection: A Case Report and Review of the Literature

Purpose

Intracranial infection after neurosurgery is one of the most serious complications, especially extensively drug-resistant (XDR) Acinetobacter baumannii (A. baumannii) seriously affects the prognosis of patients. At present, there is little experience in the treatment of this infection and limited effective treatment options, like tigecycline or polymyxin B. Therefore, this report aims to describe the efficacy of tigecycline combined with polymyxin B by intrathecal (ITH) injection in the treatment of XDR intracranial infection with A. baumannii.

Methods

We report a case of intracranial infection with XDR A. baumannii after ventricular drainage, treated by daily ITH and intravenous (IV) tigecycline, combined with polymyxin B ITH route. Moreover, tigecycline and polymyxin B treatments for XDR intracranial infection with A. baumannii that were reported in the literature were also reviewed and summarized.

Results

The white blood cells (WBCs) of the patient’s cerebrospinal fluid dropped to normal, and the symptoms of intracranial infection disappeared. The patient finally obtained good clinical results and transferred to the local hospital.

Conclusion

The polymyxin B ITH route is an ideal treatment strategy for XDR A. baumannii. The IV plus ITH tigecycline may be an effective treatment option. However, more researches should be conducted to confirm our observation.

Successful Treatment of Postneurosurgical Ventriculitis Caused by Extensively Drug-resistant Acinetobacter baumannii in a Child: Case Report

Introduction: The incidence of postneurosurgical Acinetobacter baumannii ventriculitis/meningitis, primarily due to drug-resistant strains, has increased considerably in recent years. However, limited therapeutic options are available because most antibiotics poorly penetrate the blood-brain barrier, especially in pediatric patients. Case Presentation: A five-year-old boy developed ventriculitis due to extensively drug-resistant A. baumannii (XDRAB) after bilateral frontal external ventricular drainage for spontaneous intraventricular hemorrhage. The boy was safely and successfully treated with intraventricular (IVT)/intrathecal (ITH) polymyxin B together with intravenous tigecycline plus cefoperazone/sulbactam. Conclusions: In the present case, postneurosurgical XDRAB ventriculitis was closely associated with intraventricular hemorrhage and the placement of external ventricular drainage. IVT/ITH polymyxin B combined with intravenous tigecycline and cefoperazone sulbactam could be a therapeutic option against XDRAB ventriculitis in children.

Towards a better understanding of antimicrobial resistance dissemination: what can be learnt from studying model conjugative plasmids?

Bacteria can evolve rapidly by acquiring new traits such as virulence, metabolic properties, and most importantly, antimicrobial resistance, through horizontal gene transfer (HGT). Multidrug resistance in bacteria, especially in Gram-negative organisms, has become a global public health threat often through the spread of mobile genetic elements. Conjugation represents a major form of HGT and involves the transfer of DNA from a donor bacterium to a recipient by direct contact. Conjugative plasmids, a major vehicle for the dissemination of antimicrobial resistance, are selfish elements capable of mediating their own transmission through conjugation. To spread to and survive in a new bacterial host, conjugative plasmids have evolved mechanisms to circumvent both host defense systems and compete with co-resident plasmids. Such mechanisms have mostly been studied in model plasmids such as the F plasmid, rather than in conjugative plasmids that confer antimicrobial resistance (AMR) in important human pathogens. A better understanding of these mechanisms is crucial for predicting the flow of antimicrobial resistance-conferring conjugative plasmids among bacterial populations and guiding the rational design of strategies to halt the spread of antimicrobial resistance. Here, we review mechanisms employed by conjugative plasmids that promote their transmission and establishment in Gram-negative bacteria, by following the life cycle of conjugative plasmids.

Successful Treatment of Severe Post-craniotomy Meningitis Caused by an Escherichia coli Sequence Type 410 Strain Coharboring bla NDM - 5 and bla CTX - M - 65

Intracranial infections caused by multidrug-resistant Gram-negative bacterium have led to considerable mortality due to extremely limited treatment options. Herein, we firstly reported a clinical carbapenem-resistant Escherichia coli isolate coharboring bla NDM - 5 and bla CTX - M - 65 from a patient with post-craniotomy meningitis. The carbapenem-resistant Escherichia coli strain CNEC001 belonging to Sequence Type 410 was only susceptible to amikacin and tigecycline, both of which have poor penetration through the blood-brain barrier (BBB). The bla CTX - M - 65 gene was expressed on a 135,794 bp IncY plasmid. The bla NDM - 5 gene was located on a genomic island region of an IncX3-type plasmid pNDM5-CNEC001. Based on the characteristics of the strain, we presented the successful treatment protocol of intravenous (IV) tigecycline and amikacin combined with intrathecal (ITH) amikacin in this study. Intracranial infection caused by Escherichia coli coharboring bla NDM - 5 and bla CTX - M - 65 is rare and fatal. Continuous surveillance and infection control measures for such strain need critical attention in clinical settings.