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Staphylococcus aureus; Biofilm; Infection Staphylococcus aureus; Biopelícula; Infección Staphylococcus aureus; Biopel·lícula; Infecció The aim of this study was to quantify in vitro biofilm formation by methicillin-susceptible Staphylococcus aureus (MSSA) on the surfaces of different types of commonly used vascular grafts. We performed an in vitro study with two clinical strains of MSSA (MSSA2 and MSSA6) and nine vascular grafts: Dacron (Hemagard), Dacron-heparin (Intergard heparin), Dacron-silver (Intergard Silver), Dacron-silver-triclosan (Intergard Synergy), Dacron-gelatin (Gelsoft Plus), Dacron plus polytetrafluoroethylene (Fusion), polytetrafluoroethylene (Propaten; Gore), Omniflow II, and bovine pericardium (XenoSure). Biofilm formation was induced in two phases: an initial 90-minute adherence phase and a 24-hour growth phase. Quantitative cultures were performed, and the results were expressed as log10 CFU per milliliter. The Dacron-silver-triclosan graft and Omniflow II were associated with the least biofilm formation by both MSSA2 and MSSA6. MSSA2 did not form a biofilm on the Dacron-silver-triclosan graft (0 CFU/mL), and the mean count on the Omniflow II graft was 3.89 CFU/mL (standard deviation [SD] 2.10). The mean count for the other grafts was 7.01 CFU/mL (SD 0.82). MSSA6 formed a biofilm on both grafts, with 2.42 CFU/mL (SD 2.44) on the Dacron-silver-triclosan graft and 3.62 CFU/mL (SD 2.21) on the Omniflow II. The mean biofilm growth on the remaining grafts was 7.33 CFU/mL (SD 0.28). The differences in biofilm formation on the Dacron-silver-triclosan and Omniflow II grafts compared to the other tested grafts were statistically significant. Our findings suggest that of the vascular grafts we studied, the Dacron-silver-triclosan and Omniflow II grafts might prevent biofilm formation by MSSA. Although further studies are needed, these grafts seem to be good candidates for clinical use in vascular surgeries at high risk of infections due to this microorganism. IMPORTANCE The Dacron silver-triclosan and Omniflow II vascular grafts showed the greatest resistance to in vitro methicillin-susceptible Staphylococcus aureus biofilm formation compared to other vascular grafts. These findings could allow us to choose the most resistant to infection prosthetic graft.

There is currently an urgent need to find new strategies to tackle antimicrobial resistance and biofilm-related infections. This study has two aims. First, we evaluated the

The aim of this study was to evaluate the association between biomass formation and the clinical characteristics and prognosis of Staphylococcus aureus infective endocarditis (IE).We prospectively studied 209 S. aureus strains causing IE. Biomass formation was examined using the crystal violet assay and quantified spectrophotometrically. The average (SD) optical density of the biomass was compared for each clinical, microbiological (methicillin-resistance, vancomycin MIC≥1.5μg/ml) and molecular (clonal complex, agr type and agr dysfunction) variable according to their presence or absence. The primary clinical endpoints studied were in-hospital death, severe sepsis, persistent bacteraemia, symptomatic peripheral embolisms and prosthetic valve IE.Mean age was 66.1 years, 61.5% of patients were male and the median age-adjusted Charlson comorbidity index was 5 points (IQR 3-8). In-hospital mortality was 37.3%. Strains belonging to CC5 and CC22 had optical biomass densities [mean (SD) 1.573 (1.14) vs 0.942 (0.98) p0.001 and 1.720 (0.94) vs 1.028 (1.04) p=0.001, respectively]. Strains belonging to CC5 and CC22 had significantly higher optical biomass densities [1.369 (1.18) vs 0.920 (0.93) p=0.008]. No statistically significant differences were found in the clinical endpoints studied.High biomass production was associated with CC5 and CC22 but not with higher hospital mortality, septic complications, type of endocarditis, methicillin-resistance, elevated vancomycin MIC or agr dysfunction.

Summary Hemagglutination-inhibitory antibodies are usually highly strain specific with little effect on infection with drifted or shifted strains. The significance of broadly cross-reactive non-HAI anti-influenza antibodies against conserved domains of virus glycoproteins, such as the hemagglutinin (HA) stalk, is of great interest. We characterize a cohort of 40 H1N1pmd09 influenza-infected patients and identify lower respiratory symptoms (LRSs) as a predictor for development of pneumonia. A binomial logistic regression of log10 pre-existing antibody values shows that the probability of LRS occurrence decreased with increased anti-HA full-length and stalk antibody ELISA titers. However, a multilevel logistic regression model adjusted by other potential serocorrelates demonstrates that only antibodies directed against the stalk of HA correlate with protection from lower respiratory infection, limiting disease progression. Our predictive model indicates that a threshold of protective immunity based on broadly cross-reactive HA stalk antibodies could be feasible., Graphical Abstract, Highlights Solid organ transplant recipients (SOTRs) had low levels of HAI antibodies at baseline SOTRs have high levels of pre-existing, broadly cross-reactive anti-HA stalk antibodies Anti-HA stalk antibodies correlate with lack of lower respiratory symptoms in SOTRs Presence of lower respiratory symptoms is associated with influenza pneumonia, Aydillo et al. identify lower respiratory symptoms (LRSs) as a predictor of influenza pneumonia in a cohort of transplant recipients. When pre-existing immunity was characterized, the levels of anti-HA stalk antibodies correlated independently with protection from lower respiratory infection.

