232 To Report A Rare Case of Fungal Necrotising Otitis Externa (NOE) Centred on The Left Temporomandibular Joint (TMJ)

Introduction NOE is a rare life-threatening complication of otitis externa, affecting the skull base, mastoid and temporal bones. Pseudomonas aeruginosa account for 95% of cases, making fungal NOE unusual. Complications secondary to NOE include cranial neuropathies, meningitis and dural sinus thrombophlebitis. Case-study A 67-year-old man with stage-5 chronic kidney disease presented with left otalgia and otorrhea. He was treated with antipseudomonal topical antibiotics and microsuction for months as an outpatient. Aspergillus flavus was grown on an initial swab, but subsequent cultures were negative. Computerised Tomography scans revealed inflammatory changes in the left masticator space with mastoid bone involvement suggestive of left NOE. He received three months of intravenous anti-pseudomonal antibiotics, microsuction and topical aminoglycosides. Despite interventions symptoms persisted and magnetic resonance imaging scanning revealed disease progression into the left TMJ, prompting maxillofacial surgical opinion. Following washout of the TMJ, a tissue biopsy was positive for DNA on pan-fungal PCR, and the sequence identified as Aspergillus flavus group. The patient was successfully treated with oral posoconazole and topical amphotericin and discharged home. Conclusions Fungal NOE remains poorly treated as there is limited guidance on antifungal choice and duration of treatment. It should always be considered, particularly in immunocompromised patients with intractable cases of NOE

Comparative Toxigenicity and Associated Mutagenicity of Aspergillus fumigatus and Aspergillus flavus Group Isolates Collected from the Agricultural Environment

The mutagenic patterns of A. flavus, A. parasiticus and A. fumigatus extracts were evaluated. These strains of toxigenic Aspergillus were collected from the agricultural environment. The Ames test was performed on Salmonella typhimurium strains TA98, TA100 and TA102, without and with S9mix (exogenous metabolic activation system). These data were compared with the mutagenicity of the corresponding pure mycotoxins tested alone or in reconstituted mixtures with equivalent concentrations, in order to investigate the potential interactions between these molecules and/or other natural metabolites. At least 3 mechanisms are involved in the mutagenic response of these aflatoxins: firstly, the formation of AFB1-8,9-epoxide upon addition of S9mix, secondly the likely formation of oxidative damage as indicated by significant responses in TA102, and thirdly, a direct mutagenicity observed for higher doses of some extracts or associated mycotoxins, which does not therefore involve exogenously activated intermediates. Besides the identified mycotoxins (AFB1, AFB2 and AFM1), additional “natural” compounds contribute to the global mutagenicity of the extracts. On the other hand, AFB2 and AFM1 modulate negatively the mutagenicity of AFB1 when mixed in binary or tertiary mixtures. Thus, the evaluation of the mutagenicity of “natural” mixtures is an integrated parameter that better reflects the potential impact of exposure to toxigenic Aspergilli.

Application of PCR in the Detection of Aflatoxinogenic and Non-aflatoxinogenic Strains of Aspergillus Flavus Group of Cattle Feed Isolated in Iran

