Intrathecal Antibacterial and Antifungal Therapies

New and emerging roles for inhalational and direct antifungal drug delivery approaches for treatment of invasive fungal infections

INTRODUCTION

The rising prevalence of difficult-to-treat, deep-seated invasive fungal diseases (IFD) has led to high mortality. Currently available antifungal treatments, administered predominantly orally or intravenously, may not sufficiently penetrate certain body sites, and/or are associated with systemic toxicity. Little is known about how to position alternative administration approaches such as inhalational and direct drug delivery routes.

AREAS COVERED

This review provides an updated overview of unconventional drug delivery strategies for managing IFD, focusing on inhalational (to target the lungs) and direct delivery methods to the central nervous system, bone/joint, and eyes. Novel compounds (e.g. opelconazole) and existing antifungals with innovative drug delivery systems currently undergoing clinical trials and/or used off-label in the clinical setting are discussed.

EXPERT OPINION

For both inhalational agents and direct delivery approaches, there are similar challenges that include the absence of: approved formulations for specific administration routes, delivery vehicles that are simple and safe to use whilst maintaining potency and efficiency of delivery, animal models suitable for investigating pharmacokinetic/pharmacodynamic profiles of inhaled antifungals, and consensus on the composite endpoints and intervals for of follow-up in clinical trials. To meet these challenges, cooperation of all stakeholders in drug development and regulation is required.

Successful treatment of mixed pulmonary Aspergillus and Mucor infection using intrabronchial amphotericin B infusion: a case report and literature review

BACKGROUND

Reports of pulmonary aspergillosis and mucormycosis co-infections are rare; thus, limited guidance is available on early diagnosis and treatment. We present a case of mixed pulmonary Aspergillus and Mucor infection and review the literature regarding this co-infection. The diagnosis and treatment methods are summarized to improve clinicians' understanding of the disease and to facilitate early diagnosis and treatment.

CASE PRESENTATION

A 60-year-old male farmer with poorly controlled diabetes mellitus was admitted to hospital with a fever of unknown origin that had been present for 15 days and pulmonary aspergillosis complicated by Mucor spp.

INFECTION

Because multiple lobes were involved, the infection worsened despite surgical resection and antifungal therapy. Finally, we treated this patient with a bronchoscopic infusion of amphotericin B. After four courses of bronchoscopic amphotericin B infusion, we observed rapid clinical improvement and subsequent resolution of pulmonary infiltrates.

CONCLUSION

Our case highlights the use of bronchoscopy in the successful clinical treatment of invasive fungal diseases of the lung.

Therapeutic drug monitoring of polymyxin B cerebrospinal fluid concentrations in patients with carbapenem-resistant Gram-negative bacteria-induced central nervous system infection

OBJECTIVES

Central nervous system (CNS) infections caused by carbapenem-resistant Gram-negative bacteria (CR-GNB) present a major health and economic burden worldwide. This multicentre prospective study aimed to assess the feasibility and usefulness of CSF therapeutic drug monitoring (TDM) after intrathecal/intraventricular administration of polymyxin B in patients with CNS infections.

METHODS

Forty-two patients treated with intrathecal/intraventricular administration of polymyxin B against CR-GNB-induced CNS infections were enrolled. CSF trough level (Cmin) was collected beginning on Day 2 post-polymyxin B initiation and thereafter. The primary outcomes were clinical cure and 28-day all-cause mortality.

RESULTS

All patients started with intrathecal/intraventricular administration of polymyxin B at a dose of 5 g/day, corresponding to a median CSF Cmin of 2.93 mg/L (range, 0.21-25.74 mg/L). Clinical cure was 71.4%, and the median CSF Cmin of this group was higher than that of clinical failure group [3.31 (IQR, 1.73-5.62) mg/L versus 2.25 (IQR, 1.09-4.12) mg/L; P = 0.011]. In addition, with MICs ≤ 0.5 mg/L, maintaining polymyxin B CSF Cmin above 2.0 mg/L showed a higher clinical cure rate (P = 0.041). The 28-day all-cause mortality rate was 31.0% and had no association with CSF Cmin.

CONCLUSIONS

After intrathecal/intraventricular administration of polymyxin B, CSF concentrations fluctuated considerably inter- and intra-individual. Polymyxin B CSF Cmin above 2.0 mg/L was associated with clinical cure when MICs were ≤ 0.5 mg/L, and the feasibility of TDM warrants additional clinical studies.

Candida parapsilosis intracerebral abscess and intralesional amphotericin B: a novel treatment approach to a rare infection. Illustrative case

BACKGROUND

Candida parapsilosis has been implicated in central nervous system (CNS) infections (i.e., meningitis or ventriculitis) but has not been previously reported to cause intracerebral abscesses. CNS infections secondary to C. parapsilosis are notoriously difficult to treat due to the poor CNS penetration of amphotericin B. Historically, intraventricular amphotericin B has been used to treat C. parapsilosis ventriculitis.

OBSERVATIONS

A 15-year-old female with no comorbidities presented with nonresolving headaches, photophobia, fevers, and meningism. Computed tomography (CT) of the brain revealed a right frontal abscess. After multiple drainage surgeries, subsequent CT scans showed reaccumulation of her abscess. C. parapsilosis was cultured, and the patient was then taken to the operating room where an external ventricular drain catheter was successfully placed within the abscess cavity. Pus was repeatedly aspirated, followed by the instillation of intralesional amphotericin B twice a day for 2 weeks. The patient's clinical condition improved substantially with complete resolution of symptoms, improvement of infective markers, and resolution of radiological features of the abscess. Follow-up of the patient revealed the absence of symptoms and image characteristics of abscess on CT 3 months posttreatment.

LESSONS

Intralesional amphotericin B is a novel but effective treatment of C. parapsilosis intracerebral abscess, an organism not previously described as a cause of intracerebral abscesses. https://thejns.org/doi/10.3171/CASE2484.

Bacterial Aggregation in Cerebral Spinal Fluid: The Extent it Occurs and the Clinical Ramifications

Bacteria can form aggregates in synovial fluid that are resistant to antibiotics, but the ability to form aggregates in cerebral spinal fluid (CSF) is poorly defined. Consequently, the aims of this study were to assess the propensity of four bacterial species to form aggregates in CSF under various conditions. To achieve these aims, bacteria were added to CSF in microwell plates and small flasks at static and different dynamic conditions with the aid of an incubating shaker. The aggregates that formed were assessed for antibiotic resistance and the ability of tissue plasminogen activator (TPA) to disrupt these aggregates and reduce the number of bacteria present when used with antibiotics. The results of this study show that under dynamic conditions all four bacteria species formed aggregates that were resistant to high concentrations of antibiotics. Yet with static conditions, no bacteria formed aggregates and when the CSF volume was increased, only Staphylococcus aureus formed aggregates. Interestingly, the aggregates that formed were easily dispersed by TPA and significant (p < 0.005) decreases in colony-forming units were seen when a combination of TPA and antibiotics were compared to antibiotics alone. These findings have clinical significance in that they show bacterial aggregation does not habitually occur in central nervous system infections, but rather occurs under specific conditions. Furthermore, the use of TPA combined with antibiotics may be advantageous in recalcitrant central nervous system infections and this provides a pathophysiological explanation for an unusual finding in the CLEAR III clinical trial.

