The Use of Cefiderocol as Salvage Therapy in an Infant Receiving ECMO and Continuous Renal Replacement Therapy

BACKGROUND

Infections caused by antimicrobial-resistant (AMR) pathogens are increasing worldwide, representing a serious global public health issue with high morbidity and mortality rates The treatment of Pseudomonas aeruginosa (PA) infections has become a significant challenge due to its ability to develop resistance to many of the currently available antibiotics, especially in intensive care unit (ICU) settings. Among the very few therapeutic lines available against extensively drug-resistant (XDR)-PA and/or with difficult-to-treat resistance (DTR)-PA, cefiderocol is an injectable siderophore cephalosporin not licensed for use in pediatric patients. There are only a few case reports and two ongoing trials describing the administration of this cephalosporin in infants.

CASE PRESENTATION

This report describes the case of a critically ill 8-month-old girl affected by ventilator-associated pneumonia (VAP) infection complicated by bloodstream infection (BSI) sustained by VIM-producing PA. She was treated with cefiderocol as a salvage therapy during ECMO and CRRT support.

CONCLUSIONS

In healthcare settings, treating multidrug-resistant, Gram-negative bacteria poses a serious challenge, especially in pediatric patients. Our findings suggest that cefiderocol can be considered as an off-label rescue therapy in selected pediatric cases.

Modifiable risk factors associated with later gut decolonization of carbapenem-resistant Gram-negative bacteria in children: A prospective cohort study

BACKGROUND

Nosocomial infections caused by carbapenem-resistant gram-negative bacteria (CRGNB) are associated with increased mortality and prolonged hospitalization; thus, later CRGNB-decolonization has significant clinical and public health implications.

AIM

We investigated modifiable/ non-modifiable risk factors for CRGNB-later gut decolonization in children.

METHODS

We included CRGNB-carriers (1day-16years old), hospitalized in a tertiary-level hospital (2018-2019). Upon CRGNB-carriage detection, rectal-swab cultures were taken weekly, if patients were hospitalized and monthly after discharge for 12 months. CRGNB-decolonization was defined as three consecutive negative rectal-swab cultures obtained ≥1 week apart. Modifiable (treatment administered/medical devices) and non-modifiable (age/gender/comorbidities) risk factors were recorded. Cox regression for later CRGNB-decolonization was performed.

FINDINGS

One hundred thirty CRGNB-carriers were recorded. After 12 months, 5.4% remained carriers. Risk factors for later decolonization were immunosuppression (HR: 0.52, 95%CI: 0.31-0.87), carbapenems (HR: 0.52, 95%CI: 0.30-0.91), proton-pump inhibitors (PPIs) (HR: 0.39, 95%CI: 0.24-0.64) and their duration of use, duration of hospitalization (HR: 0.90, 95%CI: 0.81-0.92, per 10 days), number of re-admissions (HR: 0.90, 95%CI: 0.86-0.96), abdominal surgery (HR: 0.33, 95%CI: 0.17-0.65), urinary catheter (HR: 0.42, 95%CI: 0.24-0.76) and duration of steroid administration (HR: 0.86, 95%CI: 0.84-0.88, per 10 days).

CONCLUSIONS

Carbapenems, PPIs and their duration of use, duration of steroids use, immunosuppression, urinary catheter, re-admissions, duration of hospitalization, and abdominal surgery are associated with later CRGNB-decolonization among children. Paediatric patients at risk of later decolonization should be under targeted screening and preemptive contact precautions. Known carriers at risk of later CRGNB-decolonization should be under meticulously applied contact precautions for longer durations.

Pharmacodynamic and immunological interactions of amphotericin B formulations and voriconazole with human neutrophils against mature Scedosporium apiospermum and Fusarium spp. biofilms

BACKGROUND

Mould infections caused by Scedosporium apiospermum and Fusarium solani species complex (FSSC) biofilms are rising among immunocompromised and immunocompetent patients. Little is known about the immunomodulatory effects of antifungal agents against these moulds. We examined the effects of deoxycholate and liposomal amphotericin B (DAmB, LAmB) and voriconazole on antifungal activities and immune responses of neutrophils (PMNs) against mature biofilms compared with their planktonic counterparts.

METHODS

Antifungal activity of human PMNs exposed to mature biofilms and planktonic cells for 24 h was determined at effector-to-target ratios of 2:1 and 5:1, alone or combined with DAmB, LAmB and voriconazole, assessed as fungal damage by XTT assay. Cytokine production was evaluated by multiplex ELISA, following PMN stimulation with biofilms in the presence/absence of each drug.

RESULTS

All drugs showed additive or synergistic effects with PMNs against S. apiospermum at 0.03-32 mg/L. They showed antagonism primarily against FSSC at 0.06-64 mg/L. Increased IL-8 was produced by PMNs exposed to S. apiospermum biofilms plus DAmB or voriconazole compared with PMNs exposed to biofilms alone (P < 0.01). During combined exposure, IL-1β was increased, an effect only counteracted by increased levels of IL-10 caused by DAmB (P < 0.01). LAmB and voriconazole caused similar IL-10 levels with those released by biofilm-exposed PMNs.

CONCLUSIONS

The synergistic, additive or antagonistic effects of DAmB, LAmB or voriconazole on biofilm-exposed PMNs are organism-specific, with FSSC exhibiting greater resilience than S. apiospermum to antifungals. Biofilms of both moulds caused dampened immune responses. The drug-mediated immunomodulating effect on PMNs, evidenced by IL-1β, enhanced host protective functions.

Pediatric cutaneous mucormycosis: case report and review of the literature

BACKGROUND

Mucormycosis has emerged as an increasingly important fungal disease for immunocompromised children and neonates, with the cutaneous form being one of its most common presentations.

