Fumigatus Group Research Articles

The N-terminus of the Aspergillus fumigatus group III hybrid histidine kinase TcsC is essential for its physiological activity and targets the protein to the nucleus.

Signaling pathways enable pathogens, such as Aspergillus fumigatus, to respond to a changing environment. The TcsC protein is the major sensor of the high osmolarity glycerol (HOG) pathway of A. fumigatus and it is also the target of certain antifungals. Insights in its function are therefore relevant for the pathogenicity and new therapeutic treatment options. TcsC was expected to be cytoplasmic, but we detected it in the nucleus and showed that it translocates to the cytoplasm upon activation. We have identified the motif that guides TcsC to the nucleus. An exchange of a single amino acid in this motif prevents a nuclear localization, but this nuclear targeting is no prerequisite for the TcsC-mediated stress response. Loss of the N-terminal 208 amino acids prevents the nuclear localization and renders TcsC unable to respond to hyperosmotic stress demonstrating that this part of the protein is of crucial importance.

On the systematic position of the horseshoe bats (Mammalia: Chiroptera) from Lesotho

Abstract The monophyletic Afro-Palaearctic clade of the horseshoe bats (Rhinolophus) comprises several species groups whose representatives can be morphologically similar to each other across groups. The only Rhinolophus species that occurs in Lesotho was traditionally attributed to the broadly distributed African desert- and savanna-dwelling bat, Rhinolophus clivosus, a member of the ferrumequinum group. In this study, we investigated the horseshoe bats from Lesotho with the help of molecular genetic and morphometric analyses to find their position within the group and the clade as well. The genetic analysis resulted in phylogenetic trees with two different topologies, although in both trees the Lesotho bats were a part of the fumigatus group instead of the ferrumequinum group. In the mitochondrial tree, the Lesotho bats were mixed with Rhinolophus damarensis. On the contrary, the Lesotho bats formed a single distinct lineage on the nuclear tree, closely related to Rhinolophus darlingi, R. fumigatus, and R. damarensis (in a single lineage each). These results indicate introgressions of mtDNA from the Lesotho bats to R. damarensis. Morphologically, the Lesotho bats grouped distinctly from other species of the fumigatus and ferrumequinum groups. We thus consider the Lesotho horseshoe bats to be a new separate species that is here described.

Nitrogen sources alter ligninase and cellulase activities of thermophilic fungi isolated from compost and vermicompost.

Fungi harboring lignocellulolytic activity accelerate the composting process of agricultural wastes; however, using thermophilic fungal isolates for this process has been paid little attention. Moreover, exogenous nitrogen sources may differently affect fungal lignocellulolytic activity. A total of 250 thermophilic fungi were isolated from local compost and vermicompost samples. First, the isolates were qualitative assayed for ligninase and cellulase activities using Congo red (CR) and carboxymethyl cellulose (CMC) as substrates, respectively. Then, twenty superior isolates harboring higher ligninase and cellulase activities were selected and quantitatively assayed for both enzymes in basic mineral (BM) liquid medium supplemented with the relevant substrates and nitrogen sources including (NH4)2SO4 (AS), NH4NO3 (AN), urea (U), AS + U (1:1), or AN + U (1:1) with final nitrogen concentration of 0.3g/L. The highest ligninase activities of 99.94, 89.82, 95.42, 96.25, and 98.34% of CR decolorization were recorded in isolates VC85, VC94, VC85, C145, and VC85 in the presence of AS, U, AS + U, AN, and AN + U, respectively. Mean ligninase activity of 63.75% in superior isolates was achieved in the presence of AS and ranked the highest among other N compounds. The isolates C200 and C184 exhibited the highest cellulolytic activity in the presence of AS and AN + U by 8.8 and 6.5 U/ml, respectively. Mean cellulase activity of 3.90 U/mL was achieved in AN + U and ranked the highest among other N compounds. Molecular identification of twenty superior isolates confirmed that all of them are belonging to Aspergillus fumigatus group. Focusing on the highest ligninase activity of the isolate VC85 in the presence of AS, the combination can be recommended as a potential bio-accelerator for compost production.

