Optimizing therapy for vancomycin-resistant enterococcal bacteremia in children

[Potential Nephrotoxicity of Combination of Vancomycin and Piperacillin-Tazobactam: Recommendations from the AG ABS of the DGPI supported by experts of the GPN]

The combination of vancomycin and piperacillin/tazobactam (V+P/T) is used for empirical antibiotic treatment of severe infections, especially in immunocompromised patients and those colonized with multidrug-resistant bacteria. Nephrotoxicity is a frequently observed adverse effect of vancomycin. Its risk can be reduced by therapeutic drug monitoring and adjusted dosing. Piperacillin/tazobactam (P/T) rarely causes interstitial nephritis. The results of retrospective cohort studies in children predominantly show a low, clinically irrelevant, additive nephrotoxicity (defined as an increase in creatinine in the serum) of both substances. Due to the limitations of the existing publications, the ABS working group of the DGPI and experts of the GPN do not recommend against the use of P/T plus vancomycin. Preclinical studies and a prospective study with adult patients, which evaluated different renal function tests as well as clinical outcomes, do not support previous findings of additive nephrotoxicity. Time-restricted use of V+P/T can minimize exposure and the potential risk of nephrotoxicity. Local guidelines, developed in collaboration with the antibiotic stewardship team, should define the indications for empirical and targeted use of P/T and V+P/T. When using combination therapy with V+P/T, kidney function should be monitored through clinical parameters (volume status, balancing, blood pressure) as well as additional laboratory tests such as serum creatinine and cystatin C.

Enterococcal Bacteremia in Children With Malignancies and Following Hematopoietic Stem Cell Transplantation: A 15-Year Single-Center Experience

BACKGROUND

Data on enterococcal bacteremia (EB) in immunocompromised children are scarce. We aimed to describe EB in children with hematologic malignancies (HM), solid tumors and/or following allogeneic hematopoietic stem cell transplantation (HSCT) and analyze their ampicillin and vancomycin resistance.

METHODS

We conducted an observational retrospective study in the tertiary-care Hadassah University Medical Center (2001-2015). We collected demographic, clinical and laboratory data on EB and compared ampicillin and vancomycin sensitive with resistant episodes.

RESULTS

Fifty-six of 1123 children developed 74 episodes of EB; 62.1% Enterococcus faecium, 36.5% Enterococcus faecalis; and 1.4% Enterococcus gallinarum. EB developed in 12.1% of HSCT patients, 5.1% of HM, 6.3% of neuroblastoma and 1.0% of other solid tumors patients. Of these episodes, 85.1% were nosocomial, and 71.6% developed while on antibiotic therapy. Resistance rates were: to ampicillin, 57.6%; to vancomycin (vancomycin-resistant enterococci), 21.6%; and higher rates among E. faecium. Among vancomycin-resistant enterococci, 1 of 16 was linezolid and 2 of 10 daptomycin resistant. Overall 7- and 30-day mortality rates were 2.7% and 5.4%, respectively. Thirty-day mortality was 18.2% in recurrent episodes and 0% in the first-time EB episodes (P = 0.006). In multivariate analysis, high treatment intensity was associated with ampicillin resistance [odds ratio (OR) = 3.18, 95% confidence interval (CI): 1.31-9.12], prior penicillin exposure (OR = 7.50, 95% CI: 1.41-39.81) and breakthrough on vancomycin (OR = 18.83, 95% CI: 3.31-101.14) with vancomycin resistance.

CONCLUSIONS

EB occurs mainly as a nosocomial infection in children receiving high-intensity chemotherapy, especially in those with neuroblastoma, HM and following HSCT. Antibiotic resistance is common. Vancomycin resistance can occur regardless of previous vancomycin use. Prognosis in immunocompromised children with EB is better than previously reported. Recurrent EB is associated with increased mortality.

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.

Enterococcal bacteremia in febrile neutropenic children and adolescents with underlying malignancies, and clinical impact of vancomycin resistance

PURPOSE

Enterococci are a common cause of bacteremia in immunocompromised patients. Although the increase of vancomycin-resistant enterococci (VRE) makes appropriate antibiotic therapy difficult, clinical characteristics of enterococcal bacteremia and the impact of VRE infection on outcomes have rarely been reported in immunocompromised children.

