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Biomedical subjects

R Russell M Paterson

Publications and source records attributed to R Russell M Paterson.

8 recordsLinked to original sources
PubMed2006

Fungi and fungal toxins as weapons.

Recent aggressive attacks on innocent citizens have resulted in governments increasing security. However, there is a good case for prevention rather than reaction. Bioweapons, mycotoxins, fungal biocontrol agents (FBCA), and even pharmaceuticals contain, or are, toxins and need to be considered in the context of the new paradigm. Is it desirable to discuss such issues? None of the fungi are (a) as toxic as botulinum toxin from Clostridium botulinum, and (b) as dangerous as nuclear weapons. One toxin may be defined as a pharmaceutical and vice versa simply by a small change in concentration or a moiety. Mycotoxins are defined as naturally occurring toxic compounds obtained from fungi. They are the biggest chronic health risk when incorporated into the diet. The current list of fungal toxins as biochemical weapons is small, although awareness is growing of the threats they may pose. T-2 toxin is perhaps the biggest concern. A clear distinction is required between the biological (fungus) and chemical (toxin) aspects of the issue. There is an obvious requirement to be able to trace these fungi and compounds in the environment and to know when concentrations are abnormal. Many FBCA, produce toxins. This paper indicates how to treat mycotoxicosis and decontaminate mycotoxins. There is considerable confusion and inconsistency surrounding this topic which requires assessment in an impartial and scientific manner.

Biological Warfare↗
PubMed2006

Ganoderma - a therapeutic fungal biofactory.

Ganoderma is a basidiomycete white rot fungus which has been used for medicinal purposes for centuries particularly in China, Japan and Korea. A great deal of work has been carried out on Ganoderma lucidum. The common names for preparations include Lingzhi, Munnertake, Sachitake, Reishi and Youngzhi. This review collates the publications detailing activities and compounds by representative species whilst considering the most valid claims of effectiveness. The biological activities reported of preparations from Ganoderma are remarkable and given most emphasis herein as distinct from structure/activity information. The metabolites consist of mainly polysaccharides and terpenoids. Many are activities against the major diseases of our time and so the present review is of great importance. The list of effects is huge ranging from anti-cancer to relieving blockages of the bladder. However, the reports have not all been tested scientifically with the convincing evidence is reserved for assays of pure compounds. It is a prime example of an ancient remedy being of great relevance to the modern era. There does appear to be an assumption that the therapeutic effects attributed to the fungus have been proven. The next step is to produce some effective medicines which may be hampered by problems of mass production.

Animals↗
PubMed2006

Survey and significance of filamentous fungi from tap water.

Fungi in drinking water are involved in the production of tastes and odours in water. Health problems are possible, originating from mycotoxins, animal pathogens and allergies. This report concerns the surveillance of mesophilic fungi in tap water and assessment of their potential for causing problems. The methods for the determination of the filamentous fungi (ff) were filtering, swabbing and baiting. Tap water, half-strength corn meal, neopeptone-glucose rose Bengal aureomycin (NGRBA) and oomycete selective agars for the enumeration of colony forming units (cfu) were used. Samples were taken consecutively over 16 months. Filtration and NGRBA gave the highest ff counts. A total of 340 taxa were isolated. There appeared to be a negative correlation between bacterial and yeast (b/y) and ff counts. Highest counts were found in winter months for ff and in the warmer months for b/y. Penicillium (40.6%) and Acremonium (38.8%) were the most frequently isolated ff. There was a difference in the pattern of isolation of the key taxa with season: penicillia predominated in early summer and Acremonium in winter. P. expansum was isolated in high numbers in May 2004. This species is associated with the production of the mycotoxin patulin and the odour secondary metabolite geosmin. P. brevicompactum was detected throughout the sampling period and is known to produce the immunosuppressive drug mycophenolic acid. Acremonium is associated with ocentol production which is responsible for bad tastes and flavours. The remaining taxa were Phialophora sp. (4.1%), Cladosporium sp. (3.5%), Rhizopus stolonifer (2.9%), Chaetomium sp. (0.6%), Alternaria sp. (0.3%), Aspergillus sp. (0.3%), mycelia sterilia (2.6%) and unidentified (6.2%). It is emphasised that few Aspergillus and no Fusarium strains were isolated. Rhizopus stolonifer was obtained. However, none of the fungi isolated at mesophilic temperature used could be described as being involved with pathogenicity per se.

