Multidrug-resistant Enterococcus faecium meningitis in a toddler: characterization of the organism and successful treatment with intraventricular daptomycin and intravenous tigecycline

Six-year analysis of key monitoring for bacterial strain distribution and antibiotic sensitivity in a hospital

BACKGROUND

With the widespread use of antimicrobial drugs, bacterial resistance has become a significant problem, posing a serious threat to public health. The prevalence of clinical infection strains in hospitals and their drug sensitivities are key to the appropriate use of antibiotics in clinical practice.

AIM

To identify prevalent bacteria and their antibiotic resistance profiles in a hospital setting, thereby guiding effective antibiotic usage by clinicians.

METHODS

Specimens from across the institution were collected by the microbiology laboratory. The VITEK 2 compact fully automatic analyzer was used for bacterial identification and antibiotic sensitivity testing, and the WHONET5.6 software was utilized for statistical analysis.

RESULTS

A total of 12062 bacterial strains of key monitoring significance were detected. Staphylococcus aureus demonstrated widespread resistance to penicillin, but none of the strains were resistant to vancomycin or linezolid. Moreover, 219 strains of methicillin-resistant coagulase-negative staphylococci and 110 strains of methicillin-resistant Staphylococcus aureus were detected. Enterococcus faecalis showed moderate resistance to the third-generation quinolones ciprofloxacin and levofloxacin, but its resistance to nitrofurantoin and tetracycline was low. Enterococcus faecium displayed significantly lower resistance to third- and fourth-generation quinolones than Enterococcus faecalis. The resistance of two key monitoring strains, Escherichia coli and Klebsiella pneumoniae, to piperacillin/tazobactam was 5%-8%. However, none of the Escherichia coli and Klebsiella pneumoniae strains were resistant to meropenem. The resistance of Acinetobacter baumannii to piperacillin/sulbactam was nearly 90%. Nonetheless, the resistance to tigecycline was low, and Pseudomonas aeruginosa demonstrated minimal resistance in the antibiotic sensitivity test, maintaining a resistance of < 10% to the cephalosporin antibiotics cefotetan and cefoperazone over the last 6 years. The resistance to amikacin remained at 0.2% over the past 3 years.

CONCLUSION

Our hospital's overall antibiotic resistance rate was relatively stable from 2017 to 2022. The detection rates of key monitoring strains are reported quarterly and their resistance dynamics are monitored and communicated to the entire hospital, which can guide clinical antibiotic selection.

Daptomycin for the treatment of acute bacterial meningitis: a narrative review

BACKGROUND

There is a growing interest in the utilization of daptomycin for the treatment of multi-drug resistant, Gram-positive infections. Pharmacokinetic studies suggest that daptomycin could penetrate into the cerebrospinal fluid, albeit to a small extent. The objective of this review was to evaluate the available clinical evidence for daptomycin use in acute bacterial meningitis of both pediatric and adult patients.

METHODS

Electronic databases were searched up to June 2022 for studies published on the topic. The inclusion criteria were met if the study reported the use of intravenous daptomycin (more than a single dose) for the treatment of diagnosed acute bacterial meningitis.

RESULTS

A total of 21 case reports were identified that met the inclusion criteria. These suggest that daptomycin could be safe and effective alternative in achieving clinical cure of meningitis. In these studies, daptomycin was used in the event of treatment failure, patient intolerance, or bacterial resistance to first-line agents.

CONCLUSIONS

Daptomycin has potential to be an alternative to standard care for meningitis caused by Gram-positive bacteria in the future; however, more robust research is required to establish an optimal dosing regimen, duration of therapy, and place in therapy for the management of meningitis.

Therapeutic Options and Outcomes for the Treatment of Children with Gram-Positive Bacteria with Resistances of Concern: A Systematic Review

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant coagulase-negative Staphylococci (MR-CoNS), and vancomycin-resistant Enterococci (VRE) are increasing worldwide and represent a threat for the limited treatment options in pediatric patients and neonates compared to adults. Recommendations in pediatrics are mainly extrapolated from adults' studies.

METHODS

A literature search for the treatment of these pathogens in children (<18 years old) was conducted in Embase, MEDLINE, and Cochrane Library. Studies reporting data on single-patient-level outcomes related to a specific antibiotic treatment for multidrug resistant (MDR) Gram-positive bacterial infection in children were included. Studies reporting data from adults and children were included if single-pediatric-level information could be identified (PROSPERO registration: CRD42022383867).

RESULTS

The search identified 11,740 studies (since January 2000), of which 48 fulfilled both the inclusion and the exclusion criteria and were included in the analysis: 29 for MRSA, 20 for VRE, and seven for MR-CoNS. Most studies were retrospective studies. Vancomycin was mainly used as a comparator, while linezolid and daptomycin were the most studied antimicrobials showing good efficacy.

CONCLUSIONS

Linezolid showed a safety and efficacy profile in a neonatal setting; daptomycin is increasingly used for MRSA, but the evidence is scarce for VRE.

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.

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.

Dexamethasone Protects Against Ischaemic Brain Injury via Inhibiting the pAkt Signalling Pathway Through Increasing Hap1

Dexamethasone has been reported to reduce the infarct volume and protect neurological function after ischaemic injury, but the mechanism of Dex in brain injury is not clear. We aimed to study the mechanism by which dexamethasone protects against ischaemic brain injury. Western blotting was to detected the expression of Hap1,TrkB, Akt and Erk; TTC staining to analyse ischemic volume; neurological deficit evaluation to test degree of ischemic injury; immunofluorescence staining to analyse the distribution of Hap1; and the MCAO model was used to study these processes. All data are expressed as the means ± SEM and were analysed by GraphPad Prism 6. P < 0.05 was considered statistically significant. After dexamethasone (Dex) treatment, Hap1 levels were increased and peaked at 2 days; then, we found that body weight was decreased in Hap1-/+ mice. Further study showed that Dex treatment reduced the ischaemic volume and improved neurological function. Finally, we showed that Hap1 regulated the levels of pTrkB, pAkt and pErk 1/2 in ischaemic injury after Dex treatment. Our data suggest that dexamethasone protects against ischaemic brain injury by inhibiting the pAkt signalling pathway through increasing Hap1.

