Alternaria Infectoria Research Articles

A Suspected Squamous Cell Carcinoma in a Renal Transplant Recipient Revealing a Rare Cutaneous Phaeohyphomycosis by Alternaria infectoria

Squamous cell carcinoma of the skin is the most common neoplasm after organ transplantation. In addition, fungal infections are increasingly described in immunocompromised patients, such as kidney recipients. We report a case of a 64-year-old woman with a renal transplant presenting with 6-month-old skin lesions. In other centers, she had undergone previous biopsies, the results of which were suggestive of squamous cell carcinoma and aspecific inflammation. Therefore, she came to our center for surgical excision. Only our clinical experience and a detailed clinical history allowed us to doubt previous diagnoses and perform further examinations. Our investigation revealed an extremely rare fungus infection: phaeohyphomycosis by Alternaria infectoria. It was successfully treated with oral terbinafine until a complete regression of the lesions was achieved. At a 16-month follow-up visit, no recurrence of the skin lesion was observed. Despite a difficult diagnosis and rare occurrence, physicians and surgeons should be aware of infection with this emerging fungus in immunocompromised patients.

Success of posaconazole therapy in a heart transplanted patient withAlternaria infectoriacutaneous infection

Cutaneous Alternaria spp. infections occur mainly in immunosuppressed patients and itraconazole is considered as the drug of choice. We report the case of a 64-year-old heart transplanted female patient with multiple cutaneous lesions caused by Alternaria infectoria. Treatment with posaconazole resulted in complete recovery. Due to lower minimal inhibitory concentrations, better distribution and less drug interactions than with itraconazole, posaconazole may become the antifungal drug to consider in the management of cutaneous infections caused by Alternaria spp. in solid organ transplant recipients.

Antifungal susceptibility profile of clinical Alternaria spp. identified by molecular methods

To analyse the susceptibility pattern of a collection of Alternaria spp. clinical isolates. The antifungal susceptibilities of 35 isolates identified by means of sequencing the internal transcribed spacer region of rDNA were analysed by European Committee on Antimicrobial Susceptibility Testing (EUCAST) methodology. No clear differences among the activity of antifungals against Alternaria alternata and Alternaria infectoria were detected, except for echinocandins.

Phaeohyphomycosis caused by Alternaria infectoria presenting as multiple vegetating lesions in a renal transplant patient

The genus Alternaria is one of the most common black moulds and appears to be increasing as a causative agent of subcutaneous phaeohyphomycosis, particularly among immunosuppressed patients.A 53-year-old patient who had received a kidney transplant presented with multiple verrucous lesions on the distal extremities. Positive histopathology and cultures, in addition to rDNA ITS region sequencing, identified the fungal isolate as Alternaria infectoria. Oral itraconazole was administered for 10 months. A follow-up at 15 months demonstrated no signs of infection.Clinical manifestations of cutaneous alternariosis vary significantly and only a few cases have been described in the literature. Although optimal treatment options remain controversial, this case of phaeohyphomycosis was successfully treated with itraconazole monotherapy.

Cutaneous Alternaria infectoria infection in a dog in association with therapeutic immunosuppression for the management of immune‐mediated haemolytic anaemia

A 4-year-old, ovariohysterectomized, English springer spaniel on immunosuppressive therapy was re-examined for the review of its immune-mediated haemolytic anaemia and the recent development of skin lesions. For the 3 months since hospital discharge, the dog had been receiving 1.3 mg/kg prednisolone and 2.6 mg/kg ciclosporin, both administered orally twice daily. Physical examination revealed hepatomegaly and multiple, purulent, crusting, erosive to ulcerative lesions over different body areas. Onychorrhexis had occurred on one digit and the underlying corium had blackened. There were two proliferative and one plaque-like lesions in the mouth. Thick walled fungal hyphae were detected in impression smears from all skin lesions and staining with periodic acid-Schiff's stain confirmed the presence of multiple fungal hyphae and spores in all biopsies examined. Fungal culture isolated a heavy, pure growth of an Alternaria sp. which was identified as A. infectoria by sequencing the internal transcribed spacer 1 region of the rRNA gene. The animal's condition prevented detailed investigation of the oral lesions. Withdrawal of the ciclosporin and reduction of the prednisolone dosage resulted in spontaneous resolution of the skin lesions within 40 days. Further gradual decrements in the prednisolone dosage to zero were carried out without recurrence of the immune-mediated haemolytic anaemia. After 12 months, there has been no recurrence of either the skin lesions or the anaemia. To the authors' knowledge, this is the first reported case of A. infectoria infection in a dog.