This study describes the clinical presentation, treatment, and outcomes of SARS-CoV-2 infection in lung transplant recipients (LTRs). This is a multicenter, retrospective study of all adult LTRs with confirmed SARS-CoV-2 infection from March 4 until April 28, 2020 in six Spanish reference hospitals for lung transplantation. Clinical and radiological data, treatment characteristics, and outcomes were reviewed. Forty-four cases were identified in that period. The median time from transplantation was 4.2 (interquartile range: 1.11-7.3) years. Chest radiography showed acute parenchymal abnormalities in 32 (73%) cases. Hydroxychloroquine was prescribed in 41 (93%), lopinavir/ritonavir (LPV/r) in 14 (32%), and tocilizumab in 19 (43%) patients. There was a strong interaction between tacrolimus and LPV/r in all cases. Thirty-seven (84%) patients required some degree of respiratory support and/or oxygen therapy, and 13 (30%) were admitted to intermediate or intensive critical care units. Seventeen (39%) patients had died and 20 (45%) had been discharged at the time of the last follow-up. Deceased patients had a worse respiratory status and chest X-ray on admission and presented with higher D-dimer, interleukin-6, and lactate dehydrogenase levels. In this multicenter LTR cohort, SARS-CoV-2 presented with high mortality. Additionally, the severity of disease on presentation predicted subsequent mortality.

Objectives Our aim was to analyze the prevalence of multidrug-resistant bacterial infections in lung transplant donors and to evaluate its influence on donor-derived bacterial infections. Methods We conducted a retrospective study of adult patients who underwent lung transplantation (2013–2016) at our hospital. Donor-derived bacterial infection was defined as the isolation of the same bacteria with identical antibiotic susceptibility patterns in the recipient and the perioperative cultures from the donor during the first month posttransplantation. We utilized a preventive antibiotic strategy adapted to the bacteria identified in donor cultures using systemic and nebulized antibiotics. Results 252 lung transplant recipients and 243 donors were included. In 138/243 (56.8%) donors, one bacterial species was isolated from at least one sample; graft colonization (118/243; 48.6%), blood cultures (5/243; 2.1%) and the contamination of preservation fluids (56/243; 23%). Multidrug-resistant bacteria were isolated from 12/243 (4.9%) donors; four Enterobacterales, four Stenotrophomonas maltophilia, three Pseudomonas aeruginosa and one methicillin-resistant Staphylococcus aureus. There was no transmission of these multidrug-resistant bacteria. Donor-derived infections, primarily tracheobronchitis due to non-MDR bacteria, were diagnosed in 7/253 (2.9%) recipients, with good clinical outcomes. Conclusions The lungs of donors colonized with multidrug-resistant bacteria may be safely used when recipients receive prompt tailored antibiotic treatment.

Background The relationship between community-acquired respiratory viruses (CARVs) and chronic lung allograft dysfunction (CLAD) in lung transplant recipients is still controversial. Methods We performed a prospective cohort study (2009–2014) in all consecutive adult patients (≥18 years) undergoing lung transplantation in the Hospital Universitari Vall d’Hebron (Barcelona, Spain). We systematically collected nasopharyngeal swabs from asymptomatic patients during seasonal changes, from patients with upper respiratory tract infectious disease, lower respiratory tract infectious disease (LRTID), or acute rejection. Nasopharyngeal swabs were analyzed by multiplex polymerase chain reaction. Primary outcome was to evaluate the potential association of CARVs and development of CLAD. Time-dependent Cox regression models were performed to identify the independent risk factors for CLAD. Results Overall, 98 patients (67 bilateral lung transplant recipients; 63.3% male; mean age, 49.9 years) were included. Mean postoperative follow-up was 3.4 years (interquartile range [IQR], 2.5–4.0 years). Thirty-eight lung transplant recipients (38.8%) developed CLAD, in a median time of 20.4 months (IQR, 12–30.4 months). In time-controlled multivariate analysis, CARV-LRTID (hazard ratio [HR], 3.00 [95% confidence interval {CI}, 1.52–5.91]; P = .002), acute rejection (HR, 2.97 [95% CI, 1.51–5.83]; P = .002), and cytomegalovirus pneumonitis (HR, 3.76 [95% CI, 1.23–11.49]; P = .02) were independent risk factors associated with developing CLAD. Conclusions Lung transplant recipients with CARVs in the lower respiratory tract are at increased risk to develop CLAD., “Community-acquired respiratory viruses (CARVs) lower respiratory tract infection” should be better than viral lower respiratory tract infection. It should be: CARVs lower respiratory tract infection, acute rejection and cytomegalovirus pneumonitis were independently associated with chronic lung allograft dysfunction.