[Off label uses of tigecycline]

INTRODUCTION

Tigecycline is a relatively new antibiotic that have very limited valid indications. When no other alternative is available, this drug is widely used off label with promising results. The objective of this study is to summarize the different off label uses of tigecycline so that we can decide when and how to prescribe it in the absence of guidelines.

MATERIAL AND METHODS

This study a revue of the literature collecting all the articles concerning the off label uses of tigecycline.

RESULTS

Tigecycline was widely prescribed, off label, to treat infections with controversial results. Randomised clinical trials were conducted to evaluate its use to treat pneumonia. The results for this indication have a respectable level of evidence. For the other indications, the data collected was insufficient to support tigecycline prescription. In fact, different protocols were used which makes it hard to evaluate the efficacy and to conclude to the best treatment regimen. A tendency to prescribe high doses of the molecule was noted in different studies. When prescribed off label, tigecycline prescriptions were associated with a higher mortality and incidence of side effects.

CONCLUSION

The tigecycline remains a valid option for the treatment of infections dues to multi-resistant bacteria especially when other alternatives are scarce or in cases of renal failure.

Use of Intraventricular Medications in Critically Ill Patients: A Systematic Review

New evidence and increased use of intracranial devices have increased the frequency of intraventricular (IVT) medication administration in the neurologic intensive care unit. Significant benefits and risks are associated with administration of medications directly into the central nervous system. This review summarizes important literature, along with key information for clinicians regarding the administration, dosing, monitoring, and adverse effects related to IVT medication usage. Multiple medications have supporting literature for their use in critically ill patients including amphotericin B, aminoglycosides, colistimethate, daptomycin, quinupristin/dalfopristin, vancomycin, alteplase, and nicardipine. Sterile preparation and delivery, along with different types of devices that support medication administration, are also reviewed. One randomized, placebo-controlled trial of alteplase demonstrated decreased mortality but no change in good functional outcome. Other reports of IVT medication use are mainly limited to case reports and retrospective case series. There is a need for increased research on the topic; however, several practical barriers decrease the likelihood of a large, placebo-controlled, prospective study for most indications. Providers should consider implementing protocols to maximize safety of IVT medication delivery to ensure optimal patient outcomes.

Intrathecal Antibacterial and Antifungal Therapies

Intrathecal administration of anti-infectives is indicated in central nervous system infections by multiresistant pathogens when drugs that can reach adequate cerebrospinal fluid (CSF) concentrations by systemic therapy are not available. Antibiotics that readily pass the blood-brain and blood-CSF barriers and/or that have low toxicity allowing an increase in the daily dosage should not be used for intrathecal therapy. Intrathecal therapy is accompanied by systemic treatment. Antibacterials indispensable for intrathecal therapy include aminoglycosides, colistin, daptomycin, tigecycline, and vancomycin. Limited experience suggests the utility of the antifungals amphotericin B and caspofungin. Intraventricular administration ensures distribution throughout the CSF compartment, whereas intralumbar dosing often fails to attain adequate antibiotic concentrations in the ventricles. The individual dose is determined by the estimated size of the CSF space and by the estimated clearance from CSF. For moderately lipophilic anti-infectives with a molecular weight above approximately 1,000 g/mol, as well as for hydrophilic drugs with a molecular weight above approximately 400 g/mol, one daily dose is normally adequate. The ventricular drain should be clamped for 15 to 120 min to facilitate the distribution of the anti-infective in the CSF space. Therapeutic drug monitoring of the trough levels is necessary only in cases of therapeutic failure.

Prevención y tratamiento de las infecciones del sitio operatorio en neurocirugía. Estado del arte

El manejo adecuado de las infecciones del sitio operatorio (ISO) en neurocirugía es fundamental para la disminución de la carga de morbilidad y mortalidad en estos pacientes. La sospecha y confirmación diagnóstica asociadas al aislamiento microbiológico son esenciales para asegurar el tratamiento oportuno y el adecuado gerenciamiento de antibióticos. En esta revisión se presenta de forma resumida los puntos fundamentales para la prevención y el tratamiento de infecciones del sitio operatorio en neurocirugía y se incluye un apartado sobre el uso de antibióticos intratecales/intraventriculares.

Acute myeloid leukemia with central nervous system extension and subdural seeding of vancomycin-resistant Enterococcus faecium after bilateral subdural hematomas treated with subdural daptomycin administration

Background:

We present a rare case of comorbid relapsed acute myeloid leukemia (AML) with the involvement of the central nervous system (CNS) and subdural seeding of vancomycin-resistant Enterococcusfaecium (VRE). The safety profile, treatment approach with pharmacokinetic considerations, and evaluation of success for bilateral subdural administration of daptomycin after subdural hematoma (SDH) are assessed.

Case Description:

A 45-year-old male with a history of AML who underwent chemotherapy (induction with 7 + 3) was admitted to oncology with relapsed AML confirmed by bone marrow biopsy, complicated by neutropenic fever and VRE bacteremia. After acute neurological changes with image confirmation of mixed- density bilateral SDHs secondary to thrombocytopenia, the patient was admitted to the neurosurgery unit and underwent bilateral burr hole craniotomies for subdural evacuation with the placement of the left and right subdural drains. Culture of the subdural specimen confirmed VRE seeding of the subdural space. The patient received the first dose of daptomycin into the bilateral subdural spaces 2 days after evacuation and was noted to have acute improvement on neurological examination, followed by a second administration to the left subdural space 5 days after evacuation with bilateral drains pulled thereafter.