METHODS

We present a cutaneous mucormycosis case in a 10-year-old girl and analyze reports of single cases and case series of cutaneous mucormycosis in ≤16-year-old patients, recorded in PUBMED from 1953 to 2020, for epidemiology, risk factors, diagnostic and therapeutic procedures and outcome.

RESULTS

113 cases were enrolled. Median age was 5 years [Interquartile Range (IQR) 10.9], without gender predominance. Underlying conditions were hematologic malignancies/disorders (25.7%), prematurity (23%), solid organ transplantation (3.5%), diabetes mellitus type 1 (4.4%), immunodeficiency and other diseases (14.2%), and no underlying conditions (29.2%). Inoculation occurred through major trauma (12.4%), including surgery and motor vehicle accidents, catheter sites (27.4%), dressings, patches and probes (11.5%), burns and farm-related accidents (8.8%). Rhizopus spp. was most frequently isolated (43.4%), followed by Lichtheimia corymbifera (9.7%), Saksenaea vasiformis (8%), Mucor and Rhizomucor spp. (5.3% each), other species/combinations (7.2%) and unspecified isolates (21.2%). Surgery was combined with antifungals in 62.8%. Each was performed solely in 27.4% and 6.2%, respectively. Amphotericin B was used in 78% (alone in 55.8% and combined with other antifungals in 22.2%) of the cases. Overall mortality was 26.5%. In regression analysis, prematurity and hematologic malignancies/disorders were associated with increased mortality, whereas combination of antifungals and surgery with improved survival.

CONCLUSION

Cutaneous mucormycosis mainly affects premature infants and children with hematologic malignancies/disorders. Outcome is improved when active antifungal therapy and surgery are combined.

Epstein-Barr Encephalitis in a Child with Congenital Human Immunodeficiency Virus Infection: A Case Report Calling for No Forgetfulness

BACKGROUND

In resource-rich settings, the rate of mother-to-child transmission of human immunodeficiency virus (HIV) has dramatically decreased by virtue of a combination of preventive strategies during the last two decades.

CASE PRESENTATION

We present a case of progressive developmental milestone loss in a toddler with previously unknown congenitally acquired human immunodeficiency virus (HIV) infection, complicated by an Epstein-Barr virus (EBV) coinfection.

CONCLUSION

Our report underscores the differential diagnosis between HIV encephalopathy and EBV encephalitis and the vertical transmission of the HIV infection, which constitutes an alarming issue in terms of public health.

Implementation of the Greek national immunization program among nursery attendees in the urban area of Thessaloniki

BACKGROUND

The growing phenomenon of vaccine hesitancy and the severe economic crisis may have affected compliance with the National Immunization Program (NIP) in Greece over the last years. We investigated compliance with the NIP among children attending nurseries in the urban area of Thessaloniki.

METHODS

A cross-sectional study was conducted, including nursery attendees born between 01/01/2014-01/10/2015 in each of the municipalities of Thessaloniki urban area. Public and private nurseries were randomly selected. Immunization data were anonymously collected from the child's health booklet. Both coverage and timeliness of immunization were recorded for all recommended vaccines according to the NIP.

RESULTS

In total, 432 children with a mean age of 2.9 years were studied, of which 245 (57 %) were attending private nurseries. Full coverage was >90 % for most of the recommended vaccines except for pneumococcal (81 %), meningococcal serogroup C (68.3 % and 82 % for 2011 and 2015 schedule, respectively), hepatitis A (38.9 %) and rotavirus (25.9%) vaccine. Delay rates for one or more doses ranged between 21-90.3 % for all vaccines; time of median delay ranged between 3.8-6.7 months. Lower coverage and higher delay rates were observed for Roma children.

CONCLUSIONS

While high coverage appears to be sustained for most of the recommended vaccines, delay of scheduled shots may compromise age-appropriate protection. Suboptimal immunization against pneumococcal, meningococcal serogroup C, hepatitis A, and rotavirus infections may increase morbidity in this age group and needs to be addressed. HIPPOKRATIA 2019, 23(4): 147-153.

Thiamine Deficiency in a Child with Short Bowel Syndrome and Review

Thiamine (vitamin B₁) is a water-soluble vitamin that is not endogenously synthesized in humans. It is absorbed by the small intestine, where it is activated. Its active form acts as a coenzyme in many energy pathways. We report a rare case of thiamine deficiency in a 3.5-year old boy with short bowel syndrome secondary to extensive bowel resection due to necrotizing enterocolitis during his neonatal age. The patient was parenteral nutrition-dependent since birth and had suffered from recurrent central catheter-related bloodstream infections. He developed confusion with disorientation and unsteady gait as well as profound strabismus due to bilateral paresis of the abductor muscle. Based on these and a very low thiamine level he was diagnosed and treated for Wernicke encephalopathy due to incomplete thiamine acquisition despite adequate administration. He fully recovered after thiamine administration. After 1999 eight more cases have been reported in the PubMed mostly of iatrogenic origin.

Forecasting models of infections due to carbapenem-resistant Gram-negative bacteria in an intensive care unit in an endemic area

OBJECTIVES

The aim of this study was to forecast the monthly incidence rates of infections [infections/1000 bed-days (IBD)] due to carbapenem-resistant Klebsiella pneumoniae (CRKP), carbapenem-resistant Pseudomonas aeruginosa (CRPA), carbapenem-resistant Acinetobacter baumannii (CRAB) and total carbapenem-resistant Gram-negative bacteria (CRGNB) in an endemic intensive care unit (ICU) during the subsequent year (December 2016-December 2017) following the observational period.

METHODS

A 52-month observational period (August 2012-November 2016) was used. Two forecasting models, including a simple seasonal model for CRGNB, CRKP and CRPA and Winters' additive model for CRAB infections, were applied.