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., A large prospective study of the epidemiology of respiratory viruses in lung transplant recipients using molecular assays demonstrates a very high incidence of respiratory viral infection and an association between respiratory virus infectious diseases, immediate allograft dysfunction, and the development of acute rejection and opportunistic infection.

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.

The immunosuppressive treatment that recipients receive from a solid organ transplantation hinders the defensive response to infection. Its transmission from the donor can cause dysfunction or loss of the graft and even death of the recipient if proper preventive measures are not established. This potential risk should be thoroughly evaluated to minimise the risk of infection transmission from donor to recipient, especially with organ transplantation from donors with infections, without increasing graft dysfunction and morbidity and mortality in the recipient. This document aims to review current knowledge about infection screening in potential donors and offer clinical and microbiological recommendations about the use of organs from donors with infection based on available scientific evidence. This work was supported by GESITRA/SEIMC, ONT and‘Plan Nacional de I+D+I’ and Instituto de Salud Carlos III(Fondo de Investigaciones Sanitarias 12/02269 and ProyectoIntegrado de Excelencia 13/00045), Subdirección General de Redesy Centros de Investigacion Cooperativa, Spanish Ministry of Econ-omy and Competitiveness, Spanish Network for Research inInfectious Diseases (REIPI RD16/0016), co-financed by the Euro-pean Development Regional Fund A way to achieve Europe.

Hydrogels (HG) have recognized benefits as drug delivery platforms for biomedical applications. Their high sensitivity to sterilization processes is however one of the greatest challenges regarding their clinical translation. Concerning infection diseases, prevention of post-operatory related infections is crucial to ensure appropriate patient recovery and good clinical outcomes. Silver nanoparticles (AgNPs) have shown good antimicrobial properties but sustained release at the right place is required. Thus, we produced and characterized thermo-sensitive HG based on Pluronic&reg, F127 loaded with AgNPs (HG-AgNPs) and their integrity and functionality after sterilization by dry-heat and autoclave methods were carefully assessed. The quality attributes of HG-AgNPs were seriously affected by dry-heat methods but not by autoclaving methods, which allowed to ensure the required sterility. Also, direct sterilization of the final HG-AgNPs product proved more effective than of the raw material, allowing simpler production procedures in non-sterile conditions. The mechanical properties were assessed in post mortem rat models and the HG-AgNPs were tested for its antimicrobial properties in vitro using extremely drug-resistant (XDR) clinical strains. The produced HG-AgNPs prove to be versatile, easy produced and cost-effective products, with activity against XDR strains and an adequate gelation time and spreadability features and optimal for in situ biomedical applications.

Aspergillus infection is a significant cause of morbi-mortality in an at-risk population. The Study Group of Fungal Infections (GEMICOMED) from the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) has reviewed announcements made in invasive aspergillosis management. We have organized our recommendations in such a way as to provide a guide in resolving different clinical situations concerning the entire spectrum of invasive diseases caused by Aspergillus in various populations. Diagnostic approach, treatment and preventions strategies are outlined. It is not our aim that these guidelines supplant clinical judgment with respect to specific patients; however, it is our objective to perform a comprehensive summary of quality of care evidence for invasive aspergillosis management in different settings.

Introduction A steroid-immunosuppressed rat model of invasive pulmonary aspergillosis was use to examine the usefulness of galactomannan enzyme immunoassay (GM) and quantitative real time PCR (RT-PCR) in evaluating the association between response and exposure after a high dose of prophylactic posaconazole. Methods Two different strains of Aspergillus fumigatus with different in vitro posaconazole susceptibility were used. Results Serum concentrations demonstrated similar posaconazole exposure for all treated animals. However, response to posaconazole relied on the in vitro susceptibility of the infecting strain. After prophylaxis, galactomannan index and fungal burden only decreased in those animals infected with the most susceptible strain. Conclusion This study demonstrated that both biomarkers may be useful tools for predicting efficacy of antifungal compounds in prophylaxis.

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 were 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.

The immunosuppressive treatment that recipients receive from a solid organ transplantation hinders the defensive response to infection. Its transmission from the donor can cause dysfunction or loss of the graft and even death of the recipient if proper preventive measures are not established. This potential risk should be thoroughly evaluated to minimise the risk of infection transmission from donor to recipient, especially with organ transplantation from donors with infections, without increasing graft dysfunction and morbidity and mortality in the recipient. This document aims to review current knowledge about infection screening in potential donors and offer clinical and microbiological recommendations about the use of organs from donors with infection based on available scientific evidence.

Medicopsis romeroi is a melanized coelomycetous fungus, mainly found in tropical and subtropical regions and an uncommon cause of infection in solid organ transplant (SOT) recipients. We describe two cases of SOT recipients diagnosed with phaeohyphomycosis due to M romeroi and provide a comprehensive literature review. These infections should be considered in patients native to tropical countries with a localized skin and soft tissue infection. Sequencing is needed for accurate identification of uncommon melanized fungi. Surgical treatment is recommended to cure the infection and co-adjunctive oral antifungals should be considered.