Fusarium species central nervous system infection

PURPOSE OF REVIEW

Fusarium species are an increasingly important cause of meningitis and invasive disease in immunocompromised patients as well as in otherwise healthy patients as observed in two recent healthcare-associated outbreaks. This review summarizes recently published information on treatment and diagnosis of this infection.

RECENT FINDINGS

Incidence of Fusarium species meningitis and invasive fusariosis are increasing. Molecular techniques are improving the speed of diagnosis. New antifungal agents in development show good in vitro activity against some Fusarium species. New technologies, including cerebrospinal fluid (CSF) filtration, may play a role in treatment of central nervous system (CNS) disease. Due to the continued prime importance of the host immune system in recovery, immunomodulatory treatments may play a role in treatment.

SUMMARY

The overall incidence of CNS fusariosis is increasing with a continued poor prognosis, but new diagnostic and treatment modalities are in development which may offer improvements.

Neuroinfectious Emergencies

OBJECTIVE

This article describes nervous system infections and complications that lead to neurologic emergencies.

LATEST DEVELOPMENTS

New research on the use of dexamethasone in viral and fungal infections is reviewed. The use of advanced MRI techniques to evaluate nervous system infections is discussed.

ESSENTIAL POINTS

Neurologic infections become emergencies when they lead to a rapid decline in a patient's function. Emergent complications may result from neurologic infections that, if not identified promptly, can lead to permanent deficits or death. These complications include cerebral edema and herniation, spinal cord compression, hydrocephalus, vasculopathy resulting in ischemic stroke, venous thrombosis, intracerebral hemorrhage, status epilepticus, and neuromuscular respiratory weakness.

Clinical treatment of cryptococcal meningitis: an evidence-based review on the emerging clinical data

Cryptococcal meningitis (CM) is a fatal fungal central nervous system (CNS) infection caused by Cryptococcus infecting the meninges and/or brain parenchyma, with fever, headache, neck stiffness, and visual disturbances as the primary clinical manifestations. Immunocompromised individuals with human immunodeficiency virus (HIV) infection or who have undergone organ transplantation, as well as immunocompetent people can both be susceptible to CM. Without treatment, patients with CM may have a mortality rate of up to 100% after hospital admission. Even after receiving therapy, CM patients may still suffer from problems such as difficulty to cure, poor prognosis, and high mortality. Therefore, timely and effective treatment is essential to improve the mortality and prognosis of CM patients. Currently, the clinical outcomes of CM are frequently unsatisfactory due to limited drug choices, severe adverse reactions, drug resistance, etc. Here, we review the research progress of CM treatment strategies and discuss the suitable options for managing CM, hoping to provide a reference for physicians to select the most appropriate treatment regimens for CM patients.

Clinical research progress on intrathecal glucocorticoids in the treatment of infections: A review

In some infectious diseases, pathogenic microorganisms can directly or indirectly cause significant inflammatory reactions in the central nervous system, leading to severe neurological dysfunction, such as suppurative meningitis, tuberculous meningitis, and febrile infections. related epilepsy syndrome, etc. In these diseases, adjuvant administration of glucocorticoids is necessary to inhibit the release of proinflammatory cytokines, and intrathecal administration can deliver the drug more directly to the target. In this article, the authors studied intrathecal glucocorticoids for the treatment of infectious inflammatory reactions in terms of pharmacological effects and mechanisms, pharmacokinetics, clinical application, and safety. The authors concluded that the article could help provide new treatment strategies for infectious diseases.

Role of Cefiderocol in Multidrug-Resistant Gram-Negative Central Nervous System Infections: Real Life Experience and State-of-the-Art

Cefiderocol is a new molecule effective against multidrug-resistant (MDR) Gram-negative pathogens. Currently, there is limited evidence regarding the use of cefiderocol in central nervous system (CNS) infections. Data on the cerebrospinal fluid penetration rate of cefiderocol are limited and heterogeneous, and there is no consensus on the dosing scheme of cefiderocol to penetrate the blood-brain barrier. We present a case series and a literature review of CNS infections caused by MDR pathogens that were treated with cefiderocol: some of these patients were treated with different dose schemes of cefiderocol and underwent therapeutic drug monitoring both on plasma and cerebrospinal fluid (CSF). The CSF penetration rates and the clinical outcomes were evaluated.

Intraventricular or intrathecal polymyxin B for treatment of post-neurosurgical intracranial infection caused by carbapenem-resistant gram-negative bacteria: a 8-year retrospective study

PURPOSE

Post-neurosurgical intracranial infection caused by carbapenem-resistant gram-negative bacteria (CRGNB) is a life-threatening complication. This study aimed to assess the current practices and clinical outcomes of intravenous (IV) combined with intraventricular (IVT)/intrathecal (ITH) polymyxin B in treating CRGNB intracranial infection.

METHODS

A retrospective study was conducted on patients with post-neurosurgical intracranial infection due to CRGNB from January 2013 to December 2020. Clinical characteristics and treatment outcomes were collected and described. Kaplan-Meier survival and multivariate logistic regression analyses were performed.

RESULTS

The study included 114 patients, of which 72 received systemic antimicrobial therapy combined with IVT/ITH polymyxin B, and 42 received IV administration alone. Most infections were caused by carbapenem-resistant Acinetobacter baumannii (CRAB, 63.2%), followed by carbapenem-resistant Klebsiella pneumoniae (CRKP, 31.6%). Compared with the IV group, the IVT/ITH group had a higher cerebrospinal fluid (CSF) sterilization rate in 7 days (p < 0.001) and lower 30-day mortality (p = 0.032). In the IVT/ITH group, patients with CRKP infection had a higher initial fever (p = 0.014), higher incidence of bloodstream infection (p = 0.040), lower CSF sterilization in 7 days (p < 0.001), and higher 30-day mortality (p = 0.005) than those with CRAB infection. Multivariate logistic regression analysis revealed that the duration of IVT/ITH polymyxin B (p = 0.021) was independently associated with 30-day mortality.

CONCLUSIONS

Intravenous combined with IVT/ITH polymyxin B increased CSF microbiological eradication and improved clinical outcomes. CRKP intracranial infections may lead to more difficult treatment and thus warrant attention and further optimized treatment.