RESULTS

The models predicted the highest infection rates for CRKP, CRAB and CRGNB in January and September 2017 (23.8/23.4, 24.6/28.5 and 46.8/46.7 IBD, respectively) and for CRPA in February and March 2017 (8.3 and 7.9, respectively). The highest observed rates for CRKP, CRAB and CRGNB were indeed in January and September 2017 (25.6/19.0, 34.2/23.8 and 59.8/42.8 IBD, respectively); and for CRPA in February and March of the same year (15.2 and 12.7, respectively). The increased rates may be associated with personnel's annual work programme and behavioural factors.

CONCLUSION

Forecasting models in endemic ICUs may assist in implementation strategies for infection control measures.

Polyclonal predominance of concurrently producing OXA-23 and OXA-58 carbapenem-resistant Acinetobacter baumannii strains in a pediatric intensive care unit

We report a predominance (64.7%) of polyclonal carbapenem-resistant Acinetobacter baumannii (CRAB) strains concurrently producing OXA-23 and OXA-58 carbapenemases in a pediatric intensive care unit in an endemic area. This is the first report of emergence of such double-OXA CRAB strains in a single unit worldwide.

Molecular Epidemiology of Endemic Carbapenem-Resistant Gram-Negative Bacteria in an Intensive Care Unit

The molecular epidemiology of endemic carbapenem-resistant Klebsiella pneumoniae (CRKP), carbapenem-resistant Pseudomonas aeruginosa (CRPA), and carbapenem-resistant Acinetobacter baumannii (CRAB) in an intensive care unit located in an endemic area with high rates of resistance was investigated. A CRPA strain producing VIM and KPC concurrently was detected for the first time in an endemic area. CRKP strains producing K. pneumoniae carbapenemase predominated and were mainly assigned to the "hyperepidemic Greek clone." Predominant OXA-23-like producing CRAB strains were assigned to multiple pulsotypes.

2302. Bloodstream Infections Due to Carbapenem-Resistant Gram-Negative Bacteria in Pediatric Intensive Care Unit (PICU): Risk Factors and Outcomes

Background

Bloodstream infections (BSI) caused by multidrug-resistant bacteria are associated with poor outcome and increased cost. We investigated risk factors for carbapenem resistance (CR) and outcome associated with the development of BSI due to Gram-negative (GN) bacteria in PICU patients, a very vulnerable population.

Methods

We reviewed the records of 1 month–15 year old patients with documented GN BSI hospitalized in a PICU from 2005 to 2017. Isolates with meropenem MIC ≥16 mg/L were considered as resistant. Demographics, clinical characteristics, potential risk factors for acquisition of resistant strains, treatment, potential source control and outcome were recorded. Outcome was determined as microbiological response (negative blood cultures) within 5 days and mortality within 30 days. Both univariate and multivariable logistic regression analysis was performed and odds ratios (OR) with 95% confidence intervals (CI) were presented.

Results

81 patients with GN BSI were studied (34.6% Pseudomonas aeruginosa, 34.6% Acinetobacter baumannii and 30.9% Enterobacteriaceae), 21 with CR isolates. Risk factors for CR BSI were: prior carbapenem use (OR: 3.86, 95% CI: 1.10, 13.82) and renal replacement therapy (OR: 3.86, 95% CI: 1.10, 13.82). In multivariable outcome analysis, high levels of CRP (OR: 0.99, 95% CI: 0.99, 0.999), renal replacement therapy (OR: 0.11, 95% CI: 0.01, 0.71) and inotrope administration (OR: 0.30, 95% CI: 0.09, 0.91) were associated with poor microbiological response, whereas source control (OR: 2.99, 95% CI: 1.01, 9.43) with better microbiological response. High PRISM score III (OR: 1.15, 95% CI: 1.04, 1.29) and CR (OR: 5.07, 95% CI: 1.47, 19.36) were both independently associated with worse outcome, whereas source control was the only independent factor preventing death (OR: 0.24, 95% CI: 0.06, 0.78). In patients with CR BSI, administration of at least two active antimicrobials was associated with better outcome (OR: 10.80, 95% CI: 1.33, 237.05).

Conclusion

Prior carbapenem use is associated with carbapenem-resistant BSI development in PICU, which in turn is an independent risk factor for mortality. Source control is associated with better microbiological response within 5 days, as well as with decreased mortality.

Disclosures

All authors: No reported disclosures.

Impact of active surveillance and infection control measures on carbapenem-resistant Gram-negative bacterial colonization and infections in intensive care

BACKGROUND

Carbapenem-resistant Gram-negative bacteria (CRGNB) infections constitute a global threat for critically ill patients and the outcome of their hospitalization. Early identification of CRGNB through rectal surveillance cultures and routine infection control measures including contact precautions, use of appropriate disinfectants, staff education on cleaning, and hand hygiene may reduce the dissemination of CRGNB.

AIM

To assess the impact of enhanced infection control measures on CRGNB infections in a nine-bed polyvalent intensive care unit in a tertiary level hospital in an endemic area.

METHODS

A quasi-experimental study, which included patients with CRGNB infection retrospectively for six months and those participating in an active surveillance programme prospectively for the subsequent 22 months. Active surveillance programme (weekly rectal swabs) was implemented including two sub-periods with infection control measures and enhanced infection control measures. CRGNB incidence, prevalence, colonization pressure, infections and compliance with infection control measures and enhanced infection control measures were recorded. Analysis was performed through time-series and interrupted time-series.