We describe two cystic fibrosis patients infected with pandrug-resistant Burkholderia cepacia complex, with the exception of ceftazidime–avibactam, who received prophylaxis with this antibiotic during lung transplantation. Although both patients had a post-operative relapse of respiratory infection, one with positive blood cultures, ceftazidime–avibactam treatment yielded a favourable outcome. 12 months after transplantation, one patient presented an excellent clinical outcome. However, the other patient died 10 months later due to severe B. cepacia sinusitis with intracranial invasion.

[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., This study was supported by Fondo de Investigacion Sanitaria (FIS), Ministerio de Sanidad, Instituto de Salud Carlos III (PI12/01719 and PI12/01205) and Ministerio de Economia y Competitividad, Instituto de Salud Carlos III, co-financed by the European Development Regional Fund A way to achieve Europe ERDF, Spanish Network for the Research in Infectious Diseases (REIPI RD12/0015).

Background Data are scarce on cytomegalovirus (CMV) and BK virus (BKV) infection after antibody-mediated rejection (ABMR). Objectives We hypothesized that the immunological response in patients with ABMR or the immune modulation associated with its treatment could predispose to CMV and BKV infection. Our objective was to investigate this hypothesis. Study design We conducted a single-center, matched case-control study (1:2 ratio) to analyze CMV and BKV replication during the first year after the ABMR diagnosis in kidney transplant recipients. Adult recipients with a histopathological diagnosis of ABMR between 2007–2015 were included as cases. Controls were kidney recipients who underwent transplantation immediately before and after the index case. Results Fifty-eight patients diagnosed with ABMR (33 chronic active ABMR and 25 acute ABMR), with their matched controls (116) were included. Forty-four cases received treatment for ABMR, including plasmapheresis (41), immunoglobulins (40), and rituximab (31). Within 1 year after ABMR, cases showed CMV replication more often than controls (9/58, 15.5% vs 7/116, 6%, OR = 4.21, CI 1.10–16.16, p = 0.04). Over the study period, CMV PCR determinations were requested more frequently in cases than controls (46/58, 79.3% vs 63/116, 54.3%, OR = 4.58, CI 1.92–10.9, p = 0.001). On multivariate analysis adjusted for CMV PCR determinations, retransplantation, antithymocyte globulin treatment and methylprednisolone treatment for acute rejection, CMV replication remained more common in cases than in controls (OR = 2.41, CI 0.49–11.73, p = 0.28). There were no differences in BKV replication in either urine or blood. Conclusions ABMR may be a risk factor for CMV but not for BKV replication in kidney transplant recipients.

The usefulness of nanotechnology to increase the bioavailability of drugs and decrease their toxicity may be a tool to deal with multiresistant P. aeruginosa (Mr-Pa) respiratory infections. We describe the preparation and the in vivo efficacy and safety of sodium colistimethate-loaded nanostructured lipid carriers (SCM-NLC) by the pulmonary and intramuscular routes. Nanoparticles showed 1-2 mg/L minimum inhibitory concentration against eight extensively drug-resistant P. aeruginosa strains. In vivo, SCM-NLC displayed significantly lower CFU/g lung than the saline and similar to that of the free SCM, even the dose in SCM-NLC group was lower than free SCM. There was no tissue damage related to the treatments. Biodistribution assessments showed a mild systemic absorption after nebulization and a notorious absorption after IM route. Altogether, it could be concluded that SCM-NLC were effective against P. aeruginosa in vivo, not toxic and distribute efficiently to the lung and liver after pulmonary or intramuscular administrations.

Reactivation of Chagas disease in the chronic phase may occur after solid organ transplantation, which may result in high parasitemia and severe clinical manifestations such as myocarditis and meningoencephalitis. The aim of the present study is to describe the prevalence of Chagas disease among solid organ–transplanted patients in a tertiary hospital from a nonendemic country. A cross-sectional study was performed at Vall d’Hebron University Hospital (Barcelona, Spain) from April to September 2016. Chagas disease screening was performed through serological tests in adult patients coming from endemic areas that had received solid organ transplantation and were being controlled in our hospital during the study period. Overall, 42 patients were included, 20 (47.6%) were male and median age was 50.5 (23–73) years. Transplanted organs were as follows: 18 kidneys, 17 lungs, and 7 livers. Three patients had Chagas disease, corresponding to a prevalence among this group of solid organ–transplanted patients of 7.1%. All three patients were born in Bolivia, had been diagnosed with Chagas disease and received specific treatment before the organ transplantation. We highly recommend providing screening tests for Chagas disease in patients with or candidates for solid organ transplantation coming from endemic areas, early treatment with benznidazole, and close follow-up to prevent clinical reactivations.

Long-term catheter-related bloodstream infections (CRBSIs) involving coagulase-negative staphylococci are associated with poor patient outcomes, increased hospitalization, and high treatment costs. The use of vancomycin lock therapy has been an important step forward in treatment of these biofilms, although failures occur in 20% of patients. In this study, we report that a high dose of daptomycin lock therapy may offer a therapeutic advantage for these CRBSIs in just 24 h of treatment.