Invasive aspergillosis caused by <i>Aspergillus non-fumigatus</i> after allogeneic hematopoietic stem cell transplantation

Objective. To study the features of invasive aspergillosis (IA) due to A. non-fumigatus versus A. fumigatus in adult (≥ 18 years) recipients of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in 2016-2021. Materials and methods. The study included 33 patients with IA caused by A. non-fumigatus (n = 20) and A. fumigatus (n = 13). A comparative analysis of cases of IA, the results of therapy and outcomes in patients after allo-HSCT in the RM Gorbacheva Research Institute was performed. Diagnostic criteria EORTC / MSGERC 2020 were used. Results. Invasive aspergillosis caused by A. non-fumigatus made up the majority (60.6 %) of IA cases with an identified pathogen registered in patients after allo-HSCT in the period from 2016 to 2021. The main etiological agents in the A. non-fumigatus group were A. niger in 13 (65 %) patients, A. flavus – in 4 (20 %). The median day of diagnosis of A. non-fumigatus IAwas + 110 days (17–2093), for A. fumigatus it was + 46 days (2–866) (p = 0.171). Overall 12-week survival was 55 % and 59.2 % in the A. non-fumigatus and A. fumigatus groups, respectively (p = 0.617). The majority of patients in both the A. fumigatus (n = 10, 77 %) and A. non-fumigatus (n = 16, 80 %) groups received voriconazole as initial antifungal therapy. Second-linetherapy was required in 2 (10 %) patients with A. non-fumigatus IA: liposomal amphotericin B and echinocandins with or with-out posaconazole, and 2 (15 %) patients in the A. fumigatus group: liposomal amphotericin B and voriconazole in combination with echinocandins. A comparative analysis showed that in patients from the two groups, none of the assessed signs (gender, age, underlying disease, disease status at the time of transplantation, time from diagnosis to allo-HSCT, source of hematopoietic stem cells, conditioning regimen, donor type, antifungal prophylaxis, cytomegalovirus reactivation, severe acute and chronic graft-versus-host disease) did not differ significantly. Conclusions. A. niger is the main causative agent of IA caused by A. non-fumigatus. Patients characteristics, their treatment and outcomes did not differ significantly between the A. non-fumigatus and A. fumigatus groups.

Indoleamine 2,3-dioxygenase adjusts neutrophils recruitment and chemotaxis in Aspergillus fumigatus keratitis.

To explore the effect of indoleamine 2,3-dioxygenase (IDO) on recruitment and chemotaxis function of neutrophils in Aspergillus fumigatus (A. fumigatus) keratitis. C57BL/6 mice models of A. fumigatus keratitis were established by inoculating hyphae of A. fumigatus evenly on the corneas. The clinical scores and inflammatory cytokines expression were measured respectively on the 1st, 3rd, 5th day after infection. The 1-MT (1 mg/mL) was administered by gavage to exert an inhibitory effect on IDO during infection. The mice were divided into control group, 1-MT group, A. fumigatus (A.F.) group, and 1-MT+A.F. groups. The corneas were monitored by slit lamp microscopy, and recorded disease scores in 3d after infection. Myeloperoxidase (MPO) assay was done to evaluate the neutrophils infiltration. Immunofluorescence staining was used to detect the recruitment of neutrophils in murine corneas. The mRNA of inflammatory cytokines was measured with reverse transcription-polymerase chain reaction (RT-PCR). The corneal inflammation and the clinical score reached the peak on the 3rd day after the corneal infection. The mRNA of inflammatory cytokines of the A.F. group reached the highest on the 3rd day after the infection accordingly. Meanwhile, the results of slit light photography indicated that inhibitors of IDO made inflammation more serious contrasted with the A.F. group on the 3rd day. Besides, imunofluorescence staining and MPO indicated that 1-MT enhanced the recruitment, infiltration and chemotaxis of neutrophils obviously in contrast to the A.F. group. RT-PCR indicated that 1-MT increased the expression of CXCL-1, ICAM-1, IL-1β, and IL-8 significantly. IDO participates in the pathogenesis of A. fumigatus keratitis and plays an important role in inducing immune protection by inhibiting neutrophils-related inflammatory reaction and suppressing recruitment and chemotaxis of the neutrophils.