Comprehensive Therapeutic Approaches to Tuberculous Meningitis: Pharmacokinetics, Combined Dosing, and Advanced Intrathecal Therapies

Tuberculous meningitis (TBM) presents a critical neurologic emergency characterized by high mortality and morbidity rates, necessitating immediate therapeutic intervention, often ahead of definitive microbiological and molecular diagnoses. The primary hurdle in effective TBM treatment is the blood-brain barrier (BBB), which significantly restricts the delivery of anti-tuberculous medications to the central nervous system (CNS), leading to subtherapeutic drug levels and poor treatment outcomes. The standard regimen for initial TBM treatment frequently falls short, followed by adverse side effects, vasculitis, and hydrocephalus, driving the condition toward a refractory state. To overcome this obstacle, intrathecal (IT) sustained release of anti-TB medication emerges as a promising approach. This method enables a steady, uninterrupted, and prolonged release of medication directly into the cerebrospinal fluid (CSF), thus preventing systemic side effects by limiting drug exposure to the rest of the body. Our review diligently investigates the existing literature and treatment methodologies, aiming to highlight their shortcomings. As part of our enhanced strategy for sustained IT anti-TB delivery, we particularly seek to explore the utilization of nanoparticle-infused hydrogels containing isoniazid (INH) and rifampicin (RIF), alongside osmotic pump usage, as innovative treatments for TBM. This comprehensive review delineates an optimized framework for the management of TBM, including an integrated approach that combines pharmacokinetic insights, concomitant drug administration strategies, and the latest advancements in IT and intraventricular (IVT) therapy for CNS infections. By proposing a multifaceted treatment strategy, this analysis aims to enhance the clinical outcomes for TBM patients, highlighting the critical role of targeted drug delivery in overcoming the formidable challenges presented by the blood-brain barrier and the complex pathophysiology of TBM.

Meropenem-Vaborbactam for the Treatment of Post-Neurosurgical Meningitis Caused by KPC Producer Klebsiella Pneumoniae: A Case Report and Review of the Literature

Meningitis and ventriculitis, due to carbapenem-resistant Enterobacterales, are frequently associated with significant morbidity and mortality. In the case of multi-drug-resistant pathogens, it is necessary to consider the limited susceptibility profile as well as the penetration of the antimicrobials into the brain. Limited data are available regarding the treatment of central nervous system infections caused by carbapenem-resistant Enterobacterales. We report a study of a patient treated with meropenem-vaborbactam in the case of post-neurosurgical meningitis due to carbapenemase-producing Klebsiella pneumoniae (CPKP).

Early Intraventricular Antibiotic Therapy Improved In-Hospital-Mortality in Neurocritical Patients with Multidrug-Resistant Bacterial Nosocomial Meningitis and Ventriculitis

BACKGROUND

Hospital-acquired multidrug-resistant (MDR) bacterial meningitis and/or ventriculitis (MEN) is a severe condition associated with high mortality. The risk factors related to in-hospital mortality of patients with MDR bacterial MEN are unknown. We aimed to examine factors related to in-hospital mortality and evaluate their prognostic value in patients with MDR bacterial MEN treated in the neurointensive care unit.

METHODS

This was a single-center retrospective cohort study of critically ill neurosurgical patients with MDR bacterial MEN admitted to our hospital between January 2003 and March 2021. Data on demographics, admission variables, treatment, time to start of intraventricular (IVT) therapy, and in-hospital mortality were analyzed. Both univariate and multivariable analyses were performed to identify determinants of in-hospital mortality.

RESULTS

All 142 included patients received systemic antibiotic therapy, and 102 of them received concomitant IVT treatment. The median time to start of IVT treatment was 2 days (interquartile range 1-5 days). The time to start of IVT treatment had an effect on in-hospital mortality (hazard ratio 1.17; 95% confidence interval 1.02-1.34; adjusted p = 0.030). The cutoff time to initiate IVT treatment was identified at 3 days: patients treated within 3 days had a higher cerebrospinal fluid (CSF) sterilization rate (81.5%) and a shorter median time to CSF sterilization (7 days) compared with patients who received delayed IVT treatment (> 3 days) (48.6% and 11.5 days, respectively) and those who received intravenous antibiotics alone (42.5% and 10 days, respectively).

CONCLUSIONS

Early IVT antibiotics were associated with superior outcomes in terms of the in-hospital mortality rate, time to CSF sterilization, and CSF sterilization rate compared with delayed IVT antibiotics and intravenous antibiotics alone.

Continuous Intrathecal Medication Delivery With the IRRA flow Catheter: Pearls and Early Experience

BACKGROUND AND OBJECTIVES

Intrathecal (IT) medications are routinely introduced through catheterization of the intraventricular space or subarachnoid space. There has been sporadic use of IT medications delivered directly to the ventricle either by intermittent injection through an external ventricular drain (EVD) or by an Ommaya reservoir with a ventricular catheter. IT medication delivery through EVD has many drawbacks, including the necessary opening of a sterile system, delivery of medication in a bolus form, and requirements to clamp the EVD after medication delivery. Despite these setbacks, IT medications delivered through EVD have been used across a wide range of applications, including antibiotic delivery treatment of vasospasm with nicardipine and delivery of tissue plasminogen activator.

METHODS

We used a newly developed active fluid exchange device to treat various severe conditions involved in the cerebral ventricles. Here, we present our treatment protocols and advice on the techniques related to successful active fluid exchange therapy.

RESULTS

Seventy patients have been treated with our system with various conditions, including subarachnoid hemorrhage, intraventricular hemorrhage, ventriculitis, and cerebral abscess. Total complication rate was 14% with only 1 catheter occlusion and low rates of hemorrhage, infection, and spinal fluid leak.

CONCLUSION

Current continuous IT medication dosages and protocols are based on reports and consensus statements evaluating intermittent instillation of medication boluses. The pharmacokinetics of continuous dosing and the therapeutic and safety profiles of the medications need to be studied in a prospective manner to evaluate the true optimal dosing standards. Furthermore, the ability to deliver continuous, sterile medications directly through an IT route will open new avenues of pharmacotherapy that were previously closed. This report serves as a basic guide for the safe and effective use of the IRRA flow active fluid exchange catheter to deliver IT medications.

Early Experiences with Intrathecal Administration of Amphotericin B Liposomal Formulation at a Neurosurgical Center

BACKGROUND

Intrathecal administration of amphotericin B represents an important adjunctive therapy for management of severe fungal meningitis. Intrathecal preparations have traditionally used amphotericin B deoxycholate. Liposomal amphotericin B is an alternative formulation with good clinical outcomes as systemic therapy, but scant data exist investigating intrathecal use.

OBJECTIVE

The aim of this exploratory study was to evaluate outcomes following intrathecal administration of liposomal amphotericin B for treatment of severe fungal meningitis.

METHODS

A national shortage of amphotericin B deoxycholate necessitated revision of institutional protocols at a southwestern neurosurgical center in Spring 2023. A starting intrathecal daily dose of 0.125-0.5 mg liposomal amphotericin B was recommended (dependent on insertion device), with 0.125-0.25 mg slow titration every 48 h and up to a 2 mg maximum daily dose.