Although chronic respiratory disease and immunosuppression are risk factors for Corynebacterium species respiratory infection, data are scarce regarding this disease in lung transplantation. Our aim was to describe the clinical characteristics and outcomes of lung transplant recipients (LTR) with respiratory isolation of Corynebacterium spp. This was a retrospective observational study performed at a referral center in Barcelona, Spain (2014 to 2016). We included all LTR in whom Corynebacterium spp. were isolated in at least one good-quality lower respiratory tract specimen. Overall, 24 of 527 (4.6%) LTR at risk during the study period were included. The main epidemiological, clinical, and microbiological data were analyzed. The most frequently isolated species were C. striatum (11/24), C. pseudodiphtheriticum (3/24), and C. amycolatum (3/24). All 19 (76%) patients who underwent bronchoscopy showed abnormalities, mainly mucosal plaques at the bronchial suture and purulent secretions. Clinical cure was achieved in 8/12 (67%) patients who fulfilled the CDC definition of lower respiratory tract infection (LRTI). To assess the clinical relevance of Corynebacterium spp., only patients with monomicrobial isolation (n = 18) were evaluated. LRTI was diagnosed in 9, and a nonsignificant association was found with a significant number of Corynebacterium sp. CFU/ml (7/9 LRTI versus 2/9 non-LRTI, P = 0.057). Persistent infection was associated with metallic bronchial stent implantation (4/4 versus 2/14, P = 0.005). The isolation of Corynebacterium spp. in respiratory specimens of lung transplant recipients may herald a respiratory tract infection or bronchial suture damage. Bronchial stent implantation is a risk factor for the persistence of Corynebacterium species infection.

Background Seasonal influenza infection may cause significant morbidity and mortality in transplant recipients. The purpose of this study was to assess the epidemiology of symptomatic influenza infection posttransplant and determine risk factors for severe disease. Methods Twenty centers in the United States, Canada, and Spain prospectively enrolled solid organ transplant (SOT) or hematopoietic stem cell transplant (HSCT) recipients with microbiologically confirmed influenza over 5 consecutive years (2010-2015). Demographics, microbiology data, and outcomes were collected. Serial nasopharyngeal swabs were collected at diagnosis and upto 28 days, and quantitative polymerase chain reaction for influenza A was performed. Results We enrolled 616 patients with confirmed influenza (477 SOT; 139 HSCT). Pneumonia at presentation was in 134 of 606 (22.1%) patients. Antiviral therapy was given to 94.1% for a median of 5 days (range, 1-42 days); 66.5% patients were hospitalized and 11.0% required intensive care unit (ICU) care. The receipt of vaccine in the same influenza season was associated with a decrease in disease severity as determined by the presence of pneumonia (odds ratio [OR], 0.34 [95% confidence interval {CI}, .21-.55], P < .001) and ICU admission (OR, 0.49 [95% CI, .26-.90], P = .023). Similarly, early antiviral treatment (within 48 hours) was associated with improved outcomes. In patients with influenza A, pneumonia, ICU admission, and not being immunized were also associated with higher viral loads at presentation (P = .018, P = .008, and P = .024, respectively). Conclusions Annual influenza vaccination and early antiviral therapy are associated with a significant reduction in influenza-associated morbidity, and should be emphasized as strategies to improve outcomes of transplant recipients.

The aim of this study was to assess the outcome and tolerability of prophylactic nebulized liposomal amphotericin B (n-LAB) in lung transplant recipients (LTR) and the changing epidemiology of Aspergillus spp. infection and colonization. We performed an observational study including consecutive LTR recipients (2003-2013) undergoing n-LAB prophylaxis lifetime. A total of 412 patients were included (mean postoperative follow-up 2.56 years; IQR 1.01-4.65). Fifty-three (12.8%) patients developed 59 Aspergillus spp. infections, and 22 invasive aspergillosis (overall incidence 5.3%). Since 2009, person-time incidence rates of Aspergillus spp. colonization and infection decreased (2003-2008, 0.19; 2009-2014, 0.09; P = 0.0007), but species with reduced susceptibility or resistance to amphotericin significantly increased (2003-2008, 38.1% vs 2009-2014, 58.1%; P = 0.039). Chronic lung allograft dysfunction (CLAD) was associated with Aspergillus spp. colonization and infection (HR 24.4, 95% CI 14.28-41.97; P = 0.00). Only 2.9% of patients presented adverse effects, and 1.7% required discontinuation. Long-term administration of prophylaxis with n-LAB has proved to be tolerable and can be used for preventing Aspergillus spp. infection in LTR. Over the last years, the incidence of Aspergillus spp. colonization and infection has decreased, but species with reduced amphotericin susceptibility or resistance are emerging. CLAD is associated with Aspergillus spp. colonization and infection.