Gastric Ulceration and Immune Suppression in Weaned Piglets Associated with Feed-Borne Bacillus cereus and Aspergillus fumigatus.

As a multifactorial cause, gastric ulceration-mediated diarrhea is widely prevalent in the weaned piglets, impairing pig health and economic benefits. With full implementation of antibiotic stewardship programs in China, Bacillus cereus (B. cereus) and Aspergillus fumigatus (A. fumigatus) were identified frequently in porcine feedstuffs and feeds of the animal industry. Association between feed-borne B. cereus and frequent diarrhea remains unclear. In the present study, we conducted a survey of B. cereus and A. fumigatus from feeds and feedstuffs in pig farms during hot season. Interestingly, B. cereus, B. subtilis, B. licheniformis and B. thuringinesis were isolated and identified from piglets’ starter meals to sow feeds, accounting for 56.1%, 23.7%, 13.7% and 6.5%, respectively. Obviously, both B. cereus and B. subtili were dominant contaminants in the survey. In an in vitro study, Deoxynivalenol (DON) contents were determined in a dose-dependent manner post fermentation with B. cereus (405 and DawuC). Subsequently, 36 weaned piglets were randomly assigned to four groups and the piglets simultaneously received the combination of virulent B. cereus (Dawu C) and A. fumigatus while animals were inoculated with B. cereus (Dawu C), A. fumigatus or PBS as the control group. Clinically, piglets developed yellow diarrhea on day 5 and significant reductions of relative body weight were observed in the B. cereus group, and co-infection group. More importantly, IgG titers against Classical swine fever virus (CSFV) and Porcine epidemic diarrhea (PED) were reduced dramatically during 14-day observation in co-infection group, the B. cereus (Dawu C) group or the A. fumigatus group. However, lower Foot and mouth disease (FMD) -specific antibodies were reduced on day 7 compared to those of the control group. Additionally, lower lymphocyte proliferations were found in the B. cereus group and the co-infection group compared to the control group. Postmortem, higher lesions of gastric ulceration were observed in the B. cereus group and the co-infection group from day 7 to day 14 compared with those of the A. fumigatus group and the control group. Compared to the A. fumigatus group, higher DON contents were detected in the stomach inoculated with B. cereus and the co-infection with A. fumigatus. In conclusion, our data support the hypothesis that B. cereus might be associated with severe diarrhea by inducing gastric ulcerations and A. fumigatus might aggravate immune suppression, threating a sustainable swine industry. It is urgently needed to control feed-borne B. cereus contamination.

Phylogenetic Analysis Of Endophytic Fungi Isolate from Bellucia pentamera Naudin Based On ITS rDNA

Endophytic fungi can produce secondary metabolites of endophytic fungi isolated from host plants. The purpose of this study is to identify and analyze the sequencing of endophytic fungi isolates with ITS and Beta-tubulin markers and phylogenetic trees. The endophytic fungi isolate DKJ1, DKJ3a, DKJ3c and DKJ4 were successfully isolated from the cardia plant (Bellucia pentamera Naudin) indicated by Aspergillus niger group, Aspergillus fumigatus group and Penicillium sp. The results of the sequencing analysis of isolates DKJ1, DKJ3a, DKJ3c, and DKJ4 were successfully amplified with an annealing temperature of 54ºC with a pair of ITS1-ITS4 primers with a molecular weight of 570 bp and a Beta-Tubulin primer with an annealing temperature of 56.1ºC molecular weight of 550 bp. From the results of identification and analysis of DNA sequencing of endophytic fungi DKJ1, DKJ3a, DKJ3c and DKJ4 with the primary pair of ITS and Beta-tubulin shows that the phylogenetic tree is different from the species obtained. ITS DKJ1 isolates have similarities with the species Aspergillus piperis CBS 112811, ITS DKJ3c has similarities with the species Aspergillus flavus var flavus strain ATCC 16833, ITS DKJ3a has similarities with Penicillium rolfsii strain NRRL 1078 species and ITS DKJ4 has similarities with Penicillium oxalicum NRRL 787 species. Whereas isolate from DKJ1 Beta-Tubulin has similarities with NRRL 4875 Aspergillus tubingensis species, DKJ3c has similarities with species of Aspergillus novoparasiticus strain DTO 223-C4 and DKJ4 has a similarity with Penicillium guaibinensis species. But there are similarities based on Cluster A (Aspergillus Group) and Cluster B (Penicillium Group) on phylogenetic trees.