RESULTS

Four cases of fungal meningitis treated with adjunctive intrathecal amphotericin B liposomal formulation were reviewed. This included three cases of coccidioidal meningitis and one case of presumed Fusarium solani meningitis following an outbreak. All patients had initial disease improvement following initiation of intrathecal amphotericin B and were able to tolerate long-term therapy. One coccidioidal meningitis patient expired of neurologic complications shortly after being moved from the intensive care unit (ICU) to a floor unit. All other patients were successfully discharged from the hospital. New headache was the only reported adverse effect, which was managed with dose reduction and did not require therapy discontinuation.

CONCLUSIONS

Liposomal amphotericin B may be feasibly administered intrathecally for the adjunctive treatment of severe fungal meningitis.

Clinical analysis of hyperbaric oxygen combined with subdural drilling and drainage in the management of subdural effusion type IV with intracranial infection in infant patients

Background

To explore the therapeutic effect of hyperbaric oxygen combined with subdural drilling and drainage (SDD) on subdural effusion type IV with intracranial infection in infant patients.

Methods

This retrospective controlled study included 328 infant patients with subdural effusion type 4 with intracranial infection between January 2005 and January 2023. 178 patients were treated by hyperbaric oxygen combined with SDD (group A). 142 cases were treated with SDD (group B). 97 infants were only received hyperbaric oxygen (group C). Clinical outcomes, the control time of intracranial infection, complications, and the degree of brain re-expansion after 6 months of treatment were compared among the three groups. According to the comprehensive evaluation of treatment effectiveness and imaging results, it is divided into four levels: cured, significantly effective, improved, and ineffective.

Results

No patient died during follow-up. The three groups were similar regarding age, sex, the general information, and clinical symptoms (p > 0.05). All intracranial infections in the children were effectively controlled. There was no difference in infection control time between group A and group B, and there was no statistical significance. However, the control time of intracranial infection between the two groups was different from that of group C, which was statistically significant. Compared with group B and group C, the degree of brain re-expansion in group A has obvious advantages and significant differences. The effective rates of the three groups were 83.7%, 58.5%, and 56.7%, respectively. There were 28 cases of subcutaneous hydrops in group A and 22 cases of subcutaneous hydrops in group B after operation, and no other serious complications.

Conclusion

The SDD is safe and effective for infant patients with intracranial infections through fluid replacement and intrathecal antibacterial. Hyperbaric oxygen is effective as an adjuvant therapy to promote brain re-expansion.

Invasive pulmonary and central nervous system aspergillosis in a child: A case report and literature review

RATIONALE

Children with haematological malignancies have a higher risk of developing aggressive pulmonary aspergillosis and a higher mortality rate. The most common site of extrapulmonary aspergillosis in children is the central nervous system (CNS), and the death rate is higher when CNS is affected. Therefore, early diagnosis and treatment of invasive aspergillosis are essential for reducing mortality.

PATIENT CONCERNS

We report a case of an 8-year-old girl with acute lymphoblastic leukaemia who developed invasive pulmonary aspergillosis complicated by CNS aspergillosis. Aspergillus was confirmed by metagenomic sequencing of pathogenic microorganisms.

DIAGNOSES

Invasive pulmonary and central nervous system aspergillosis.

INTERVENTIONS

The patient was treated with combined systemic antifungal agents (voriconazole and liposomal amphotericin B) and intrathecal injection of amphotericin B.

OUTCOMES

The treatment was well tolerated and resulted in remarkable clinical and radiological head improvements.

LESSONS

Invasive aspergillosis has a high mortality rate and requires early diagnosis and treatment. Pathogenic microbial metagenomic sequencing is a convenient method to assist in the early diagnosis of aspergillosis. Voriconazole is the drug of choice for the treatment of invasive aspergillosis. When CNS aspergillosis occurs, it can be combined with other systemic antifungal drugs and intrathecal injection of amphotericin B.

Refinement of intrathecal catheter design to enhance neuraxial distribution

BACKGROUND

Delivery of therapeutics via indwelling intrathecal catheters is highly efficacious for targeting of pain, spasticity, neuraxial cancer and neurodegenerative disorders. However, current catheter designs have some major limitations. Given limited CSF flow, fixed intrathecal volume and the large distance of the rostro-caudal spinal axis, current intrathecal delivery routes fail to achieve adequate drug distribution. Additionally open catheter systems are plagued with cellular ingrowth and debris accumulation if used intermittently.

NEW METHOD

RESULTS/COMPARISON WITH EXISTING METHOD(S): High speed imaging showed micro-valve catheters greatly increase fluid exit velocities compared to typical open-ended catheters, which prevents pooling of injectate proximal to the opening. When implanted intrathecally in rats, small injection volumes (7.5 μL) of dye or AAV9-RFP, resulted in an even rostro-caudal distribution along the spinal axis and robust transfection of neurons from cervical to lumbar dorsal root ganglia. In contrast, such injections with an open-ended catheter resulted in localized distribution and transfection proximal to the delivery site. Our poly micro-valve catheter design resulted in equivalent transfection rates of cervical DRG neurons using 100x lower titer of AAV9-RFP. Unlike open port catheters, no debris accumulation was observed in the lumen of implanted catheters, showing potential for long-term intermittent use.

CONCLUSIONS

This catheter platform, suitable for small animal models is easily scalable for human use and addresses many of the problems observed with common catheter systems.

Effects of modified external ventricular drainage vs. an Ommaya reservoir in the management of hydrocephalus with intracranial infection in pediatric patients

Background

Hydrocephalus with intracranial infection (HII) may cause pathological changes in brain tissue structure and irreversible damage to the nervous system. However, intracranial infection is a contraindication to ventriculo-peritoneal (VP) shunt surgery, and the prognosis is improved by early infection control and intracranial pressure reduction. This study evaluated the safety and efficacy of the Ommaya reservoir vs. modified external ventricular drainage (M-EVD) in the management of HII in pediatric patients.

Methods

This retrospective controlled study included 45 pediatric patients with HII treated with an Ommaya reservoir (n = 24) or M-EVD (n = 21) between January 2018 and December 2022. Clinical outcomes, cerebrospinal fluid (CSF) test results, complications, and outcomes were compared between the Ommaya reservoir and M-EVD groups.

Results

No patient died during the follow-up period. The two groups were similar regarding age, sex, admission temperature, weight, preoperative serum protein and albumin concentrations, CSF analysis (white blood cell count, glucose concentration, and protein content), and clinical symptoms (P > 0.05). Both groups had significant changes in the CSF test results postoperatively compared with preoperatively (P < 0.05). In the M-EVD group, the median days for 13 children to remove the external drainage tube and receive VP shunt was 19 days. The longest drainage tube retention time was 61 days, and there was no intracranial infection or serious complication related to the drainage tube. After the placement of the Ommaya, the median time required for CSF to return to normal was 21 days, and a total of 15 patients underwent VP shunt surgery.

