Isolation and identification of Rhizomucor pusillus from pleural zygomycosis in an immunocompetent patient.

Zygomycosis is usually an invasive mycotic disease caused by fungi in the class Zygomycetes. It often occurs in immunocompromised patients, but sporadic cases without apparent immune impairment have been described. This report presents the first case of pleural zygomycosis caused by Rhizomucor pusillus, an uncommon pathogen of human infection. A 19-year-old man was found to have pleuritis several days after a drainage catheter was implanted to cure a pneumothorax caused by a ruptured bulla. Local pneumonectomy to resect the ruptured bulla and vacuuming of the pleural fluid was performed. Rhizomucor pusillus was cultured from the pleural fluid and irregular broad sparsely septate hyphae, consistent with zygomycetes, were histologically detected in the thickened pleura of the resected bulla. The catheter was suspected of having been contaminated with the fungus, but no evidence could be obtained. His fungal pleuritis subsided without any antifungal medical therapy and his immunocompetence seemed to contribute to limiting the infection.

Fungal infection of mantis shrimp (Oratosquilla oratoria) caused by two anamorphic fungi found in Japan.

Two fungal pathogens of the mantis shrimp (Oratosquilla oratoria) in Yamaguchi and Aichi Prefectures, Japan are described as the new species Plectosporium oratosquillae and Acremonium sp. (a member of the Emericellopsis marine clade). Both fungi infect the gills of the mantis shrimp, which become brown or black due to melanization. The former species is characterized by its slow growth on artificial seawater yeast extract peptone glucose (PYGS) agar, pale yellow to pale orange or grayish yellow colonies, short cylindrical solitary phialides with a wavy tip, and one-celled ellipsoidal conidia. Although lacking the two-celled conidia demonstrated by the type species Plectosporium tabacinum, the taxonomic placement of the new species was confirmed by DNA sequence analysis of the internal transcribed spacer (ITS) region of ribosomal DNA (ITS1, 5.8S rDNA and ITS2). Acremonium sp., the other causal pathogen, differs from P. oratosquillae by its fast growth on PYGS agar, pale orange to salmon-colored colonies, long, slender conidiophores consisting of solitary phialides with tips lacking an undulate outline, and typically cylindrical conidia. Analysis of ITS and beta-tubulin gene sequences placed this fungus within the phylogenetically distinct Emericellopsis (anam. Acremonium) marine clade. Various physiological characteristics of both pathogens were also investigated. This is the first report of a fungal infection found on the mantis shrimp in Japan.

Molecular phylogenetics of strains morphologically identified as Fonsecaea pedrosoi from clinical specimens.

A phylogenetic study based on sequence analysis of the ribosomal internal transcribed spacer (ITS) 1, 5.8S and ITS2 region was performed in 33 strains morphologically identified as Fonsecaea pedrosoi from clinical specimens and living environments, preserved at the Research Center for Pathogenic Fungi and Microbial Toxicoses, Chiba University. The strains of Fonsecaea were divided into two major clades: Group A, representing F. pedrosoi sensu de Hoog et al.; and Group B, representing F. monophora. We identified new lineages: Group B was further clustered into three subgroups, B-1, B-2 and B-3, which were phylogenetically distinct from each other. The subgroups B-1, B-2 and B-3 are thought to be mainly predominant in Africa and Central and South America, Japan and China, and Europe and North America, respectively. Thus, polymorphism in Group B is rather considered to be caused by its geographic parameter. We demonstrate for the first time that all clinical isolates from Japan are monophyletic, belonging to a new lineage of F. monophora.

Two new dioxopiperazine derivatives, arestrictins A and B, isolated from Aspergillus restrictus and Aspergillus penicilloides.

In the course of searching for bioactive substances, two new dioxopiperazine derivatives, arestrictins A (1) and B (2), were isolated along with the known dioxopiperazine, cristatin A (3), and the known peptide, asperglucide (4), from the organic extract of the xerophilic fungi, Aspergillus restrictus and Aspergillus penicilloides. The absolute structures of 1 and 2, except for the configuration of the secondary alcohol in 1, were established by spectroscopic and chemical investigation. The absolute configuration of cristatin A (3) was also determined.

Three new types of indoloditerpenes, emindole PA-PC, from Emericella purpurea. Revision of the structure of emindole PA.

Three new type indoloditerpenes, emindoles PA (1), PB (2), and PC (3), were isolated from the mycelium of Emericella purpurea along with the sesterterpenes variecolol and variecolactone, and the dicyanide derivatives epurpurins A to C. The structures of 1-3 were confirmed by the spectroscopic investigation. The structure of emindoles PA (1) was revised from our preliminary report. Emindoles PA (1), PB (2), and PC (3) are the indoloditerpenes having a new type of carbon skeleton.

Genetic identification and detection of human pathogenic Rhizopus species, a major mucormycosis agent, by multiplex PCR based on internal transcribed spacer region of rRNA gene.

