m208 Chaetomium globosum

Allergens within Molds and other Microorganisms

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  • Latin name: Chaetomium globosum
  • Family: Chaetomiaceae
  • Common names: Yeast
Mold
A mold, which may result in allergy symptoms in sensitised individuals.

Allergen Exposure

Geographical distribution
Chaetomium is a dematiaceous filamentous fungus belonging to a large genus of saprobic ascomycetes found in soil, air, plant debris, dung, straw, paper, bird feathers, and seeds (1). More than 100 species have been described, the most common ones being C. atrobrunneum, C. funicola, C. globosum, and C. strumarium. C. globosum is the most frequently encountered species (2). Several are very common in indoor environments (C. elatum, C. globosum, C. murorum) (3). Most grow best at between 25 and 35°C (3). Most species cause degradation of cellulose-rich substrates, such as components in soil, straw or wood. The fungus requires cellulose-rich medium for sporulation, and growth of Chaetomium globosum is often stimulated in the presence of Aspergillus fumigatus, which excretes such compounds as sugar phosphates and phospho-glyceric acid (2).
 
Chaetomium colonies are rapidly growing. They have a cottony appearance and are initially white in colour, the mature colonies becoming grey to olive, and later sometimes tan to red or brown to black. Microscopically, C. globosum has distinctive small brown "lemon" or "football-shaped" ascospores. The spores, formed inside the fruiting bodies, are forced out an opening and spread by wind, insects, water splash.
 
One species, C. piluliferum, produces an extensive Botryotrichum asexual state that is often detected growing on building materials (3). Some species are known to produce mycotoxins, including the chaetoglobosin and chaetomin toxins produced by C. globosum. Sterigmatocystin is produced by rare species. Other compounds produced (which may not be mycotoxins in the strict sense) include a variety of mutagens (4).
 
Some species can in rare cases be agents of opportunistic invasive disease (5, 6). C. globosum is among these, being the most common species isolated in at least 9 clinical cases of infection (1).
 
A 73-year-old woman, with long-standing pain and secretion from her left maxillary sinus, was found to have an infection of A. fumigatus and Chaetomium spp (2).
 
Some species are thermophilic and neurotropic in nature (7, 8), in particular C. atrobrunneum, C. strumarium and C. perlucidum (5). The ability of these species to grow at elevated temperatures may contribute to their neurotropic potential. Although Chaetomium species are rarely implicated in human disease, their spectrum of mycoses includes onychomycosis (9), sinusitis (2), empyema (10), pneumonia (11, 12), and fatal disseminated cerebral disease in immunocompromised hosts (13-15) and intravenous drug users (5). The majority of reports have involved patients with hematologic malignancies and/or immunosuppression secondary to bone marrow or solid organ transplantation (16-17). Chaetomium spp. are among the fungi causing infections referred to, as a group, as phaeohyphomycosis. Fatal deep mycoses due to Chaetomium atrobrunneum have been reported in an immunocompromised host. Brain abscess, peritonitis and cutaneous lesions may also develop due to Chaetomium spp. (8, 9, 18). 
 
Environment
Chaetomium species are commonly found on paper products, wood, and natural fiber textiles (such as jute-backed carpets, canvas, etc.). They are also common in natural environments on a variety of plant material, and are frequently isolated from natural substrata and seen at low levels in outside air.
 
C. globosum has been reported to be one of the top 12 species of microfungi isolated from North American wallboard (19). C. globosum has also been found in kitchens and bathrooms, and in wallpaper, mattresses and carpets (20). Water leakage through roofs, rising damp, and defective plumbing installations have been reported to be the main sources for water damage with subsequent mold growth. Materials most susceptible to mold attacks were water-damaged, aged organic cellulose-containing materials such as wood, jute, wallpaper, and cardboard, in which the molds most frequently encountered were Penicillium (68%), Aspergillus (56%), Chaetomium (22%) (21).
 
Chaetomium spp. have been found in the atmosphere of Karachi City (22) and even in the desert environment of Saudi Arabia, where these fungi were found inhabiting household environments including bedrooms, drawing rooms, living rooms, kitchens and bathrooms (23). They have also been isolated from the dust of air-conditioners (24).
 
