In vitro and in vivo antimicrobial activity of sodium colistimethate and amikacin-loaded nanostructured lipid carriers (NLC).

Sodium colistimethate (SCM) and amikacin (AMK) are among the few antibiotics effective against resistant P. aeruginosa, K. pneumoniae and A. baumannii; however, their toxicity severely limits their use. Enclosing antibiotics into nanostructured lipid carriers (NLC) might decrease drug toxicity and improve antibiotic disposition. In this work, SCM or AMK was loaded into different NLC formulations, through high pressure homogenization, and their in vitro and in vivo effectiveness was analyzed. The encapsulation process did not reduce drug effectiveness since in vitro SCM-NLC and AMK-NLC drug activity was equal to that of the free drugs. As cryoprotectant, trehalose showed better properties than dextran. Instead, positive chitosan coating was discarded due to its limited cost-efficiency. Finally, the in vivo study in acute pneumonia model revealed that intraperitoneal administration was superior to the intramuscular route and confirmed that (-) SCM-NLC with trehalose, was the most suitable formulation against an extensively drug-resistant A. baumannii strain.

European Space Agency experiments on thermodiffusion of fluid mixtures in space.

This paper describes the European Space Agency (ESA) experiments devoted to study thermodiffusion of fluid mixtures in microgravity environment, where sedimentation and convection do not affect the mass flow induced by the Soret effect. First, the experiments performed on binary mixtures in the IVIDIL and GRADFLEX experiments are described. Then, further experiments on ternary mixtures and complex fluids performed in DCMIX and planned to be performed in the context of the NEUF-DIX project are presented. Finally, multi-component mixtures studied in the SCCO project are detailed.

Epidemiology and Immediate Indirect Effects of Respiratory Viruses in Lung Transplant Recipients: A 5-Year Prospective Study.

The epidemiology of respiratory viruses (RVs) in lung transplant recipients (LTRs) and the relationship of RVs to lung function, acute rejection (AR) and opportunistic infections in these patients are not well known. We performed a prospective cohort study (2009-2014) by collecting nasopharyngeal swabs (NPSs) from asymptomatic LTRs during seasonal changes and from LTRs with upper respiratory tract infectious disease (URTID), lower respiratory tract infectious disease (LRTID) and AR. NPSs were analyzed by multiplex polymerase chain reaction. Overall, 1094 NPSs were collected from 98 patients with a 23.6% positivity rate and mean follow-up of 3.4 years (interquartile range 2.5-4.0 years). Approximately half of URTIDs (47 of 97, 48.5%) and tracheobronchitis cases (22 of 56, 39.3%) were caused by picornavirus, whereas pneumonia was caused mainly by paramyxovirus (four of nine, 44.4%) and influenza (two of nine, 22.2%). In LTRs with LRTID, lung function changed significantly at 1 mo (p = 0.03) and 3 mo (p = 0.04). In a nested case-control analysis, AR was associated with RVs (hazard ratio [HR] 6.54), Pseudomonas aeruginosa was associated with LRTID (HR 8.54), and cytomegalovirus (CMV) replication or disease was associated with URTID (HR 2.53) in the previous 3 mo. There was no association between RVs and Aspergillus spp. colonization or infection (HR 0.71). In conclusion, we documented a high incidence of RV infections in LTRs. LRTID produced significant lung function abnormalities. Associations were observed between AR and RVs, between P. aeruginosa colonization or infection and LRTID, and between CMV replication or disease and URTID.

Epidemiology of invasive respiratory disease caused by emerging non-Aspergillus molds in lung transplant recipients.