Conclusion:

In this patient, the complication of relapsed AML may have contributed to the rare extension of VRE into the CNS space. Screening for patients at risk of AML with CNS involvement and addressing coagulopathy and risk of infection may help mitigate morbidity. Bilateral administration of subdural daptomycin bolus into the subdural space was tolerated and possibly contributed to the patient’s neurological improvement during an extended hospital course.

Tigecycline treatment in a liver transplant infant with carbapenem-resistant Escherichia coli infection: Case report

INTRODUCTION

During the past decade, the rate of carbapenem resistance among Enterobacteriaceae, mostly in Escherichia coli and Klebsiella pneumoniae, has significantly increased worldwide. It is a great challenge for the choice of drug treatment especially in children.Tigecycline is the first drug in the glycylcycline class of antibiotics. For children, the China Food and Drug Administration and US Food and Drug Administration postulated that tigecycline is not recommended. It must be used only as salvage therapy for life-threatening infections in critically ill children who have no alternative treatment options.

PATIENT CONCERNS

A male pediatric case of 4.5 months was blood stream infection after liver transplantation. The blood cultures obtained grew Gram-negative rods, which reportedly grew a strain of extended-spectrum β-lactamase and carbapenemases-producing Escherichia coli within 10 hours. All bacterial isolates were found to be resistant to all antimicrobial agents except aminoglycosides and tigecycline.

DIAGNOSES

Complicated intra-abdominal infection, central line-associated blood stream infection.

INTERVENTIONS

The blood stream infection with carbapenem-resistant Escherichia coli after liver transplantation was cured by tigecycline.

OUTCOMES

The patient's condition continued to improve, then transferred to general ward.

CONCLUSION

The following report, to our knowledge, is the youngest liver transplantation patient who used tigecycline treatment around the world. It provides reference and experience for the use of tigecycline in infants with severe infections.

Intraventricular Plus Intravenous Tigecycline for the Treatment of Daptomycin Nonsusceptible Vancomycin-Resistant Enterococci in an Infant with Ventriculoperitoneal Shunt Infection

BACKGROUND

Ventriculoperitoneal (VP) shunt infection, which is 1 of the most important complications of VP shunt is observed at a rate of 4%-17%. Staphylococcus epidermidis is the most common causative agent. Vancomycin-resistant Enterococcus (VRE) is an increasingly common nosocomial pathogen that rarely causes central nervous system infections globally. Current treatment options that have shown appreciable activity against various VRE infections include daptomycin, linezolid, inquinupristin/dalfopristin, and tigecycline. Daptomycin has a particular mode of action and a potent bactericidal activity, making it a useful addition to the clinician's antibiotic collection. Global surveillance data indicate <1.0% rates of daptomycin resistance in enterococci.

CASE DESCRIPTION

Here, we describe, to the best of our knowledge, the first case of successful intraventricular plus intravenous use of tigecycline to treat VP shunt infections caused by daptomycin resistant VRE faecium.

CONCLUSION

Tigecycline is a life-saving option in the treatment of resistant nosocomial infections but it has not yet been approved for use and there are not enough data in terms of dose and side effects associated with its use in children.

In search of novel protein drug targets for treatment of Enterococcus faecalis infections

Enterococcus faecalis (Ef) is one of the major pathogens involved in hospital-acquired infections. It can cause nosocomial bacteremia, surgical wound infection, and urinary tract infection. It is important to mention here that Ef is developing resistance against many commonly occurring antibiotics. The occurrence of multidrug resistance (MDR) and extensive-drug resistance (XDR) is now posing a major challenge to the medical community. In this regard, to combat the infections caused by Ef, we have to look for an alternative. Rational structure-based drug design exploits the three-dimensional structure of the target protein, which can be unraveled by various techniques such as X-ray crystallography or nuclear magnetic resonance (NMR) spectroscopy. In this review, we have discussed the complete picture of Ef infections, the possible treatment available at present, and the alternative treatment options to be explored. This study will help in better understanding of novel biological targets against Ef and the compounds, which are likely to bind with these targets. Using these detailed structural informations, rational structure-based drug design is achievable and tight inhibitors against Ef can be prepared.

Intravenous and Intraventricular Daptomycin Plus Intravenous Linezolid Treatment of an Infant with Vancomycin-Resistant Enterococci-Induced Ventriculoperitoneal Shunt Infection

BACKGROUND

The rate of ventriculoperitoneal (VP) shunt infection is reported between 3% and 20%. Vancomycin-resistant enterococci (VRE) are increasingly prevalent nosocomial pathogens worldwide, and they rarely cause infections to the central nervous system. Daptomycin is a cyclic lipopeptide effective antibiotic because of its rapid bactericidal effect. It is a life-saving treatment option for meningitis, bacteremia, sepsis, endocarditis, and urinary system infections caused by VRE.

CASE DESCRIPTION

Here, we present a 2.5-month-old infant boy with a ventriculoperitoneal shunt infection caused by vancomycin-resistant Enterococcus faecium. This is the first report of a pediatric VP shunt infection caused by VRE and treated with a combination of intravenous (IV) linezolid IV and intraventricular (IVT) daptomycin.