Nutritional constraints on displacement of Fusarium pseudograminearum from cereal straw by antagonists

Displacement of the fungus Fusarium pseudograminearum from stubble by antagonists is a potential means of biocontrol of crown rot in cereals. The role of carbon and nitrogen nutrition in interactions between the pathogen and the antagonists Fusarium equiseti, Fusarium nygamai, Trichoderma harzianum and the non-antagonistic straw fungus Alternaria infectoria was investigated. Sole carbon source utilization patterns on Biolog plates were similar among the three Fusarium species, suggesting a possible role for competition. However, carbon niche overlap was unlikely to be important in antagonism by T. harzianum. Straw medium supplemented with sugars generally reduced the inhibitory effect of antagonists on growth of F. pseudograminearum in dual culture, indicating that availability of simple carbon sources does not limit antagonism. Adding nitrogen as urea, nitrate or ammonium to straw medium had little effect on antagonism by F. equiseti and F. nygamai, but ammonium addition removed the inhibitory effect of T. harzianum on growth of F. pseudograminearum. Displacement of F. pseudograminearum from straw by all fungi in a Petri dish assay was greater when urea or nitrate was used as a nitrogen source than with ammonium. All forms of nitrogen significantly increased displacement of F. pseudograminearum from straw under simulated field conditions when straws were either inoculated with T. harzianum or exposed to resident soil microbes. However, in 2 out of 3 experiments urea and nitrate were more effective than ammonium. The results suggest that availability of nitrogen, but not carbon, is limiting the activities of antagonists of F. pseudograminearum in straw, and the way nitrogen is applied can influence the rate of displacement and mortality of the pathogen in host residues.

PCR detection and identification of Alternaria species-groups in processed foods based on the genetic marker Alt a 1

In this study, a PCR method based on oligonucleotide primers targeting the Alt a 1 gene has been developed for the rapid detection of DNA from Alternaria spp. and for identification of Alternaria alternata, Alternaria porri, Alternaria radicina, and Alternaria infectoria species-groups in raw materials and processed food products. The assay design consists of two steps. First, a duplex PCR using primers Dir5cAlta1–Inv4Alta1 (that amplifies a specific DNA fragment of approximately 195 bp in all Alternaria spp.) and 18Sfweu–18Srveu (that amplifies a conserved 99 bp fragment on all the eukaryotic species), allows detection of Alternaria spp. DNA in foodstuffs with a high sensitivity and specificity. As a second step, identification of Alternaria species-groups is obtained through a seminested PCR method, without the need for sequencing PCR products. The specificity of the primer pairs designed was verified by PCR analysis of DNA from various Alternaria cultures, and also from several non target species. The detection limit of the method was approximately 10 2 CFU/ml, either in viable culture, heat inactivated culture or inoculated tomato pulp. Nevertheless, a sensitivity of 10 3 CFU/ml was obtained for tomato pulp inoculated with A. alternata or A. porri cultures heat inactivated at 90 °C for 5 min. PCR analysis of commercial foodstuff samples demonstrated the presence of DNA from A. alternata species-group in 100% of spoiled tomato samples, and 8% of tomato products, whilst 36.4% of cereal based infant food samples analyzed contained DNA from A. infectoria species-group.

