Diagnosis and management of Aspergillus diseases: executive summary of the 2017 ESCMID-ECMM-ERS guideline.

The European Society for Clinical Microbiology and Infectious Diseases, the European Confederation of Medical Mycology and the European Respiratory Society Joint Clinical Guidelines focus on diagnosis and management of aspergillosis. Of the numerous recommendations, a few are summarized here. Chest computed tomography as well as bronchoscopy with bronchoalveolar lavage (BAL) in patients with suspicion of pulmonary invasive aspergillosis (IA) are strongly recommended. For diagnosis, direct microscopy, preferably using optical brighteners, histopathology and culture are strongly recommended. Serum and BAL galactomannan measures are recommended as markers for the diagnosis of IA. PCR should be considered in conjunction with other diagnostic tests. Pathogen identification to species complex level is strongly recommended for all clinically relevant Aspergillus isolates; antifungal susceptibility testing should be performed in patients with invasive disease in regions with resistance found in contemporary surveillance programmes. Isavuconazole and voriconazole are the preferred agents for first-line treatment of pulmonary IA, whereas liposomal amphotericin B is moderately supported. Combinations of antifungals as primary treatment options are not recommended. Therapeutic drug monitoring is strongly recommended for patients receiving posaconazole suspension or any form of voriconazole for IA treatment, and in refractory disease, where a personalized approach considering reversal of predisposing factors, switching drug class and surgical intervention is also strongly recommended. Primary prophylaxis with posaconazole is strongly recommended in patients with acute myelogenous leukaemia or myelodysplastic syndrome receiving induction chemotherapy. Secondary prophylaxis is strongly recommended in high-risk patients. We strongly recommend treatment duration based on clinical improvement, degree of immunosuppression and response on imaging.

Initial antifungal strategy does not correlate with mortality in patients with candidemia.

The incidence of Candida bloodstream infections (BSIs) has increased over time, especially in medical wards. The objective of this study was to evaluate the impact of different antifungal treatment strategies on 30-day mortality in patients with Candida BSI not admitted to intensive care units (ICUs) at disease onset. This prospective, monocentric, cohort study was conducted at an 1100-bed university hospital in Rome, Italy, where an infectious disease consultation team was implemented. All cases of Candida BSIs observed in adult patients from November 2012 to April 2014 were included. Patients were grouped according to the initial antifungal strategy: fluconazole, echinocandin, or liposomal amphotericin B. Cox regression analysis was used to identify risk factors significantly associated with 15-day and 30-day mortality. During the study period, 130 patients with candidemia were observed (58 % with C. albicans, 7 % with C. glabrata, and 23 % with C. parapsilosis). The first antifungal drug was fluconazole for 40 % of patients, echinocandin for 57.0 %, and liposomal amphotericin B for 4 %. During follow-up, 33 % of patients died. The cumulative mortality 30 days after the candidemia episode was 30.8 % and was similar among groups. In the Cox regression analysis, clinical presentation was the only independent factor associated with 15-day mortality, and Acute Physiology and Chronic Health Evaluation (APACHE) II score and clinical presentation were the independent factors associated with 30-day mortality. No differences in 15-day and 30-day mortality were observed between patients with and without C. albicans candidemia. In patients with candidemia admitted to medical or surgical wards, clinical severity but not the initial antifungal strategy were significantly correlated with mortality.

In vitro activity of Citrus bergamia (bergamot) oil against clinical isolates of dermatophytes.

OBJECTIVES: Recently, bergamot oil was shown to be a potent antifungal agent in vitro against clinically important Candida species. In this study, the activities of bergamot natural essence and its furocoumarin-free and distilled extracts on dermatophytes such as Trichophyton, Microsporum and Epidermophyton species were investigated. METHODS: In vitro susceptibility testing assays on 92 clinical isolates of dermatophytes (Trichophyton mentagrophytes n = 20, Trichophyton rubrum n = 18, Trichophyton interdigitale n = 15, Trichophyton tonsurans n = 2, Microsporum canis n = 24, Microsporum gypseum n = 1 and Epidermophyton floccosum n = 12) were performed using the CLSI M38-A broth microdilution method, except for employing an inoculum of 1-3 x 10(3) cfu/mL. MICs were determined at a visual endpoint reading of 80% inhibition compared with the growth control. RESULTS: MICs (v/v) of all fungi ranged from 0.156% to 2.5% for the natural essence, from 0.02% to 2.5% for the distilled extract, and from 0.08% to 1.25% for the furocoumarin-free extract. The three isolates of T. tonsurans and M. gypseum exhibited the highest MIC values. CONCLUSIONS: Data from this study indicate that bergamot oil is active in vitro against several common species of dermatophytes, suggesting its potential use for topical treatment of dermatophytoses.

In vitro activity of bergamot natural essence and furocoumarin-free and distilled extracts, and their associations with boric acid, against clinical yeast isolates.

