The utilization of concentrated solar energy as external heat source for methane steam reforming has been investigated. Molten salts at temperatures up to 550°C can be used as solar heat carrier and storage system, and hydrogen selective membranes can be used to drive reforming reaction at lower temperatures than conventional (<550°C), with hydrogen purification achieved thereby. The combination of new technologies such as membranes and membrane reactors, concentrating solar power (CSP) systems, and molten salt heat carriers, allows a partial decarbonation of the fossil fuel together with the possibility to carry solar energy in the current natural gas grid. Different plant configurations and operating conditions have been analyzed using a mathematical model and AspenPlus simulator. © 2008 American Institute of Chemical Engineers AIChE J, 2008

To characterize the epidemiology and prognostic factors of invasive fusariosis in hematopoietic stem cell transplant (HSCT) recipients, the records of HSCT recipients from 9 hospitals (7 in Brazil and 2 in the United States) were retrospectively reviewed. Sixty-one cases were identified: 54 in allogeneic HSCT recipients and 7 in autologous HSCT recipients. The incidence of fusariosis among allogeneic HSCT recipients varied between a range of 4.21-5.0 cases per 1000 in human leukocyte antigen (HLA)--matched related transplant recipients to 20.19 cases per 1000 in HLA-mismatched transplant recipients. The median time period between transplantation and diagnosis of fusariosis was 48 days. Among allogeneic HSCT recipients, a trimodal distribution was observed: a first peak before engraftment, a second peak at a median of 62 days after transplantation, and a third peak >1 year after transplantation. The actuarial survival was 13% (median, 13 days). Persistent neutropenia was the single prognostic factor for death identified by multivariate analysis.

A total of 399 consecutive episodes of bloodstream infections in adult patients with haematologic malignancies and solid tumours were evaluated prospectively over a 26-month period, with the aim of determining the clinical characteristics and the microbiological profile of the patients relative to neutrophil count. The overall 30-day mortality rate was 32% (35% in non-neutropenic patients vs. 26% in neutropenic patients, p=0.05). Main diagnoses were solid tumours (33%) and lymphoma (29%). Most of the episodes of bloodstream infection (58%) occurred in non-neutropenic patients. Acute leukaemia and bone marrow transplantation predominated in the neutropenic group. Non-neutropenic patients tended to be older and to have a higher frequency of solid tumours and advanced or uncontrolled diseases. Indwelling central venous catheters were present in 51% of the episodes, with a predominance of long-term catheters in neutropenic haematologic patients. Concomitant infections were observed more frequently in non-neutropenic patients. There were 1,040 noninfectious comorbid conditions, most of which were present in non-neutropenic patients. The causative pathogens were predominantly gram-negative bacilli (56%). Escherichia coli and Klebsiella pneumoniae were isolated more frequently from neutropenic patients, while Staphylococcus aureus and Acinetobacter spp. were more frequent in non-neutropenic patients. Seventy-four percent of the episodes of candidaemia occurred in patients with central venous catheters, with non-albicans strains predominating. The results of this study highlight the heterogeneity of cancer patients with bloodstream infections and the value of stratifying risk factors and aetiologic agents according to neutrophil count.

