Biomedical subjects

Bruce B Jarvis

Publications and source records attributed to Bruce B Jarvis.

8 recordsLinked to original sources

PubMed2006

Four psychrotolerant species with high chemical diversity consistently producing cycloaspeptide A, Penicillium jamesonlandense sp. nov., Penicillium ribium sp. nov., Penicillium soppii and Penicillium lanosum.

Penicillium jamesonlandense is a novel species from Greenland that grows exceptionally slowly at 25 degrees C and has an optimum temperature for growth of 17-18 degrees C. The novel species is more psychrotolerant than any other Penicillium species described to date. Isolates of this novel species produce a range of secondary metabolites with a high chemical diversity, represented by kojic acid, penicillic acid, griseofulvin, pseurotin, chrysogine, tryptoquivalins and cycloaspeptide. Penicillium ribium, another novel psychrotolerant species from the Rocky Mountains, Wyoming, USA, produces asperfuran, kojic acid and cycloaspeptide. Originally reported from an unidentified Aspergillus species isolated from Nepal, cycloaspeptide A is reported here for the first time from the two novel Penicillium species and two known psychrotolerant species with high chemical diversity, Penicillium soppii and Penicillium lanosum. All species, except P. ribium, produce a combination of cycloaspeptide and griseofulvin. However, P. ribium (3/5 strains) produced the precursor to griseofulvin, norlichexanthone. The type strain of Penicillium jamesonlandense sp. nov. is DAOM 234087(T) (=IBT 21984(T) = IBT 24411(T) = CBS 102888(T)) and the type strain of Penicillium ribium sp. nov. is DAOM 234091(T) (=IBT 16537(T) = IBT 24431(T)).

Genetic Variation↗

PubMed2004

Mycotoxins as harmful indoor air contaminants.

Fungal metabolites (mycotoxins) that pose a health hazard to humans and animals have long been known to be associated with mold-contaminated food and feed. In recent times, concerns have been raised about exposures to mycotoxin-producing fungi in indoor environments, e.g., damp homes and buildings. The principal mycotoxins that contaminate food and feed (alfatoxins, fumonisins, ochratoxin A, deoxynivalenol, zearalenone) are rarely if ever found in indoor environments, but their toxicological properties provide an insight into the difficulties of assessing the health effects of related mycotoxins produced by indoor molds. Although the Penicillium and Aspergillus genera of fungi are major contaminants of both food and feed products and damp buildings, the particular species and hence the array of mycotoxins are quite different in these environments. The mycotoxins of these indoor species and less common mycotoxins from Stachybotrys and Chaetomium fungi are discussed in terms of their health effects and the need for relevant biomarkers and long-term chronic exposure studies.

Air Microbiology↗

PubMed2003

Stachybotrys chartarum: a fungus for our time.

Stachybotrys chartarum, a fungus found in damp buildings and sometimes ascribed a role in building-related illnesses, produces a variety of secondary metabolites including trichothecenes, triprenylated phenolics, and a new class of diterpenoids called atranones. A related fungus, Memnoniella echinata also produces trichothecenes and the triprenylated phenolics. Herein the production of these compounds from cultures of the above are reviewed.

Air Pollution, Indoor↗

PubMed2003

Stachybotrys chartarum: cause of human disease or media darling?

This is a review of the literature of associations of the saprotrophic fungus Stachybotrys chartarum sensu lato with human and animal illnesses. This fungus grows on very wet cellulose-based building materials. S. chartarum has been the subject of considerable media attention because of temporal associations of exposure with unexpected and dramatic outcomes such as infant pulmonary hemosiderosis and neurocognitive damage. It is generally accepted that living or working in mouldy environments is associated with building related asthma, exacerbating asthma in mould-sensitive asthmatics and increased rates of upper respiratory disease. However, such relationships are with building-associated moulds, comprising many species that colonize wet or damp building materials, and are not specific to S. chartarum. There is limited evidence that severe lung damage can occur from building exposure to S. chartarum but possibly only under conditions of exposure that approach those associated with handling contaminated straw. There is no positive evidence in the literature to account for putative neurological damage resulting from exposure to this mould.

Allergens↗

PubMed2003

Analysis for mycotoxins: the chemist's perspective.