Occupational exposure, which could result in allergy, may occur from handling Black pepper, White pepper and Brazil nuts (25), and Cashew kernels (26, 27). These fungi has also been shown to be present in Tobacco samples (28).
 
Chaetomium spp., in particular C. thermophilum, have been shown to be present in combine harvester Wheat and Sorghum dust and in the atmosphere of their hay sites (29). This fungus may also be present in Anise and Fennel seeds, as reported in a study from Egypt (30).
 
Unexpected exposure
See under Geographical distribution.
 
Allergens
No allergens have yet been characterised.

Potential Cross-reactivity

The allergenic potential of this species or other species in the genus has not been well studied. However, because the types of clinical symptoms caused by the various species differ considerably, a common allergen, although possible, cannot be deduced, and therefore neither can cross-reactivity between species. Whether all members of the genus may result in allergic reactions can also not be deduced.

Clinical Experience

IgE-mediated reactions
Hypersensitivity reactions to the Chaetomium genus, especially C. globosum, in particular IgE-mediated reactions, have not been well studied. It appears that organisms in the genus rarely induce IgE-mediated reactions in sensitised individuals, but whether this impression is a result of limited research or the actual low allergenic potential of the fungi is not clear. Whether few or many or all members of the genus can result in allergic reactions cannot be deduced; a conservative view is probably reasonable, as the types of non-IgE clinical reactions vary considerably among the various species. This is in spite of Chaetomium species producing airborne spores that are often found in spore counts.
 
In a study in Sao Paulo, Brazil, evaluating sensitisation in 201 patients with asthma and/or allergic rhinitis to 42 airborne fungi using skin specific IgE tests, 15 were shown to be sensitised to Chaetomium (31).
 
Other reactions
See under Geographical distribution for mycotoxin production and other toxicity, and for infections.

Compiled by Dr Harris Steinman, harris@zingsolutions.com.

References:

