Absidia Corymbifera

Absidia corymbifera

Absidia corymbifera showing a typical pyriform-shaped sporangium with a conical-shaped columella and pronounced apophysis.

Colonies are fast growing, floccose, white at first becoming pale grey with age, and up to 1.5 cm high.

Sporangiophores are hyaline to faintly pigmented, simple or sometimes branched arising solitary from the stolons, in groups of three, or in whorls of up to seven.

Rhizoids are very sparingly produced and may be difficult to find without the aid of a dissecting microscope to examine the colony on the agar surface.

Sporangia are small (10-40 um in diameter) and are typically pyriform in shape with a characteristic conical-shaped columella and pronounced apophysis, often with a short projection at the top.

Sporangiospores vary from subglobose to oblong-ellipsoidal (3.0-7.0 x 2.5-4.5 um), are hyaline to light grey and are smooth-walled.

Temperature: optimum 35-37C; maximum 45C.

The genus Absidia is characterized by a differentiation of the hyphae into arched stolons bearing more or less verticillate sporangiophores at the internode, and rhizoids formed at the point of contact with the substrate (at the node). This feature separates species of Absidia from the genus Rhizopus, where the sporangia arise from the nodes and are therefore found opposite the rhizoids. The sporangia are relatively small, globose, pyriform- or pear-shaped and are supported by a characteristic funnel-shaped apophysis. This distinguishes Absidia from the genera Mucor and Rhizomucor, which have large, globose sporangia without an apophysis. Absidia currently contains 21 mostly soil-borne species. A. corymbifera is the only species of Absidia known to cause disease in man and animals. 2

Clinical significance Absidia corymbifera is a common human pathogen, causing pulmonary, rhinocerebral, disseminated, CNS or cutaneous types of infection. It is also often associated with animal disease, especially mycotic abortion. A. corymbifera has a world-wide distribution mostly in association with soil and decaying plant debris.

Clinical group: Opportunistic mycoses Mycosis: Zygomycosis

Further reading Domsch, K.H., W. Gams, and T.H. Anderson. 1980. Compendium of soil fungi. Volume 1. Academic Press, London, UK.

Kwon-Chung, K.J. and J.E. Bennett. 1992. Medical Mycology. Lea & Febiger, Philadelphia and London.

Fungi Species A-D 3

Acremonium sp.

Acremonium sp. showing long awl-shaped phialides producing cylindrical, one-celled conidia mostly aggregated in slimy heads at the apex of each phialide.

Colonies are usually slow growing, often compact and moist at first, becoming powdery, suede-like or floccose with age, and may be white, grey, pink, rose or orange in color.

Hyphae are fine and hyaline and produce mostly simple awl-shaped erect phialides.

Conidia are usually one-celled (ameroconidia), hyaline or pigmented, globose to cylindrical, and mostly aggregated in slimy heads at the apex of each phialide.

This genus is distinguished from hyaline isolates of Phialophora by the absence or very limited development of a collarette on the phialide and the predominant formation of well differentiated, awl-shaped phialides with a basal septum. Microconidial Fusarium isolates may be confused with Acremonium, but they usually grow faster and have colonies with a characteristic fluffy appearance.

For identification, potato dextrose agar and cornmeal agar are the most suitable media to use and exposure to daylight is recommended to maximize culture color characteristics.

Clinical significance The genus Acremonium currently contains 100 species, of which most are saprophytic, being isolated from dead plant material and soil. A number of species are recognized as opportunistic pathogens of man and animals, causing mycetoma, onychomycosis, and hyalohyphomycosis, these include A. falciforme, A. kiliense and A. recifei, A. alabamensis, A. potroni, A. roseo-griseum and A. strictum. However, many reports only identify Acremonium species to genus level. Clinical manifestations of hyalohyphomycosis caused by Acremonium; include arthritis, osteomyelitis, peritonitis, endocarditis, pneumonia, cerebritis and subcutaneous infection.