CONCLUSION

The patient was admitted to the medical center with umbilical discharge, and shunt revision was applied with the thought of shunt dysfunction. Intermittent umbilical cerebrospinal fluid (CSF) leakage continued, and the patient experienced a fever 2 weeks after the operation. VRE growth in his CSF culture was treated by meropenem and linezolid. Upon continuation of the growth afterwards, the patient was referred to our hospital and underwent extraventricular drainage, and IV linezolid, IV daptomycin (8 mg/kg per day), and IVT daptomycin (2.5 mg/kg per day) was scheduled as treatment. On the fifth day of treatment, there was no growth in the culture, and no side effects were observed during the treatment. A VP shunt was placed in the patient for the 15 days of IV daptomycin plus IVT treatment, and 36 days of linezolid. No infection was observed in the 8-month follow-up period.

Intraventricular tigecycline for the treatment of shunt infection: a case in pediatrics

Ventriculoperitoneal (VP) shunt infections are seen in 3%-17% of patients with VP shunts. These infections may cause severe morbidity and mortality. Staphylococci are the most common cause of CSF shunt-associated infections, although gram-negative bacteria (especially multidrug-resistant [MDR] and extensive drug-resistant [XDR] bacteria) also play an important role. Due to increased antibiotic resistance, sometimes off-label usage of antibiotics is considered. Tigecycline is one of these antibiotics. It should not be used unless there are no other antibiotic treatment options available, especially in children. It belongs to the glycylcycline class of antibiotic agents and inhibits protein translation in bacteria by binding to the 30S ribosomal subunit. The authors describe the case of a patient who had an XDR Klebsiella pneumoniae-positive VP shunt infection. After removal of his VP shunt, an external ventricular drain was inserted, and the patient was treated with a combination of intravenous (1.2 mg/kg/day) and intraventricular (4 mg/day) tigecycline in addition to his meropenem (120 mg/kg/day) treatment. On the 7th day of the combined therapy, his CSF culture was sterile. Because tigecycline distribution into the tissues is not sufficient with intravenous administration, combining it with intraventricular infusion can provide new treatment methods. However, further studies are needed for its use as a treatment method in children.

Preliminary experience with tigecycline treatment for severe infection in children

Severe infection is a primary cause of mortality in children facing challenges from multidrug-resistant (MDR) pathogens, particularly MDR Acinetobacter baumannii. Tigecycline has an expanded spectrum of antibacterial activity, and some successful instances of its use in children have been reported. We conducted a retrospective chart review of children treated at a tertiary hospital between May 1, 2012 and May 1, 2017 to examine the efficacy and safety of tigecycline in children with severe infection. A total of 110 patients (69 males) were enrolled in this study, including 46 MDR A. baumannii infection patients, encompassing 51 A. baumannii strains. Totally, the median duration of tigecycline therapy was 10 days (range, 2-47 days), with a clinical improvement rate of 47.27% (52/110). In A. baumannii infection group, the clinical improvement rate was 50% (23/46) and the microbiology eradication rate was 50.98% (26/51). No adverse events were reported during therapy; however, in one case, a 9-year-old boy with hematologic disease developed tooth discoloration.Conclusion: Although some patients benefited from tigecycline, the efficacy and safety of tigecycline should not be overvalued. Additional data from randomized controlled trials are required to assess the administration of tigecycline. What is Known: • Severe infection is a primary cause of mortality in pediatric patients and its treatment is facing challenges from an increasing number of multidrug-resistant (MDR) pathogens. • Tigecycline has an expanded spectrum of antibacterial activity. • Several case reports have indicated that tigecycline could be used as a salvage therapy in children when options are limited or non-existent. What is New: • We found that rate of clinical improvement was different in various groups of different infection. The efficacy of tigecycline should not be overvalued. • Six dosage models and different infection types were observed in our series, with different improvement and eradication rate, indicating that more data are required to identify a proper tigecycline dosage.

Tigecycline salvage therapy for critically ill children with multidrug-resistant/extensively drug-resistant infections after surgery

OBJECTIVE

The aim of this study was to evaluate the efficacy and safety of salvage therapy of tigecycline in critically ill children with infections caused by multidrug-resistant (MDR)/extensively drug-resistant (XDR) bacteria after surgery.

METHODS

A retrospective chart review was performed of critically ill children after surgery who had received tigecycline for ≥3days between June 2012 and May 2016 in the surgical intensive care unit of a tertiary level children's hospital.

RESULTS

Of 6442 consecutive children admitted after surgery, a total of 22 were enrolled. They had a median age of 7.5 months (interquartile range (IQR), 6 months to 4 years) and a median weight of 7.3kg (IQR, 5.1-12.5kg). Patients received tigecycline for a median 17days (IQR, 12-20 days). The median intensive care unit stay was 56days (IQR, 38-61 days) and median hospital stay was 78days (IQR, 61-94 days). Tigecycline was prescribed as culture-directed therapy in 91% of patients and as empirical therapy in 9%. Clinical success was reported in 86% of the patients. The all-cause mortality in this cohort was 18%. No serious adverse effects of tigecycline were detected in these patients.

CONCLUSIONS

Tigecycline salvage therapy was successful in 86% of critically ill pediatric patients with MDR/XDR infections after surgery, with no severe adverse effects.

Vancomycin-resistant enterococcus infection in the hematopoietic stem cell transplant recipient: an overview of epidemiology, management, and prevention

Vancomycin-resistant enterococcus (VRE) is now one of the leading causes of nosocomial infections in the United States. Hematopoietic stem cell transplantation (HSCT) recipients are at increased risk of VRE colonization and infection. VRE has emerged as a major cause of bacteremia in this population, raising important clinical questions regarding the role and impact of VRE colonization and infection in HSCT outcomes as well as the optimal means of prevention and treatment. We review here the published literature and scientific advances addressing these thorny issues and provide a rational framework for their approach.