Surface mycobiota on Argentinean dry fermented sausages

The diversity of the mycobiota community occurring on the surface of fermented dry sausages and in the environment of the processing plants was studied. The manufacturing plants (five in total) were located in three different areas of southern Buenos Aires province (Argentina). Samples were collected from two types of fermented sausages (short and long ripening time) at two times of the year (winter and summer) and at different types of plants (artisanal and industrial). A total of 342 samples were examined and 822 isolates belonging to six genera and 16 fungal species were identified. In most cases, Penicillium was the genus most frequently isolated. Penicillium nalgiovense, P. nordicum, P. solitum and P. chrysogenum were the most abundant species. The characteristics of the plants and the season were the influencing factors on the composition of the mycobiota. Under conditions of high humidity and in ripening rooms with reduced ventilation, Mucor racemosus was most prevalent. Eurotium amstelodami and Aspergillus spp were detected mainly during the summer when the temperature was higher. A high number of species isolated from the surface of the sausage was also isolated from air samples. Geotrichum candidum, Alternaria infectoria and P. glabrum were found only in air samples. P. chrysogenum, P . nalgiovense and P. nordicum showed different levels of antibacterial activity in sensitive bioassay with Micrococcus luteus.

Phomenins and fatty acids from Alternaria infectoria

Taxa of the Alternaria infectoria species group are the predominant Alternaria spp. found in cereals in Northern Europe. While several pyrones have been isolated from A. infectoria and described as taxonomical markers for species identification, information about the bioactivity of metabolites from the fungus is missing. Bioassay-guided fractionation of rice culture extracts from several strains of A. infectoria linked the observed toxicity of the extracts in MRC-5 cells to free fatty acids, i.e. linoleic acid and α-linolenic acid. The fungus also produced a cytotoxic pyrone, which upon isolation and NMR spectroscopic analysis was identified as a mixture of phomenins A and B (approximately 10:1), which have not previously been isolated from an Alternaria species.

Molecular identification of phaeohyphomycosis due to Alternaria infectoria in a patient with acute myeloid leukemia—a case report

We report the case of a 15-year old with acute myeloid leukemia who developed breakthrough invasive fungal rhinitis. The fungus was identified as Alternaria infectoria by polymerase chain reaction (PCR) and successfully treated by surgical excision and combination antifungal therapy, emphasizing the utility of fungal PCR in timely diagnosis of invasive fungal infections.

Detection of (1→3)-β- d -Glucan as an Adjunct to Diagnosis in a Mixed Population with Uncommon Proven Invasive Fungal Diseases or with an Unusual Clinical Presentation

This single-center observational prospective study evaluated the performance of (1-->3)-beta-D-glucan as an adjunct diagnostic tool in 12 patients with proven invasive fungal disease with different risk factors. The infections were due to either uncommon fungal pathogens such as dematiaceous molds (Scedosporium apiospermum, Alternaria infectoria, and Cladosporium macrocarpum) and hyaline septate molds (Fusarium solani and Blastoschizomyces capitatus) or Aspergillus spp. with unusual clinical presentations.

Potato carrot agar with manganese as an isolation medium for Alternaria, Epicoccum and Phoma

A semi-selective medium for isolation of Alternaria spp., Epicoccum sp. and Phoma spp. from soil and plant samples was developed. The basal medium was a modified potato carrot agar (PCA), containing 10 g/L of potato and carrot. It is known that the target genera sporulate well on standard PCA when grown at 25 °C with an alternating light/dark cycle consisting of 8 h of cool-white daylight followed by 16 h darkness. Addition of 1.5% MnCl 2 4 H 2O (w/v) inhibited most other fungi than Alternaria, Epicoccum and Phoma species when tested on pure cultures. The mycobiota of two soil samples and eight grain samples were examined using PCA-Mn and three commonly used isolation media, DRYES, DG18 and V8. On the three conventional media growth of several genera was observed with the predominant being Aspergillus, Eurotium, Fusarium, Mucor, Penicillium and Rhizopus. Of these only F. oxysporum and F. verticillioides were able to grow on PCA-Mn. Alternaria infectoria and Epicoccum nigrum were present in three cereal grain samples, but emerged to a far lower degree on the three conventional media compared to PCA-Mn. Three black spored fungi, identified as Phoma eupyrena, Paraconiothyrium minitan and one unknown species, were isolated from the two soil samples when incubated on PCA-Mn but were absent on the three conventional media.