Fungi Species A-D 4

Clinical group: Opportunistic mycoses Mycosis: Hyalohyphomycosis

Further reading Domsch, K.H., W. Gams, and T.H. Anderson. 1980. Compendium of soil fungi. Volume 1. Academic Press, London, UK.

Kwon-Chung, K.J. and J.E. Bennett. 1992. Medical Mycology. Lea & Febiger, Philadelphia and London.

Fungi Species A-D 5

Alternaria sp.

Alternaria alternata showing branched acropetal chains and multicelled, obclavate to obpyriform conidia with short conical beaks.

Colonies are fast growing, black to olivaceous-black or greyish, and are suede-like to floccose.

Microscopically, branched acropetal chains (blastocatenate) of multicelled conidia (dictyoconidia) are produced sympodially from simple, sometimes branched, short or elongate conidiophores.

Conidia are obclavate, obpyriform, sometimes ovoid or ellipsoidal, often with a short conical or cylindrical beak, pale brown, smooth-walled or verrucose.

Alternaria species soon lose their ability to sporulate in culture. Potato dextrose agar and cornmeal agar are the most suitable media to use, and incubation under near ultra-violet light is recommended to maintain sporulation. Temperature: optimum 25-28C; maximum 31-32C.

Clinical significance The genus contains 44 species of which most are plant parasites, but a few species are ubiquitous and are also frequently soil-borne. A. alternata is the commonest of these. Although usually seen as saprophytic contaminants, Alternaria species are recognized causative agents of mycotic keratitis and phaeohyphomycosis. Clinical manifestations include cutaneous infections, paranasal sinusitis, osteomyelitis and peritonitis in patients on continuous ambulatory peritoneal dialysis (CAPD).

Clinical group: Opportunistic mycoses Mycosis: Phaeohyphomycosis

Further reading Domsch, K.H., W. Gams, and T.H. Anderson. 1980. Compendium of soil fungi. Volume 1. Academic Press, London, UK.

Kwon-Chung, K.J. and J.E. Bennett. 1992. Medical Mycology. Lea & Febiger, Philadelphia and London.

Fungi Species A-D 6

Apophysomyces elegans

Culture of Apophysomyces elegans

Colonies are fast growing, white becoming creamy white to buff with age, downy with no reverse pigment, and are composed of broad, sparsely septate (coenocytic) hyphae typical of a zygomycetous fungus.

Sporangiophores are unbranched, straight or curved, slightly tapering towards the apex, up to 200 um long, 3-5 um in width near the apophysis, and hyaline when young but developing as the culture ages, a sepia to brown pigmentation and a conspicuous sub-apical thickening 10-16 um below the apophysis with age.

Sporangiophores arise at right angles from the aerial hyphae and often have a septate basal segment resembling the "foot cell" commonly seen in Aspergillus.

Rhizoids are thin-walled, sub-hyaline and predominantly unbranched.

Sporangia are multispored, small (20-50 in diameter), typically pyriform in shape, hyaline at first, sepia colored when mature, columellate and strongly apophysate. Columellae are hemispherical in shape and the apophyses are distinctively funnel- or bell-shaped.

Sporangiospores are smooth-walled, mostly oblong, occasionally subglobose, (3-4 x 5-6 um) and sub-hyaline to sepia in mass.

Good growth at 26, 37 and 42C.

Fungi Species A-D 7

Young sporangium (left) and mature sporangium (right) of Apophysomyces elegans showing distinctive funnel-shaped apophyses and a conspicuous pigmented sub-apical thickening below the apophysis

Apophysomyces elegans is readily distinguishable from other zygomycetes of medical importance, especially the morphologically similar, strongly apophysate pathogen Absidia corymbifera. A. elegans has sporangiophores with distinctive funnel- or bell- shaped apophyses and hemispherical-shaped columellae, a conspicuous pigmented sub-apical thickening which constricts the lumen of the sporangiophore below the apophysis, and distinctive foot cells.