FINDINGS

During the active surveillance programme, enhanced infection control measures led to a steeper downwards trend in incidence, prevalence, and colonization pressure for CRGNB compared to the infection control measures sub-period. The linear trend was for carbapenem-resistant Klebsiella pneumoniae (CRKP) and Pseudomonas aeruginosa (CRPA) infections to decrease from 19.6 to 8.1 infections per 1000 bed-days (IBD) (P = 0.001) and from 5.1 to 1.79 IBD (P = 0.043), respectively. By contrast, carbapenem-resistant Acinetobacter baumannii infections increased from 5.2 to 15.3 IBD (P = 0.001).

CONCLUSION

Enhanced infection control measures including enhanced hand hygiene, active surveillance combined with contact precautions, education, audits and feedback policies and interventions could reduce CRKP and CRPA in endemic areas.

Molecular epidemiology of carbapenem-resistant Pseudomonas aeruginosa in an endemic area: comparison with global data

Carbapenem-resistant Pseudomonas aeruginosa (CRPA) is an endemic problem in certain countries including Greece. CRPA and multidrug-resistant P. aeruginosa (MDRPA) firstly emerged in our region during the 80s, right after the launch of imipenem and meropenem as therapeutic agents against P. aeruginosa infections. The role of outer membrane protein (Opr) inactivation has been known to contribute to imipenem resistance since many years, while efflux overexpression systems have been mainly associated with meropenem resistance. Among carbapenemases, metallo-β-lactamases (MBL) and mostly Verona integron-mediated (VIM) MBL's have played the most crucial role in CRPA emergence. VIM-2 and VIM-4 producing CRPA, usually belonging to clonal complexes (CC) 111 and 235 respectively, have most frequently been isolated. Bla_VIM-2 and bla_VIM-4 are usually associated with a class 1 integron. VIM-17 also has appeared in Greece. On the other hand, other VIM subtypes detected in a global level, such as VIM-3, VIM-5, VIM-6, VIM-7, VIM-11, VIM-14, VIM-15, VIM-16 and VIM-18 have not yet emerged in Greece. However, new VIM subtypes will probably emerge in the future. In addition, MBL carbapenemases other than VIM, detected worldwide have not yet appeared. A single CRPA isolate producing KPC has emerged in our region several years ago. The study of the molecular basis of Opr deficiency and efflux overexpression remains a challenge for the future. In this article, we review the molecular epidemiology of CRPA in an endemic area, compared to global data.

Cluster-distinguishing genotypic and phenotypic diversity of carbapenem-resistant Gram-negative bacteria in solid-organ transplantation patients: a comparative study

Purpose. Solid-organ transplant recipients may display high rates of colonization and/or infection by multidrug-resistant bacteria. We analysed and compared the phenotypic and genotypic diversity of carbapenem-resistant (CR) strains of Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii isolated from patients in the Solid Organ Transplantation department of our hospital.Methodology. Between March 2012 and August 2013, 56 CR strains from various biological fluids underwent antimicrobial susceptibility testing with VITEK 2, molecular analysis by PCR amplification and genotypic analysis with pulsed-field gel electrophoresis (PFGE). They were clustered according to antimicrobial drug susceptibility and genotypic profiles. Diversity analyses were performed by calculating Simpson's diversity index and applying computed rarefaction curves.Results/Key findings. Among K. pneumoniae, KP-producers predominated (57.1 %). VIM and OXA-23 carbapenemases prevailed among P. aeruginosa and A. baumannii (89.4 and 88.9 %, respectively). KPC-producing K. pneumoniae and OXA-23 A. baumannii were assigned in single PFGE pulsotypes. VIM-producing P. aeruginosa generated multiple pulsotypes. CR K. pneumoniae strains displayed phenotypic diversity in tigecycline, colistin (CS), amikacin (AMK), gentamicin (GEN) and co-trimoxazole (SXT) (16 clusters); P. aeruginosa displayed phenotypic diversity in cefepime (FEP), ceftazidime, aztreonam, piperacillin, piperacillin-tazobactam, AMK, GEN and CS (9 clusters); and A. baumannii displayed phenotypic diversity in AMK, GEN, SXT, FEP, tobramycin and rifampicin (8 clusters). The Simpson diversity indices for the interpretative phenotype and PFGE analysis were 0.89 and 0.6, respectively, for K. pneumoniae strains (P<0.001); 0.77 and 0.6 for P. aeruginosa (P=0.22); and 0.86 and 0.19 for A. baumannii (P=0.004).Conclusion. The presence of different antimicrobial susceptibility profiles does not preclude the possibility that two CR K. pneumoniae or A. baumannii isolates are clonally related.

Molecular epidemiology of carbapenem-resistant Acinetobacter baumannii in Greece: an extended review (2000–2015)

Carbapenem-resistant Acinetobacter baumannii (CRAB) is endemic in Greece. CRAB initially emerged in 2000 and since then, carbapenemases still have a crucial role in CRAB appearance, except for a few cases resulting from efflux pump or outer-membrane protein mechanisms. OXA-type carbapenemases present the highest prevalence worldwide and bla OXA-23-like and bla OXA-58-like are the most important genes found; VIM-yielding CRAB have also been detected, while a single CRAB isolate producing NDM has quite recently emerged in Greece. The predominant OXA-23 producers are associated with multilocus sequence typing Pasteur scheme sequence type 2 clonal strains of the international clone II. The emergence of colistin-resistant CRAB has complicated the treatment of such infections and the interpretation of susceptibility data. Infection control measures and adjusted antimicrobial treatment strategies could confine CRAB spread. The aim of this review is to go through the molecular epidemiology of CRAB, in an endemic area and highlight its potential future evolution.

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.

Comparison of cotrimoxazole vs. second-generation cephalosporins for prevention of urinary tract infections in children

BACKGROUND

Antimicrobial prophylaxis is recommended for the prevention of urinary tract infections (UTI) in high-risk children. However, there is growing concern about the use of β-lactams as prophylaxis and subsequent development of antibiotic resistance.