OBJECTIVES: Our aim was to assess the impact of positive cultures for non-Aspergillus molds on the risk of progression to invasive fungal infection (IFI), and the effect of prophylactic nebulized liposomal amphotericin B (n-LAB) on these pathogens. METHODS: This was an observational study (2003-2013) including lung transplant recipients (LTR) receiving lifetime n-LAB prophylaxis, in whom non-Aspergillus molds were isolated on respiratory culture before and after transplantation (minimum 1-year follow-up). RESULTS: We studied 412 patients, with a mean postoperative follow-up of 2.56 years (interquartile range 1.01-4.65). Pre- and post-transplantation respiratory samples were frequently positive for non-Aspergillus molds (11.9% and 16.9% of LTR respectively). Post transplantation, 10 (2.42%) patients developed non-Aspergillus mold infection (4 Scedosporium species, 4 Purpureocillium species, 1 Penicillium species, and 1 Scopulariopsis species); 5 (1.21%) had IFI, with 60% IFI-related mortality. Non-Aspergillus molds with intrinsic amphotericin B (AB) resistance were more commonly isolated in bronchoscopy samples than AB-variably sensitive or AB-sensitive molds (54.5% vs. 25%, P = 0.04) and were associated with a higher risk of infection (56.3% vs. 1.3%%, P < 0.01). CONCLUSIONS: In LTR undergoing n-LAB prophylaxis, pre- and post-transplantation isolation of non-Aspergillus molds is frequent, but IFI incidence (1.21%) is low. Purpureocillium is an emerging mold. AB-resistant non-Aspergillus species were found more often in bronchoscopy samples and were associated with a higher risk of infection.

Prevention strategies for cytomegalovirus disease and long-term outcomes in the high-risk transplant patient (D+/R-): experience from the RESITRA-REIPI cohort.

BACKGROUND: Cytomegalovirus (CMV)-negative recipients of a graft from a CMV-positive donor (D+/R-) are at high risk of CMV disease. Current preventive strategies include universal prophylaxis (UP) and preemptive therapy (PT). However, the best strategy to prevent CMV disease and achieve better long-term outcomes remains a matter of debate. METHODS: We analyzed the incidence of CMV disease and long-term outcomes including graft dysfunction and patient mortality at 5 years after transplantation with both preventive strategies. High-risk (D+/R-) kidney and liver transplant recipients from the RESITRA cohort were included. RESULTS: Of 2410 kidney or liver transplant patients, 195 (8.3%) were D+/R-. The final cohort included 58 liver and 102 kidney recipients. UP was given in 92 patients and 68 received PT; 10.9% and 36.8% developed CMV disease, respectively (P < 0.01). The independent risk factors for CMV disease were PT strategy (hazard ratio [HR], 3.30; 95% confidence interval [CI], 1.6-6.9), kidney transplantation (HR, 3.8; 95% CI, 1.4-9.9), and cyclosporine immunosuppression (HR, 2.4; 95% CI, 1.2-4.7). PT strategy was also a risk factor for CMV disease in both liver transplantation (HR, 11.0; 95% CI, 1.2-98.7) and kidney transplantation (HR, 2.7; 95% CI, 1.3-6.0), independently. The development of CMV replication during the first 2 years after transplantation was a risk factor for graft dysfunction at 5 years after transplantation (odds ratio, 3.4; 95% CI, 1.3-9.0). Nevertheless, no significant differences were seen in either graft dysfunction or mortality between the 2 strategies. CONCLUSIONS: The study supports the benefit of the UP strategy to prevent CMV disease in D+/R- liver or kidney transplant patients. The development of CMV replication during the first 2 years after transplantation was associated with graft dysfunction at 5 years after transplantation.

Daptomycin is safe and effective for the treatment of gram-positive cocci infections in solid organ transplantation.

INTRODUCTION: Infections caused by resistant gram-positive cocci (GPC), especially to glycopeptides, are difficult to treat in solid organ transplant (SOT) recipients as a result of lower effectiveness and high rates of renal impairment. The aim of this study was to evaluate the use of daptomycin in this population. METHODS: Over a 2-year period (March 2008-2010) in 9 Spanish centers, we enrolled all consecutive recipients who received daptomycin to treat GPC infection. The study included 43 patients, mainly liver and kidney transplant recipients. RESULTS: The most frequent infections were catheter-related bacteremia caused by coagulase-negative staphylococci (23.2%), skin infection caused by Staphylococcus aureus (11.5%), and intra-abdominal abscess caused by Enterococcus faecium (20.9%). The daily daptomycin dose was 6 mg/kg in 32 patients (74.4%). On day 7 of daptomycin treatment, median estimated area under the curve was 1251 µg/mL/h. At the end of follow-up, analytical parameters were similar to the values at the start of therapy. No changes were observed in tacrolimus levels. No patient required discontinuation of daptomycin because of adverse effects. Clinical success at treatment completion was achieved in 37 (86%) patients. Three patients died while on treatment with daptomycin. CONCLUSION: In summary, daptomycin was a safe and useful treatment for GPC infection in SOT recipients.