The Use of Daptomycin to Treat Methicillin-Resistant Staphylococcus Epidermidis Bacteremia in a Critically Ill Child with Renal Failure

Daptomycin is excreted primarily unchanged by the kidney. Dosage regimens in children with renal failure remain to be determined. We report the case of an 8-year-old child with multiorgan failure undergoing continuous peritoneal dialysis, successfully treated with intravenous daptomycin for methicillin-resistant Staphylococcus epidermidis bacteremia. A dosage of 8 mg/kg every 48 hour was used. Plasma peak and trough concentrations of daptomycin were 68 mg/L and 14.6 mg/L, respectively, on day 6 of treatment. The dosage regimen achieved daptomycin exposure comparable to that reported in adults undergoing continuous ambulatory peritoneal dialysis and receiving recommended dosages.

Use of Tigecycline in Pediatric Patients With Infections Predominantly Due to Extensively Drug-Resistant Gram-Negative Bacteria

BACKGROUND.

Emergence of extensively drug-resistant (XDR) bacteria has forced clinicians to use off-label antimicrobial agents such as tigecycline. We present our experience on salvage use of tigecycline for the treatment of infections caused by XDR Gram-negative bacteria in critically ill children and review published cases.

METHODS.

We conducted a retrospective chart review in pediatric departments of a tertiary level hospital from January 2009 to May 2014. Patients were identified using pharmacy database. For the literature review, relevant articles were identified from PubMed.

RESULTS.

In our case series, 13 children (7 males) with a median age of 8 years (range, 2.5 months-14 years) received tigecycline for ≥2 days as treatment for healthcare-associated infections including 5 bacteremias, 6 lower respiratory tract infections, and 3 other infections. Isolated pathogens were XDR Gram-negative bacteria except 1. A loading dose (range, 1.8-6.5 mg/kg) was given in all except 2 cases. Maintenance dose was given at 1-3.2 mg/kg q12 h. Other antimicrobials including colistin and aminoglycosides (85% and 62%, respectively) were coadministered to all patients. No serious adverse events were detected in these very ill children. Twenty cases of children treated with tigecycline were previously published, mostly for multidrug-resistant/XDR bacteria. An episode of acute pancreatitis and neutrophil engraftment delay in 2 cases were reported during tigecycline treatment. Analyzing reported and all our cases together, mortality in bloodstream infections was 86%, whereas in nonbacteremic cases it was 24% (P = .009).

CONCLUSIONS.

Tigecycline, given at the range of administered doses as salvage therapy and in combination with other antimicrobial agents, seemed to be well tolerated in a series of mainly critically ill pediatric patients and demonstrated relatively good clinical response in nonbacteremic patients.

Use of tigecycline in pediatric clinical practice

INTRODUCTION

Tigecycline, a derivative of minocycline, is an extended-spectrum antimicrobial agent. It has a restricted approval field in children and the experience of its adoption in clinical practice is reserved for cases of challenging infections. The aim of this review was to summarize evidence regarding the use of tigecycline in infants and children, focusing on the drug's clinical efficacy data and tolerability profile. Areas covered: We have conducted a literature search of the Cochrane Library, EMBASE, and MEDLINE databases, from their inception through 5 January 2017, using the following terms: tigecycline, newborn, infant, child, pediatrics, adolescent, human, clinical trial, and case report. Articles were excluded if they were redundant or not pertinent. Bibliographies of all relevant articles were also evaluated. Seventeen publications were included: 1 pharmacokinetic study, 16 case reports. In the selected publications, the patients' mean age was 4.45 years, 38.7% of children was <3 years old and favorable clinical response was achieved in 74.2% of cases. Expert commentary: Tigecycline may be a considerable option in life-threatening infections in pediatric patients. Its administration is well tolerated and has demonstrated a good clinical response in nonbacteremic patients. However, the available clinical records are limited and more studies are needed.

2017 Infectious Diseases Society of America's Clinical Practice Guidelines for Healthcare-Associated Ventriculitis and Meningitis

The Infectious Diseases Society of America (IDSA) Standards and Practice Guidelines Committee collaborated with partner organizations to convene a panel of 10 experts on healthcare-associated ventriculitis and meningitis. The panel represented pediatric and adult specialists in the field of infectious diseases and represented other organizations whose members care for patients with healthcare-associated ventriculitis and meningitis (American Academy of Neurology, American Association of Neurological Surgeons, and Neurocritical Care Society). The panel reviewed articles based on literature reviews, review articles and book chapters, evaluated the evidence and drafted recommendations. Questions were reviewed and approved by panel members. Subcategories were included for some questions based on specific populations of patients who may develop healthcare-associated ventriculitis and meningitis after the following procedures or situations: cerebrospinal fluid shunts, cerebrospinal fluid drains, implantation of intrathecal infusion pumps, implantation of deep brain stimulation hardware, and general neurosurgery and head trauma. Recommendations were followed by the strength of the recommendation and the quality of the evidence supporting the recommendation. Many recommendations, however, were based on expert opinion because rigorous clinical data are not available. These guidelines represent a practical and useful approach to assist practicing clinicians in the management of these challenging infections.

