Echinocandin persistence directly impacts the evolution of resistance and survival of the pathogenic fungus Candida glabrata.

Recent epidemiological studies documented an alarming increase in the prevalence of echinocandin-resistant (ECR) Candida glabrata blood isolates. ECR isolates are known to arise from a minor subpopulation of a clonal population, termed echinocandin persisters. Although it is believed that isolates with a higher echinocandin persistence (ECP) are more likely to develop ECR, the implication of ECP needs to be better understood. Moreover, replacing laborious and time-consuming traditional approaches to determine ECP levels with rapid, convenient, and reliable tools is imperative to advance our understanding of this emerging concept in clinical practice. Herein, using extensive ex vivo and in vivo systemic infection models, we showed that high ECP isolates are less effectively cleared by micafungin treatment and exclusively give rise to ECR colonies. Additionally, we developed a flow cytometry-based tool that takes advantage of a SYTOX-based assay for the stratification of ECP levels. Once challenged with various collections of echinocandin-susceptible blood isolates, our assay reliably differentiated ECP levels in vitro and predicted ECP levels in real time under ex vivo and in vivo conditions when compared to traditional methods relying on colony-forming unit counting. Given the high and low ECP predictive values of 92.3% and 82.3%, respectively, our assay showed a high agreement with traditional approach. Collectively, our study supports the concept of ECP level determination in clinical settings and provides a robust tool scalable for high-throughput settings. Application of this tool facilitates the interrogation of mutant and drug libraries to further our understanding of persister biology and designing anti-persister therapeutics. IMPORTANCE: Candida glabrata is a prevalent fungal pathogen able to replicate inside macrophages and rapidly develop resistance against frontline antifungal echinocandins. Multiple studies have shown that echinocandin resistance is fueled by the survival of a small subpopulation of susceptible cells surviving lethal concentrations of echinocandins. Importantly, bacterial pathogens that exhibit high antibiotic persistence also impose a high burden and generate more antibiotic-resistant colonies. Nonetheless, the implications of echinocandin persistence (ECP) among the clinical isolates of C. glabrata have not been defined. Additionally, ECP level determination relies on a laborious and time-consuming method, which is prone to high variation. By exploiting in vivo systemic infection and ex vivo models, we showed that C. glabrata isolates with a higher ECP are associated with a higher burden and more likely develop echinocandin resistance upon micafungin treatment. Additionally, we developed an assay that reliably determines ECP levels in real time. Therefore, our study identified C. glabrata isolates displaying high ECP levels as important entities and provided a reliable and convenient tool for measuring echinocandin persistence, which is extendable to other fungal and bacterial pathogens.

Imperfect cross-linking of xanthan for pH-responsive bio-based composite moist wound dressings by stencil printing.

The work addresses the use of bio-based and -degradable materials for the production of a moist, adaptive and anti-microbial wound dressing. The dressing is targeted to exhibit a pH-dependent active agent release. Xanthan hydrogel structures are coated on cellulose fabrics via stencil printing and subsequently cross-linked using glyoxal. By alteration of the cross-linker content from 1 to 6% by mass, the hydrogel elasticity can be tuned within a range of 2-16 kPa storage modulus. Increasing initial glyoxal concentrations also result in higher amounts of glyoxal release. Glyoxal, an anti-microbial agent with approval in veterinary medicine, is mostly released upon wound application supporting infection management. As wound simulation, normal saline, as pH 5 and pH 8 buffer solutions, were used. The release profile and magnitude of approx. 65%-90% glyoxal is pH-dependent. Increased release rates of glyoxal are present in pH 8 fluids, which mostly base on faster hydrogel swelling. Higher total glyoxal release is present in pH 5 fluid and normal saline after 3 days. Accordingly, a pH-dependent release profile was encountered. As glyoxal attacks any cell unselectively, it is expected to be effective against antibiotic resistant bacteria. By stencil printing the dressing size can be adjusted to minimize healthy glyoxal tissue exposure.

Interaction in vitro of pulmonary surfactant with antifungal agents used for treatment and prevention of invasive aspergillosis.