Conclusion

The Ommaya reservoir and M-EVD are safe and effective for pediatric patients with HII. Both methods reduce the intracranial pressure and alleviate the symptoms of hydrocephalus, although there are differences between the two methods.

New Antibiotics for the Treatment of Nosocomial Central Nervous System Infections

Nosocomial central nervous system (CNS) infections with carbapenem- and colistin-resistant Gram-negative and vancomycin-resistant Gram-positive bacteria are an increasing therapeutic challenge. Here, we review pharmacokinetic and pharmacodynamic data and clinical experiences with new antibiotics administered intravenously for the treatment of CNS infections by multi-resistant bacteria. Cefiderocol, a new siderophore extended-spectrum cephalosporin, pharmacokinetically behaves similar to established cephalosporins and at high doses will probably be a valuable addition in our therapeutic armamentarium for CNS infections. The new glycopeptides dalbavancin, telavancin, and oritavancin are highly bound to plasma proteins. Although effective in animal models of meningitis, it is unlikely that they reach effective cerebrospinal fluid (CSF) concentrations after intravenous administration alone. The β-lactam/β-lactamase inhibitor combinations have the principal problem that both compounds must achieve adequate CSF concentrations. In the commercially available combinations, the dose of the β-lactamase inhibitor tends to be too low to achieve adequate CSF concentrations. The oxazolidinone tedizolid has a broader spectrum but a less suitable pharmacokinetic profile than linezolid. The halogenated tetracycline eravacycline does not reach CSF concentrations sufficient to treat colistin-resistant Gram-negative bacteria with usual intravenous dosing. Generally, treatment of CNS infections should be intravenous, whenever possible, to avoid adverse effects of intraventricular therapy (IVT). An additional IVT can overcome the limited penetration of many new antibiotics into CSF. It should be considered for patients in which the CNS infection responds poorly to systemic antimicrobial therapy alone.

Novel Nitric Oxide Donor-Azole Conjugation Strategy for Efficient Treatment of Cryptococcus neoformans Infections

Invasive fungal infections (IFIs) such as cryptococcal meningitis (CM) remain a serious health issue worldwide due to drug resistance closely related to biofilm formation. Unfortunately, available antifungal drugs with ideal safety and promising potency are still lacking; thus, the research of new candidate and therapeutic approach is urgently needed. As an important gas messenger molecule, nitric oxide (NO) shows vital inhibition on various microorganism biofilms. Hence, three series of novel NO-donating azole derivatives were designed and synthesized, and the in vitro antifungal activity as well as the mechanism of action was investigated. Among them, 3a and 3e displayed excellent antifungal activity against Cryptococcus neoformans and biofilm depending on the release of NO. Moreover, a more stable analogue 3h of 3a demonstrated markedly anti-CM effects via intranasal dropping, avoiding the first-pass effects and possessing a better brain permeability bypass blood-brain barrier. These results present a promising antifungal candidate and intranasal dropping approach for the treatment of CM, warranting further studies.

Bacterial ventriculoperitoneal shunt infections: changing trends in antimicrobial susceptibility, a 7-year retrospective study from Pakistan

BACKGROUND

Ventriculoperitoneal (VP) shunt infections in adults represent a severe complication and make treatment more challenging. Therefore, drug susceptibility patterns are crucial for therapeutic decisions and infection control in neurosurgical centers. This 7-year retrospective study aimed to identify the bacteria responsible for adult VP shunt infections and determine their drug susceptibility patterns.

METHODS

This single-center study was performed from 2015 to 2021 in Lahore, Pakistan, and included CSF cultures from VP shunt infections. Demographic data, causative organisms, and antimicrobial susceptibility testing results were collected. Multivariate analysis of variance (MANOVA) and two-sample t-tests were used to analyze and compare the antibiotic sensitivity trends over the study period.

RESULTS

14,473 isolates recovered from 13,937 CSF samples of VP shunt infections were identified and analyzed for their susceptibility patterns to antimicrobials. The proportion of Gram-negative and Gram-positive bacteria were 11,030 (76%) and 3443 (24)%, respectively. The predominant bacteria were Acinetobacter species (n = 5898, 41%), followed by Pseudomonas species (n = 2368, 16%) and coagulase-negative Staphylococcus (CoNS) (n = 1880, 13%). 100% of Staphylococcus aureus (S.aureus) and CoNS were sensitive to vancomycin and linezolid (n = 2580). However, 52% of S. aureus (719/1,343) were methicillin-resistant Staphylococcus aureus (MRSA). Acinetobacter showed maximum sensitivity to meropenem at 69% (2759/4768). Pseudomonas was 80% (1385/1863 sensitive to piperacillin-tazobactam, Escherichia coli (E. coli) showed 72% to amikacin (748/1055), while Klebsiella spp. was 57% (574/1170) sensitive to piperacillin-tazobactam. The sensitivity of piperacillin-tazobactam and meropenem for Gram-negative bacteria decreased significantly (p < 0.05) over 7 years, with 92.2% and 88.91% sensitive in 2015 and 66.7% and 62.8% sensitive in 2021, respectively.

CONCLUSION

The significant decrease in the effectiveness of carbapenem and beta-lactam/beta-lactamase inhibitor combination drugs for the common Gram-negative causative agents of VP shunt infections suggests that alternative antibiotics such as colistin, fosfomycin, ceftazidime/avibactam, ceftolozane/tazobactam, and tigecycline should be considered and in consequence included in testing panels. Additionally, it is recommended to adopt care bundles for the prevention of VP shunt infection.

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.

Alternative Antimicrobial Irrigation Strategies for the Treatment of Infections in Children: A Review of the Existing Literature

As a synergistic treatment approach with systemic antimicrobial therapy or a systemic antibiotic-sparing strategy, the local administration of antimicrobial agents has been proposed as an alternative route for complicated infections. With the rationale of concentrating the active principle in the desired target site, avoiding potentially toxic systemic levels and bypassing anatomical and physiological barriers, local irrigation or infusion of antibiotics may effectively shorten the antimicrobial therapy course and reduce both infection-related and systemic therapy-related complications. Although evidence from the adult population supports its use in selected patients with an acceptable safety profile, data specifically focused on the pediatric population are limited. To provide a rapid and easily accessible tool for clinical practice, we synthesized the most relevant evidence on the use of local antimicrobial agents in common severe infections in children: meningitis, mediastinitis, pleural infections, recurrent urinary infections, and peritonitis. A literature search was performed using predefined combined keywords through an electronic research database (PubMed). Described molecules, dosages, routes, treated age groups, and related efficacy have been summarized for prompt application to clinical practice. It should, however, be noted that the evidence for the pediatric population remains limited, and the local administration of several molecules remains off-label. A careful multidisciplinary and patient-tailored evaluation, as well as a rational use of available guidelines, should always be the basis of clinical decision making in settings where local administration of antibiotics may be considered.

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.

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.