OBJECTIVES: There is very little information, to date, on the antifungal activity of bergamot oil. In this study, we investigated the in vitro activity of three bergamot oils (natural essence, furocoumarin-free extract and distilled extract) against clinically relevant Candida species. We studied the two derivatives, components of Italian pharmaceutical products, that are supposed to be less toxic than the essential oil. METHODS: In vitro susceptibility of 40 clinical isolates of Candida spp. (Candida albicans, n=20; Candida glabrata, n=13; Candida krusei, n=4; Candida tropicalis, n=2; Candida parapsilosis, n=1), associated with symptomatic and asymptomatic vulvovaginal candidiasis, was determined using a modification of the NCCLS M27-A2 broth microdilution method. MICs were evaluated for each of the oils alone and combined with sub-inhibitory concentrations of the well-known antiseptic, boric acid. To boric acid, all isolates had MIC values ranging from 0.094% to 0.187% (w/v). RESULTS: At 24 h readings, the MIC(90 )s (for all isolates) were (v/v): 5% for natural essence of bergamot, 2.5% for the furocoumarin-free extract, and 1.25% for the distilled extract. At the 48 h reading, these values increased to >10%, 5% and 2.5%, respectively. At both readings, MIC(90 )s for all oil+boric acid combinations were significantly lower than corresponding values for the oils alone (P <0.05). CONCLUSIONS: These data indicate that bergamot oils are active in vitro against Candida spp., suggesting their potential role for the topical treatment of Candida infections.

Long-QT syndrome-associated missense mutations in the pore helix of the HERG potassium channel.

BACKGROUND: Mutations in the human ether-à-go-go-related gene (HERG) cause chromosome 7-linked long-QT syndrome (LQTS), an inherited disorder of cardiac repolarization that predisposes affected individuals to arrhythmia and sudden death. METHODS AND RESULTS: Here, we characterize the physiological consequences of 3 LQTS-associated missense mutations (V612L, T613M, and L615V) located in the pore helix of the HERG channel subunit. Mutant HERG subunits were heterologously expressed in Xenopus oocytes alone or in combination with wild-type HERG subunits. Two-microelectrode voltage-clamp techniques were used to record currents, and a single oocyte chemiluminescence assay was used to assay surface expression of epitope-tagged subunits. When expressed alone, V612L and T613M HERG subunits did not induce detectable currents, and L615V induced very small currents. Coexpression of mutant and wild-type HERG subunits caused a dominant-negative effect that varied for each mutation. CONCLUSIONS: These findings define the physiological consequences of mutations in HERG that cause LQTS and indicate the importance of the pore helix of HERG for normal channel function.

Single HERG delayed rectifier K+ channels expressed in Xenopus oocytes.

HERG is a K+ channel with properties similar to the rapidly activating component (I(Kr)) of delayed rectifier K+ current, which is important for repolarization of human cardiac myocytes. In this study, we have characterized the single-channel properties of HERG expressed in Xenopus oocytes. Currents were measured in cell-attached patches with an extracellular K concentration of 120 mM. The single HERG channel conductance, determined at test potentials between -50 and -110 mV, was 12.1 +/- 0.6 pS. At positive test potentials (+40 to +80 mV), the probability of channel opening was low and slope conductance was 5.1 +/- 0.6 pS. The mean channel open times at -90 mV were 2.9 +/- 0.5 and 11.8 +/- 1.0 ms, and the mean channel closed times were 0.54 +/- 0.02 and 14.5 +/- 5.3 ms. Single HERG channels were blocked by MK-499, a class III antiarrhythmic agent that blocks I(Kr) in cardiac myocytes. The development of block was more rapid in inside-out patches than in cell-attached patches or in whole cell recordings, indicating that block occurs from the cytoplasmic side of the membrane. The single-channel properties of HERG are similar to I(Kr) channels of isolated cardiac myocytes, which provides further evidence that HERG proteins coassemble to form I(Kr) channels.

Coassembly of K(V)LQT1 and minK (IsK) proteins to form cardiac I(Ks) potassium channel.

The slowly activating delayed-rectifier K+ current, I(Ks), modulates the repolarization of cardiac action potentials. The molecular structure of the I(Ks) channel is not known, but physiological data indicate that one component of the I(Ks), channel is minK, a 130-amino-acid protein with a single putative transmembrane domain. The size and structure of this protein is such that it is unlikely that minK alone forms functional channels. We have previously used positional cloning techniques to define a new putative K+-channel gene, KVLQT1. Mutations in this gene cause long-QT syndrome, an inherited disorder that increases the risk of sudden death from cardiac arrhythmias. Here we show that KVLQT1 encodes a K+ channel with biophysical properties unlike other known cardiac currents. We considered that K(V)LQT1 might coassemble with another subunit to form functional channels in cardiac myocytes. Coexpression of K(V)LQT1 with minK induced a current that was almost identical to cardiac I(Ks). Therefore, K(V)LQT1 is the subunit that coassembles with minK to form I(Ks) channels and I(Ks) dysfunction is a cause of cardiac arrhythmia.