BACKGROUND: Optimizing antifungal therapy is important to improve outcomes in severely immunocompromised patients. OBJECTIVES: We analysed the in vitro interaction between pulmonary surfactant and antifungal agents used for management of invasive pulmonary aspergillosis. METHODS: Amphotericin B formulations, mould-active triazoles and echinocandins were tested in vitro against 24 clinical isolates of different Aspergillus spp. with and without the addition of a commercial porcine surfactant (Curosurf®; Poractant alfa, Nycomed, Austria). The data are presented as MIC or minimum effective concentration (MEC) ranges, as MIC or MEC values that inhibited 90% of the isolates (MIC90 or MEC90) and as geometric mean (GM) MIC or MEC values. RESULTS: For amphotericin B products, addition of surfactant to a final concentration of 10% led to a statistically significant reduction of the GM MIC for all Aspergillus isolates tested after 24 h (0.765 versus 0.552 mg/L; P < 0.05). For the mould-active triazoles, addition of 10% surfactant resulted in a significantly higher GM MIC at 48 h (0.625 versus 0.898 mg/L; P < 0.05). For the echinocandins, the addition of 10% surfactant led to a significantly higher GM MEC after both 24 h (0.409 versus 0.6532 mg/L; P < 0.01) and 48 h (0.527 versus 0.9378 mg/L; P < 0.01). There were no meaningful differences between individual members of the three existing classes of antifungal agents or between the different Aspergillus spp. tested. CONCLUSIONS: Using EUCAST methodology, addition of porcine surfactant up to a concentration of 10% had a minor, and presumably non-relevant, impact on the in vitro activity of antifungal agents used in prophylaxis and treatment of invasive pulmonary aspergillosis.

Global guideline for the diagnosis and management of mucormycosis: an initiative of the European Confederation of Medical Mycology in cooperation with the Mycoses Study Group Education and Research Consortium.

Mucormycosis is a difficult to diagnose rare disease with high morbidity and mortality. Diagnosis is often delayed, and disease tends to progress rapidly. Urgent surgical and medical intervention is lifesaving. Guidance on the complex multidisciplinary management has potential to improve prognosis, but approaches differ between health-care settings. From January, 2018, authors from 33 countries in all United Nations regions analysed the published evidence on mucormycosis management and provided consensus recommendations addressing differences between the regions of the world as part of the "One World One Guideline" initiative of the European Confederation of Medical Mycology (ECMM). Diagnostic management does not differ greatly between world regions. Upon suspicion of mucormycosis appropriate imaging is strongly recommended to document extent of disease and is followed by strongly recommended surgical intervention. First-line treatment with high-dose liposomal amphotericin B is strongly recommended, while intravenous isavuconazole and intravenous or delayed release tablet posaconazole are recommended with moderate strength. Both triazoles are strongly recommended salvage treatments. Amphotericin B deoxycholate is recommended against, because of substantial toxicity, but may be the only option in resource limited settings. Management of mucormycosis depends on recognising disease patterns and on early diagnosis. Limited availability of contemporary treatments burdens patients in low and middle income settings. Areas of uncertainty were identified and future research directions specified.

The impact of bacteremia on lipoprotein concentrations and patient's outcome: a retrospective analysis.

Bacteremia is a major clinical challenge requiring early treatment. Metabolic alterations occur during bacteremia, and accordingly plasma concentrations of lipoproteins LDL-C and HDL-C are substantially changed. We questioned whether bacteremia with Gram-negative versus Gram-positive bacteria causes contrasting changes of lipoprotein levels in order to differentiate between the 2-g stain types and if there is a relation with outcome parameters namely ICU-admission, 30-day mortality, duration of hospitalization. This is a retrospective dual-center cross-sectional study, including 258 patients with bacteremia. Plasma lipid levels were analyzed within 48 h to positive blood culture. Upon admission, HDL-C, LDL-C, and total cholesterol (p = 0.99) in plasma did not significantly differ between patients with Gram-negative and Gram-positive bacteremia, while significantly higher triglyceride concentrations were found in Gram-negative bacteremia (p < 0.05). 30-day mortality and ICU admission were associated with lower LDL-C and HDL-C concentrations as compared to survivors and non-ICU patients, and patients with HDL-C < 20 mg dl-1 and LDL-C < 55 mg dl-1 had a relative risk (RR) of 2.85 for ICU therapy requirement and RR = 2 of death within 30 days. Reduced HDL-C and LDL-C concentrations were associated with adverse patient's outcome in bacteremia. Discrimination between Gram-negative and Gram-positive pathogens upon lipoprotein patterns is unlikely.

Multicenter comparison of the ISO standard 20776-1 and the serial 2-fold dilution procedures to dilute hydrophilic and hydrophobic antifungal agents for susceptibility testing.

A multicenter study was conducted to assess the accuracy of the ISO standard 20776-1 and the serial 2-fold dilution procedures for antifungal susceptibility testing. Fluconazole trays can be accurately prepared by following ISO and serial dilution schemes. However, itraconazole trays showed a significant lack of reproducibility that was independent of which method was followed.

Zygomycosis and other rare filamentous fungal infections in solid organ transplant recipients.