Tigecycline Therapy in an Infant for Ventriculoperitoneal Shunt Meningitis

Shunt infections are seen in 3% to 20% of patients who have cerebrospinal fluid (CSF) shunts. Although the staphylococcal species are the most common cause of shunt-related infections, Gram-negative bacteria are increasingly reported with higher mortality rates. Tigecycline, a glycylcycline, is not approved for children. But in the era of nosocomial infections due to multidrug-resistant pathogens, it can be the life-saving option. We report an infant with ventriculoperitoneal shunt-related meningitis treated with a tigecycline combination regimen. A 5-month-old boy who had a ventriculoperitoneal shunt was admitted with meningitis. Extended spectrum β-lactamase-producing Klebsiella pneumoniae grew in the CSF. At the end of the fourth week of intravenous meropenem plus gentamicin therapy, carbapenem-resistant K pneumoniae grew in the CSF (mean inhibitory concentration value for meropenem >4 μg/mL, by E-test). The infected shunt was removed, and an external ventricular drainage catheter was inserted. With permission, intravenous tigecycline (1.2 mg/kg per dose twice a day) and intrathecal amikacin were added to the meropenem. Intrathecal amikacin could be given for only 7 days. On the sixth day of tigecycline treatment, the CSF was sterilized. Antibiotic therapy was given and consisted of a total of 60 days of meropenem and 20 days of tigecycline therapy. Because no available efficacy and safety data from randomized-controlled studies exist, tigecycline must be used only as salvage therapy, in combination with other drugs, for critically ill children who have no alternative treatment options.

Clinical Effectiveness, Safety Profile, and Pharmacokinetics of Daptomycin in Pediatric Patients: A Systematic Review

Infections by Gram-positive pathogens pose a public health risk, especially due to increasing antibiotic resistance. Daptomycin has efficacy against most clinically important Gram-positive bacteria. Although experience regarding use of daptomycin in adults is increasing, studies on pediatric populations are limited. We aimed to evaluate the efficacy, safety, and pharmacokinetics of daptomycin in pediatric settings. We searched MEDLINE and Clinicaltrials.gov (through April 2016) and included 29 original studies in the final analysis. Available evidence suggests that daptomycin in pediatric patients has a favorable safety and tolerability profile and is an efficacious alternative for treatment of Gram-positive bacteremia, endocarditis, and infections of the skin, soft tissues, joints, and bones, especially when resistant strains are involved. However, future studies need to address several issues to determine the optimal dose and various pharmacokinetic parameters in different pediatric age groups.

Minocycline and Tigecycline: What Is Their Role in the Treatment of Carbapenem-Resistant Gram-Negative Organisms?

Carbapenem-resistant organisms are increasingly common worldwide, particularly in India and are associated with high mortality rates especially in patients with severe infection such as bacteremia. Existing drugs such as carbapenems and polymyxins have a number of disadvantages, but remain the mainstay of treatment. The tetracycline class of antibiotics was first produced in the 1940s. Minocycline, tetracycline derivative, although licensed for treatment of wide range of infections, has not been considered for treatment of multidrug-resistant organisms until recently and needs further in vivo studies. Tigecycline, a derivative of minocycline, although with certain disadvantages, has been frequently used in the treatment of carbapenem-resistant organisms. In this article, we review the properties of minocycline and tigecycline, the common mechanisms of resistance, and assess their role in the management of carbapenem-resistant organisms.

Successful treatment of postoperative multidrug-resistant Acinetobacter baumannii meningitis by tigecycline

Tigecycline is a broad-spectrum antibiotic with activity against multidrug-resistant (MDR) bacteria. It has limited indications. Studies are necessary to elaborate new guidelines. Here we report a case of postoperative MDR Acinetobacter baumannii meningitis treated by tigecycline combined with colimycin for 21 days. The treatment was well tolerated with a favourable outcome. In conclusion, tigecycline was shown to be effective in a case of MDR A. baumannii meningitis.

Multidrug-Resistant Organisms: Considerations in Antibiotic Selection and Administration

Managing infections caused by multidrug-resistant organisms is a significant clinical challenge. Multidrug-resistant organisms' treatment is complicated in the pediatric population because of the lack of primary data, treatment guidelines, rapidly changing pharmacokinetic/pharmacodynamic parameters, and fewer approved antibiotic indications and dosing guidance. Treatment decisions must incorporate available pediatric data, clinical experience, and careful extrapolation from adult data while considering the unique challenges faced by children with complicated infections.

Purulent pericarditis with quadruple valve endocarditis

Patient: Male, 7

Final Diagnosis: Purulent pericarditis with quadruple valve endocarditis

Symptoms: —

Medication: (4S,4aS,5aR,12aS)-9-[2-(tert-butylamino)acetamido]-4,7 bis(dimethylamino)-1,4,4a,5,5a,6,11,12aoctahydro-3,10,12,12a-tetrahydroxy-1,11-dioxo-2 naphthacenecarboxamide

Clinical Procedure: Pericardiocentisis

Specialty: Cardiology

Daptomycin in paediatrics: current knowledge and the need for future research

To overcome the problems stemming from antimicrobial resistance, there have been several attempts to develop new antimicrobials in recent years. Of the highly potent drugs targeting resistant Gram-positive bacteria, daptomycin has a number of attractive characteristics that suggest its possible use in the treatment of serious infections due to these organisms. Although several pharmacokinetic and clinical studies in adults have provided data to determine how this drug should be prescribed to obtain the maximal clinical efficacy without significant risks of severe adverse events, we have not yet solved all of the problems related to the use of this antibiotic in paediatric patients. In this paper, the resolved and lingering problems of daptomycin treatment in newborns and children are reviewed and discussed. Studies have indicated that daptomycin is a promising therapeutic option for the treatment of paediatric diseases caused by MDR Gram-positive bacilli. However, before daptomycin can be licensed for use in newborns and children, further studies are needed to establish the appropriate dosages for paediatric patients of different ages. The data collected in adults can only be transferred to children older than 12 years, and the information available is not sufficient to determine the dosage that will assure the highest antimicrobial efficacy with only marginal risks of adverse events in younger patients. Thus, studies in neonates and younger infants are urgently needed to permit the use of daptomycin in the first months of life, a period in which infections due to MDR Gram-positive pathogens are increasing.