METHODS

In this prospective, randomized, crossover controlled trial we compared cotrimoxazole (SXT) and second-generation cephalosporins (2GC) as UTI prophylaxis in children ranging in age from 1 to 60 months. Eligible patients were 1:1 randomized to receive either SXT or 2GC for the initial 6-month period (1 course), then switched to the other antimicrobial agent class for the subsequent course, with switching continuing after each course until the end of the study. Urethral orifice cultures (UOCs) were obtained at the time of switching antimicrobial prophylaxis.

RESULTS

Among 97 children (mean age 13.6 months) on prophylaxis, breakthrough UTIs occurred during 13.3 % (10/75) of SXT courses and 10.3 % (8/78) of 2GC courses (p = 0.62). 2GC failed earlier than SXT (mean ± standard error: 0.81 ± 0.1 vs. 2.37 ± 0.36 months, respectively; p = 0.028). Pseudomonas aeruginosa and Enterococcus spp. were more frequently isolated after 2GC courses than after SXT courses [22.6 vs. 4.8 % (p = 0.02) and 20.7 vs. 4.8 % (p = 0.035), respectively]. Prophylaxis with 2GC significantly increased resistance to both 2GC and SXT, while SXT prophylaxis did not affect susceptibility to 2GC.

CONCLUSIONS

While SXT and 2GC appear to be equally efficacious as UTI prophylaxis in children, the latter exert a broader effect on patients' flora and development of bacterial resistance, suggesting that SXT may be more appropriate for UTI prophylaxis than 2GC.

Fulminant Epstein-Barr virus-associated hemophagocytic syndrome in a renal transplant patient and review of the literature

We describe a rare fulminant case of Epstein-Barr virus-associated hemophagocytic syndrome (HPS) in a 37-year-old female renal transplant patient, indistinguishable from severe sepsis clinically and in the laboratory. HPS involves rapidly escalating immune system activation, resulting in a cytokine cascade, which can, especially in immunocompromised patients, lead to multi-organ failure, and even death. Thirty-two Herpesviridae-associated HPS cases in renal transplant patients have been reported and are reviewed. Overall mortality is 47% (15/32 cases).

Nosocomial bloodstream infections in neurosurgery: a 10-year analysis in a center with high antimicrobial drug-resistance prevalence

BACKGROUND

Data on nosocomial bloodstream infections (NBSI) in neurosurgery is limited. This study aimed to analyze the epidemiology, microbiology, outcome, and risk factors for death in neurosurgical patients with NBSI in a multidrug resistant setting.

METHODS

Neurosurgical patients with a confirmed NBSI within the period 2003-2012 were retrospectively analyzed. NBSI was diagnosed when a pathogen was isolated from a blood sample obtained after the first 48 h of hospitalization. Patients' demographic, clinical, and microbiological data were recorded and analyzed using univariate and multivariate analysis.

RESULTS

A total of 236 patients with NBSI were identified and 378 isolates were recovered from blood cultures. Incidence of NBSI was 4.3 infections/1000 bed-days. Gram-negative bacteria slightly predominated (54.5 %). The commonest bacteria were coagulase-negative staphylococci (CoNS, 26 %), Klebsiella pneumoniae (15.3 %), Pseudomonas aeruginosa (14.8 %), and Acinetobacter baumannii (13.2 %). Carbapenem resistance was found in 90 % of A. baumannii, in 66 % of P. aeruginosa, and in 22 % (2003-2007) to 77 % (2008-2012) of K. pneumoniae isolates (p < 0.05). Most CoNS and Staphylococcus aureus isolates (94 and 80 %, respectively) were methicillin-resistant. All Gram-negative isolates were sensitive to colistin and all Gram-positive isolates were sensitive to vancomycin and linezolid. Antimicrobial consumption decreased after 2007 (p < 0.05). Overall mortality was 50.4 %. In multivariate analysis, advanced age and stay in an Intermediate Care Unit (IMCU) were independent risk factors for in-hospital mortality (p < 0.05).

CONCLUSIONS

Overall, high incidence of NBSI and considerable resistance of Gram-positive and particularly Gram-negative bacteria were noted in neurosurgical patients. Mortality was high with advanced age and stay in IMCU being the most important death-related factors.

Molecular epidemiology of carbapenem-resistant Klebsiella pneumoniae in Greece

Hospital infections caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) constitute a worldwide problem associated with high rates of treatment failure and mortality. In Greece, CRKP have emerged in 2002 due to VIM carbapenemase production and later due to KPC, NDM and OXA-48-like carbapenemases that have become endemic. The molecular epidemiology of CRKP strains is dynamic, as antibiotic consumption and worldwide traveling are strongly associated with global spread of CRKP isolates. Lately, porin defects, such as disruption of OmpK35 and production of OmpK36 variant, have also contributed to carbapenem resistance. In the coming years, the high prevalence of CRKP will require intense infection control measures, while novel molecular patterns may appear. To our knowledge, this is the first review analyzing the molecular epidemiology of CRKP strains in Greece.

Differential effects of antifungal agents on expression of genes related to formation of Candida albicans biofilms

The purpose of this study was to analyse specific molecular mechanisms involved in the intrinsic resistance of C. albicans biofilms to antifungals. We investigated the transcriptional profile of three genes (BGL2, SUN41, ECE1) involved in Candida cell wall formation in response to voriconazole or anidulafungin after the production of intermediate and mature biofilms. C. albicans M61, a well-documented biofilm producer strain, was used for the development of intermediate (12 h and 18 h) and completely mature biofilms (48 h). After exposure of cells from each biofilm growth mode to voriconazole (128 and 512 mg l(-1)) or anidulafungin (0.25 and 1 mg l(-1)) for 12-24 h, total RNA samples extracted from biofilm cells were analysed by RT-PCR. The voriconazole and anidulafungin biofilm MIC was 512 and 0.5 mg l(-1) respectively. Anidulafungin caused significant up-regulation of SUN41 (3.7-9.3-fold) and BGL2 (2.2-2.8 fold) in intermediately mature biofilms; whereas, voriconazole increased gene expression in completely mature biofilms (SUN41 2.3-fold, BGL2 2.1-fold). Gene expression was primarily down-regulated by voriconazole in intermediately, but not completely mature biofilms. Both antifungals caused down-regulation of ECE1 in intermediately mature biofilms.