Fungi cause severe infections in solid organ transplant (SOT) recipients. Recently, a shift towards non-Aspergillus filamentous fungal infections (nAFFI) was noticed. In a series of 2878 SOTs (kidney, pancreas, islets, liver, heart, lung, and bowel) performed between January 1995 and December 2006 at the Innsbruck medical university, eleven cases of nAFFI were diagnosed. The encountered species included Zygomyzetes (n = 8), and Alternaria alternate, Pseudallescheria boydii, Trichoderma spp. (one each); there were three liver and three heart, one intestinal, pancreas, lung, bilateral forearm and renal recipient each. Five patients died from nAFFI (zygomycosis: 4, Pseudallerichia boydii: 1); four were diagnosed postmortem. In five cases infection was surgically treated in combination with antifungals. Risk factors for nAFFI were renal failure (73%) and intensified immunosuppression (73%); two cases were associated with post-transplant lymphoproliferative disorder, one with graft versus host disease. An increase in the incidence of nAFFI was observed parallel to introduction of caspofungin and voriconazole (three cases until 12/2003, seven cases thereafter). NAFFI are increasingly found in SOT recipients. If diagnosed in time, the outcome seems acceptable. Intensified immunosuppression and exposure to antifungals not active against zygomycetes may be risk factors. Surgical therapy may play an important role in these infections.

Enterocolitis due to simultaneous infection with rotavirus and Clostridium difficile in adult and pediatric solid organ transplantation.

Diarrhea is a well-known complication of immunosuppression but is also frequently caused by pathogens such as Clostridium difficile (CD) and rotavirus (RV). Three adult and five pediatric solid organ recipients (SORs) developed diarrhea with simultaneous identification of CD and RV. Rotavirus was identified using an immunochromatografic- or enzyme-linked immunosorbent assay; CD was identified using a rapid immunoassay or enzyme immunoassay. One adult renal, one adult kidney-pancreas, one adult liver, and five pediatric liver recipients were affected. Onset of RV/CD infection ranged from 2 weeks to 4 years posttransplant. All patients presented with enterocolitis causing significant fluid and electrolyte loss. In adults, CD was treated with metronidazole and in children with oral vancomycin. RV infection was treated with fluid/electrolyte replacement. During diarrhea, a significant rise in tacrolimus serum level was noted. All patients cleared CD. One child developed recurrent episodes of RV infection and died from bacterial sepsis; the renal recipient died 6 months posttransplant from myocardial infarction. The remaining six patients are currently alive with well-functioning grafts. Simultaneous infection with CD and RV may lead to severe diarrhea in SORs. Both pathogens should be considered in SOR presenting with diarrhea.

Early identification of bacteria leading to central venous catheter contamination.

UNLABELLED: Catheter-related bloodstream infections (CRBSI) are a common problem in patients after central venous catheterization. Using DNA analysis we compared bacteria found on the tip of central venous catheters removed because of clinical signs of CRBSI with bacteria found on needle, dilator, and guidewire used for insertion of these catheters. In five of seven central venous catheters removed because of clinical signs of CRBSI, bacteria on the catheter tip were genetically identical to bacteria found on the insertion device, proving that catheter contamination in these cases was caused by contacting bacteria during the initial puncture. These findings may be important for antibiotic prophylaxis or therapy in patients at risk for CRBSI. IMPLICATIONS: In five of seven central venous catheters removed because of clinical signs of catheter-related blood infections, DNA analysis showed bacteria found on the catheter tip to be identical with bacteria found on the puncture kits used for insertion of these catheters.

Case Reports. Chronic and acute Aspergillus meningitis.

Cerebral aspergillosis usually occurs in severely immunocompromized hosts, is difficult to diagnose, and has a poor prognosis. After 14 months of chronic meningitis, ventriculitis, choroid plexitis, and lumbar arachnoiditis, which was complicated by acute hydrocephalus, Aspergillus, suspected to be from the candidus group, was isolated from the cerebrospinal fluid (CSF) of a previously healthy man. Thereafter Aspergillus antigen was found in stored plasma and CSF samples. He was treated with voriconazole and itraconazole. In a haemodialysis patient affected by an acute meningococcal meningitis, following a 3-day symptom-free interval, symptoms and signs of acute meningitis had reappeared and were unresponsive to a broad antimicrobial coverage. However, they resolved within 5 days after liposomal amphotericin B treatment had been started. From his CSF Aspergillus-DNA was identified and Aspergillus fumigatus isolated by culture. These two different clinical cases show that Aspergillus-DNA and antigen detection tests represent an advance in the diagnosis and liposomal amphotericin B, voriconazole, and itraconazole are an advance in the treatment of Aspergillus meningitis.