Evaluation of isavuconazole MIC strips for susceptibility testing of Aspergillus and Scedosporium species.

Isavuconazole is a new triazole with an expanded-spectrum and potent activity against moulds and yeasts. It has been authorized for use in adults for the treatment of invasive aspergillosis and for mucormycosis. The only commercially available isavuconazole susceptibility test is the minimum inhibitory concentration (MIC) strip isavuconazole test. The objective of this study was to assess the in vitro activity of isavuconazole using gradient concentration MIC strips, compared with the EUCAST broth microdilution reference method. A total of 147 clinically relevant fungal isolates comprising 120 Aspergillus sp. and 27 Scedosporium apiospermum complex were tested for susceptibility to isavuconazole using the EUCAST broth microdilution method and by the MIC strip isavuconazole test. The percent essential agreement between the two methods was calculated within a 1-fold dilution. The geometric means for the MICs using the EUCAST reference methods and the strip test were respectively: 0.60 mg/l and 0.65 mg/l for A. fumigatus, 0.70 mg/l and 0.77 mg/l for A. flavus, 1.50 mg/l and 1.25 mg/l for A. niger, 0.41 mg/l and 0.38 mg/l for A. terreus, 1.22 mg/l and 1.08 mg/l for S. apiospermum complex. The isavuconazole MIC strips showed good agreement with the EUCAST reference method. Isavuconazole MIC strips could be useful for susceptibility testing of Aspergillus sp. and S. apiospermum complex.

A prospective international Aspergillus terreus survey: an EFISG, ISHAM and ECMM joint study.

OBJECTIVES: A prospective international multicentre surveillance study was conducted to investigate the prevalence and amphotericin B susceptibility of Aspergillus terreus species complex infections. METHODS: A total of 370 cases from 21 countries were evaluated. RESULTS: The overall prevalence of A. terreus species complex among the investigated patients with mould-positive cultures was 5.2% (370/7116). Amphotericin B MICs ranged from 0.125 to 32 mg/L, (median 8 mg/L). CONCLUSIONS: Aspergillus terreus species complex infections cause a wide spectrum of aspergillosis and the majority of cryptic species display high amphotericin B MICs.

The role of obestatin in glucose and lipid metabolism.

Obestatin is a 23 amino acid peptide encoded by the ghrelin gene, which, like ghrelin, is mainly produced by the stomach, as well as by a wide range of other tissues. Obestatin remains a controversial peptide, as the initial finding of its binding to the orphan receptor GPR39 and the inhibitory effect on food intake has been questioned. In fact, to date, its biological effects are still largely unknown, although it is becoming clear that obestatin is a pleiotropic hormone, exerting a variety of effects in different cell types and tissues. Indeed, besides regulating cell proliferation and survival, obestatin has been shown to regulate glucose and lipid metabolism, both in vitro, in pancreatic ß-cells and adipocytes, and in vivo in rodents. Furthermore, its positive effects on glucose homeostasis, combined with the anti-inflammatory actions, make this peptide appealing as a candidate for treating metabolic disorders such as insulin resistance and diabetes.

Looking for Candida nivariensis and C. bracarensis among a large Italian collection of C. glabrata isolates: results of the FIMUA working group.

Two recently described pathogenic Candida species, C. nivariensis and C. bracarensis, share many phenotypic characteristics with C. glabrata and are easily misidentified as such. The aim of this study was to determine the occurrence of these cryptic species in Italy. One thousand yeast isolates collected in 14 Italian regions and identified as C. glabrata by phenotypic and biochemical methods were included in this study: 928 were screened on CHROMagar and 72 were analysed by a multiplex PCR. None of these cryptic species was identified despite the nationwide distribution and the variety of biological origin of the isolates.

Acylated and unacylated ghrelin levels in normal weight and obese children: influence of puberty and relationship with insulin, leptin and adiponectin levels.