A 5-Year Epidemiological Study of Nosocomial Bloodstream Infections in a Neurosurgery Department

The characteristics of nosocomial bloodstream infections (BSIs) in a neurosurgical department were studied over a 5-year period. The rate of nosocomial BSI was 3.0%. Gram-negative bacteria were the most commonly isolated pathogens (65.9% of isolates). For all the pathogens isolated, the rate of resistance to commonly used antimicrobial agents was high. Of the 101 patients with nosocomial BSI, 50 (49.5%) died during their stay at the Department of Neurosurgery. At the same time, overall mortality rate among neurosurgical inpatients without nosocomial BSI was 5.4% (ie, 175 of 3,216 patients died).

Successful management of an outbreak due to carbapenem-resistant Acinetobacter baumannii in a neonatal intensive care unit

The investigation and successful management of a monoclonal Acinetobacter baumannii outbreak in a neonatal intensive care unit are described. Upon the first clustered carbapenem-resistant A. baumannii (CRAB) infections, a bundle of actions were taken, including enhanced infection control, active surveillance (weekly stool samples), case-control study, staff education, daily audits and discontinuation of new admissions. Between September and December 2011, eight neonates developed 10 CRAB infections (five blood, four respiratory and one eye). A total of 216 active surveillance cultures were obtained from 96 neonates (43 % had ≥2 samples). During weeks 12, 16 and 17, active surveillance detected 3, 1 and 2 new CRAB acquisitions, respectively. Prevalence of infections/colonizations decreased, and no event occurred after 20th week. A colonized neonate developed CRAB sepsis and died. All CRAB isolates harboured bla OXA-58 and the intrinsic chromosomal bla OXA-51 carbapenemase genes.

CONCLUSION

Active surveillance and enhanced infection control measures effectively contained spread of CRAB clone in the neonatal intensive care unit.

In vitro interactions between farnesol and fluconazole, amphotericin B or micafungin against Candida albicans biofilms

OBJECTIVES

Biofilm formation by Candida albicans poses an important therapeutic challenge in human diseases. Typically, conventional antifungal agents encounter difficulty in treating and fully eradicating biofilm-related infections. Novel therapeutic approaches are needed to treat recalcitrant Candida biofilms. Farnesol is a quorum-sensing molecule, which induces apoptosis, inhibits Ras protein pathways and profoundly affects the morphogenesis of C. albicans. We therefore investigated the interactions between farnesol and different classes of antifungal agents.

METHODS

The combined antifungal effects of triazoles (fluconazole), polyenes (amphotericin B) and echinocandins (micafungin) with farnesol against C. albicans biofilms were assessed in vitro. Antifungal activity was determined by the XTT metabolic assay and confocal microscopy. The nature and the intensity of the interactions were assessed using the Loewe additivity model [fractional inhibitory concentration (FIC) index] and the Bliss independence (BI) model.

RESULTS

Significant synergy was found between each of the three antifungal agents and farnesol, while antagonism was not observed for any of the combinations tested. The greatest synergistic effect was found with the farnesol/micafungin combination, for which the BI-based model showed the observed effects as being 39%-52% higher than expected if the drugs had been acting independently. The FIC indices ranged from 0.49 to 0.79, indicating synergism for farnesol/micafungin and farnesol/fluconazole and no interaction for farnesol/amphotericin B. Structural changes in the biofilm correlated well with the efficacies of these combinations. The maximum combined effect was dependent on the farnesol concentration for micafungin and amphotericin B.

CONCLUSIONS

Farnesol exerts a synergistic or additive interaction with micafungin, fluconazole and amphotericin B against C. albicans biofilms, thus warranting further in vivo study.

Pathogenesis and host defence against Mucorales: the role of cytokines and interaction with antifungal drugs

Innate immune response, including macrophages, neutrophils and dendritic cells and their respective receptors, plays an important role in host defences against Mucorales with differential activity against specific fungal species, while adaptive immunity is not the first line of defence. A number of endogenous and exogenous factors, such as cytokines and growth factors as well as certain antifungal agents have been found that they influence innate immune response to these organisms. Used alone or especially in combination have been shown to exert antifungal effects against Mucorales species. These findings suggest novel ways of adjunctive therapy for patients with invasive mucormycosis.

Mannose binding lectin and ficolin-2 polymorphisms are associated with increased risk for bacterial infections in children with B acute lymphoblastic leukemia

BACKGROUND

We aimed to investigate whether the presence of mannose binding lectin (MBL2), ficolin 2 (FCN2) polymorphisms or the combined deficiency significantly influence the risk and subsequently the frequency of chemotherapy-induced bacterial infections in children with B acute lymphoblastic leukemia (B-ALL).

PROCEDURE

MBL2 polymorphisms for exon 1 and FCN2 polymorphisms for promoter regions -986, -602, -557, -64, -4 and exon 8 regions +6,359, +6,424 were determined in children with B-ALL. FCN2 haplotype was determined by gene sequencing. Number and duration of FN episodes as well as number of bacterial infections were recorded during induction chemotherapy.