<p class="1Body">Aflatoxins are among the most important Mycotoxins that are mainly produced by various <em>Aspergillus </em>species, specially <em>Aspergillus flavus</em> and <em>Aspergillus parasiticus</em>. Aflatoxins are carcinogenetic and immunosuppressive, so that can lead to acute liver damage, cirrhosis of the liver and hepatocarcinoma induction. Consuming the feed contaminated by <em>Aspergillus</em> puts humans and animals under the danger of Aflatoxins that are considered as an important threats for human and animal health. The purpose of the present study was to make distinction between Aflatoxinogenetic and non-Aflatoxinogenetic strains and <em>Aspergillus Flavus</em> using PCR and TLC and the expression of five Aflatoxin biosynthesis genes including <em>aflD (nor-1)</em>, <em>aflP( omtA)</em>, <em>aflO (omtB)</em>, <em>aflQ(ordA)</em>, <em>aflR</em> in 40 strains was investigated using PCR. In this study, a number of 40 <em>Aspergillus flavus</em> strains from 67 species of cattle feed from 21 industrial warehouses of various areas of Tehran and Alborz were used. After isolation and culture in exclusive environment of yeast extract of sucrose agar, the isolated <em>Aspergillus</em> strains were investigated by microscopic and macroscopic methods. In order to make distinction between Aflatoxinogenetic and non-Aflatoxinogenetic strains, PCR method and TLC techniques were used. The results showed that only 7 strains (1, 3, 5, 14, 22, 34, and 38) were Aflatoxin-producers fungi and the rest 33 samples were non-Afatoxin-producers fungi. Since <em>Aspergillus flavus</em> is the main contaminator of cattle feed, there is a need to develop a simple, rapid and sensitive method to identify Aflatoxigenetic fungi, particularly between Aflatoxinogenetic and non-Aflatoxinogenetic strains of AF.</p>

Polymerase Chain Reaction–Mediated Characterization of Molds Belonging to the Aspergillus flavus Group and Detection of Aspergillus parasiticus in Peanut Kernels by a Multiplex Polymerase Chain Reaction

The Aspergillus flavus group covers species of A. flavus and Aspergillus parasiticus as aflatoxin producers and Aspergillus oryzae and Aspergillus sojae as koji molds. Genetic similarity among these species is high, and aflatoxin production of a culture may be affected by cultivation conditions and substrate composition. Therefore, a polymerase chain reaction (PCR)-mediated method of detecting the aflatoxin-synthesizing genes to indicate the degree of risk a genotype has of being a phenotypic producer was demonstrated. In this study, 19 strains of the A. flavus group, including A. flavus, A. parasiticus, A. oryzae, A. sojae, and one Aspergillus niger, were subjected to PCR testing in an attempt to detect four genes, encoding for norsolorinic acid reductase (nor-1), versicolorin A dehydrogenase (ver-1), sterigmatocystin O-methyltransferase (omt-1), and a regulatory protein (apa-2), involved in aflatoxin biosynthesis. Concurrently, the strains were cultivated in yeast-malt (YM) broth for aflatoxin detection. Fifteen strains were shown to possess the four target DNA fragments. With regard to aflatoxi-genicity, all seven aflatoxigenic strains possessed the four DNA fragments, and five strains bearing less than the four DNA fragments did not produce aflatoxin. When peanut kernels were artificially contaminated with A. parasiticus and A. niger for 7 days, the contaminant DNA was extractable from a piece of cotyledon (ca. 100 mg), and when subjected to multiplex PCR testing using the four pairs of primers coding for the above genes, they were successfully detected. The target DNA fragments were detected in the kernels infected with A. parasiticus, and none was detected in the sound (uninoculated) kernels or in the kernels infected with A. niger.

Aspergillus Colonization and Aflatoxin Contamination in Peanut Genotypes with Resistance to Other Fungal Pathogens

Indirect selection tools would be valuable in the development of peanut (Arachis hypogaea) cultivars with resistance to aflatoxin contamination. The objective of this study was to determine whether resistance to other fungi could be used as an indirect selection tool for resistance to colonization of peanut by Aspergillus flavus group fungi or aflatoxin contamination. Nine peanut genotypes with resistance to late leaf spot (Cercosporidium personatum) or white mold (Sclerotium rolfsii) were evaluated for 2 years at Tifton, GA, and Yuma, AZ. Plots were subjected to late-season heat and drought stress. None of the genotypes exhibited less colonization of shells or kernels by A. flavus group fungi than cv. Florunner when tested in Georgia or Arizona. None of the genotypes showed a reduced level of aflatoxin contamination in comparison to Florunner at either location. These results indicate that the mechanisms of resistance to other fungi operating in these genotypes are not effective in providing resistance to colonization by A. flavus group fungi or reducing aflatoxin contamination. Therefore, resistance to these fungi cannot be used as an indirect selection tool for resistance to aflatoxin contamination.