BACKGROUND: Ghrelin circulates in blood as acylated (AG) and unacylated (UAG) ghrelin. The physiological role of the two forms is poorly understood, in particular in childhood. Aim of the study was to evaluate the AG and UAG levels in obese and normal weight (NW) children, pre-pubertal and pubertal, and their relationship with insulin, leptin and adiponectin levels. SUBJECTS AND METHODS: A population based study in which AG, UAG, leptin, adiponectin, glucose, insulin, testosterone or estradiol levels, insulinemic indexes were evaluated in 82 NW and 58 obese (OB) children. RESULTS: Both ghrelin forms in NW were higher (AG, p<0.02; UAG, p<0.0001) than in OB subjects, with similar ratio AG/UAG . While no differences were observed for gender, puberty AG (p<0.01) and UAG (p<0.0001) levels were higher in pre-pubertal than pubertal NW and OB subjects. Adiponectin levels in NW subjects were higher (p<0.001), while leptin and insulin levels were lower (p<0.0001) than in OB subjects. NW children showed homeostasis model assessment (HOMA) and HOMAß indices lower than OB children (p<0.0001) with a higher a quantitative insulin sensitivity check index (p<0.0001). AG and UAG levels correlated to each other (p<0.0001), each showing a negative correlation to age, height, weight and body mass index. Both forms, but more strongly UAG, correlated with adiponectin, leptin, and insulin. CONCLUSIONS: OB children show lower levels of both AG and UAG when compared to NW subjects, with lower levels during puberty. These results demonstrate a peculiar strong relationship between UAG levels and metabolic parameters in the pediatric population, suggesting a role for UAG in metabolic functions.

Acylated/unacylated ghrelin ratio in cord blood: correlation with anthropometric and metabolic parameters and pediatric lifespan comparison.

CONTEXT: Ghrelin is a peptide with multiple functions that circulates in acylated (AG) and unacylated (UAG) forms. However, the role of ghrelin in neonates (NN) remains to be clarified. OBJECTIVE: The aim of this study was to determine ghrelin concentrations of the two forms in NN to clarify their biological roles. As such, ghrelin levels at birth were compared with those in later life. SETTING AND DESIGN: Tertiary Care Center. In this cross-sectional study, we evaluated AG, UAG, AG/UAG ratio, and insulin levels in venous cord blood from NN and in fasted normal weight (NW) and obese (OB) children, both prepubertal and pubertal. SUBJECTS: We studied 82 NN, 82 NW, and 58 OB children. RESULTS: AG levels were lower in NN than in NW and OB children (P<0.0001), more specifically the prepubertal NW and OB children (P<0.0001). UAG levels were higher in NN than in NW and OB children (P<0.0001). Therefore, the AG/UAG ratio was lower in NN than in NW and OB children (P<0.0001). NN showed insulin levels similar to NW and lower than OB children (P<0.0001). At birth UAG was positively correlated with AG (Pearson: 0.425; P<0.0001) and negatively with insulin (-0.253; P<0.02). In NW and OB, UAG and AG were positively correlated to each other and negatively correlated with insulin and body mass index (-0.566; P<0.0001). CONCLUSIONS: NN compared with children, showed higher UAG and lower AG levels. The AG/UAG ratio showed a very different profile in NN, being lower than in NW and OB children, thus suggesting a different metabolic function for the two forms in NN. Further studies are needed to clarify the exact role of the different ghrelin forms in NN.

Detection of fungal DNA in lysis-centrifugation blood culture for the diagnosis of invasive candidiasis in neonatal patients.

We report data concerning the detection of fungal DNA directly from lysis-centrifugation blood culture to assess its value in the detection of fungaemia in 86 of the 347 patients admitted to the neonatal intensive-care unit between January 2009 and December 2010. The sensitivity and specificity of the PCR were 87.5% and 98.5%, respectively, with a positive predictive value of 93.3% and a negative predictive value of 97.1%. Detection of fungal DNA directly from blood culture Isolator 1.5 microbial tubes, without prior cultivation, is a promising approach for the rapid detection of Candida spp. in neonates with suspected candidaemia.

Role of probiotics in the prevention of the enteric colonization by Candida in preterm newborns: incidence of late-onset sepsis and neurological outcome.