Fast inactivation causes rectification of the IKr channel.

The mechanism of rectification of HERG, the human cardiac delayed rectifier K+ channel, was studied after heterologous expression in Xenopus oocytes. Currents were measured using two-microelectrode and macropatch voltage clamp techniques. The fully activated current-voltage (I-V) relationship for HERG inwardly rectified. Rectification was not altered by exposing the cytoplasmic side of a macropatch to a divalent-free solution, indicating this property was not caused by voltage-dependent block of outward current by Mg2+ or other soluble cytosolic molecules. The instantaneous I-V relationship for HERG was linear after removal of fast inactivation by a brief hyperpolarization. The time constants for the onset of and recovery from inactivation were a bell-shaped function of membrane potential. The time constants of inactivation varied from 1.8 ms at +50 mV to 16 ms at -20 mV; recovery from inactivation varied from 4.7 ms at -120 mV to 15 ms at -50 mV. Truncation of the NH2-terminal region of HERG shifted the voltage dependence of activation and inactivation by +20 to +30 mV. In addition, the rate of deactivation of the truncated channel was much faster than wild-type HERG. The mechanism of HERG rectification is voltage-gated fast inactivation. Inactivation of channels proceeds at a much faster rate than activation, such that no outward current is observed upon depolarization to very high membrane potentials. Fast inactivation of HERG and the resulting rectification are partly responsible for the prolonged plateau phase typical of ventricular action potentials.

Spectrum of HERG K+-channel dysfunction in an inherited cardiac arrhythmia.

Long QT syndrome (LQT) is an autosomal dominant disorder that can cause sudden death from cardiac arrhythmias. We recently discovered that mutations in HERG, a K+-channel gene, cause chromosome 7-linked LQT. Heterologous expression of HERG in Xenopus oocytes revealed that HERG current was similar to a well-characterized cardiac delayed rectifier K+ current, IKr, and led to the hypothesis that mutations in HERG reduced IKr, causing prolonged myocellular action potentials. To define the mechanism of LQT, we injected oocytes with mutant HERG complementary RNAs, either singly or in combination with wild-type complementary RNA. Some mutations caused loss of function, whereas others caused dominant negative suppression of HERG function. These mutations are predicted to cause a spectrum of diminished IKr and delayed ventricular repolarization, consistent with the prolonged QT interval observed in individuals with LQT.

A mechanistic link between an inherited and an acquired cardiac arrhythmia: HERG encodes the IKr potassium channel.

Mutations in HERG cause an inherited cardiac arrhythmia, long QT syndrome (LQT). To define the function of HERG, we expressed the protein in Xenopus oocytes. The biophysical properties of expressed HERG are nearly identical to the rapidly activating delayed rectifier K+ current (IKr) in cardiac myocytes. HERG current is K+ selective, declines with depolarizations above 0 mV, is activated by extracellular K+, and is blocked by lanthanum. Interestingly, HERG current is not blocked by drugs that specifically block IKr in cardiac myocytes. These data indicate that HERG proteins form IKr channels, but that an additional subunit may be required for drug sensitivity. Since block of IKr is a known mechanism for drug-induced cardiac arrhythmias, the finding that HERG encodes IKr channels provides a mechanistic link between certain forms of inherited and acquired LQT.

Development of a yeast retrotransposon-based system useful for screening of potentially active anti-retroviral compounds.

We have developed a new system suitable for easy inexpensive screening of substances potentially active against HIV and other retroviruses. The system evaluates the ability of substances to inhibit the high-frequency induced retrotransposition of the yeast transposable element Ty917, and is based on an engineered version of the retrotransposon which carries a dominant selectable marker useful for scoring transposition events. The system performance was evaluated using two nucleoside analogues of proved anti-HIV activity, 3'-azido-3'deoxythymidine (AZT) and 2',3'-dideoxycytidine (ddC). Both substances were able to inhibit Ty917 transposition and could have been detected as potentially active antiretroviral drugs using the new screening system.

[Vasodilator therapy in chronic thromboembolic cor pulmonare. Description of a case with unfavorable hemodynamic effects]. / La terapia con vasodilatatori nel cuore polmonare cronico tromboembolico. Descrizione di un caso con effetti emodinamici sfavorevoli.

Vasodilator agents have been used to decrease pulmonary arterial pressure in patients with chronic thromboembolic pulmonary hypertension (CTPH). A case is reported of a patient who had a severe hemodynamic deterioration after 10 mg of sublingual nifedipine. A review of cases of CTPH treated with vasodilators is also discussed.