The increasing shortage of organs for transplantation has prompted transplant programs to investigate the use of extended criteria donors, such as those with transmissible infectious diseases. Successful cases of organ transplantation (mostly kidney and liver) from Trypanosoma cruzi seropositive donors to seronegative recipients have been reported. We present a case of lung transplantation from a donor serologically positive for Chagas disease to a seronegative recipient, and provide a review of the literature. Left single lung transplantation was performed in a 44-year-old Spanish woman presenting with interstitial lung disease in February 2016. The deceased donor was a Colombian immigrant living in Spain who was serologically positive for Chagas disease. Oral administration of 5 mg/kg/day benznidazole divided in three doses for 60 days was given for specific Chagas disease prophylaxis after transplantation. Periodic follow-up with serological reverse transcription polymerase chain reaction to detect T. cruzi DNA were performed until 6 months after the end of treatment. All results were negative, indicating that transmission of T. cruzi had not occurred. In a review of the literature, two similar cases were identified in Argentina and the United States. In both cases T. cruzi infection was detected posttransplant in the recipients, after which they were treated with benznidazole. The course of the patient described herein confirms that lungs from donors with chronic T. cruzi infection can be used successfully as allografts, and that posttransplant prophylaxis with benznidazole may reduce the probability of transmission of T. cruzi to the recipient.

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. J.T.S. holds a research contract from the Fundación para la Formación e Investigación de los Profesionales de la Salud de Extremadura (FundeSalud), Instituto de Salud Carlos III. M.F.R. holds a clinical research contract “Juan Rodés” (JR14/00036) from the Spanish Ministry of Economy and Competitiveness, Instituto de Salud Carlos III.

Staphylococcus aureus is a major cause of bacteremia and, even with appropriate clinical management, causes high morbidity and mortality due to its involvement in endovascular complications and metastatic infections. Through different pathogenic in vivo and in vitro models we investigated the behavior of S. aureus most relevant clonal complexes (CCs) causing endovascular complications. We analyzed 14 S. aureus strains representing CC5, CC8, CC15, CC30 and CC45 that caused endovascular complications, including methicillin susceptible and resistant isolates and strains with different functionality of the agr global regulator. Their adherence to collagen, interaction with the endothelium, resistance to immune attack, capacity to form biofilm and virulence in the Galleria mellonella model were analyzed. CC30 and CC45 showed greater adhesion to collagen and CC8 showed a trend towards higher rate of intracellular persistence in endothelial cells. All CCs exhibited similar tolerance to neutrophil antimicrobial peptide hNP-1 and were capable of forming biofilms under static conditions. The virulence assay in the Galleria mellonella model demonstrated that CC15 and CC30 were the most and least virulent, respectively. The analysis of the genomic sequences of the most relevant virulence genes identified some CC15 specific gene patterns (absence of enterotoxins and sak gene) and variants (mainly in leucocidins and proteases), but did not reveal any gene or variant that could be responsible for the increased virulence detected for CC15 strains. Even though all the CCs were capable of causing endovascular complications, our results showed that different CCs are likely to produce these complications through different mechanisms which, if confirmed in more sophisticated models, would indicate the need to more specific management and therapeutic approaches.

Pseudomonas aeruginosa strain PAO1 has become the reference strain in many laboratories. One enzyme that is essential for its cell division is the ribonucleotide reductase (RNR) enzyme that supplies the deoxynucleotides required for DNA synthesis and repair. P. aeruginosa is one of the few microorganisms that encodes three different RNR classes (Ia, II and III) in its genome, enabling it to grow and adapt to diverse environmental conditions, including during infection. In this work, we demonstrate that a lack of RNR activity induces cell elongation in P. aeruginosa PAO1. Moreover, RNR gene expression during anaerobiosis differs among P. aeruginosa strains, with class III highly expressed in P. aeruginosa clinical isolates relative to the laboratory P. aeruginosa PAO1 strain. A single point mutation was identified in the P. aeruginosa PAO1 strain class III RNR promoter region that disrupts its anaerobic transcription by the Dnr regulator. An engineered strain that induces the class III RNR expression allows P. aeruginosa PAO1 anaerobic growth and increases its virulence to resemble that of clinical strains. Our results demonstrate that P. aeruginosa PAO1 is adapted to laboratory conditions and is not the best reference strain for anaerobic or infection studies.

Solid organ transplant (SOT) recipients have a significant risk of invasive fungal diseases (IFD) caused mainly by Candida spp. and Aspergillus spp. Candida spp. is the most frequent agent of IFD in the transplant recipient. The absence of clinical trials and the epidemiological differences in IFD in different transplant programmes mean that there are no definitive recommendations for the diagnosis, treatment and prevention of IFD in SOT, so most of the evidence must be based on clinical experience.