OBJECTIVE: To evaluate the efficacy of probiotics in the prevention of gastrointestinal colonization by Candida species, of late-onset sepsis and neurological outcome in preterm newborns. STUDY DESIGN: A prospective study was conducted in 249 preterms who were subdivided into three groups: one group (n=83) was supplemented with Lactobacillus (L.) reuteri, one group with L. rhamnosus (n=83) and the other with no supplementation (n=83). The fungal colonization in the gastrointestinal tract, the late onset of sepsis and clinical parameters were recorded. A neurological structured assessment was further performed at 1 year of age. RESULT: Candida stool colonization was significantly higher (P<0.01) in the control group than in the groups treated with probiotics. The L. reuteri group presented a significantly higher reduction in gastrointestinal symptoms than did the L. rhamnosus and control groups. Infants treated with probiotics showed a statistically significant lower incidence of abnormal neurological outcome than did the control group. CONCLUSION: The use of both probiotics seems to be effective in the prevention of gastrointestinal colonization by Candida, in the protection from late-onset sepis and in reducing abnormal neurological outcomes in preterms.

In vitro susceptibility of nondermatophyte molds isolated from onycomycosis to antifungal drugs.

Despite many advances in antifungal drug development and therapy, onychomycosis due to nondermatophyte molds (NDM) remains difficult to treat. Using a reference microdilution method (CLSI M38-A), the antifungal susceptibility to bifonazole, ciclopiroxolamine, fenticonazole, itraconazole, ketoconazole, miconazole, terbinafine and tioconazole of 64 molds isolated from toenail onychomycosis was studied. All the strains showed good susceptibility to ciclopiroxolamine. Aspergillus had excellent susceptibility to itraconazole followed by miconazole, ketoconazole, tioconazole, fenticonazole and terbinafine. The isolated species had variable susceptibility to bifonazole. Scopulariopsis had wide MIC ranges for all antifungal drugs tested except ciclopiroxolamine. Fusarium and Acremonium had reduced susceptibility to antifungal drugs tested. Nevertheless, some strains show low MICs for ketoconazole, miconazole and tioconazole.Studies to evaluate in vitro susceptibility testing using CLSI methods for NDM onychomycosis should be undertaken.

Pluripotent stem cells isolated from human amniotic fluid and differentiation into pancreatic beta-cells.

Human amniotic fluid (HAF) contains multipotent stem cells [amniotic fluid-derived stem cells (AFSC)] which can differentiate into a variety of different cell types. Recently, we demonstrated that obestatin, a peptide encoded by the ghrelin gene, exerts anti-apoptotic effects in pancreatic beta-cells and human islets and increases the expression of genes involved in beta-cells differentiation. We investigated whether: 1) AFSC would differentiate into pancreatic beta-cells and 2) obestatin would increase beta-cells differentiation from AFSC. Fluorescence-activated cell sorting analysis and immunocytochemical staining showed the presence of mesenchymal and endothelial markers in AFSC. Real-time PCR evidenced the expression of Octamer binding transcription factor 4 (OCT-4), a marker of pluripotency, during the early differentiation phase. However, the beta-cells differentiation marker duodenal homeobox factor-1 (PDX-1) could not be detected. Obestatin increased OCT-4 expression but had no effect on beta-cells differentiation. These results suggest that, at least under the experimental conditions used in this study, AFSC do not differentiate into beta-cells and obestatin has no additional effect.

Experience with the Platelia Candida ELISA for the diagnosis of invasive candidosis in neonatal patients.

This preliminary study evaluated the use of the Platelia Candida antigen kit for the diagnosis of invasive candidosis in 70 of 184 pre-term infants admitted to a neonatal intensive care unit between March 2004 and March 2006. The frequency of confirmed candidaemia was 6.5%. The sensitivity and specificity of the assay were 94.4% and 94.2%, respectively, with a positive predictive value of 85% and a negative predictive value of 98%. These results suggest that the inclusion of regular serological surveillance for mannanaemia in some pre-term infants would complement blood cultures for the early detection of candidosis.

Insulin-like growth factor binding protein-3 induces angiogenesis through IGF-I- and SphK1-dependent mechanisms.