The regulative effects of Aspergillus fumigatus on expression of glucocorticoid receptor in asthmatic rats

Objective: To study the regulative effects of Aspergillus fumigatus (A.fumigatus) on expression of glucocorticoid receptor (GCR) in asthmatic rats. Methods: Wistar rats were randomly divided into 4 groups: a normal control group (UC), a normal control with A. fumigatus group (UC+ AF), an OVA group (OVA), and an OVA with A. fumigatus group (OVA+ AF). OVA and OVA+ AF groups were sensitized and challenged with OVA to establish asthmatic models. UC and UC+ AF groups were given normal saline as controls. After the last challenge, OVA+ AF and UC+ AF groups were given A. fumigatus spores intranasally. Airway hyper-responsiveness, eosinophil percentage (Eos%) and serum IgE level were measured to confirm the establishment of asthmatic models. Sections of pulmonary tissue were stained with hematoxylin-eosin (HE) and the expression of GCR mRNA and protein in lung tissues were measured by qRT-PCR and Western blot. Lung tissues and blood were plated on the potato dextrose agar(PDA)medium and cultured for 24 h to measure the number of colony. Results: The Penh value, Eos% in BALF and serum IgE level in UC+ AF group were slightly higher than those in the UC group (all the P>0.05). The Penh value, Eos% in BALF and serum IgE level in OVA group were significantly higher than those in the UC group (all the P<0.05). The Penh value in OVA+ AF group was significantly increased compared with the OVA group at the concentration of 25 g/L and 50 g/L of methacholine (all the P>0.05). Pulmonary histology revealed that both OVA group and OVA+ AF group showed high levels of inflammatory cell infiltration of bronchus and lung vessels, interstitial edema and smooth muscle thickening, while the UC and UC + AF groups were normal. Compared with the UC group, the expressions of GCR mRNA and protein in UC+ AF group and OVA group were decreased significantly (GCR mRNA in UC, UC+ AF and OVA group were 0.93±0.15, 0.65±0.10, 0.72±0.22, respectively, F=10.744, P<0.01; GCR protein in UC, UC+ AF and OVA group were 100±0, 89±8, 82±15, respectively, F=18.939, P<0.01). The expressions of GCR mRNA and protein in OVA+ AF group were further decreased than those in OVA group (GCR mRNA: OVA group: 0.72±0.22 vs OVA+ AF group: 0.52±0.08, t=2.462, P<0.05; GCR protein: OVA group: 81.88±15.41 vs OVA+ AF group: 59.09±7.60, t=2.997, P<0.05). The ratio of A. fumigatus colonization in lung tissues in OVA+ AF group (4/8) was higher than the UC+ AF group (0/8). Conclusion:A. fumigatus exposure can down-regulate the expression of GCR in the lung, which maybe an important mechanism of steroid-resistant asthma.

The role of Dectin-1/Raf-1 signal cascade in innate immune of human corneal epithelial cells against Aspergillus fumigatus infection.

