Melanized (dematiaceous) fungal infections simulating skin cancer in African organ transplant recipients

Fungi are the most frequent skin infections in organ transplant recipients (OTRs) and usually present as superficial mycoses. Deeper infections are much less common, potentially more serious and the incidence is higher in the first few months post-transplant. We report two African OTRs with deep fungal infections caused by dematiaceous (melanized, pigmented or black) fungi, who both presented with suspected skin malignancies. A 60-year-old Nigerian man developed a painful, ulcerated, amelanotic, bleeding nodule on his right fourth toe 2 months after renal transplantation. Clinical differential diagnoses included Kaposi sarcoma (KS), amelanotic acral melanoma and subungual squamous cell carcinoma (SCC). However, histology showed pseudoepitheliomatous hyperplasia, extensive mixed inflammation, multinucleated giant cells and pigmented septate hyphae with rounded 'budding' forms. Periodic acid-Schiff, Grocott and Masson-Fontana stains were positive, and Alcian blue stain was negative, consistent with infection by a dematiaceous fungus. Fungal 18S polymerase chain reaction (PCR) was positive and culture identified Nigrograna mackinnonii. Treatment with oral itraconazole was supervised virtually during the COVID-19 pandemic. After 6 months there was minimal response and he opted for amputation of the digit. A 61-year-old Nigerian man presented 2 months after renal transplantation with a 2-cm diameter nodule on his left thigh at the site of a previous burn. This failed to respond to antibiotics. Magnetic resonance imaging was suggestive of possible malignancy, but surgery was deferred because of the COVID-19 pandemic. Two months later the lesion was 5 cm in diameter and verrucous with an 8-cm sessile, purplish plaque on his right forearm. Atypical KS, lymphoma and chronic burns-associated SCC were all considered. However, histology from both lesions was similar to the first patient. Fungal culture and 18S PCR confirmed infection with the dematiaceous fungus Alternaria alternata. At his request, the right thigh lesion was excised. The lesion on his forearm has partially responded to 8 months of ongoing oral itraconazole. In our African OTR cohort, KS is more common than deep fungal infection. However, despite this suspicion of skin malignancy, both patients had phaeohyphomycoses caused by dematiaceous fungi. Characterized by the presence of melanin in their cell walls, > 130 species of these plant pathogens and soil saprophytes are implicated in human disease, particularly in immunocompromised individuals. Although localized skin diseases (phaeohyphomycoses, chromoblastomycosis and mycetoma) are the most common manifestations, rare disseminated, central nervous system and pulmonary infections may prove fatal. Although uncommon, deep fungal infection should be considered in atypical skin lesions in OTRs;histology, tissue culture and fungal PCR are critical to confirming this diagnosis.

An inaugural survey of cereal, oilseed and vegetable crop diseases in the Yukon Territory in 2020