RESULTS

Forty-four children with B-ALL (median age 4.3 years, 65.9% males) suffered from 142 FN episodes and 92 bacterial infections (40.2% Gram positive and 59.8% Gram negative). MBL2 low-risk genotype was found in 59.1%, medium-risk in 31.8% and high-risk in 9%. FCN2 low-risk haplotypes were detected in 38.2%, medium-risk in 44.1% and high-risk in 17.6%. MBL2 genotype and FCN2 haplotype were not associated with increased frequency of FN episodes. MBL2 medium/high-risk genotype and FCN2 medium/high-risk haplotype were associated with prolonged duration of FN (P = 0.007 and P = 0.001, respectively) and increased number of bacterial infections (P = 0.001 and P = 0.002, respectively). The combined MBL2/FCN2 medium/high-risk genotype was associated with an increased number of bacterial infections (P = 0.001).

CONCLUSIONS

MBL2 and FCN2 single or combined deficiencies are associated with increased duration of FN episodes as well as increased number of bacterial infections in children with B-ALL suggesting a prognostic role of these genes.

Renal abscess due to Pseudomonas aeruginosa: report of two cases

We report two cases of renal abscess due to Pseudomonas aeruginosa in previously healthy children. The first patient was a nine-year old girl with a three-week history of intermittent fever and the second was a three-year old boy with a four-day history of fever. Pseudomonas aeruginosa was isolated from the urine cultures of both children. In both cases ultrasound and CT/MRI scans revealed the formation of a renal abscess. The patients were successfully treated with administration of antipseudomonal drugs for seven and five weeks, respectively. In both children no surgical intervention was required and the follow-up revealed no impact on the overall renal function or arterial pressure.

Drug-resistant tuberculosis in two children in Greece: report of the first extensively drug-resistant case

Extensively drug-resistant (XDR) tuberculosis (TB) represents a serious and growing problem in both endemic and non-endemic countries. We describe a 2.5-year-old girl with XDR-pulmonary TB and an 18-month-old boy with pre-XDR-central nervous system TB. Patients received individualized treatment with second-line anti-TB agents based on genotypic and phenotypic drug susceptibility testing results. Both children achieved culture conversion 3 months and 1 month after treatment initiation, respectively. The child with XDR-pulmonary TB showed evidence of cure while treatment adverse events were managed without treatment interruption. The child with pre-XDR-central nervous system TB after 6-month hospitalization with multiple infectious complications had a dismal end due to hepatic insufficiency possibly related to anti-TB treatment. This is the first report of children with pre-XDR and XDR TB in Greece, emphasizing the public health dimensions and management complexity of XDR TB.

Immunotherapy against invasive mold infections

Invasive infections due to filamentous fungi, such as Aspergillus spp., Zygomycetes, Scedosporium and Fusarium spp., cause significant morbidity and mortality in immunocompromised patients with hematological malignancies, recipients of hematopoietic stem cell transplants and those with chronic granulomatous disease. Despite antifungal therapy, the outcome is often unfavorable in these patients; immune restoration is considered as the cornerstone of successful treatment. Important aspects of human immune response against fungi include effective innate immune response expressed as effective phagocytic functions and a balance between proinflammatory and regulatory adaptive immune responses. A number of immunomodulatory approaches, including the administration of enhancing cytokines, adoptive transfer of pathogen-specific T lymphocytes and granulocyte transfusions have been investigated as adjunctive treatments against serious mold infections. Despite encouraging in vitro and in vivo data, current clinical evidence is not sufficient to allow firm recommendations on the use of these immunomodulatory modalities in serious mold infections.

Immunotherapy of Cryptococcus infections

Despite appropriate antifungal treatment, the management of cryptococcal disease remains challenging, especially in immunocompromised patients, such as human immunodeficiency virus-infected individuals and solid organ transplant recipients. During the past two decades, our knowledge of host immune responses against Cryptococcus spp. has been greatly advanced, and the role of immunomodulation in augmenting the response to infection has been investigated. In particular, the role of 'protective' Th1 (tumour necrosis factor-α, interferon (IFN)-γ, interleukin (IL)-12, and IL-18) and Th17 (IL-23 and IL-17) and 'non-protective' Th2 (IL-4, IL-10, and IL-13) cytokines has been extensively studied in vitro and in animal models of cryptococcal infection. Immunomodulation with monoclonal antibodies against the capsular polysaccharide glucuronoxylomannan, glucosylceramides, melanin and β-glucan and, lately, with radioimmunotherapy has also yielded promising results in animal models. As a balance between sufficiently protective Th1 responses and excessive inflammation is important for optimal outcome, the effect of immunotherapy may range from beneficial to deleterious, depending on factors related to the host, the infecting organism, and the immunomodulatory regimen. Clinical evidence supporting immunomodulation in patients with cryptococcal infection remains too limited to allow firm recommendations. Limited human data suggest a role for IFN-γ. Identification of surrogate markers characterizing patients' immunological status could possibly suggest candidate patients for immunotherapy and the type of immunomodulation to be administered.

Serum levels of daptomycin in pediatric patients

BACKGROUND

Limited data are available on the pharmacokinetics and optimal dosage of daptomycin, a lipopeptide compound possessing activity against Gram-positive bacteria, in the pediatric population, particularly in neonates and infants. We determined serum levels of daptomycin in hospitalized pediatric patients treated with various dosages of this agent.

METHODS

Blood samples were obtained from pediatric patients of all ages with normal renal function who had received daptomycin between May 2009 and December 2010. Serum levels prior ("trough") and 30 min after end of the infusion ("peak") were determined using an ultra-performance liquid chromatography-UV detection method.