Immunogenicity of pandemic influenza A H1N1/2009 adjuvanted vaccine in pediatric solid organ transplant recipients.

The aim of this study was to assess the immunogenicity of a vaccine against this virus in a prospective cohort of transplanted pediatric patients without previous influenza infection who received one dose of MF59®-adjuvanted pandemic H1N1/2009 vaccine. Seventeen patients who were being regularly followed up at the Outpatient Clinic of the Children's Transplant Unit (liver and kidney transplantation) in Hospital Universitari Vall d'Hebron (Barcelona) were included. Seroconversion was demonstrated in 15 of 17 (88.2%) vaccinated children. There were no rejection episodes or major adverse events. The MF59(®) -adjuvanted pandemic H1N1/2009 vaccine was safe and elicited an adequate response.

Influenza A H1N1/2009 infection in pediatric solid organ transplant recipients.

AIM AND METHOD: The aim of this study was to describe the clinical characteristics and outcome of pandemic influenza A H1N1/2009 (pH1N1) infection, in a retrospective cohort of pediatric patients with kidney and/or liver transplant and confirmed pH1N1 infection from June to December 2009, diagnosed in 2 Spanish teaching hospitals. RESULTS: Forty-nine patients were included. Pneumonia was diagnosed in 4 patients (8.2%), and 3 of them required respiratory support. There were no related deaths. CONCLUSION: Antiviral treatment within 48 h was associated with a lower likelihood of pneumonia (0/38, 0%) than treatment started after 48 h (4/11, 36.3%) (P < 0.01).

Therapy with m-TOR inhibitors decreases the response to the pandemic influenza A H1N1 vaccine in solid organ transplant recipients.

Concern has been raised regarding the response to vaccination in solid organ transplant recipients (SOTR) undergoing immunosuppressant regimens and the possibility of rejection related to the immune response associated with pandemic influenza H1N1-2009 vaccination. The goal of this study was to assess the immunogenicity, efficacy and safety of the pandemic vaccine in SOTR. We performed a multicenter prospective study in SOTR receiving the pandemic vaccine. Immunological response was determined in serum 5 weeks after vaccination by microneutralization assays, and immunoglobulins were measured by ELISA. Three hundred and forty-six SOTR were included. Preexisting seroprotection was detected in 13.6% of cases and rates of seroconversion and seroprotection after vaccination were 73.1% and 82.9%, respectively. Patients with baseline antibody titers had better geometric mean titers (GMT)-post after pandemic vaccination (339.4 vs. 121.4, p < 0.001). Younger age, liver disease and m-TOR inhibitor therapy were independently associated with lower seroprotection and GMT-post. There were no major adverse effects or rejection episodes. Pandemic vaccine was safe in SOTR and elicited an adequate response, although lower than in healthy individuals. This is the first study describing a decreased response after vaccination in patients receiving mTOR inhibitors who presented lower seroprotection rates and lower GMT-post.

Immunosuppressive therapy and infection after kidney transplantation.

BACKGROUND: The role of immunosuppressive drugs in the development of infection in transplant recipients has been poorly analyzed. OBJECTIVE: To evaluate the possible association between infection and immunosuppression regimens in a large cohort of renal transplant recipients. METHODS: All renal transplant recipients included in the RESITRA prospective cohort from August 2003 to February 2005 with a minimum follow-up of 3 months were studied. An intention-to-treat analysis was performed and patients were analyzed in groups according to the type of induction and initial maintenance therapy. Viral, bacterial, and fungal infections occurring during this period were evaluated. RESULTS: A total of 1398 renal transplant recipients were studied. A maintenance regimen containing sirolimus was independently associated with a lower risk of cytomegalovirus (CMV) infection (odds ratio [OR], 0.16; 95% confidence interval [CI], 0.05-0.54) and with a higher rate of surgical site infection (OR, 3.21; 95% CI, 1.26-8.21). Excluding treatment used for acute rejection episodes, no other factors related to the immunosuppression regimens were associated with the development of bacteremia, urinary infections, pneumonia, or other infections. CONCLUSION: The use of sirolimus as maintenance therapy in kidney recipients is associated with a low rate of CMV infection and with a higher risk of surgical site infection.