Various kinds of field crops growing on two commercial farms in the Whitehorse area of the southern Yukon Territory were surveyed for diseases in summer 2020 by staff of the Agriculture Branch of the Government of Yukon. They included barley, wheat, canola, beets, broccoli, cabbage, carrots, potatoes and turnips. Fields were visited one or more times during July and August. The incidence and severity of diseases were visually assessed on a crop-by-crop basis and samples were collected for laboratory analysis of the pathogens present, if any. Both infectious and non-infectious diseases were present on most crops. The infectious diseases were caused by various species of plant pathogenic bacteria and fungi that were common on these crops growing in other areas of Canada. INTRODUCTION AND METHODS: The 2020 field crop disease survey is believed to be the first organized study of its kind on agricultural crops in the Territory. In his book, "An Annotated Index of Plant Diseases in Canada . . . ", I.L. Conners lists over 300 records of plant diseases on trees, shrubs, herbs and grasses in the Yukon that were published by individuals who were surveying forests and native vegetation mainly for federal government departments, universities and other agencies (Conners 1967). The objectives of the 2020 survey were: (1) to determine the kinds and levels of diseases on selected Yukon crops, (2) to identify the major pathogen species attacking Yukon crops, and (3) to use the results to plan future surveillance activities aimed at helping producers to improve their current disease management programs. All of the fields included in the 2020 survey were situated on two commercial farms, which were designated as Farm #1 and #2, in the Whitehorse area in the southern Yukon (Fig. 1). The crops surveyed included cereals (barley and wheat), oilseeds (canola) and vegetables (beets, broccoli, cabbage, carrots, potatoes and turnips). Fields were visited one or more times in the mid- to late growing season (July/August) at a time when damage from diseases was most noticeable. Symptoms were visually assessed on a crop-by-crop basis by determining their incidence and severity. Incidence was represented by the percentage of plants, leaves, heads, kernels, etc., damaged in the target crop, while severity was estimated to be the proportion of the leaf, fruit, head, root/canopy area, etc., affected by a specific disease as follows: Proportion of the canopy affected based on a 0-4 rating scale, where: 0 = no disease symptoms, 1 = 1-10% of the crop canopy showing symptoms;2 = 11-25% showing symptoms, 3 = 26- 50% showing symptoms, and 4 = > 50% showing symptoms. Photographs of affected plants were taken and sent to plant pathologists across Western Canada for their opinions on causation. Where possible, representative samples of plants with disease symptoms were packaged and sent to the Alberta Plant Health Lab (APHL) in Edmonton, AB for diagnostic analyses. Background information, such as the general cultural practices and cropping history, was obtained from the producers wherever possible. GPS coordinates were obtained for each field to enable future mapping Cereals: Individual fields of barley (11 ha) and wheat (30 ha) located at Farm #1 were surveyed. The barley was a two-row forage cultivar 'CDC Maverick', while the wheat was an unspecified cultivar of Canada Prairie Spring (CPS) Wheat. Plant samples were taken along a W-shaped transect for a total of five sampling points for the barley field (< 20 ha) and ten sampling points for the wheat field (> 20 ha). The first visit, which occurred on July 30, involved visual inspection and destructive sampling wherein plants were collected and removed from the field for a detailed disease assessment at a lab space in Whitehorse. There, the roots were rinsed off and the plants were examined for disease symptoms. The second visit to these fields, which occurred on August 27, only involved visual examination of the standing crop. Oilseeds: A single 40 ha field of Polish canola (cv. 'Synergy') was examined o

Proteinase-activated receptor-2 antagonist C391 inhibits Alternaria-induced airway epithelial signalling and asthma indicators in acute exposure mouse models.

BACKGROUND AND PURPOSE: Despite the availability of a variety of treatment options, many asthma patients have poorly controlled disease with frequent exacerbations. Proteinase-activated receptor-2 (PAR2) has been identified in preclinical animal models as important to asthma initiation and progression following allergen exposure. Proteinase activation of PAR2 raises intracellular Ca2+ , inducing MAPK and ß-arrestin signalling in the airway, leading to inflammatory and protective effects. We have developed C391, a potent PAR2 antagonist effective in blocking peptidomimetic- and trypsin-induced PAR2 signalling in vitro as well as reducing inflammatory PAR2-associated pain in vivo. We hypothesized that PAR2 antagonism by C391 would attenuate allergen-induced acutely expressed asthma indicators in murine models. EXPERIMENTAL APPROACH: We evaluated the ability of C391 to alter Alternaria alternata-induced PAR2 signalling pathways in vitro using a human airway epithelial cell line that naturally expresses PAR2 (16HBE14o-) and a transfected embryonic cell line (HEK 293). We next evaluated the ability for C391 to reduce A. alternata-induced acutely expressed asthma indicators in vivo in two murine strains. KEY RESULTS: C391 blocked A. alternata-induced, PAR2-dependent Ca2+ and MAPK signalling in 16HBE14o- cells, as well as ß-arrestin recruitment in HEK 293 cells. C391 effectively attenuated A. alternata-induced inflammation, mucus production, mucus cell hyperplasia and airway hyperresponsiveness in acute allergen-challenged murine models. CONCLUSIONS AND IMPLICATIONS: To our best knowledge, this is the first demonstration of pharmacological intervention of PAR2 to reduce allergen-induced asthma indicators in vivo. These data support further development of PAR2 antagonists as potential first-in-class allergic asthma drugs.