Management of Extensive Central Nervous System Cladophialophora bantiana Infection in a 9-Year-Old Child

BACKGROUND

Pediatric central nervous system (CNS) phaeohyphomycosis is a rare invasive fungal infection associated with high mortality.

METHODS

We describe a child with progressive neurologic symptoms whose ultimate diagnosis was Cladophialophora bantiana -associated CNS phaeohyphomycosis. We discuss her clinical presentation, medical and surgical management and review the current literature.

RESULTS

A 9-year-old female presented with acute onset of headaches, ophthalmoplegia and ataxia. Initial infectious work-up was negative, including serial fungal cerebrospinal fluid cultures. Over 2 months, she experienced progressive cognitive and motor declines, and imaging revealed worsening meningitis, ventriculitis and cerebritis. Ultimately, Cladophialophora was detected by plasma metagenomic next-generation sequencing (mNGS). Fourth ventricle fluid sampling confirmed the diagnosis of C. bantiana infection. Given the extent of her disease, complete surgical resection was not feasible. She required multiple surgical debridement procedures and prolonged antifungal therapy, including the instillation of intraventricular amphotericin B. With aggressive surgical and medical management, despite her continued neurologic deficits, she remains alive 3 years after her initial diagnosis. To our knowledge, this is one of a few published pediatric cases of CNS phaeohyphomycosis and the first with the causative pathogen identified by plasma mNGS.

CONCLUSION

CNS phaeohyphomycosis is a serious, life-threatening infection. The preferred management includes a combination of surgical resection and antifungal therapy. In cases complicated by refractory ventriculitis, intraventricular antifungal therapy can be considered as adjuvant therapy. Direct sampling of the CNS for pathogen identification and susceptibility testing is the gold standard for diagnosis; however, the use of plasma mNGS may expedite the diagnosis.

Healthcare-associated central nervous system infections

PURPOSE OF REVIEW

The aim of this review is to provide a practical and updated summary on healthcare-associated central nervous system infections and their management.

RECENT FINDINGS

The term 'healthcare-associated ventriculitis and meningitis' has recently been coined and clinical practical guidelines have been published on the management of these nosocomial infections. Many aspects have still to be further investigated (e.g. cerebrospinal fluid biomarkers, indications for novel antibiotics, intrathecal antimicrobial regimens).

SUMMARY

Clinicians should maintain a high index of suspicion for healthcare-associated central nervous system infections in patients with specific risk factors (i.e. recent neurosurgery, cerebrospinal shunts, drains or implantable devices, head/spinal traumatic events), taking into account systemic signs, and alterations in microbiological, imaging, cerebrospinal fluid findings. The diagnosis is often difficult to confirm because of reduced levels of consciousness or coma. Both Gram-positive and Gram-negative (often multidrug-resistant or even pandrug-resistant) microorganisms may be the cause. Selection of antibiotics must consider susceptibility and penetration into the central nervous system. Ineffective treatments are frequent, and mortality can reach 60%. Future research should focus on the diagnostic performance of biomarkers and on the use of novel antimicrobial regimens, especially for the treatment of difficult to treat infections.

Population pharmacokinetic model of vancomycin in postoperative neurosurgical patients

Objective: Vancomycin is commonly used in postoperative neurosurgical patients for empirical anti-infective treatment due to the low success rate of bacterial culture in cerebrospinal fluid (about 20%) and the high mortality of intracranial infection. At conventional doses, the rate of target achievement for vancomycin trough concentration is low and the pharmacokinetics of vancomycin varies greatly in these patients, which often leads to treatment failure. The objective of this study was to establish a population pharmacokinetic (PPK) model of vancomycin in postoperative neurosurgical patients for precision medicine.

Method: A total of 895 vancomycin plasma concentrations from 560 patients (497 postoperative neurosurgical patients) were retrospectively collected. The model was analyzed by nonlinear mixed effects modeling method. One-compartment model and mixed residual model was employed. The influence of covariates on model parameters was tested by forward addition and backward elimination. Goodness-of-fit, bootstrap and visual predictive check were used for model evaluation. Monte Carlo simulations were employed for dosing strategies with AUC₂₄ targets 400–600.

Result: Estimated glomerular filtration rate (eGFR), body weight (BW) and mannitol had significant influence on vancomycin clearance (CL). eGFR(mL/min)=144×(Scr/a)b×0.993age, for female, a = 0.7, Scr ≤ 0.7 mg/dl, b = −0.329, Scr > 0.7 mg/dl, b = −1.209; for male, a = 0.9, Scr ≤ 0.9 mg/dl, b = −0.411, Scr > 0.9 mg/dl, b = −1.210. Vancomycin clearance was accelerated when co-medicated with mannitol and increased with eGFR and BW. In the final model, the population typical value is 7.98 L/h for CL and 60.2 L for apparent distribution volume, CL (L/h)=7.98×(eGFR/115.2)0.8×(BW/70)0.3×eA, where A = 0.13 when co-medicated with mannitol, otherwise A = 0. The model is stable and effective, with good predictability.

Conclusion: In postoperative neurosurgical patients, a higher dose of vancomycin may be required due to the augmented renal function and the commonly used mannitol, especially in those with high body weight. Our vancomycin PPK model could be used for individualized treatment in postoperative neurosurgical patients.

Clinical cure of a difficult-to-treat resistant Pseudomonas aeruginosa ventriculitis using cefiderocol: a case report and literature review

Ventriculitis is a complication of meningitis (community-acquired or nosocomial) or other central nervous system (CNS) infections such as brain abscess. They are associated with a different spectrum of microorganisms, from resistant gram-negative bacilli to staphylococci, that can lead serious illness with high mortality. Difficult-to-treat resistance (DTR) gram-negative bacilli may increase to 20% of deaths respective to susceptible isolates of the same bacteria. We present the first report of a clinical cured case of DTR Pseudomonas aeruginosa ventriculitis in which cefiderocol penetration into the CNS has been confirmed in blood and cerebrospinal fluid. Cefiderocol might be considered for difficult-to-treat CNS infections in view of the recent new cases published as well as our case.

Spatial and temporal variation of routine parameters: pitfalls in the cerebrospinal fluid analysis in central nervous system infections

The cerebrospinal fluid (CSF) space is convoluted. CSF flow oscillates with a net flow from the ventricles towards the cerebral and spinal subarachnoid space. This flow is influenced by heartbeats, breath, head or body movements as well as the activity of the ciliated epithelium of the plexus and ventricular ependyma. The shape of the CSF space and the CSF flow preclude rapid equilibration of cells, proteins and smaller compounds between the different parts of the compartment. In this review including reinterpretation of previously published data we illustrate, how anatomical and (patho)physiological conditions can influence routine CSF analysis. Equilibration of the components of the CSF depends on the size of the molecule or particle, e.g., lactate is distributed in the CSF more homogeneously than proteins or cells. The concentrations of blood-derived compounds usually increase from the ventricles to the lumbar CSF space, whereas the concentrations of brain-derived compounds usually decrease. Under special conditions, in particular when distribution is impaired, the rostro-caudal gradient of blood-derived compounds can be reversed. In the last century, several researchers attempted to define typical CSF findings for the diagnosis of several inflammatory diseases based on routine parameters. Because of the high spatial and temporal variations, findings considered typical of certain CNS diseases often are absent in parts of or even in the entire CSF compartment. In CNS infections, identification of the pathogen by culture, antigen detection or molecular methods is essential for diagnosis.