Colony Count, Microbial↗
PubMed2006

A practical approach for identifications based on mycotoxin characters of Penicillium.

The taxonomy of the penicillia is unstable particularly in the important antibiotic and mycotoxin-producing subgenus Penicillium. There are difficulties relating identifications to mycotoxin production. Also, the validity of dual nomenclature for pleomorphic fungi is under discussion increasingly. Patulin is an important mycotoxin produced by various fungi and has strict limits in the European Union. The mycotoxin and/or the isoepoxydon dehydrogenase (IDH) gene of the metabolic pathway have been assessed in 318 strains predominately of subgenus Penicillium. These data were used to classify the isolates. Subgenus Penicillium contained most of the IDH and patulin positives. The species and varieties in subgenus Penicillium which were associated with patulin detection can be reduced to one name, viz. Penicillium Pen p+ (p = patulin). This has been extended to other mycotoxin producing penicillia to indicate the scope of the scheme. The classification will lead to the number of taxa being reduced, while avoiding species names and hence dual nomenclature. Culture independent analysis of environmental samples is mentioned. The scheme could be used with advantage for other fungi.

DNA, Fungal↗
PubMed2006

FISH and Calcofluor staining techniques to detect in situ filamentous fungal biofilms in water.

Filamentous fungi are a ubiquitous and diverse group of eukaryotic organisms and may contribute, along with bacteria, yeasts, protozoa and viruses, to the formation of biofilms in water distribution systems. However, fungal involvement in biofilms has not been demonstrated unambiguously. Furthermore, these fungi may be responsible for the production of tastes, odours and mycotoxins in drinking water making their early detection important. The detection of fme these problems a combination of two fluorescent techniques for direct detection was tested: (a) Fluorescence In Situ Hybridization (FISH) employing the universal rRNA probe EUK516, labelled with the red Cy3, followed by (b) staining with Calcofluor White MR2 fluorescent dye which stains fungal cell walls blue. Pure cultures of Penicillium brevicompactum were used to establish the methods followed by separate experiments with real water biofilm samples in PVC-C and cast iron coupons. FISH demonstrated eukaryotic microrganisms after approximately 5 h while the calcofluor method revealed chitinous filamentous structures in less than one hour. When the two methods were combined, additional resolution was obtained from the images of filamentous walls (blue) with intact protoplasm (red). In conclusion, FISH and Calcofluor staining provide rapid, direct and unambiguous information on the involvement of ff in biofilms which form in water.

Benzenesulfonates↗
PubMed2004

Solutions to Penicillium taxonomy crucial to mycotoxin research and health.

The stability of taxonomy within Penicillium is reviewed with respect to mycotoxin production. Identification remains difficult despite the availability of modern methods. Proficiency testing is rare and conventional identifications do not inform reliably as to whether mycotoxins were detected/produced. A solution which consists of identifying a Penicillium strain as terverticillate and then undertaking mycotoxin analysis is described.

Health↗
PubMed2004

The isoepoxydon dehydrogenase gene of patulin biosynthesis in cultures and secondary metabolites as candidate PCR inhibitors.

The European Union (EU) has introduced statutory limits for patulin in fruit products. Species definitions need to be unambiguous for this capability, especially to determine 'weak spots' in food, drink and feed production. Fungi were analysed for the isoepoxydon dehydrogenase (IDH) gene of the patulin metabolic pathway to indicate potential patulin production. In several cases inhibition of PCR product formation was indicated. Dilution as a means of overcoming PCR inhibition and to determine optimal concentrations was assessed and the ramifications for nucleic acid analysis in general are highlighted. The inhibitors may be secondary metabolites. However, inhibition was not involved obviously for Penicillium brevicompactum. The gene was detected frequently from Aspergillus section Clavati and Penicillium subgenus Penicillium species. Some strains within certain species were negative for the gene. Detection of the gene product in Byssochlamys is reported.

Culture Media↗