Angiogenesis is critical for development and repair, and is a prominent feature of many pathological conditions. Based on evidence that insulin-like growth factor binding protein (IGFBP)-3 enhances cell motility and activates sphingosine kinase (SphK) in human endothelial cells, we have investigated whether IGFBP-3 plays a role in promoting angiogenesis. IGFBP-3 potently induced network formation by human endothelial cells on Matrigel. Moreover, it up-regulated proangiogenic genes, such as vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMP)-2 and -9. IGFBP-3 even induced membrane-type 1 MMP (MT1-MMP), which regulates MMP-2 activation. Decreasing SphK1 expression by small interfering RNA (siRNA), blocked IGFBP-3-induced network formation and inhibited VEGF, MT1-MMP but not IGF-I up-regulation. IGF-I activated SphK, leading to sphingosine-1-phosphate (S1P) formation. The IGF-I effect on SphK activity was blocked by specific inhibitors of IGF-IR, PI3K/Akt and ERK1/2 phosphorylation. The disruption of IGF-I signaling prevented the IGFBP-3 effect on tube formation, SphK activity and VEGF release. Blocking ERK1/2 signaling caused the loss of SphK activation and VEGF and IGF-I up-regulation. Finally, IGFBP-3 dose-dependently stimulated neovessel formation into subcutaneous implants of Matrigel in vivo. Thus, IGFBP-3 positively regulates angiogenesis through involvement of IGF-IR signaling and subsequent SphK/S1P activation.

Unacylated as well as acylated ghrelin promotes cell survival and inhibit apoptosis in HIT-T15 pancreatic beta-cells.

Ghrelin is mainly produced by the stomach, although it is expressed in other tissues, including the pancreas. Among its pleiotropic actions, ghrelin prevents the development of diabetes in rats and exerts mitogenic and antiapoptotic effects in different cell types. In addition, a ghrelin-producing epsilon-cell population has been demonstrated in rodent islets, suggesting a direct role in the control of islet cell survival. In this study, we investigated the effect of acylated ghrelin (AG) and unacylated ghrelin (UAG) on cell survival of HIT-T15 pancreatic beta cells. We show that both AG and UAG equally prevented beta cell death induced by serum withdrawal. In addition, both peptides inhibited serum starvation-induced apoptosis. These findings indicate that UAG and AG prevent cell death and apoptosis of pancreatic beta cells. Since only AG, but not UAG, binds the GRLN receptor, a different and as yet unknown receptor is likely involved in these survival mechanisms.

H9c2 cardiac muscle cells express all somatostatin receptor subtypes.

The aim of the present study was to verify the hypothesis that SS receptor subtypes (SSTRs) are expressed by H9c2 cardiac muscle cells. SSTRs expression was investigated by RT-PCR and Western blot analysis at both mRNA and protein level. Our findings demonstrate that H9c2 cells express all SSTR subtypes I-5 (SSTRI-5) at the mRNA and protein level. Thus, H9c2 cells would represent a new model to study the direct biological activities of SS and its analogues at the cardiac level.

Insulin-like growth factor binding protein-3 mediates serum starvation- and doxorubicin-induced apoptosis in H9c2 cardiac cells.

Insulin-like growth factor binding protein 3 (IGFBP-3) modulates the activity of IGF-I, which exerts antiapoptotic action upon the myocardiocyte. IGFBP-3 also exerts IGF-independent actions to inhibit cell growth and induce apoptosis, mediating the effects of several antiproliferative agents. We hypothesized that IGFBP-3 mediates cardiomyocyte apoptosis. IGFBP-3 expression was studied in H9c2 rat cardiac cells cultured in serum-deprived medium in the absence or presence of 1 microM doxorubicin during a 72 h time-span. To a greater degree than serum withdrawal, doxorubicin induced IGFBP-3 up-regulation that was time-dependent. IGFBP-3 mRNA levels positively correlated with the degree of apoptosis. Exogenous IGFBP-3 decreased cell viability and induced apoptosis in serum-starved cells exposed to doxorubicin. IGFBP-3 antisense oligonucleotides markedly decreased apoptosis induced by either serum withdrawal or doxorubicin. Binding studies revealed specific high-affinity sites for IGFBP-3 in H9c2 cardiomyocytes, with binding characteristics typical of receptor-ligand interactions. These findings indicate that IGFBP-3 could play proapoptotic action at the myocardial level and suggest a novel role for this protein in cardiovascular dysfunction.