A multicenter study of valganciclovir prophylaxis up to day 120 in CMV-seropositive lung transplant recipients.

Seventy-six cytomegalovirus (CMV)-seropositive lung transplant recipients receiving valganciclovir (900 mg/day) for CMV prophylaxis were compared with a group of 87 patients receiving oral ganciclovir (3000 mg/day). Prophylaxis was administered to day 120 post-transplantation and follow-up was 1 year. In addition, a study was conducted on risk factors for CMV infection/disease. CMV disease incidence was 7.9% and 16.1% for valganciclovir and oral ganciclovir, respectively (p = 0.11). Patients receiving valganciclovir had fewer viral syndromes (2.6% vs. 11.5%, p < 0.05), a similar rate of tissue-invasive disease (5.2% vs. 4.6%, p = ns), longer time-to-onset of CMV infection/disease (197.5 vs. 155.2 days, p < 0.05), and a lower probability of infection/disease while on prophylaxis (1.3% vs. 12.6%, p < 0.01). Nonetheless, leukopenia incidence was higher with valganciclovir (15.8% vs. 2.3%, p < 0.01), as was the need for treatment withdrawal due to adverse effects (11.8% vs. 1.1%, p < 0.01). CMV infection was similar in both groups (32.9% vs. 34.5%). Induction therapy with basiliximab and glucocorticosteroid treatment were independent risk factors for developing CMV infection/disease. In conclusion, valganciclovir prophylaxis results in a low incidence of CMV disease in lung transplant recipients and appears more effective than oral ganciclovir. Despite the comparatively higher incidence of adverse events with valganciclovir, the drug can be considered safe for prophylaxis.

Impact of valganciclovir on Epstein-Barr Virus polymerase chain reaction in pediatric liver transplantation: preliminary report.

UNLABELLED: Preemptive therapy with ganciclovir has been recommended in the pediatric liver transplant strategy to avoid the development of posttransplant lymphoproliferative disorder (PTLD) from an high Epstein-Barr virus (EBV) is detected. We sought viral load to analyze the response to preemptive therapy with valganciclovir (VGC) in children with liver transplantations and an high quantitative EBV-PCR. METHODS: From June 2005 to December 2007, we tested 979 EBV-PCR among 80 pediatric liver transplant recipients, from those 21/80 PCR were tested from the date of transplantation and 59/80 belonged to the historical cohort (7/59 had a prior history of PTLD). Patients were divided into 2 groups depending upon whether they did (n = 22) or did not (n = 19) receive VGC treatment. The response to VGC was considered complete, if the PCR was negative at 30 and 60 days of treatment; and partial, when the PCR decreased at least 50%. Ganciclovir blood levels tested in 109 cases instances and correlated with the EBV-PCR. RESULTS: A total of 369 (33%) positive PCR were detected in 36/80 patients (mean, 75,000 copies; range = 5000-4,200,000). Among the 22 episodes treated for 30 days, 34% showed complete responses, 41%, partial, and 23%, no response. Among the non-treated group the rates were 6%, 25%, and 68%, respectively (P = .01). However, no differences were observed among those episodes treated for 60 days. At the administered doses, hardly any patient reached the recommended ganciclovir therapeutic level at 2 hours (6 micro/mL). However, the mean PCR was lower when the ganciclovir levels were greater than 4 mg/L when compared with lower levels (P = .03). CONCLUSION: After 30 days of treatment there was a response to VGC in the EBV viral load. There was high interpatient variability of ganciclovir serum concentrations, suggesting the need for pharmacokinetic monitoring to optimize treatment. There was a relationship between the concentration of ganciclovir and the EBV viral load.

Non-anatomical intestinal transplantation.

INTRODUCTION: Intestinal transplantation is the only long-range treatment option for patients with intestinal failure. We report an exceptional case of isolated intestinal transplantation with the implant in a non-anatomical position. CLINICAL CASE: The patient was a thirty-eight-year-old man (60 kg weight, 180 cm height, 18.3 body mass index) with intestinal failure and home parenteral nutrition due to a short-bowel syndrome for which intestinal transplantation was indicated. The patient had a vascular malformation with the cava vein located left to the aorta, and the intestine was implanted with a 180 masculine rotation around the mesenteric axis, so that the implant s superior mesenteric artery and vein matched the recipient s cava and aorta. Postoperative follow-up was excellent and the patient was discharged after six weeks with a 10-kg gain in body weight. DISCUSSION: This non-anatomical intestinal implantation of the small bowel, previously unreported, offers technical advantages over other options. Adequate intestinal function represents a unique model to prove the viability of intestinal implants in a non-anatomical position.