To investigate the expression of the v-raf-1 murine leukemia viral oncogene homolog 1 (Raf-1) and its role in the innate immune response of human corneal epithelial cells (HCECs) infected by Aspergillus fumigatus. HCECs were cultured in vitro. They were randomly divided into 4 groups, including control group, Aspergillus fumigatus group, GW5074 (an inhibitor of Raf-1) group and Laminarin [an inhibitor of Dendriti-cell-associated C-type lectin 1 (Dectin-1)] group. The protein expression level of total Raf-1 and p-Raf-1was measured by Western blot. The expression of IL-6 and IL-8 mRNA in each group was detected by real-time polymerase chain reaction. In Aspergillus fumigatus group, total Raf-1 protein levels in HCECs remained unchanged at 5, 15, 30 and 45min after infection, while p-Raf-1 expression was significantly enhanced at 30min after infection compared with control group. However, the expression of p-Raf-1 was apparently declined after treated with GW5074 or Laminarin compared with Aspergillus fumigatus group. The expression levels of IL-6, IL-8 mRNA were significantly increased after stimulation with fumigatus compared with control group. Pre-treated with GW5074 significantly inhibited Aspergillus fumigatus-induced upregulation of IL-8 and IL-6. Aspergillus fumigatus stimulation can elevate the expression of p-Raf-1 in HCECs in vitro. Dectin-1/Raf-1 signal pathway may play a role on regulating the expression of inflammatory cytokines, including IL-6 and IL-8.

The importance of mold sensitivity in nonallergic rhinitis patients.

In recent studies, local specific immunoglobulin E (sIgE) production against allergens in nasal mucosa and a positive response to a nasal allergen provocation test (NAPT) have been demonstrated in some patients initially diagnosed as nonallergic rhinitis (NAR) or idiopathic rhinitis (IR). The aim of this study was to evaluate the presence of local allergic rhinitis (LAR) in patients who experience rhinitis symptoms in indoor and outdoor moldy conditions and to investigate the role of the NAPT in diagnosis. A total of 40 NAR patients with a history of persistent rhinitis and who had negative skin-prick tests (SPTs) and serum sIgE levels to common aeroallergens, as well as 20 healthy subjects were included in the study. NAPTs were performed with Aspergillus fumigatus (group 1) or a mixture of Alternaria alternata and Cladosporium herbarum extracts (group 2). In patient nasal lavage fluids, tryptase and mold sIgE levels were not significantly different from the control group. NAPT with Aspergillus fumigatus was positive in 8 of 12 NAR patients (66.6%) in group 1 and NAPT with the mixture of extracts was positive in 9 of 13 NAR patients (69.2%) in group 2. This study suggests that LAR may exist in a significant number of the persistent rhinitis patients who were previously considered as NAR based on negative SPTs or serum sIgE tests. To the best of our knowledge, this is the first study evaluating a nasal local allergic response to both indoor and outdoor molds.

English

This study investigates the effect of nucleotide-binding oligomerization domains (NODs) signal pathway in invasive pulmonary aspergillosis. Mice were randomly divided into three groups: 1) normal mice (control group), 2) normal mice infected with Aspergillus fumigates, 3) normal mice treated with immunosuppressant and inoculated with A. fumigatus (IPA Model). Mice were sacrificed at different time points after inhaling A. fumigatus spores by nose. Their lungs were extracted under sterile condition, and were used to count the fungal colonies; and also the pathological sections of lungs were observed by HE staining. RT-PCR was used to detect the expression of the NOD1, NOD2 and RIP2 mRNA of mice lung. Western blot was used to detect the expression of TNF-&alpha;. 72 h after inhaling A. fumigatus spores, a large number of hyphae and severe inflammation were found in the lung of IPA model mice group; and the lung burden of IPA mice were more than that of normal+A. fumigatus group at each time points. When compared with normal+A. fumigatus group, the expressions of NOD1 and RIP2 mRNA were persistently descending in IPA model mice group; the expression of NOD2 mRNA was abnormally raised in early stage of infection (24 h), then decreased in the later stage. However, in normal+A. fumigatus group, proinflammatory cytokine TNF-&alpha; exhibited high expression at the early stages of infection, and the highest expression levels appeared at 48 or 72 h, then decreased and returned to normal level. In the group of the IPA mouse, proinflammatory cytokines TNF-&alpha; were released at slow and low level. Persistently low expression of NOD1 and RIP2, was seen in early excessive activation. Key words: Invasive pulmonary aspergillosis (IPA), nucleotide-binding oligomerization domains (NODs), RIP2, pathogenesis.