An updated approach to healthcare-associated meningitis

Among hospital-associated infections, healthcare-associated central nervous system infections are quite important because of high morbidity and mortality rates. The causative agents of healthcare-associated meningitis differ according to the status of immune systems and underlying diseases. The most frequent agents are Gram-negative bacilli (Pseudomonas spp., Acinetobacter spp., Escherichia coli and Klebsiella pneumoniae) and Gram-positive cocci (Staphylococcus aureus and coagulase-negative staphylococci). There are currently several problems in the treatment strategies of healthcare-associated meningitis due to a globally increasing resistance problem. Strategies targeting multidrug-resistant pathogens are especially limited. This review focuses on healthcare-associated meningitis and the current treatment strategies with a particular focus on methicillin-resistant Staphylococcus aureus (MRSA) meningitis.

Treatment strategies for central nervous system infections: an update

INTRODUCTION

Central nervous system infection continues to be an important cause of mortality and morbidity worldwide. Our incomplete knowledge on the pathogenesis of how meningitis-causing pathogens cause CNS infection and emergence of antimicrobial resistance has contributed to the mortality and morbidity. An early empiric antibiotic treatment is critical for the management of patients with bacterial meningitis, but early recognition of bacterial meningitis continues to be a challenge.

AREAS COVERED

This review gives an overview on current therapeutic strategies for CNS infection with a focus on recent literature since 2010 on bacterial meningitis. Bacterial meningitis is a medical emergency, requiring early recognition and treatment. The selection of appropriate empiric antimicrobial regimen, after incorporating the epidemiology of bacterial meningitis, impact of vaccination, emergence of antimicrobial-resistant bacteria, role of adjunctive therapy and the current knowledge on the pathogenesis of meningitis and associated neuronal injury are covered.

EXPERT OPINION

Prompt treatment of bacterial meningitis with an appropriate antibiotic is essential. Optimal antimicrobial treatment of bacterial meningitis requires bactericidal agents able to penetrate the blood-brain barrier, with efficacy in cerebrospinal fluid. Emergence of CNS-infecting pathogens with resistance to conventional antibiotics has been increasingly recognized, but development of new antibiotics has been limited. More complete understanding of the microbial and host factors that are involved in the pathogenesis of bacterial meningitis and associated neurologic sequelae is likely to help in developing new strategies for the prevention and therapy of bacterial meningitis.

Failure of high-dose daptomycin for bacteremia caused by daptomycin-susceptible Enterococcus faecium harboring LiaSR substitutions

High-dose daptomycin (DAP) therapy failed in a neutropenic patient with bloodstream infection caused by a DAP-susceptible Enterococcus faecium (minimum inhibitory concentration, 3 µg/mL) harboring genetic changes associated with DAP resistance, with persistent bacteremia and selection of additional resistances. Daptomycin monotherapy should be used cautiously against DAP-susceptible E. faecium strains with minimum inhibitory concentrations >2 µg/mL.

Successful treatment of ventriculostomy-associated meningitis caused by multidrug resistant coagulase-negative Staphylococcus epidermidis using low-volume intrathecal daptomycin and loading strategy

OBJECTIVE

To report successful use of low-volume intrathecal (IT) daptomycin and loading strategy for the treatment of ventriculostomy-associated meningitis.

CASE SUMMARY

A 23-year-old man with a history of multiple ventriculoperitoneal shunt revisions resulting from multidrug-resistant Staphylococcus epidermidis shunt infection presented with meningitis despite suppressive antibiotic therapy. After source control surgery, the patient improved with intravenous daptomycin plus IT vancomycin. Then, 4 days later, significant ventriculostomy output occurred, and the S epidermidis was confirmed to be intermediately sensitive to vancomycin (MIC = 8 µg/mL) and susceptible to daptomycin (MIC = 2 µg/mL). IT vancomycin was changed to IT daptomycin 5 mg in 3 mL normal saline (NS) every 24 hours for 3 days, then every 72 hours for 18 days. The cerebrospinal fluid (CSF) was sterile after 1 day of IT daptomycin and remained so. Creatine kinase remained normal throughout the course of treatment. The patient was discharged on hospital day 50 without antibiotics.

DISCUSSION

IT daptomycin has been reported for adult doses ranging from 5 to 10 mg once every 24 to 72 hours in volumes ranging from 5 to 10 mL; drug accumulation has been seen after the third dose of once every 24 hours dosing, and delayed improvement has been seen with once every 72 hours dosing. We planned for rapid load and CSF sterilization and extended the dosing interval once drug accumulation was expected to have occurred.

CONCLUSIONS

IT daptomycin 5 mg diluted to 3 mL in NS and dosed in a loading strategy was effective and without adverse sequelae.

Clinical pharmacokinetics of antibacterials in cerebrospinal fluid

In the past 20 years, an increased discrepancy between new available antibacterials and the emergence of multidrug-resistant strains has been observed. This condition concerns physicians involved in the treatment of central nervous system (CNS) infections, for which clinical and microbiological success depends on the rapid achievement of bactericidal concentrations. In order to accomplish this aim, the choice of drugs is based on their disposition toward the cerebrospinal fluid (CSF), which is influenced by the physicochemical characteristics of antibacterials. A reduced distribution into CSF has been documented for beta-lactams, especially cephalosporins and carbapenems, on the basis of their hydrophilic nature. However, they represent a cornerstone of the majority of combined therapeutic schemes for their ability to achieve bactericidal concentrations, especially in the presence of inflamed meninges. The good tolerability of beta-lactams makes possible high daily dose intensities, which may be associated with increased probability of cure. Furthermore, the adoption of continuous infusion seems to be a fruitful option. Fluoroquinolones, namely moxifloxacin, and antituberculosis drugs, together with the agents such as linezolid, reach the highest CSF/plasma concentration ratio, which is greater than 0.8, and for most of these drugs it is near 1. For all drugs that are currently used for the treatment of CNS infections, the evaluation of pharmacokinetic/pharmacodynamic parameters, on the basis of dosing regimens and their time-dependent or concentration-dependent pattern of bacterial killing, remains an important aspect of clinical investigation and medical practice.