Mycotoxins are fungal metabolites that pose a health risk to exposed animals and humans. In recent years, concern has mounted regarding human exposure to mycotoxins via inhalation of mold spores produced in damp buildings and homes. Although mycotoxins can be detected in such buildings, reliable means for measuring an occupant's level of exposure to most mycotoxins are lacking. The author briefly reviews the chemical methods currently available for mycotoxin analysis, outlining accepted practices and discussing the limitations of these measurements.

Air Pollution, Indoor↗

PubMed2002

Chemistry and toxicology of molds isolated from water-damaged buildings.

There is increasing evidence of health risks associated with damp buildings and homes in which high levels of microbes are found. Although concerns have traditionally centered on microbial pathogens and allergenic effects, recent work has suggested that fungi pose the more serious risk. Evidence is accumulating that certain toxigenic molds are particularly a risk for human health through exposure, via inhalation, of fungal spores. Many of these fungi produce toxins (mycotoxins) some of which have been shown to cause animal and human intoxications, usually in an agricultural setting. The fungus, Stachybotrys chartarum (S. atra) is considered to be one of the more serious threats to people living and working in water-damaged buildings. This mold has a long history of being responsible for animal toxicoses, and in recent years, being associated with infant pulmonary hemosiderosis (bleeding in the lungs) of infants exposed to spores of this fungus in their homes. S. atra produces a variety of potent toxins and immunosuppressant agents, including a novel class of diterpenes (atranones) of unusual structure. More research is needed to determine the impact to health resulting from inhalation of toxigenic mold spores.

Animals↗

PubMed2002

A Stachybotrys chartarum isolate from soybean.

As part of our effort to investigate fungi associated with soybean roots, Stachybotrys chartarum was isolated from soybean root lesions. Since this fungus has not been reported to cause a disease of soybean, the objectives were to identify and characterize this fungus using biological, chemical, and molecular approaches. Fungal morphology was examined using light and environmental scanning electron microscopy. Phialides bearing conidia arose from determinate, macronematous, dark olivaceous conidiophores. The phialides were obovate or ellipsoidal in whorls. Conidia were unicellular, round or ellipsoidal, 5-13 x 4-7 microm, initially hyaline with smooth walls then dark brown to black and rough-walled when mature. Radial growth of the fungus on cornmeal, oatmeal and potato dextrose agar was 38, 47, and 33 mm in diam., respectively, after 10 days at 25 degrees C. Pathogenicity was performed using sorghum grain colonized by S. chartarum placed below sown soybean seeds in a soil: sand (1:1) steam-pasteurized mix. Three weeks after inoculation, root lesions ranged from 7 to 25 mm long. The fungus was reisolated from soybean root lesions and was reidentified as S. chartarum. Biochemical analysis indicated that this soybean isolate produced satratoxins G and H along with roridin L-2, as well as the spircyclic lactones and lactams in rice culture. PCR using a S. chartarum-specific primer StacR3 and IT51 amplified a 198-bp DNA fragment from the total genomic DNA. The DNA sequence of the ITS region was 100% identical to the S. chartarum strain ATCC 9182, one nucleotide mismatch with S. chartarum strain UAMH 7900, and differed from all published sequences of 12 other species of Stachybotrys and 2 species of Memnoniella in GenBank with genetic divergence ranging from 5.26 to 9.98%. This molecular evidence further supports the identification of S. chartarum isolated from soybean root lesions.

Chromatography, High Pressure Liquid↗

PubMed2002

Metabolite profiles of Stachybotrys isolates from water-damaged buildings and their induction of inflammatory mediators and cytotoxicity in macrophages.

The metabolite profiles of 20 Stachybotrys spp. isolates from Finnish water-damaged buildings were compared with their biological activities. Effects of purified compounds on cytotoxicity and production of inflammatory mediators such as nitric oxide, IL-6 and TNFalpha in murine RAW264.7 macrophage cells were studied. The 11 isolates belonging to the satratoxin-producing chemotype were highly cytotoxic to the macrophages. The isolates inducing inflammatory mediators all belonged to the atranone-producing chemotype, but pure atranones B, and D did not elicit a response in the bioassay. Altogether, cytotoxicity of Stachybotrys sp. isolates appear to be related to satratoxin production whereas the specific component inducing inflammatory responses in atranone-producing isolates remains obscure.

Air Microbiology↗