Chymostatin as a therapeutic agent of aspergillosis in murine model

The purpose of this study was to evaluate the therapeutic effect of chymostatin, as an elastase inhibitor, in mice with invasive aspergillosis. Two Aspergillus fumigatus (A. fumigatus) isolates obtained from animals (bovine mastitis and avian endophthalmitis) along with elastase-producing A. fumigatus ATCC 26933 were inoculated to seven mice groups according to the protocol. The induction of aspergillosis was confirmed by tissue cultures as well as histopathological examination. Chymostatin, as an elastase inhibitor, was used in treating the infected animals at doses of 50, 100, and 200 μM in four different times. There was no mortality in mice group 6 (mice treated with elastase-producing A. fumigatus ATCC 26933 + 200 μM chymostatin). The mortality rate was calculated approximately 50 % in mice infected with elastase-producing A. fumigatus (group 2). The highest colony forming units was observed in the kidney (35.3 %) and the lowest in the liver (5.9 %). Moreover, Aspergillus hyphae were observed in different tissues obtained from died mice in all groups except group 6. The results showed that chymostatin at a dose of 200 μM could be useful as a feasible replacement agent for the treatment of invasive aspergillosis.

A new method to create experimental model of noninvasive fungal sinusitis in rabbits

Objective To investigate a new method for creating experimental model of noninvasive fungal sinusitis in rabbits.Methods Twenty-five New Zealand white rabbits(50 sides)were divided into seven groups: control group(n=6 sides),sham-operation group(n=6 sides),mucosal-scratched group(n=6 sides),ostia-blocked group(n=6 sides), Aspergillus fumigatus inoculated group(n=8 sides),mucosal-scratched plus Aspergillus fumigatus inoculated group(n=9 sides),and ostia-blocked plus Aspergillus fumigatus inoculated group(n=9 sides).The experiment was divided according to whether the maxillary sinus mucosa was wounded or not and whether the natural ostia were blocked or not.On days 14 and 28 after Aspergillus fumigatus inoculation,histopathologic and mycological examinations of both maxillary cavities and mucous membrane were performed to confirm the establishment of the model.Results Aspergillus fumigatus plus ostial obstruction group had a positive rate of 88.9%(8/9 sides) on day 14 and 77.8%(7/9 sides) on day 28 in fungal culture.Aspergillus fumigatus plus mucosa wound yielded a positive rate of 44.4%(4/9 sides) on day 14 and 22.2%(2/9 sides) on day 28.Conclusion Aspergillus fumigatus inoculation combined with an blocked ostium can be used to establish experimental model of noninvasive maxillary fungal sinusitis.

In vivoandin situimaging of experimental invasive pulmonary aspergillosis using fibered confocal fluorescence microscopy

Invasive pulmonary aspergillosis (IPA) is a highly fatal disease in immunosuppressed patients. In this study, we assessed fibered confocal fluorescence microscopy (FCFM), a new endoscopic technique that enables in vivo microscopic imaging of the distal lung, as a tool for in vivo imaging of IPA. IPA was induced in immunosuppressed rats using a wild strain of Aspergillus fumigatus (n = 6) or a fluorescent transformed TAG-RFP A. fumigatus strain (n = 10). Subpleural areas of pulmonary infection were imaged in vivo using FCFM employing a transthoracic approach. Results were compared to three immunosuppressed control groups, i.e., non-inoculated rats (n = 4), rats inoculated with sterile Phospate-buffer saline (PBS; n = 5), and rats inoculated with Geosmithia argillacea (n = 6). Only hyphae of TAG-RFP A. fumigatus were detectable both in vitro and in vivo by FCFM. In vivo, a local infiltration of fluorescent alveolar macrophages was observed with FCFM in IPA areas in all fungal infections groups, but also in focal inflammatory areas in the immunosuppressed PBS group. A specific fibrillar fluorescence was observed in IPA areas with the TAG-RFP A. fumigatus group, with a 83% sensitivity, a 100% specificity, a 100% positive predictive value and 94% negative predictive value. FCFM provides a new tool to study host-aspergillus interactions in vivo.