Pharmacokinetics and pharmacodynamics of peptide antibiotics

Antimicrobial resistance is a major global health challenge. As few new efficacious antibiotics will become available in the near future, peptide antibiotics continue to be major therapeutic options for treating infections caused by multidrug-resistant pathogens. Rational use of antibiotics requires optimisation of the pharmacokinetics and pharmacodynamics for the treatment of different types of infections. Toxicodynamics must also be considered to improve the safety of antibiotic use and, where appropriate, to guide therapeutic drug monitoring. This review focuses on the pharmacokinetics/pharmacodynamics/toxicodynamics of peptide antibiotics against multidrug-resistant Gram-negative and Gram-positive pathogens. Optimising antibiotic exposure at the infection site is essential for improving their efficacy and minimising emergence of resistance.

Conventional Antifungals for Invasive Infections Delivered by Unconventional Methods; Aerosols, Irrigants, Directed Injections and Impregnated Cement

The administration of approved antifungals via unapproved formulations or administration routes (such as aerosol, direct injection, irrigation, topical formulation and antifungal-impregnated orthopedic beads or cement) may be resorted to in an attempt to optimize drug exposure while minimizing toxicities and/or drug interactions associated with conventional (systemic) administrations. Existing data regarding such administrations are mostly restricted to uncontrolled case reports of patients with diseases refractory to conventional therapies. Attribution of efficacy and tolerability is most often problematic. This review updates prior published summaries, reflecting the most recent data and its application by available prevention and treatment guidelines for invasive fungal infections. Of the various dosage forms and antifungals, perhaps none is more widely reported than the application of amphotericin B-containing aerosols for the prevention of invasive mold infections (notably Aspergillus spp.).

Clinical Pharmacogenetics Implementation Consortium Guideline for the Use of Aminoglycosides Based on MT-RNR1 Genotype

Aminoglycosides are widely used antibiotics with notable side effects, such as nephrotoxicity, vestibulotoxicity, and sensorineural hearing loss (cochleotoxicity). MT-RNR1 is a gene that encodes the 12s rRNA subunit and is the mitochondrial homologue of the prokaryotic 16s rRNA. Some MT-RNR1 variants (i.e., m.1095T>C; m.1494C>T; m.1555A>G) more closely resemble the bacterial 16s rRNA subunit and result in increased risk of aminoglycoside-induced hearing loss. Use of aminoglycosides should be avoided in individuals with an MT-RNR1 variant associated with an increased risk of aminoglycoside-induced hearing loss unless the high risk of permanent hearing loss is outweighed by the severity of infection and safe or effective alternative therapies are not available. We summarize evidence from the literature supporting this association and provide therapeutic recommendations for the use of aminoglycosides based on MT-RNR1 genotype (updates at https://cpicpgx.org/guidelines/ and www.pharmgkb.org).

Current Perspectives on the Diagnosis and Management of Healthcare-Associated Ventriculitis and Meningitis

Ventriculitis or post-neurosurgical meningitis or healthcare-associated ventriculitis and meningitis (VM) is a severe infection that complicates central nervous system operations or is related to the use of neurosurgical devices or drainage catheters. It can further deteriorate patients who have already presented significant neurologic injury and is associated with high morbidity, mortality, and poor functional outcome. VM can be difficult to distinguish from aseptic meningitis, inflammation that follows hemorrhagic strokes and neurosurgical operations. The associated microorganisms can be either skin flora or nosocomial pathogens, most commonly, Gram-negative bacteria. Classical microbiology can fail to isolate the culprit pathogen. Novel cerebrospinal fluid (CSF) biomarkers and molecular microbiology can fill the diagnostic gap and expedite pathogen identification and treatment. The pathogens may demonstrate significant resistant patterns and their antibiotic treatment can be difficult, as many important drug classes, including the beta-lactams and the glycopeptides, hardly penetrate to the CSF, and do not achieve therapeutic levels at the site of the infection. Treatment modifications, such as higher daily dose and prolonged or continuous administration, might increase antibiotic levels in the site of infection and facilitate pathogens clearance. However, in the case of therapeutic failure or infection due to difficult-to-treat bacteria, the direct antibiotic instillation into the CSF, in addition to the intravenous antibiotic delivery, may help in the resolution of infection. However, intraventricular antibiotic therapy may result in aseptic meningitis and seizures, concerning the administration of aminoglycosides, polymyxins, and vancomycin. Meanwhile, bacteria form biofilms on the catheter or the device that should routinely be removed. Novel neurosurgical treatment modalities comprise endoscopic evacuation of debris and irrigation of the ventricles. VM prevention includes perioperative antibiotics, antimicrobial impregnated catheters, and the implementation of standardized protocols, regarding catheter insertion and manipulation.

Efficacy of Vancomycin and Meropenem in Central Nervous System Infections in Children and Adults: Current Update

The current antimicrobial therapy of bacterial infections of the central nervous system (CNS) in adults and pediatric patients is faced with many pitfalls as the drugs have to reach necessary levels in serum and cross the blood-brain barrier. Furthermore, several studies report that different factors such as the structure of the antimicrobial agent, the severity of disease, or the degree of inflammation play a significant role. Despite the available attempts to establish pharmacokinetic (PK) modeling to improve the required dosing regimen for adults and pediatric patients, conclusive recommendations for the best therapeutic strategies are still lacking. For instance, bacterial meningitis, the most common CNS infections, and ventriculitis, a severe complication of meningitis, are still associated with 10% and 30% mortality, respectively. Several studies report on the use of vancomycin and meropenem to manage meningitis and ventriculitis; therefore, this review aims to shed light on the current knowledge about their use in adults and pediatric patients. Consequently, studies published from 2015 until mid-July 2021 are included, and data about the study population, levels of drugs in serum and cerebrospinal fluid (CSF), and measured PK data in serum and CSF are provided. The overall aim is to provide the readers a recent reference that summarizes the pitfalls and success of the current therapy and emphasizes the importance of performing more studies to improve the clinical outcome of the current therapeutical approach.

Treatment of MRSA infections in India: Clinical insights from a Delphi analysis

PURPOSE

International and Indian guidelines for the management of patients with methicillin-resistant Staphylococcus aureus (MRSA) infections are available, but the local guidelines are not MRSA-specific. This study aimed to provide clinical insights for the treatment of MRSA infections in India.