BACKGROUND: Mucormycosis is an invasive opportunistic infection caused by fungi belonging to the order Mucorales. Due to the lack of laboratory tests, the diagnosis of mucormycosis is notoriously difficult. Added with its rapid progression as well as the debilitated state of the patients who contract the disease, mortality is extremely high. OBJECTIVE: The goal of this study was to genetically identify human pathogenic Rhizopus species, a major mucormycosis agent, by the internal transcribed spacer (ITS) region of rRNA gene. METHODS: Primers were designed to identify five Rhizopus species known to cause human disease by multiplex PCR. PCR was done not only with test strains and clinical isolates, but also with clinical samples from cutaneous mucormycosis patients. Sporangiospore morphology was observed by scanning electron microscopy to confirm the correlation of phenotypic and genotypic features. RESULTS: Multiplex PCR identified five Rhizopus species including Rhizopus oryzae, where R. azygosporus could only be distinguished from R. microsporus by certain polymorphisms that were present in its sequence. When this multiplex PCR was applied to clinical samples from three mucormycosis patients (paraffin sections from all and sera from one patient), Rhizopus DNA corresponding to the isolated pathogens were specifically detected. CONCLUSION: While fungal DNA detection from clinical samples is a rigorously studied area, this is the first report to genetically identify and detect Rhizopus species from human mucormycosis specimens. This may expand the possibility of this multiplex PCR system not only to identify isolated fungi, but also as a screening method for visceral mucormycosis.

[Fungal spoilage of foods and its risk assessment].

From the second half of the 1990s, an increased regard has been given to the fungal spoilage of foods as follows: 1) post-harvest diseases and losses of fruits and vegetables, 2) deterioration of low water activity foods by xerophilic fungi, 3) contamination of psychrotolerant or psychrophilic fungi on foodstuffs and processed foods during storage and distribution at low temperature, and 4) spoilage of heat processed foods and soft drinks by heat-resistant fungi. In accordance with an international concern about food safety, mycotoxin contamination of foods has gained much global attention in recent times owing to its potential health hazards. The evaluation of mycotoxin hazards is principally based on the determination of a no-observed effect level (NOEL) in long-term toxicological studies, and the application of a safety factor (usually 100). In addition to hazard assessment, data on the natural occurrence of mycotoxins in various commodities and food intake data are needed to enable exposure assessment. Thus risk assessment of mycotoxins is, in fact, the product of hazard assessment and exposure assessment. In 1997, the FAO/WHO Joint Expert Committee on Food Additives (JECFA) considered estimates of the carcinogenic potency of aflatoxins and the potential risks associated with their intake. Recently the Codex Alimentarius Commission (Codex) has established standards for aflatoxin M1 in milk and for patulin in apple juice. The Codex is an international organization, supported by FAO/WHO, aiming at facilitating world trade and protecting the health of the consumer by developing international standards for food and feeds. Apart from aflatoxins, the JECFA has measured a provisional tolerable daily intake (TDI) for ochratoxin A, patulin, deoxynivalenol, T-2/HT-2 toxins, zearalenone and fumonisins. In 2001, the mycotoxins evaluated or re-evaluated at the JECFA meeting included ochratoxin A, deoxynivalenol, T-2/HT-2 toxins, fumonisins, and aflatoxin M1. In Japan, specific regulations now exist for deoxynivalenol (1.1 ppm) in wheat grains and for patulin (50 ppb) in apple juice and its products.

[Safety of rice grains and mycotoxins - a historical review of yellow rice mycotoxicoses].

Aflatoxins, the most powerful mycotoxins, were brought to the attention fo the people in the early 1960s with the outbreak of the turkey "X" disease in England. However, the history of mycotoxin research in Japan began 100 years ago. In 1891, Sakaki demonstrated that moldy, unpolished rice was fatal to experimental animals, with symptoms indicating paralysis of the central nervous system (Shoshin-kakke). In 1920, Prof. I. Miyake and Dr. Takada first reported that Penicillium commune, which was known as a causal agent of "Mossy diseased rice" was found to be toxic to experimental animals by feeding the moldy rice to rabbits and rats.With such a historical background, taking the idea of "rice, fungus and toxin" as a working hypothesis, Miyake and his co-workers discovered the first sample of yellow rice grains from Taiwanese and domestic rice, from which was isolated a species of Penicillium and later identified it with P. citreonigrum (=P. toxicarium). The fungus produced a highly toxic metabolite, citreoviridin. Unfortunately because this study was published during wartime, it failed to alert the world to the potential or actual dangers of the toxicity of common molds. After World War II, Japanese people suffered for some years from a shortage in domestic rice production and depended on foreign countries to supply rice, which led to the toxicological screening on fungal isolates from polluted rice grains by Dr. Tsunoda and his co-workers. AMong the isolates from imported rice, there were two species of Penicillium which were particularly associated with high toxicity; P. islandicum responsible for brownish discolored rice, and P. citrinum responsible for yellowish rice. P. islandicum produces two hepatotoxic metabolites: luteoskyrin and cyclochlorotine, while a nephrotoxic of P. citrinum is citrinin. These toxicological characters, including the induction of cancer and chemical structures, were studied by Profs. uraguchi, Saito, Shibata, Tatsuno and their co-workers. In this way, toxic disturbances associated with the consumption of rice contaminated with these Peniciliium species occurred and became known under the collective name of the "Yellow rice syndrome". Although no human cases of poisoning were recorded, scientists in the field of mycotoxin research recommended to the Japanese Government that administrative action should be taken to protect the people against any possible hazards from "yellow rice". Consequently, mycological inspections of imported rice were started by the government. The safety control system for domestic rice during post-harvest handling and long-term storage has been progressively established after learning of these problems.

The genus Thecotheus (Pezizales) in Australia: T. urinamans sp. nov. from urea-treated jarrah (Eucalyptus marginata) forest.

The genus Thecotheus is reported in Australia for the first time. A new species, Thecotheus urinamans is described and illustrated and included in a key to all known species of the genus. Critical macro- and micromorphological comparisons are presented to distinguish the new species from several closely related species, particularly the widespread fungus Thecotheus crustaceus. Thecotheus urinamans was growing on rotting, moist, plant litter from an experimental plot treated with urea (ammonia) in the indigenous jarrah (Eucalyptus marginata) forest of Western Australia.