Resumen Fundamento y objetivo Las enfermedades pulmonares intersticiales (EPI) constituyen, despues del enfisema, la segunda indicacion de trasplante pulmonar (TP). El objetivo del presente estudio es la revision de los resultados del TP en la EPI en el Hospital Vall d’Hebron (Barcelona). Pacientes y metodo Se estudian retrospectivamente 150 pacientes, 87 (58%) varones, con una edad media de 48 anos (extremos 20-67), en los que se indico un TP por una EPI entre agosto de 1990 y enero de 2010, y que representan el 30% del total de TP (150/496) realizados en Cataluna. Ciento cuatro (69%) fueron trasplantes unipulmonares (TUP), y 46 (31%), trasplantes bipulmonares (TBP). Los diagnosticos postoperatorios fueron: 94 (63%) neumonia intersticial usual, 23 (15%) neumonia intersticial no especifica, 11(7%) neumonia intersticial no clasificable y un 15% miscelanea. Se describen los resultados funcionales, las complicaciones y la supervivencia. Resultados La supervivencia actuarial fue del 87, 70 y 53% a uno, 3 y 5 anos, respectivamente. Las causas de muerte mas frecuentes incluyen la disfuncion precoz del injerto y el desarrollo de rechazo cronico en forma de bronquiolitis obliterante (BOS). El incremento medio postoperatorio de la capacidad vital forzada y del forced expiratory volume in the first second (FEV 1 , «volumen espiratorio forzado en el primer segundo») fue similar en el TUP y el TBP. El mejor FEV 1 posterior al TP se alcanzo al decimo mes (extremos 1-36). El 16% de los pacientes se reintegro al trabajo. En algun momento de la evolucion se diagnostico rechazo agudo, confirmado histologicamente en 53 (35%) pacientes. La prevalencia de BOS entre los supervivientes fue del 20% al ano, 45% a los 3 anos y del 63% a los 5 anos. Conclusion El TP es hasta ahora el unico tratamiento capaz de alargar la vida de los pacientes con EPI avanzada y en nuestro medio ha permitido que uno de cada 6 pacientes haya vuelto a trabajar. Sin embargo, el rechazo cronico sigue siendo el principal problema a resolver en el futuro.

The effectiveness of daptomycin versus vancomycin for treating experimental methicillin-susceptible (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) catheter-related infection by antibiotic-lock technique was assessed.One MSSA strain and one clinical MRSA isolate were used. A preliminary in vitro study determined the minimum biofilm eradication concentration (MBEC) of vancomycin and daptomycin. An intravenous catheter was implanted in New Zealand white rabbits. Infection was induced by 24 h locking the catheter with 0.3 mL of broth culture containing MSSA or MRSA. The 24 h of antibiotic-lock treatment groups were: control, vancomycin 10 mg/mL, daptomycin 5 mg/mL and daptomycin 50 mg/mL.Daptomycin showed greater in vitro activity than vancomycin against biofilm bacteria (MBECs of vancomycin and daptomycin for MSSA,2000 mg/L and 7 mg/L; MRSA,2000 mg/L and 15 mg/L). Daptomycin 5 mg/mL achieved significant reductions relative to vancomycin 10 mg/mL in log10 cfu recovered from catheter tips for both strains (P 0.05). Only daptomycin 50 mg/mL achieved negative catheter tip cultures (up to 75% in MSSA and 85% in MRSA, P 0.05), showing the greatest median log10 cfu reduction compared to controls (6.07 in MSSA and 6.59 in MRSA, P 0.05).Daptomycin 50 mg/mL showed the highest activity against both strains biofilms.

Spontaneous bacterial peritonitis (SBP) in liver transplantation (LT) recipients who progress to cirrhosis has received little attention. We investigated the adequacy of empirical treatment with third-generation cephalosporins for SBP in this population and the impact of transplantation on the evolution of the infection. We performed a cohort study with 138 SBP episodes: 19 in LT patients and 119 in non-LT patients. The etiology of SBP was identified for 73.7% of the episodes in LT patients and for 38.7% of the episodes in non-LT patients (P = 0.004). The main microorganisms in recipients were Escherichia coli (35.7%) and Streptococcus pneumoniae (21.4%). The etiologies did not differ in non-LT patients. The cephalosporin sensitivity was similar in the 2 groups (85.7% versus 78.4%, P = 0.7). LT recipients developed renal failure (57.9% versus 25.2%, P = 0.004) and encephalopathy (42.1% versus 22%, P = 0.08) more often than non-LT patients, and the mortality rates during episodes (52.6% versus 13.4%, P 18 odds ratio (OR) = 6.1 and being an LT recipient (OR = 4.45). At 6 months, the risk factors for mortality were a MELD score > 18 (OR = 3.08), being an LT recipient (OR = 3.47), a known etiology (OR = 2.08), and the presence of hepatocellular carcinoma (OR = 3.73).

Data from published studies regarding risk factors for liver biopsy (LB)–related infectious complications in liver transplant recipients are inconsistent. We carried out a retrospective cohort study analyzing consecutive LBs for orthotopic liver transplant patients at a tertiary hospital (2001-2011): there were 667 LB procedures (575 percutaneous procedures and 92 transjugular procedures) in 286 liver transplant recipients. There were 20 complications in 19 patients (overall incidence = 3.0%): 10 were infectious complications (8 cases of bacteremia and 2 cases of peritonitis). The causal microorganisms were mainly Pseudomonas aeruginosa (4 patients) and Enterobacteriaceae (4 patients). All complications occurred with biopsies performed in patients hospitalized for more than 48 hours (381 biopsies for 201 patients); hence, only this group was included in the risk factor analysis. The variables associated with the development of infectious complications after LB were the presence of impaired biliary drainage at the time of biopsy (40% versus 15.1%, P = 0.03) and low albumin levels (2.4 versus 3.1 g/dL, P = 0.01). In conclusion, according to our experience, infectious complications secondary to LB in liver transplant recipients are related to hospitalization at the time of biopsy, particularly in the presence of impaired biliary drainage and low albumin levels. Liver Transpl 20:552–556, 2014. © 2014 AASLD.