Donor infection and transmission to the recipient of a solid allograft.

Transmission of infection from donor to recipient is a potential complication of transplantation. More data on this issue are needed to expand the insufficient donor pool. This study evaluates the incidence of donor nonviral infection, transmission from infected donors and the effect of donor infection on 30-day recipient survival. Data from 211 infected donors contributing to 292 (8.8%) of 3322 consecutive transplant procedures within RESITRA (Spanish Research Network for the Study of Infection in Transplantation) were prospectively compiled and analyzed. Lung was the most likely transplanted organ carried out with an infected donor and Staphylococcus aureus was the most commonly isolated microorganism. In more than a half of donors, the lung was the site of infection. Donor-to-host transmission was documented in 5 patients out of 292 (1.71%), 2 of whom died of the acquired infection (40%). Nonetheless, there was no difference in 30-day patient survival when comparing transplant procedures performed with organs from infected or uninfected donors. In conclusion, donor infection is not an infrequent event, but transmission to the recipient is quite low. Hence, with careful microbiological surveillance and treatment, the number of organs available for transplantation may be increased.

Impact of Staphylococcus aureus phenotype and genotype on the clinical characteristics and outcome of infective endocarditis. A multicentre, longitudinal, prospective, observational study.

OBJECTIVE: We aimed to evaluate the impact of Staphylococcus aureus phenotype (vancomycin MIC) and genotype (agr group, clonal complex CC) on the prognosis and clinical characteristics of infective endocarditis (IE). METHODS: We performed a multicentre, longitudinal, prospective, observational study (June 2013 to March 2016) in 15 Spanish hospitals. Two hundred and thirteen consecutive adults (≥18 years) with a definite diagnosis of S. aureus IE were included. Primary outcome was death during hospital stay. Main secondary end points were persistent bacteraemia, sepsis/septic shock, peripheral embolism and osteoarticular involvement. RESULTS: Overall in-hospital mortality was 37% (n = 72). Independent risk factors for death were age-adjusted Charlson co-morbidity index (OR 1.20; 95% CI 1.08-1.34), congestive heart failure (OR 3.60; 95% CI 1.72-7.50), symptomatic central nervous system complication (OR 3.17; 95% CI 1.41-7.11) and severe sepsis/septic shock (OR 4.41; 95% CI 2.18-8.96). In the subgroup of methicillin-susceptible S. aureus IE (n = 173), independent risk factors for death were the age-adjusted Charlson co-morbidity index (OR 1.17; 95% CI 1.03-1.31), congestive heart failure (OR 3.39; 95% CI 1.51-7.64), new conduction abnormality (OR 4.42; 95% CI 1.27-15.34), severe sepsis/septic shock (OR 5.76; 95% CI 2.57-12.89) and agr group III (OR 0.27; 0.10-0.75). Vancomycin MIC ≥1.5 mg/L was not independently associated with death during hospital nor was it related to secondary end points. No other genotype variables were independently associated with in-hospital death. CONCLUSIONS: This is the first prospective study to assess the impact of S. aureus phenotype and genotype. Phenotype and genotype provided no additional predictive value beyond conventional clinical characteristics. No evidence was found to justify therapeutic decisions based on vancomycin MIC for either methicillin-resistant or methicillin-susceptible S. aureus.

Management of multidrug resistant Gram-negative bacilli infections in solid organ transplant recipients: SET/GESITRA-SEIMC/REIPI recommendations.