Interactions of temperature and water potential in displacement of Fusarium pseudograminearum from cereal residues by fungal antagonists

Fusarium pseudograminearum ( Fp) is a stubble-borne fungus that causes crown rot in wheat and barley. Displacement of Fp from stubble by other fungi was explored. Fungi were isolated from field collections of stubble and identified using morphological and molecular methods. The most abundant species were Alternaria sp., Sterile sp. 1 and Fp. Representative isolates of all species were screened in dual culture with Fp to select candidates for detailed experiments on displacement. Trichoderma harzianum ( Th), Alternaria infectoria ( Ai), Fusarium equiseti ( Fe) and Fusarium nygamai ( Fn) were chosen as representing the range of interaction types found. The effects of temperature (5–35 °C) and water potential (−0.3 to −5 MPa) on growth rates, displacement of Fp from infested barley straw and dual culture interaction with Fp were determined. Th was the strongest antagonist overall, but displaced Fp very poorly at the lowest temperatures and water potentials. It was more antagonistic than expected from effects on growth at high temperature and less antagonistic than expected at low temperature. Fe and Fn showed consistent mutual antagonism with Fp on contact in dual culture and gave moderate displacement of Fp from straw, with Fe being the most effective antagonist under cool dry conditions. Ai gave very poor displacement of Fp from straw, despite being the most common straw fungus, confirming that displacement was due to antagonism and not just the presence of other fungi. The type of interaction in dual culture was consistent with degree of displacement from straw and could be used to indicate which environmental conditions were most limiting for an antagonist. The ability to displace Fp under cool dry conditions appears to be critical.

Alternaria infectoria brain abscess in a child with chronic granulomatous disease

In the present report, we describe the first case of a phaeohyphomycotic brain abscess in a 5-year-old boy with chronic granulomatous disease (CGD) admitted to hospital with seizures. A computed tomography (CT) scan revealed a cerebral abscess and the microbiology study showed a dark, melanin-pigmented fungus, exhibiting only sterile hyphae. This fungus was identified by the amplification and sequencing of the 5.8S RNA gene and of the adjacent internal transcriber spacer domains, ITS1 and ITS2, as Alternaria infectoria. Due to the impossibility of a surgical excision, and although several therapeutic strategies were attempted, the patient died. Limitations in the routine identification procedures and therapeutic options of this emerging opportunistic agent are highlighted in this report.

Sensitivity of the Alternaria infectoria species-group 1 to cycloheximide

A possibility of using cycloheximide tolerance and/or sensitivity as an additional diagnostic tool for distinguishing morphologically related species within common small-spored Alternaria has been tested during this study. A total of 33 strains from four Alternaria species-groups, namely Alternaria alternata, Alternaria arborescens, Alternaria infectoria and Alternaria tenuissima were tested for their growth response to 100 microg m(-1) cycloheximide in potato carrot agar. All A. infectoria strains were completely inhibited, showing no growth at all even after prolonged incubation. In contrast, all other strains representing the remnant three species exhibited a high resistance to this antibiotic. Cycloheximide sensitivity represents a further important physiological character for distinguishing A. infectoria from the three similar species. The relevance of these findings corresponds with the potential ability of the Alternaria species produce mycotoxins. Cycloheximide may be in future used in the design of selective media for the isolation of some potentially toxigenic food-borne Alternaria species such as A. alternata, A. tenuissima and/or A. arborescens, for example in screening cereals for toxigenic Alternaria spp. and for their direct separation from nontoxigenic representatives of A. infectoria species-group.