Background Influenza vaccine effectiveness is not optimal in solid organ transplant recipients (SOTR). We hypothesized that a booster dose might increase it. Methods TRANSGRIPE 1-2 is a phase 3, randomized, controlled, multicenter, open-label clinical trial. Patients were randomly assigned (1:1 stratified by study site, type of organ, and time since transplantation) to receive 1 dose (control group) or 2 doses (booster group) of the influenza vaccine 5 weeks apart. Results A total of 499 SOTR were enrolled. Although seroconversion at 10 weeks did not meet significance in the modified intention-to-treat population, seroconversion rates were significantly higher in the booster arm for the per-protocol population (53.8% vs 37.6% for influenza A(H1N1)pdm; 48.1% vs 32.3% for influenza A(H3N2); and 90.7% vs 75% for influenza B; P < .05). Furthermore, seroprotection at 10 weeks was higher in the booster group: 54% vs 43.2% for A(H1N1)pdm; 56.9% vs 45.5% for A(H3N2); and 83.4% vs 71.8% for influenza B (P < .05). The number needed to treat to seroprotect 1 patient was

Objectives The effectiveness of anidulafungin versus liposomal amphotericin B (LAmB) for treating experimental Candida parapsilosis catheter-related infection by an antifungal-lock technique was assessed. Methods Two clinical strains of C. parapsilosis (CP12 and CP54) were studied. In vitro studies were used to determine the biofilm MICs (MBIC50 and MBIC90) by XTT reduction assay and LIVE/DEAD biofilm viability for anidulafungin and LAmB on 96-well microtitre polystyrene plates and silicone discs. An intravenous catheter was implanted in New Zealand white rabbits. Infection was induced by locking the catheter for 48 h with the inoculum. The 48 h antifungal-lock treatment groups included control, 3.3 mg/mL anidulafungin and 5.5 mg/mL LAmB. Results Anidulafungin showed better in vitro activity than LAmB against C. parapsilosis growing in biofilm on silicone discs. MBIC90 of LAmB: CP12, >1024 mg/L; CP54, >1024 mg/L. MBIC90 of anidulafungin: CP12, 1 mg/L; CP54, 1 mg/L (P ≤ 0.05). Moreover, only anidulafungin (1 mg/L) showed >90% non-viable cells in the LIVE/DEAD biofilm viability assay on silicone discs. No differences were observed between the in vitro susceptibility of anidulafungin or LAmB when 96-well plates were used. Anidulafungin achieved significant reductions relative to LAmB in log10 cfu recovered from the catheter tips for both strains (P ≤ 0.05). Only anidulafungin achieved negative catheter tip cultures (CP12 63%, CP54 73%, P ≤ 0.05). Conclusions Silicone discs may be a more reliable substrate for the study of in vitro biofilm susceptibility of C. parapsilosis. Anidulafungin-lock therapy showed the highest activity for experimental catheter-related infection with C. parapsilosis.

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.

Nowadays, lung transplantation is an established treatment option of end-stage pulmonary parenchymal and vascular disease. Post-transplant infections are a significant contributor to overall morbidity and mortality in the lung transplant recipient that, in turn, are higher than in other solid organ transplant recipients. This is likely due to several specific factors such as the constant exposure to the outside environment and the colonized native airway, and the disruption of usual mechanisms of defense including the cough reflex, bronchial circulation, and lymphatic drainage. This chapter will review the common infections that develop in the lung or heart–lung transplant recipient, including the general risk factors for infection in this population, and specific features of prophylaxis and treatment for the most frequent bacterial, viral, and fungal infections. The effects of infection on lung transplant rejection will also be discussed.

Invasive fungal infections (IFI) represent a serious threat for patients undergoing solid organ transplantation (SOT). IFI in SOT has a significant incidence and mortality not due to negligence. The management of IFI in SOT involves specific recommendations and has been individualized to the type of transplant and patient. The current review presents an overview of epidemiology, diagnosis, treatment and prevention of IFI in TOS. Depending on risk factors for different IFIs and transplant type, this paper includes the main recommendations based on previous publications and on the opinion of the authors on the prophylaxis and treatment of these patients. These recommendations highlight epidemiology changes and the emergence of new antifungals. The current document has focused mainly on Candidaspp. and Aspergillusspp., with a special mention to the rest of yeasts and moulds that are common in SOT.

Clostridium difficile-associated disease (CDAD) is the most common cause of nosocomial diarrhea. Information about CDAD in solid organ transplant (SOT) recipients is scarce. To determine its epidemiology and risk factors, we conducted a cohort study in which 4472 SOT patients were prospectively included in the RESITRA/REIPI (Spanish Research Network for the Study of Infection in Transplantation) database between July 2003 and July 2006. Forty-two episodes of CDAD were diagnosed in 36 patients. The overall incidence was 0.94%. Median onset of infection was 31.5 days (range 6–741); in half the cases, onset occurred during the first month after transplantation. In 26% of cases, there was no previous antibiotic use. Independent risk factors for CDAD using Cox regression analysis were previous use of first- and second-generation cephalosporins (HR 3.68; 95%CI 1.8–7.52; P