METHODS

We used a three-step modified Delphi method to obtain insights. Ten experts comprising infectious disease specialists, microbiologists, pulmonologists, and critical care experts agreed to participate in the analysis. In round 1, a total of 161 statements were circulated to the panel and the experts were asked to 'agree' or 'disagree' by responding 'yes' or 'no' to each statement and provide comments. The same process was used for 73 statements in round 2. Direct interaction with the experts was carried out in round 3 wherein 35 statements were discussed. At least 80% of the experts had to agree for a statement to reach concordance.

RESULTS

Eighty-eight statements in round 1, thirty-eight statements in round 2, and eight statements in round 3 reached concordance and were accepted without modification. The final document comprised 152 statements on the management of various syndromes associated with MRSA such as skin and soft tissue infections, bacteremia and endocarditis, pneumonia, bone and joint infections, and central nervous system infections.

CONCLUSIONS

This analysis will assist clinicians in India to choose an appropriate course of action for MRSA infections.

Deciphering the role of nanoparticles for management of bacterial meningitis: an update on recent studies

Meningitis is an inflammation of the protective membranes called meninges and fluid adjacent the brain and spinal cord. The inflammatory progression expands all through subarachnoid space of the brain and spinal cord and occupies the ventricles. The pathogens like bacteria, fungi, viruses, or parasites are main sources of infection causing meningitis. Bacterial meningitis is a life-threatening health problem that which needs instantaneous apprehension and treatment. Nesseria meningitidis, Streptococcus pneumoniae, and Haemophilus flu are major widespread factors causing bacterial meningitis. The conventional drug delivery approaches encounter difficulty in crossing this blood-brain barrier (BBB) and therefore are insufficient to elicit the desired pharmacological effect as required for treatment of meningitis. Therefore, application of nanoparticle-based drug delivery systems has become imperative for successful dealing with this deadly disease. The nanoparticles have ability to across BBB via four important transport mechanisms, i.e., paracellular transport, transcellular (transcytosis), endocytosis (adsorptive transcytosis), and receptor-mediated transcytosis. In this review, we reminisce distinctive symptoms of meningitis, and provide an overview of various types of bacterial meningitis, with a focus on its epidemiology, pathogenesis, and pathophysiology. This review describes conventional therapeutic approaches for treatment of meningitis and the problems encountered by them while transmitting across tight junctions of BBB. The nanotechnology approaches like functionalized polymeric nanoparticles, solid lipid nanoparticles, nanostructured lipid carrier, nanoemulsion, liposomes, transferosomes, and carbon nanotubes which have been recently evaluated for treatment or detection of bacterial meningitis have been focused. This review has also briefly summarized the recent patents and clinical status of therapeutic modalities for meningitis.

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.

Antimicrobial use in central nervous system infections

PURPOSE OF REVIEW

Central nervous system (CNS) infections are associated with high rates of morbidity and mortality. The purpose of this review is to summarize current antimicrobial therapies, as well as, updates in the management of community-acquired meningitis and healthcare-associated meningitis and ventriculitis.

RECENT FINDINGS

Due to the increasing rates of multidrug resistant and extensively-drug resistant organisms, available antimicrobials are limited. Novel treatment options include newer systemic antimicrobials and antimicrobials that have previously limited data in the management of CNS infections. Although limited by retrospective data, intrathecal (IT) and intraventricular (IVT) routes of administration offer the opportunity for antimicrobials that conventionally have minimal cerebrospinal fluid (CSF) penetration to achieve high CSF concentrations while minimizing systemic exposure.

SUMMARY

Updates in the use of systemic, IT, and IVT antimicrobials offer promise as therapeutic options for CNS infections. Additional pharmacokinetic and prospective data are needed to confirm these findings.

Epidemiology of patients with central nervous system infections, mainly neurosurgical patients: a retrospective study from 2012 to 2019 in a teaching hospital in China

BACKGROUND

Central nervous system (CNS) infections are relatively rare but are associated with high mortality worldwide. Empirical antimicrobial therapy is crucial for the survival of patients with CNS infections, and should be based on the knowledge of the pathogen distribution and antibiotic sensitivities. The aim of this study was to investigate the features of pathogens in patients with CNS infections in North China and evaluate the risk factors for mortality and multi-drug-resistant (MDR) bacterial infections.

METHODS

A retrospective study was conducted with patients with positive cerebrospinal fluid (CSF) cultures in a teaching hospital from January 2012 to December 2019. The following data were collected: demographic characteristics, laboratory data, causative organisms and antimicrobial sensitivity results. Data were analyzed with SPSS 16.0. Univariate analysis and binary logistic regression analyses were performed to identify the risk factors for mortality and MDR bacterial infections.

RESULTS

A total of 72 patients were diagnosed with CNS infections, and 86 isolates were identified. The proportions of Gram-positive bacteria, Gram-negative bacteria and fungi were 59.3, 30.2 and 10.5%, respectively. The predominant Gram-positive bacteria was Coagulase-negative Staphylococci. Acinetobacter baumannii, Escherichia coli and Klebsiella spp. were the predominant Gram-negative bacteria. Compared to 2012-2015 years, the proportion of Gram-negative bacteria increased markedly during 2016-2019 years. Coagulase-negative Staphylococci, Streptococcus pneumoniae and Enterococcus faecium had 100% sensitivity to vancomycin, teicoplanin and linezolid. Acinetobacter baumannii and Klebsiella pneumoniae were 100% sensitive to tigecycline. Escherichia coli had 100% sensitivity to amikacin, meropenem and imipenem. The overall mortality rate in the 72 patients was 30.6%. In multivariate analysis, age > 50 years, pulmonary infections and CSF glucose level < the normal value were associated with poor outcomes. CSF adenosine deaminase level > the normal value and the presence of external ventricular drainage/lumbar cistern drainage were associated with MDR bacterial infections.

CONCLUSIONS

The mortality rate due to CNS infections reached 30.6% in our study. The proportion of Gram-negative bacteria has increased markedly in recent years. We should give particular attention to patients with risk factors for mortality and MDR bacterial infections mentioned above.

Combination therapy for disseminated strongyloidiasis with associated vancomycin-resistant, linezolid-intermediate Enterococcus faecium meningitis: A case report

WHAT IS KNOWN AND OBJECTIVE

The rhabditid nematode Strongyloides stercoralis is the major causative agent of disseminated strongyloidiasis (DS). In rare cases, DS has caused enterococcal meningitis. If DS-associated vancomycin-resistant Enterococcus faecium (VRE) meningitis is suspected, combination antibiotic therapy should be considered.

CASE SUMMARY

We present a case of a 61-year-old male who developed DS associated with vancomycin-resistant and linezolid-intermediate E. faecium meningitis after receiving corticosteroids. The VRE meningitis was treated with high-dose daptomycin 12 mg/kg, linezolid, tigecycline and quinupristin/dalfopristin. Despite negative cultures, the patient expired.

WHAT IS NEW AND CONCLUSION

In patients with DS-associated VRE meningitis, early use of combination therapy may be warranted to improve patient outcomes.