Alternaria infectoria species‐group associated with black point of wheat in Argentina

Regional surveys are being conducted in Argentina to assess the presence of wheat (Triticum aestivum) pathogens on grains across the main cropping area. During 2001 and 2002, grain samples with a dark brown or blackish discoloration around the embryo end, known as black point, were observed on several cultivars across the wheat region of Buenos Aires Province. Seed analysis by blotter and agar tests (Neergaard, 1979) showed up to 55% of prevalence (number of samples infected over the total) of Alternaria spp. and a mean natural infection of 37%. Morpho-cultural studies were carried out on potato carrot agar. The isolates were typified as belonging to the A. infectoria species-complex according to their sporulation pattern and the production of long secondary conidiophores (Andersen et al., 2002). Pathogenicity tests were carried out in Petri dishes following two standard methods: blotter test and agar test using 2% potato dextrose agar, inoculating wheat seeds with a conidial suspension (2 × 105 conidia mL−1) of 20 selected isolates. Seeds were incubated for seven days at 20 ± 2°C in a growth chamber under 12 h fluorescent plus near ultraviolet photoperiod. No disease symptoms were observed in the controls. Infected seeds became totally or partially black and seedlings from them appeared weak with reduced vigour. Black point is known to affect grain quality adversely, impairing flour, semolina and their products (Mathur & Cunfer, 1993). Simmons (1992) organized the genus Alternaria into 14 species-groups based on characteristics of conidia and chain formation. The A. infectoria species-group comprises nine known species and an unknown number of distinct taxa yet to be described. In Europe, North America and Australia studies have shown that grain samples are infected with A. alternata and A. infectoria species-groups ranging from low levels to 100%. In Argentina, previous records of Alternaria spp. refer to A. alternata associated with black point in wheat. However, in this study the vast majority of Alternaria strains conformed to the A. infectoria complex. The incidence levels of this group are gaining importance and have increased in recent years probably due to changes in cropping systems in most of the different agroclimatic zones of Argentina. This is the first published report of Alternaria infectoria species-complex causing black point in wheat grains in Argentina. This highlights the necessity to better understand the relationship of this group with the deterioration of wheat sub-products and the risk of harmful mycotoxins production.

Life-history traits of soil collembolans in relation to food quality

Preference studies of many different collembolan species have categorised collembolans being selective in their food choice. To clarify whether collembolan food selectivity is related to fitness parameters, three species, Folsomia fimetaria, Protaphorura armata and Heteromurus nitidus, were fed three fungal species, Alternaria infectoria, Mucor hiemalis and Penicillium hordei, representing fungi of high, medium and low preference. The fungal diets were grown on soil and collembolan growth, survival and fecundity were measured. The fungus A. infectoria supported growth, survival and reproduction best in all three species of collembolans, while the fungus P. hordei was of low food quality. M. hiemalis was of medium quality and F. fimetaria was the only collembolan reproducing on M. hiemalis. F. fimetaria favoured reproduction over growth when confined to M. hiemalis. When P. armata was fed M. hiemalis it reached a size where reproduction normally starts, but no young were produced. This suggests that M. hiemalis lacks nutrients necessary for reproduction. H. nitidus did not perform well on any of the fungi offered, which were generally of low food quality for this species. In this study, where the fungal growth substrate is soil, there is a clear relationship between collembolan fitness and their food choice in contrast to some other studies where substrates optimised for fungal growth had been used. We show that specific fungal species are important for resource allocation to growth or reproduction and closely connected with food choice. Further, we argue that natural fungal growth substrates, such as soil, should be used in experiments of this kind.

Alternariosis cutánea en receptor de trasplante hepático

We describe the case of a liver transplant patient with a cutaneous alternariosis due to Alternaria infectoria. Cutaneous lesions regressed with the decrease in daily doses of immunosuppressors. The skin lesion remains cicatricial after one year of follow-up.

Relapse of cutaneous alternaria infectoria in a renal transplant recipient after 2 years

This article does not have an abstract.

Novel Chemotaxonomic Markers of the Alternaria infectoria Species-Group

Two new structurally related metabolites, novae-zelandin A (1) and novae-zelandin B (2), as well as the novel metabolite 4Z-infectopyrone (3) were purified from extracts of filamentous fungi belonging to the Alternaria infectoria species-group. The structures were elucidated by a combination of 1D and 2D NMR spectroscopic data and MS data. 1-3 are important chemotaxonomic markers of the A. infectoria species-group and exhibit structures similar to those of known biologically active compounds, suggesting that they could be potential phytotoxins.