Corynebacterium diphtheriae still represents a global medical challenge, particularly due to the significant number of individuals susceptible to diphtheria and the emergence of non-toxigenic strains as the causative agents of invasive infections. In this study, we characterized the clinical and microbiological features of what we believe to be the first case of C. diphtheriae infection of a percutaneous nephrostomy catheter insertion site in an elderly patient with a fatal bladder cancer. Moreover, we demonstrated the potential role of adherence, biofilm formation and fibrin deposition traits in C. diphtheriae from the catheter-related infection. Non-toxigenic C. diphtheriae isolated from the purulent discharge (named strain BR-CAT5003748) was identified by the API Coryne system (code 1 010 324) and a multiplex PCR for detection of dtxR and tox genes. Strain BR-CAT5003748 showed resistance to oxacillin, ceftazidime and ciprofloxacin. In experiments performed in vitro, the catheter isolate was classified as moderately hydrophobic and as moderately adherent to polystyrene surfaces. Glass provided a more effective surface for biofilm formation than polystyrene. Micro-organisms adhered to (.1.5¾10 6 c.f.u.) and multiplied on surfaces of polyurethane catheters. Microcolony formation (a hallmark of biofilm formation) and amorphous accretions were observed by scanning electron microscopy on both external and luminal catheter surfaces. Micro-organisms yielded simultaneous expression of localized adherence-like and aggregative-like (LAL/AAL) adherence patterns to HEp-2 cells. Interestingly, the coagulase tube test resulted in the formation of a thin layer of fibrin embedded in rabbit plasma by the non-toxigenic BR-CAT5003748 strain. In conclusion, C. diphtheriae should be recognized as a potential cause of catheter-related infections in at-risk populations such as elderly and cancer patients. LAL/AAL strains may be associated with virulence traits that enable C. diphtheriae to effectively produce biofilms on catheter surfaces. Biofilm formation and fibrin deposition could have contributed to the persistence of C. diphtheriae at the infected insertion site and the obstruction of the nephrostomy catheter. INTRODUCTIONInfections due to bacteria that form biofilms are a clinical problem (Donlan, 2001;Rao et al., 2008 Non-diphtherial corynebacteria have been reported to be infecting pathogens or copathogens in at-risk populations such as immunocompromised patients and patients with indwelling medical devices (Cavendish et al., 1994;Esteban et al., 1999;Wang et al., 2001;Dobler & Braveny, 2003;Schiffl et al., 2004;Lee et al., 2005;Teixido et al., 2007;Dalal & Likhi, 2008).Corynebacterium diphtheriae infections represent a global medical challenge, particularly due to the significant rise in the percentage of adults susceptible to diphtheria (MattosGuaraldi et al., 2001) and the emergence of non-toxigenic strains as the causative agents of endocarditis and other systemic infections . This pathogen is also becoming successful i...

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The identification of the microbiology profile of BSI and the recognition of possible risk factors in high-risk cancer patients may help in planning and conducting more effective infection control and preventive measures, and may also allow further analytical studies for reducing severe infectious complications in such groups of patients.

Yeasts belonging to the genus Hansenula are rarely encountered as the cause of infection in clinical practice. A wide spectrum of infections caused by these fungi can be seen, ranging from asymptomatic fungaemia to severe disease. We describe an outbreak of 24 cases of infection due to H. anomala in an oncological hospital in Rio de Janeiro, Brazil. The median age of the patients was 11 years, of whom 54.2% were female; 91.7% of the Hansenula fungaemia occurred in the haematology unit. The most frequent primary disease diagnosis was leukaemia (62.5%), and all of those infected had had a central venous catheter or peripheral venous catheter and had been treated previously with broad-spectrum antibiotics. Numerous other risk factors were observed in our cases: previous use of steroids, chemotherapy, radiation therapy and neutropenia (data not shown). No deaths could be attributed to Hansenula.

The aim of this study was to describe the epidemiology and microbiology of bloodstream infections (BSIs) among adult surgical cancer patients and to determine independent factors that influence in-hospital mortality. The study enrolled 112 consecutive episodes of BSIs in adult surgical cancer patients during a 26-month period. The median age of the patients was 64.5 years, and crude in-hospital mortality was 19.6%. The median time from surgery to the index blood culture was 11 days and from index blood culture to death was 4.5 days. Seventy-five percent of the patients had an advanced tumor disease, 36.6% were under intensive care, and 68.7% had a central venous catheter in place at the time the bloodstream infection was diagnosed. Associated infected sites were present in 57.1% of the episodes. There were 328 noninfectious co-morbid conditions. Poor performance status, weight loss, hypoalbuminemia, and ventilatory support accounted for 67.4% of them. There was a predominance of aerobic gram-negative bacilli (62%), followed by gram-positive cocci (26.6%) and fungi (9.3%). The observed mortality rates associated with these organism groups were similar (23.6% vs 15% vs 28.6%, respectively; P=0.44). The most frequent organisms were Enterobacter spp., coagulase-negative staphylococci, Klebsiella spp., Acinetobacter spp., and fungi. Nonfermentative strains predominated in patients with catheters. Thirty-five (30.2%) pathogens were considered resistant. There was no significant difference in the mortality rate between patients with resistant and those with nonresistant organisms (20% vs 26%, respectively; P=0.49). Logistic regression analysis showed > or = 4 co-morbid conditions, advanced tumor, thoracic surgery, catheter retention, and pulmonary infiltrates as independent predictors of mortality. Medical and infection control measures addressing certain variables amenable to intervention might reduce the negative impact of postoperative infectious morbidity and mortality of BSIs in adult surgical cancer patients.