Cunninghamella Mold
Species
The
U.S. Government's Occupational
Safety and Health Administration [OSHA]
lists
the following as the health effects of Cunninghamella mold:
Allergen,
Irritant, Hypersensitivity pneumonitis, Dermatitis. |
|
Taxonomic Classification
|
|
Description and Natural Habitats
Cunninghamella
is a filamentous fungus found in soil and plant material, particularly at
Mediterranean and subtropical zones. It has also been recovered from
animal material, cheese, and Brazil nuts. In addition to being a common
contaminant, Cunninghamella is an opportunistic fungus that may
cause infections in immunocompromised hosts. Species
The genus Cunninghamella
currently contains seven species. While Cunninghamella bertholletiae,
Cunninghamella elegans, and Cunninghamella echinulata are
the most common species, Cunninghamella bertholletiae is the only
known human and animal pathogen. The nomenclature for Cunninghamella
species is rather complicated. While some authorities accept Cunninghamella
bertholletiae, Cunninghamella elegans, and Cunninghamella
echinulata as separate species, others tend to use the names Cunninghamella
bertholletiae and Cunninghamella echinulata as the synonyms of Cunninghamella
elegans. However, the latter approach is not very convincing, since
the purely gray color of its colonies and its inability to grow at 45°C
clearly differentiates Cunninghamella elegans from Cunninghamella
bertholletiae. Thus, we prefer to follow the previous approach and
accept the existence of the three species separately in the genus Cunninghamella. Pathogenicity and Clinical SignificanceCunninghamella spp. are among the causative agents of zygomycosis. Although the term mucormycosis has often been used for this syndrome, zygomycosis is now the preferred term for this angio-invasive disease. Trauma, diabetes mellitus, immunosuppression due to various reasons (hematological malignancies, organ transplantation, AIDS), and desferoxamine therapy are the major risk factors for development of zygomycosis. Among the other genera belonging to the class zygomycetes, Cunninghamella is particularly sensitive to desferoxamine therapy. Lastly and importantly, Cunninghamella infections have been reported in a number of cases receiving antifungal prophylaxis with itraconazole.
Cunninghamella
bertholletiae may cause rhinocerebral, pulmonary, cutaneoarticular,
and disseminated forms of zygomycosis. The infection usually starts after
inhalation of the spores or inoculation of the fungus following the
primary breakdown of the skin integrity due to a trauma. Macroscopic FeaturesCunninghamella colonies are rapidly growing (mature in 4 days), cottony, and white to tannish-gray in color. The reverse is pale. Cunninghamella elegans produces purely gray colonies. While Cunninghamella bertholletiae may grow at temperatures as high as 45°C, Cunninghamella elegans fails to grow at this temperature. Microscopic Features
Nonseptate
or sparsely septate broad hyphae, sporangiophores, terminal vesicles,
sporangioles (sporangiola; sing. sporangiolum), and sporangiospores are
visualized. Sporangiophores are erect and form short lateral branches each
of which terminates in a swollen vesicle. The vesicle (30-65 µm in
diameter) has spine-like denticles on its surface. Sporangioles (5-8 x
6-14 µm) are round to oval in shape, one-spored, and are formed on these
denticles. Sporangiospores are one-celled, solitary, and globose to ovoid
in shape. The walls of the spores often have needle-like crystals.
Zygospores have tuberculate projections and may form only after
appropriate mating studies. Laboratory Precautions
No special
precautions other than general laboratory precautions are required. Susceptibility
Very few data
are available and there is as yet no standard method for in vitro
susceptibility testing of Cunninghamella species. In an in vitro
study where two Cunninghamella echinulata strains were tested, the
rank of MICs was found to be voriconazole, ketoconazole, amphotericin
B, itraconazole. On the other hand, amphotericin B,
ketoconazole, and itraconazole generated considerably high MICs for some
isolates of Cunninghamella spp. in other workers' hands. Liposomal
amphotericin B has been used for treatment of Cunninghamella
infections. However, prognosis is often poor.
|
|
|
The mycological information gathered and organized in this extensive
research on different Pathogenic Molds was sourced out from the
list of informative websites below: |
|
|
BROWSE THIS WEBSITE:
|
|
|
|