FT-IR Spectroscopy for Rapid Differentiation of Aspergillus flavus, Aspergillus fumigatus, Aspergillus parasiticus and Characterization of Aflatoxigenic Isolates Collected from Agricultural Environments

In agricultural areas, Aspergillus flavus, Aspergillus fumigatus and Aspergillus parasiticus are commonly identified in various feedstuffs and bioaerosols originated from feed handling. Some isolates belonging to these fungal species could produce mycotoxins and constitute a risk factor for human and animal health. In this study, Fourier-transform infrared spectroscopy was used for a rapid detection and characterization of 99 isolates collected from agricultural areas. The results showed a first cluster corresponding to strains previously attributed to the A. fumigatus group according to current taxonomic concepts, and a second cluster divided in 2 groups around reference strains of A. flavus and A. parasiticus species. The toxigenic capacity of isolates was evaluated by high performance liquid chromatography coupled to mass spectrometry. In the A. flavus group, only 6 strains of A. parasiticus and 4 strains of A. flavus were able to produce aflatoxins on culture media. FT-IR spectroscopy, respectively, allowed the differentiation of non-toxigenic and toxigenic A. flavus and A. parasiticus isolates at 75 and 100%. Discrimination between toxigenic and non-toxigenic A. fumigatus was not possible because all of the isolates produced at least one mycotoxin.

Epicutaneous Antigen Exposure Primes for Experimental Eosinophilic Esophagitis in Mice

Eosinophilic esophagitis (EE) is frequently associated with atopic disease, including dermatitis and asthma. Data are emerging that atopic skin may provide an early entry point for antigen sensitization. We aimed to test the hypothesis that epicutaneous exposure to antigen primes for subsequent respiratory antigen-induced EE. Wild-type and genetically engineered mice were subjected to epicutaneous antigen sensitization and the development of experimental EE, and immune responses were examined. We show that exposure to antigen via the epicutaneous route primes for marked eosinophilic inflammation in the esophagus triggered by a single airway antigen challenge. The development of experimental EE is associated with significant skin eosinophilia, accelerated bone marrow eosinophilopoiesis, blood eosinophilia, and large increases in serum antigen-specific immunoglobulin G1/immunoglobulin E using ovalbumin or Aspergillus fumigatus as the epicutaneous antigen. Mechanistic analysis with gene-targeted mice showed that interleukin-5 was required for esophageal eosinophilia and that interleukin-4, interleukin-13, and STAT6 contributed to a lesser extent. These findings provide the first evidence that epicutaneous exposure to allergens potently primes for EE via a Th2-dependent mechanism.

Mannose-binding lectin binds to a range of clinically relevant microorganisms and promotes complement deposition.

Mannose-binding lectin (MBL) is a collagenous serum lectin believed to be of importance in innate immunity. Genetically determined low levels of the protein are known to predispose to infections. In this study the binding of purified MBL to pathogens isolated from immunocompromised children was investigated by flow cytometry. Diverse Candida species, Aspergillus fumigatus, Staphylococcus aureus, and beta-hemolytic group A streptococci exhibited strong binding of MBL, whereas Escherichia coli, Klebsiella species, and Haemophilus influenzae type b were characterized by heterogeneous binding patterns. In contrast, beta-hemolytic group B streptococci, Streptococcus pneumoniae, and Staphylococcus epidermidis showed low levels of binding. Bound MBL was able to promote C4 deposition in a concentration-dependent manner. We conclude that MBL may be of importance in first-line immune defense against several important pathogens.