Bacterial meningitis: new therapeutic approaches

Bacterial meningitis remains a disease with high mortality and long-term morbidity. Outcome critically depends on the rapid initiation of effective antibiotic therapy. Since a further increase of the incidence of pathogens resistant to antibacterials can be expected both in community-acquired and nosocomial bacterial meningitis, the choice of an optimum initial empirical antibiotic regimen will gain significance. In this context, the use of antibiotics which are bactericidal but do not lyse bacteria, may emerge as a therapeutic option. Conversely, the role of corticosteroids, which decrease the entry of hydrophilic antibacterials into the cerebrospinal fluid, as adjunctive therapy will probably decline as a consequence of the increasing antibiotic resistance of bacteria causing meningitis. Consequent vaccination of all children at present is the most efficient manner to reduce disease burden.

Tigecycline treatment of infection caused by KPC-producing Escherichia coli in a pediatric patient

Tigecycline shows great antimicrobial activity against both Gram-positive and Gram-negative bacteria, and has been considered to be an appropriate choice in controlling infection caused by multi-drug resistant (MDR) pathogens, such as carbapenemase-producing Enterobacteriaceae (CPE). Although many clinical trials evaluate the efficacy and safety of tigecycline on adults, rare reports recommend tigecycline to treat pediatric patient. In this study, we presented a clinical case with tigecycline as an anti-infectious agent on a 14-year-old child who was suffering from infection of intraperitoneal abscess caused by Klebsiella pneumoniae carbapenemases (KPC)-producing Escherichia coli with extreme drug resistant profile. By accessing the clinical outcome and efficacy of the patient, and the side effects of tigecycline, our research explored the documented experience of tigecycline on controlling infection caused by CPE isolate in children.

Antimicrobial susceptibility among Gram-positive organisms collected from pediatric patients globally between 2004 and 2011: results from the Tigecycline Evaluation and Surveillance Trial

The Tigecycline Evaluation and Surveillance Trial (TEST) was designed to monitor global longitudinal changes in bacterial susceptibility to a panel of antimicrobial agents, including tigecycline. In this study, we examine susceptibility among Gram-positive isolates collected from pediatric patients globally between 2004 and 2011. A total of 9,422 Gram-positive isolates were contributed by 1,255 centers, predominantly from Europe and North America. One-third of Staphylococcus aureus isolates were methicillin resistant, peaking in prevalence in 2007. All S. aureus isolates (n = 3,614) were susceptible to linezolid, tigecycline, and vancomycin; minocycline, imipenem, and meropenem were also highly active (>92% susceptibility). Ampicillin and penicillin susceptibility increased significantly during the study period (P < 0.0001 for both). Streptococcus pneumoniae isolates (n = 3,373) were highly susceptible to vancomycin (100%), linezolid (>99%), and levofloxacin and tigecycline (both >96%); imipenem susceptibility was low (32%) in Africa while minocycline susceptibility was low in Asia-Pacific Rim (38%). Penicillin resistance occurred in one-fifth of all S. pneumoniae isolates, with penicillin susceptibility ranging from 14% in Africa to 65% in Europe. Streptococcus agalactiae isolates (n = 1,056) were highly susceptible to most antimicrobials, although only 16% were susceptible to minocycline. Enterococcus faecalis isolates (n = 1,112) were highly susceptible (>97%) to ampicillin, linezolid, penicillin, tigecycline, and vancomycin globally, but only 34% were minocycline susceptible; minocycline susceptibility decreased significantly from 2004 to 2011 (P < 0.001). Tigecycline and linezolid were highly active against Enterococcus faecium (n = 267) globally (100% and 98% susceptible, respectively). Tigecycline and linezolid were highly active against Gram-positive pathogens from pediatric patients in TEST 2004 to 2011, with vancomycin and the carbapenems performing well against most pathogens.

Daptomycin plus trimethoprim/sulfamethoxazole combination therapy in post-neurosurgical meningitis caused by linezolid-resistant Staphylococcus epidermidis

Post-neurosurgical infection is a serious complication that occurs in approx. 4% of all patients undergoing neurosurgical procedures and is associated with high morbidity and mortality rates and prolonged length of intensive care unit (ICU) stay. Coagulase-negative staphylococci (CoNS), especially methicillin-resistant Staphylococcus epidermidis (MRSE), are the most frequent pathogens involved in CNS post-neurosurgical meningitis. Treatment is challenging especially in patients with meningitis due to multidrug- resistant (MDR) CONS. Herein, we report a unique case of post-neurosurgical meningitis due to MRSE resistant to linezolid (a molecular analysis revealed the presence of the mutation G2576T on domain V of the 23S rRNA gene) and with reduced susceptibility to glycopeptides, successfully treated with a combination of daptomycin at 10 mg/kg daily plus trimethoprim/sulfamethoxazole (TMP/SMX). This antibiotic combination showed an indifferent interaction in in vitro studies. Daptomycin serum and cerebrospinal fluid (CSF) concentrations, determined through blood and CSF samples drawn just prior to and 4 h after the third dose, were 18.9-0.78 and 51.65-3.1 mg/L, respectively. These values allowed us to approximate a 5-6% penetration rate of the drug through an inflamed blood-brain barrier. In conclusion, although further studies are needed, combination of high-dose daptomycin plus TMP/SMX is a reasonable option for treatment of meningitis caused by multidrug-resistant S. epidermidis.