LUNG ACE2 AND TMPRSS2 GENE EXPRESSION VARIES WITH ALLERGEN EXPOSURES IN MURINE MODELS OF ASTHMA

Introduction: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) requires angiotensin-converting enzyme 2 (ACE2) and the transmembrane protease, serine 2 (TMPRSS2) for cell entry. Prior studies have reported that allergen exposure can downregulate ACE2 expression. Here, we sought to determine if exposure to distinct combinations of allergens results in the differential expression of ACE2 and TMPRSS2 in the mouse lung. Methods: We utilized three established murine models of asthma: 1. Alum/Ovalbumin (OVA) model;2. House dust mite (HDM)/OVA model;3. Mixed-allergen (MA) model using OVA, HDM, Aspergillus fumigatus and Alternaria alternata. Phosphate-buffered saline (PBS) treated mice were used as controls. Lung RNA was extracted using the RNeasy Mini Kit (Qiagen) according to the manufacturer’s protocol, and complementary DNA was synthesized. Quantitative PCR (qPCR) was performed 24 hours after the last challenge utilizing validated primers for ACE2 and TMPRSS2. Analysis was performed using one-way ANOVA. Results: Here we report that ACE2 mRNA expression was lower in the MA and Alum/OVA-treated mice compared to the controls (p-value < 0.0001). No difference was seen in the ACE2 mRNA expression between HDM/OVA and PBS-treated mice. Furthermore, HDM/OVA-treated mice expressed higher levels of TMPRSS2 mRNA compared to controls (p-value < 0.01). No difference was seen in the TMPRSS2 mRNA expression between the MA or Alum/OVA, and the PBS-treated mice. Conclusion: The exposure to distinct combinations of allergens results in unique patterns of ACE2 and TMPRSS2 gene expression in the mouse lung. Further studies are required to evaluate the effects of allergen exposure with the susceptibility to SARS-CoV-2 infection.

Terrific improvement of refractory atopic dermatitis with benralizumab (anti-IL5 receptor) therapy

In 2012 a 25-year-old man presented to our outpatient clinic for severe atopic dermatitis (AD) and severe allergic eosinophilic asthma in polisensitivity (house dust mite, cat, gramineous plants, birch, milk protein and, in particular, Alternaria). His clinical history was also characterized by gastro-esophageal reflux disease and chronic rhinitis without polyposis, with septal deviation and turbinate hypertrophy, worthy of surgical intervention. History taking revealed egg and cow milk protein allergy and severe asthma since the first months of life, with frequent hospital admissions due to exacerbations. AD was severe and diffuse, involving especially face, neck, back and superior limbs, often complicated by impetigo. The esthetic, social and psychological impact led him to quit his job as a barman. At presentation, the Eczema Area and Severity Index (EASI) score was 72/72. Laboratory tests showed eosinophilic count ranging between 1.060 and 2.140/mm3, and high serum levels of total Immunoglobulin E (5.939 kUI/L). Tryptase levels were normal and autoantibody analysis was negative. Parasite stool examination was negative. Nasal swab tested positive for Staphylococcus aureus, which was treated with Sulfamethoxazole-Trimethoprim. Asthma Control Test was 15/25, pulmonary function tests (PFTs) showed mild obstruction (FEV1 4.43 L, 103%, FEV1/FVC 69%), with positive bronchodilator testing (FEV1 5.12 L, + 670 mL, + 16%). Firstly, he was treated with topical steroids and sometimes with oral corticosteroids, with poor response. Then, in July 2019, he initiated therapy with cyclosporine 3-5 mg/kg. Soon, the drug had to be discontinued due to adverse effects (gastrointestinal symptoms and infections). In November 2019, at the age of 32 years, he started therapy with monoclonal antibody anti-IL-5 receptor alpha (benralizumab 30 mg 1 subcutaneous vial every 4 weeks for the first three administrations and then every 8 weeks), with a terrific clinical improvement of AD since the first administrations and with benefit on asthma control (ACT after the first administration increased up to 25/25;PFTs could not be performed, due to SARS-CoV-2 pandemic). This therapy has always been well tolerated. The eosinophilic count decreased to 0/mm3 after the first administration. At the moment, after one year of therapy, AD is almost fully disappeared (EASI SCORE 4/72), despite being in free diet, and the quality of life of the patient has definitely improved.

Polyketone metabolites isolated from Rhodiola tibetica endohytic fungus Alternaria sp. HJT-Y7 and their SARS-CoV-2 virus inhibitory activitives.

Six new polyketone metabolites, compounds (1-6) and seven known polyketone compounds (7-13) were isolated from Rhodiola tibetica endophytic fungus Alternaria sp. The structural elucidation of five new polyketone metabolites were elucidated on the basis of spectroscopic including 2D NMR and HRMS and spectrometric analysis. Inhibition rate evaluation revealed that compounds 1(EC50 = 0.02 mM), 3(EC50 = 0.3 mM), 6(EC50 = 0.07 mM), 8(EC50 = 0.1 mM) and 9(EC50 = 0.04 mM) had inhibitory effect on the SARS-CoV-2 virus.