METHODS

We enrolled children and adolescents (< 19 years of age) with underlying malignancies who were diagnosed with enterococcal bacteremia during febrile neutropenia between 2010 and 2017. Medical records of the enrolled children were retrospectively reviewed to evaluate the clinical characteristics of enterococcal bacteremia and impact of VRE infection on outcomes.

RESULTS

Thirty-six episodes of enterococcal bacteremia were identified in 30 patients. VRE infection was identified in 11 episodes (30.6%); the 7- and 30-day mortalities were 27.8% and 44.4%, respectively. Acute lymphoblastic leukemia (50.0%) and acute myeloid leukemia (30.6%) were the most common underlying disorders. Three (8.3%) of the patients were in complete remission, and palliative and reinduction chemotherapies were administered in 47.2% and 36.1% of episodes, respectively. Empirical antibiotic therapy was appropriate in 64.0% of patients with vancomycin-susceptible enterococcal infection and in none of the VRE-infected patients (p = 0.001). However, the 30-day mortality was not significantly different between the two patient groups (44.0% vs. 45.5%, p = 1.000).

CONCLUSIONS

Most episodes of enterococcal bacteremia occurred in advanced stages of underlying malignancies, and still showed high mortality. The prognosis seemed to be related to the underlying disease condition rather than vancomycin resistance of the isolated enterococci, although the number of enrolled patients was small.

Vancomycin-resistant enterococci colonisation, risk factors and risk for infection among hospitalised paediatric patients: a systematic review and meta-analysis

The objective of this study was to estimate the rate and significance of colonisation with vancomycin-resistant enterococci (VRE) among hospitalised children. The PubMed and EMBASE databases were systematically searched (last accessed on 29 May 2016) to identify studies evaluating VRE colonisation of the gastrointestinal tract of hospitalised children in non-outbreak periods. Of 945 non-duplicate citations, 19 studies enrolling 20 234 children were included. The overall and paediatric intensive care unit (PICU) rate of VRE colonisation were both 5% [95% confidence interval (CI) 3-8% overall and 95% CI 2-9% in the PICU] but was 23% in haematology/oncology units (95% CI 18-29%). Studies that were exclusively performed in haematology/oncology units reported significantly higher rates compared with all other studies in the univariate and multivariate analyses (P = 0.001). Previous vancomycin [risk ratio (RR) = 4.34, 95% CI 2.77-6.82] or ceftazidime (RR = 4.15, 95% CI 2.69-6.40) use was a risk factor for VRE colonisation. Importantly, VRE colonisation increased the risk of subsequent VRE infection (RR = 8.75, 95% CI 3.19-23.97). In conclusion, a high rate of VRE colonisation was found among hospitalised children in institutions that performed targeted screening. Importantly, colonised children were almost 9 times more likely to develop subsequent VRE infection. Judicious use of specific antibiotics along with intensification of infection control measures should be considered in high-prevalence institutions. Also, the high incidence of VRE colonisation among children with haematological/oncological diseases identifies a high-risk population.

Proper use of antibiotics: situation of linezolid at the intensive care unit of the Tunisian Military Hospital

Linezolid was introduced in clinical practice in the early 2000s. It was considered to be an ideal reserve drug for treatment of vancomycin-resistant Enterococcus spp. (VRE) and vancomycin-resistant Staphylococcus aureus (VRSA). The aim of our study was to describe and evaluate the use of linezolid in clinical practice at the intensive care unit (ICU) of the Tunisian military hospital. This is a thirty-month retrospective study including patients treated with linezolid at the ICU of the Tunisian military hospital. Data collection was realized using the patients' medical files and prescriptions. A pharmacist conducted an extended medication history and checked if an advice from an infectious disease-physician and a microbiological documentation were requested. A total of 80 patients were included. Forty-one per cent of indications were outside the Marketing Authorization (MA) criteria, and were mainly sepsis and postoperative mediastinitis (32% and 4% of total prescriptions, respectively). This antibiotic was used as a first-line therapy in 58% of cases. The advice from an infectious-disease physician was requested for 33% of prescriptions. Only 20% of infections were documented microbiologically, of which 35% were caused by methicillin resistant coagulase-negative Staphylococcus. Linezolid is an interesting therapeutic alternative in case of infections due to multi-resistant bacteria and/or complex clinical situations. Therefore, its prescription must be rationalized in order to slow down the emergence of resistance to this antibiotic. The high frequency of its use outside the MA criteria shows the importance of carrying out more clinical trials to evaluate its effectiveness and safety for new indications.