Morphological characteristics of Aspergillus fumigatus strains isolated from patient samples.

The Aspergillus fumigatus group splits into the anamorphic A. fumigatus series and the teleomorphic Neosartorya fischeri series. The species A. fumigatus Fresenius is the most common species within the A. fumigatus series. Forty-seven clinical isolates out of the A. fumigatus group were obtained from patients with diseases such as localized and invasive aspergilloses or allergic disorders due to Aspergillus and were mainly isolated from respiratory secretions. Isolates were studied concerning macro- and micromorphological parameters. All isolates were shown to be isolates of the species A. fumigatus Fresenius. In general, the macro- and micromorphological variability between the different isolates was low. Four isolates (DSM 10661, DSM 10662, DSM 10705, DSM 11069) showed significant differences towards the type strain A. fumigatus Fresenius ATCC 1022; one of these isolates was highly atypical (DSM 10705).

Detection of Aspergillus Ribosomal RNA Using Biotinylated Oligonucleotide Probes

Aspergillosis continues to be a devastating disease entity that results in significant mortality in immunosuppressed patients. Rapid diagnosis is often required to initiate appropriate therapy. Although the histopathologist may be able to visualize fungal organisms in tissue specimens, the histology of Aspergillus species may overlap with a variety of fungi, so diagnosis often relies on fungal cultures that can take weeks to complete. Recently, an in situ hybridization assay targeting Aspergillus 5S ribosomal RNA (rRNA) was reported. This assay proved to be useful when fungal cultures were negative or not performed but when fungi compatible with Aspergillus species were identified in tissue sections. That study was performed to compare the probe described in the previous study (5S-1 probe) with two other probes specific for Aspergillus. Two customly designed 21- and 23-base oligonucleotide probes complementary to 5S (5S-2 probe) and 18S (18S-1 probe) rRNA of Aspergillus were synthesized and labeled with multiple biotin moieties at the 3' termini. By GenBank analysis, the sequence of the 18S-1 probe was shown to have 90% to 100% homology to Aspergillus fumigatus group, Aspergillus flavus, Aspergillus niger, Aspergillus terreus, Aspergillus parasiticus, Aspergillus tamarii, and Aspergillus glaucus group; the 5S-2 probe was homologous to Aspergillus flavus, Aspergillus niger, Aspergillus nidulans, Aspergillus awamori, and Aspergillus wentii. In situ hybridization was performed on 43 cases of Aspergillus infection including 41 localized aspergillomas in the lung, brain, sinonasal tract, and ear, and 2 cases of invasive aspergillosis involving pleura and soft tissue of the scapular region. The results were compared with those obtained using a previously reported 5S-1 probe. In situ hybridization was positive in 38, 38, and 40 cases with the 5S-1, 5S-2, and 18S-1 probes, respectively. The 18S-1 probe was most useful because of a wider detection spectrum. In situ hybridization for Aspergillus rRNA provides a useful means for rapidly and accurately identifying Aspergillus in tissues and may be useful if fungal organisms suggestive of Aspergillus species are present but if cultures are negative or have not been performed.

Recherche de nouvelles activités saccharifiantes thermostables chez les champignons filamenteux

We have searched for producers of a saccharifying activity with improved thermostability compared with industrial amyloglucosidases. These producers were chosen among thermophilic, thermotolerant, or even mesophilic fungi. Among the 846 isolated strains, five species (two Thermoascus spp., a member of the Aspergillus fumigatus group, and two members of the Aspergillus niger group) showed an amyloglucosidasic complex with the required property. Whereas the first three of these were thermophilic or thermotolerant strains, the latter two strengthen the idea that mesophilic strains can produce thermostable enzymes. The thermostability of the saccharifying complex of the Thermoascus spp., established with a half-life measure, was found to be far better than the other ones. The industrial use of these strains was discussed, and Thermoascus crustaceus seems to be the most advantageous one. Key words: filamentous fungi, amyloglucosidases, thermostability, Thermoascus.