    1. Guarro, J., L. Soler, and M. G. Rinaldi. Pathogenicity and antifungal susceptibility of Chaetomium species. Eur. J. Clin. Microbiol. Infect. Dis. 1995;14:613-618
    2. Aru A, Munk-Nielsen L, Federspiel BH. The soil fungus Chaetomium in the human paranasal sinuses. Eur Arch Otorhinolaryngol 1997;254(7):350-2.
    3. von Arx, J. A., J. Guarro, and M. J. Figueras.. The ascomycete genus Chaetomium. Beih. Nova Hedwigia 1986;84:1-162
    4. Jarvis BB, Miller JD. Mycotoxins as harmful indoor air contaminants. Appl Microbiol Biotechnol 2005;66(4):367-72
    5. Abbott, S.P., L. Sigler, R. McAleer, D.A. McGough, M.G. Rinaldi and G. Mizell. 1996. Fatal cerebral mycoses caused by the ascomycete Chaetomium strumarium. J Clin Micro 1996;33:2692-2698
    6. Sigler, L. and P.E. Verweij. 2003. Aspergillus, Fusarium, and other opportunistic moniliaceous fungi. In: Manual of clinical microbiology 8th Ed. (Murray et al., Eds.). American Society for Microbiology, Washington. Pp. 1726-1760.
    7. Larone, D. H. 1995. Medically Important Fungi - A Guide to Identification, 3rd ed. ASM Press, Washington, D.C.
    8. Sutton, D. A., A. W. Fothergill, and M. G. Rinaldi (ed.). 1998. Guide to Clinically Significant Fungi, 1st ed. Williams & Wilkins, Baltimore.
    9. Stiller, M. J., S. Rosenthal, R. C. Summerbell, J. Pollack, and A. Chan. Onychomycosis of the toenails caused by Chaetomium globosum. J. Am. Acad. Dermatol. 1992;26:775-776
    10. Lesire, V., E. Hazouard, P. F. Dequin, M. Delain, M. Therizol-Ferly, and A. Legras. Possible role of Chaetomium globosum in infection after autologous bone marrow transplantation. Intensive Care Med. 1999;25:124-125
    11. Hoppin, E. C., E. L. McCoy, and M. G. Rinaldi. Opportunistic mycotic infection caused by Chaetomium in a patient with acute leukemia. Cancer 1983;52:555-556.
    12. Yeghen, T., L. Fenelon, C. K. Campbell, et al. Chaetomium pneumonia in a patient with acute myeloid leukaemia. J. Clin. Pathol. 1996;49:184-186
    13. Anandi, V., T. J. John, A. Walter, et al. Cerebral phaeohyphomycosis caused by Chaetomium globosum in a renal transplant recipient. J. Clin. Microbiol. 1989;27:2226-2229
    14. Guppy, K. H., C. Thomas, K. Thomas, and D. Anderson. Cerebral fungal infections in the immunocompromised host: a literature review and a new pathogen—Chaetomium atrobrunneum: case report. Neurosurgery 1998;43:1463-1469
    15. Thomas, C., D. Mileusnic, R. B. Carey, M. Kampert, and D. Anderson. Fatal Chaetomium cerebritis in a bone marrow transplant patient. Hum. Pathol. 1999;30:874-879
    16. Teixeira AB, Trabasso P, Moretti-Branchini ML, Aoki FH, Vigorito AC, Miyaji M, Mikami Y, Takada M, Schreiber AZ. Phaeohyphomycosis caused by Chaetomium globosum in an allogeneic bone marrow transplant recipient. Mycopathologia. 2003;156(4):309-12.
    17. Tomsikova A. Causative agents of nosocomial mycoses. Folia Microbiol (Praha). 2002;47(2):105-12
    18. Friedman, A. H. 1998. Cerebral fungal infections in the immunocompromised host: A literature review and a new pathogen - Chaetomium atrobrunneum: Case report - Comment. Neurosurgery. 43:1469.
    19. Miller, J.D., Laflamme, A.M., Sobol, Y., Lafontaine, P., and Greenhalgh, R. Fungi and fungal products in some Canadian houses. International Biodeterioration 1988; 24:103-120.
    20. Summerbell, R. Health effect of Stachybotrys, known and inferred. Ontario Ministry of Health, May 1998.
    21. Gravesen S, Nielsen PA, Iversen R, Nielsen KF. (1999). Microfungal Contamination of Damp Buildings--Examples of Risk Constructions and Risk Materials. Environmental Health Perspectives, Supplements Volume 107, Suppl 3:505-8.
    22. Afzal M, Mehdi F.S. Atmospheric Fungi of Karachi City Pakistan J Biol Sciences 2002:5(6):707-709
    23. Bokhary HA, Parvez S. Fungi inhabiting household environments in Riyadh, Saudi Arabia. Mycopathologia. 1995;130(2):79-87
    24. Bagy MM, Gohar YM. Mycoflora of air-conditioners dust from Riyadh, Saudi Arabia. J Basic Microbiol. 1988;28(9-10):571-7.
    25. Freire FC, Kozakiewicz Z, Paterson RR. Mycoflora and mycotoxins in Brazilian black pepper, white pepper and Brazil nuts. Mycopathologia. 2000;149(1):13-9.
    26. Freire FC, Kozakiewicz Z, Paterson RR. Mycoflora and mycotoxins of Brazilian cashew kernels. Mycopathologia. 1999;145(2):95-103.
    27. Pitt JI, Hocking AD, Bhudhasamai K, Miscamble BF, Wheeler KA, Tanboon-Ek P. The normal mycoflora of commodities from Thailand. 1. Nuts and oilseeds. Int J Food Microbiol. 1993;20(4):211-26.
    28. el-Maghraby OM, Abdel-Sater MA. Mycoflora and natural occurrence of mycotoxins in tobacco from cigarettes in Egypt. Zentralbl Mikrobiol. 1993;148(4):253-64.
    29. Abdel-Hafez SI, Moubasher AH, Shoreit AA, Ismail MA. Fungal flora associated with combine harvester wheat and sorghum dusts from Egypt. J Basic Microbiol 1990;30(7):467-79.
    30. Moharram AM, Abdel-Mallek AY, Abdel-Hafez AI. Mycoflora of anise and fennel seeds in Egypt. J Basic Microbiol. 1989;29(7):427-35.
    31. Mohovic J, Gambale W, Croce J. Cutaneous positivity in patients with respiratory allergies to 42 allergenic extracts of airborne fungi isolated in Sao Paulo, Brazil. Allergol Immunopathol (Madr) 1988;16(6):397-402

2006