RESULTS

A total of four daptomycin dosages and four patients were studied. Three patients were infants (gestational age: 29-38 weeks, age at sampling 26-65 days) and the fourth was a 7-year-old boy. A dosage of 6 mg/kg/12 h of daptomycin to the infants resulted in trough concentrations of <4-8.4 mg/l and peak concentrations of 10.9-17.7 mg/l. Comparable levels were observed after one of the infants received a dosage of 11 mg/kg/12 h, while a further dosage increase to 15 mg/kg/12 h yielded peak concentrations of 35.5 mg/l. The 7-year-old child received a daptomycin dosage of 12 mg/kg once daily; trough and peak levels were 4.2 and 103.4 mg/l, respectively.

CONCLUSIONS

A dosage of daptomycin 6 mg/kg/12 h in small infants results in lower peak and similar trough concentrations compared with a dosage of 4 mg/kg/day administered to adults. This results suggests that daptomycin dosages of more than 6 mg/kg/12 h may be needed for this pediatric age group to achieve a similar drug exposure as adults.

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome (APECED) due to AIRET16M mutation in a consanguineous Greek girl

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome (APECED) or autoimmune polyendocrine syndrome type 1 (APS-1) is a rare autosomal recessive disease caused by mutations of the AutoImmune REgulator (AIRE) gene, an important mediator of tolerance to self-antigens. It is characterized by two out of three major components: chronic mucocutaneous candidiasis, hypoparathyroidism and Addison's disease. We present an 11-year-old girl suffering from recurrent episodes of mucocutaneous candidiasis and onychomycosis from 1 to 6 years of age, and transient alopecia at the age of 4 years. Hypoparathyroidism and dental enamel hypoplasia were diagnosed at 8 years. Autoantibodies to thyroid and adrenal glands were not detected and all other endocrine functions have remained normal. Genetic analysis revealed that the patient was homozygous for the mutation T16M in exon 1 of the AIRE gene (p.T16M, c.47C>T). This is the first APECED case reported for carrying this mutation in homozygous form. Parents were third cousins and heterozygous carriers of this mutation.

Fungal biomass is a key factor affecting polymorphonuclear leucocyte-induced hyphal damage of filamentous fungi

Previous studies have not systematically assessed the effect of fungal biomass on polymorphonuclear leucocyte (PMN)-induced hyphal damage (HD) of filamentous fungi. We hypothesised that fungal biomass is a significant factor affecting PMN-induced HD. One isolate each consisting of a volume of 2 x 10(4) conidia ml(-1) of Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus, Rhizopus oryzae, Rhizopus microsporus, Cunninghamella bertholletiae, Scedosporium prolificans and Fusarium solani were incubated for six different time periods yielding biomass values between 0.01 and 0.1 optical density (OD, 405 nm). Polymorphonuclear leucocyte were added at effector-target (E : T) ratios of 5 : 1, 10 : 1, 20 : 1, 50 : 1 and 100 : 1, and HD was assessed by XTT [2,3-bis-(2-methoxy-4-nitro-5-sulphophenyl)-2H-tetrazolium-5-carboxanilide] metabolic assay. Hyphal damage decreased with increasing biomass following the sigmoid (E(max)) model (median R(2): 0.87). Hyphal damage at 0.01 OD exceeded HD at 0.1 OD (P < 0.01) by >twofold in 64 out of 80 comparisons. The sigmoid curves were shifted to the right with higher E : T ratios; the EC(50) values (OD values showing HD halfway between maximal and minimal HD) obtained for 50 : 1 or 100 : 1 were higher than for 5 : 1 (P < 0.01). Using the same E : T ratio, interspecies differences were observed; for 5 : 1, lower EC(50) values were obtained for A. flavus and the zygomycete species. In conclusion, PMN-induced HD decreases with increasing biomass. This effect is both species-dependent and E : T ratio-dependent.

Differential correlation between rates of antimicrobial drug consumption and prevalence of antimicrobial resistance in a tertiary care hospital in Greece

OBJECTIVE

To investigate whether there is a correlation between the rates of antimicrobial drug consumption in hospital departments and the prevalence of antimicrobial resistance among clinically important bacteria recovered in the hospital.

DESIGN

Retrospective study.

SETTING

Tertiary care hospital in Greece.

METHODS

Data on antimicrobial consumption (from January 2001 through December 2004) were expressed as defined daily doses per 100 bed-days. The prevalence of antimicrobial resistance among isolates of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, and Enterococcus faecium recovered during the same time period were calculated by the microbiology department. We then performed the following analyses: (1) a comparison of the consumption rates for different antimicrobial groups in individual hospital departments, (2) a comparison of the prevalence of resistance to different antimicrobials, and (3) a correlation analysis of antimicrobial consumption rates and the prevalence of antimicrobial resistance.

RESULTS

The rates of antimicrobial consumption and the prevalence of resistance varied substantially among the hospital's departments. The annual rate of consumption for carbapenems correlated with the rate of consumption for glycopeptides and third-generation cephalosporins (P < .05). Among P. aeruginosa isolates, the prevalence of imipenem resistance correlated with the prevalence of resistance to amikacin, ciprofloxacin, and ceftazidime (P < .05). The rate of carbapenem consumption correlated with the prevalence of imipenem resistance among P. aeruginosa and A. baumannii isolates (P < .05). The rate of aminoglycoside consumption correlated with the prevalence of amikacin resistance among P. aeruginosa, K. pneumoniae, and E. coli isolates (P < .05). However, the rate of consumption for fluoroquinolones and glycopeptides had no correlation with the prevalence of ciprofloxacin resistance among gram-negative bacteria or vancomycin resistance among E. faecium isolates.

CONCLUSIONS

These data are suggestive of a differential relationship between antimicrobial consumption and the prevalence of antimicrobial resistance among various species and for various antimicrobial agents. These findings may help to optimize antimicrobial prescription policies in the hospital, especially in departments that have both high rates of antimicrobial consumption and a high prevalence of antimicrobial resistance.