Solid organ transplant (SOT) recipients are especially at risk of developing infections by multidrug resistant (MDR) Gram-negative bacilli (GNB), as they are frequently exposed to antibiotics and the healthcare setting, and are regulary subject to invasive procedures. Nevertheless, no recommendations concerning prevention and treatment are available. A panel of experts revised the available evidence; this document summarizes their recommendations: (1) it is important to characterize the isolate's phenotypic and genotypic resistance profile; (2) overall, donor colonization should not constitute a contraindication to transplantation, although active infected kidney and lung grafts should be avoided; (3) recipient colonization is associated with an increased risk of infection, but is not a contraindication to transplantation; (4) different surgical prophylaxis regimens are not recommended for patients colonized with carbapenem-resistant GNB; (5) timely detection of carriers, contact isolation precautions, hand hygiene compliance and antibiotic control policies are important preventive measures; (6) there is not sufficient data to recommend intestinal decolonization; (7) colonized lung transplant recipients could benefit from prophylactic inhaled antibiotics, specially for Pseudomonas aeruginosa; (8) colonized SOT recipients should receive an empirical treatment which includes active antibiotics, and directed therapy should be adjusted according to susceptibility study results and the severity of the infection.

Blood and tissue distribution of posaconazole in a rat model of invasive pulmonary aspergillosis.

Posaconazole is the recommended prophylactic agent in patients at high risk of invasive fungal infection, since adequate drug levels seem to be reached in target sites despite the relatively low levels detected in blood. The objective of this study is to obtain pharmacokinetic (PK) information associated to blood and tissue distribution of posaconazole in an animal model of invasive pulmonary aspergillosis. The PK parameters in lung samples were systematically higher than in serum. After multiple-dose administration of posaconazole, a significant accumulation of the drug was evident in lung tissue. The PK behavior of posaconazole in this particular experimental model is similar to that observed in humans. Thus, we believe this model could be a valid tool to evaluate posaconazole exposure-response relationship.

Management of cytomegalovirus infection in solid organ transplant recipients: SET/GESITRA-SEIMC/REIPI recommendations.

Cytomegalovirus (CMV) infection remains a major complication of solid organ transplantation. Because of management of CMV is variable among transplant centers, in 2011 the Spanish Transplantation Infection Study Group (GESITRA) of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) developed consensus guidelines for the prevention and treatment of CMV infection in solid organ transplant recipients. Since then, new publications have clarified or questioned the aspects covered in the previous document. For that reason, a panel of experts revised the evidence on CMV management, including immunological monitoring, diagnostics, prevention, vaccines, indirect effects, treatment, drug resistance, immunotherapy, investigational drugs, and pediatric issues. This document summarizes the recommendations.

Risk factors for invasive aspergillosis in solid-organ transplant recipients: a case-control study.

BACKGROUND: To facilitate the design of strategies for prevention of invasive aspergillosis in solid-organ transplant recipients, this study investigates whether the development of early-onset and late-onset aspergillosis are related to different risk factors, thereby distinguishing 2 risk populations for this serious complication. METHODS: A retrospective case-control study was performed, including 156 cases of proven or probable invasive aspergillosis in patients recruited from 11 Spanish centers since the start of the centers' transplantation programs. RESULTS: Among all patients, 57% had early-onset IA (i.e., occurred during the first 3 months after transplantation). Risk factor analysis in this group identified as significantly associated risk factors a more complicated postoperative period, repeated bacterial infections or cytomegalovirus disease, and renal failure or the need for dialysis. Among patients with late-onset infections (i.e., occurred > 3 months after transplantation), who comprised 43% of cases, the patients at risk were older, were in an overimmunosuppressed state because of chronic transplant rejection or allograft dysfunction, and had posttransplantation renal failure. CONCLUSIONS: Risk factors in patients with early-onset cases and patients with late-onset cases of posttransplantation invasive aspergillosis are not the same, a fact that could have implications for the preventive approaches used for this infection.

Efficacy of high loading doses of liposomal amphotericin B in the treatment of experimental invasive pulmonary aspergillosis.

This study aimed to investigate whether initial treatment of experimental pulmonary aspergillosis with high loading doses can be used as an alternative to standard therapeutic regimens. Steroid-immunosuppressed rats, infected intratracheally with Aspergillus fumigatus, received either amphotericin B deoxycholate (d-AmB) 1 mg/kg/day, liposomal amphotericin B (L-AmB) 5 mg/kg/day, or underwent a 3-day course of L-AmB 10 mg/kg, or 10 mg/kg for the first 3 or 4 days of treatment, followed by 3 mg/kg until the end of treatment. Therapy started 24 h after fungal challenge and lasted for 7 days. Compared to controls, survival was improved significantly in animals receiving any L-AmB regimen (p