Agar block method to induce sporulation of Apophysomyces elegans

Laboratory identification of some zygomycetous fungi, especially Apophysomyces elegans and Saksenaea vasiformis may be difficult or delayed because of the mould's failure to sporulate on the primary isolation media or on subsequent subculture onto potato dextrose agar. Sporulation may be stimulated by the use of nutrient deficient media, like Czapek Dox agar, cornmeal-glucose-sucrose-yeast extract agar, or by using the agar block method described by Ellis and Ajello (1982).

Fungi Species A-D 8

Briefly, a small block of agar is cut from a well established culture grown on PDA and is placed in the centre of petri dish containing 1% agar in distilled water. After 21 days at 26C look for sporangium formation at the periphery of the petri dish.

Clinical significance

Apophysomyces elegans is a rare human pathogen usually associated with invasive lesions following traumatic implantation of the fungus through the skin. It is a soil fungus with a tropical to sub-tropical distribution.

Clinical group: Opportunistic mycoses, Mycosis: Zygomycosis Subcutaneous mycoses

Further reading

De Hoog G.S. and J Guarro. 1995. Atlas of clinical fungi. Centraalbureau voor Schimmelcultures, Baarn and Delft, The Netherlands.

Kwon-Chung, K.J. and J.E. Bennett. 1992. Medical Mycology. Lea & Febiger, Philadelphia and London.

Fungi Species A-D 13

Aspergillus nidulans

Teleomorph: Emericella nidulans

Culture of Aspergillus nidulans

On Czapek dox agar, colonies are typically plain green in color with dark red- brown cleistothecia developing within and upon the conidial layer. Reverse may be olive to drab-gray or purple-brown.

Conidial heads are short, columnar (up to 70 x 30 um in diameter) and biseriate.

Conidiophores are usually short, brownish and smooth-walled.

Conidia are globose (3.0-3.5 um in diameter) and rough-walled.

Conidial head of A. nidulans. Note: conidial heads are short, columnar and biseriate. Conidiophores are usually short, brownish and smooth-walled. Conidia are globose and rough-walled.

Fungi Species A-D 14

Cleistothecium of Emericella nidulans (anamorph A. nidulans) showing numerous reddish-brown ascospores . Cleistothecia of A. nidulans are often surrounded by a mass of Hülle cells which are up to 25 um in diameter.

Thick-walled Hülle cells of Emericella nidulans.

Clinical significance Aspergillus nidulans is a typical soil fungus with a world-wide distribution. It has also been reported as a causative agent of aspergillosis in humans and animals. Clinical group: Opportunistic mycoses Mycosis: Aspergillosis

Further reading De Hoog G.S. and J Guarro. 1995. Atlas of clinical fungi. Centraalbureau voor Schimmelcultures, Baarn and Delft, The Netherlands.

Kwon-Chung, K.J. and J.E. Bennett. 1992. Medical Mycology. Lea & Febiger, Philadelphia and London.

Fungi Species A-D 15

Aspergillus niger

Culture of Aspergillus niger

On Czapek dox agar, colonies consist of a compact white or yellow basal felt covered by a dense layer of dark-brown to black conidial heads. Conidial heads are large (up to 3 mm x 15-20 um in diameter), globose, dark brown, becoming radiate and tending to split into several loose columns with age. Conidiophores are smooth-walled, hyaline or turning dark towards the vesicle. Conidial heads are biseriate with the phialides borne on brown, often septate metulae. Conidia are globose to subglobose (3.5-5.0 um in diameter), dark brown to black and rough- walled.

Conidial head of A. niger. Note: conidial heads are biseriate, large, globose, dark brown, becoming radiate with the phialides borne on metulae.

Clinical significance Aspergillus niger is one of the most common and easily identifiable species of the genus Aspergillus, with its white to yellow mat later bearing black conidia. This is the third most common species associated with invasive pulmonary aspergillosis. It is also often a causative agent of aspergilloma and is the most frequently

Fungi Species A-D 16 encountered agent of otomycosis. A. niger may also be a common laboratory contaminant. Clinical group: Opportunistic mycoses Mycosis: Aspergillosis

Further reading De Hoog G.S. and J Guarro. 1995. Atlas of clinical fungi. Centraalbureau voor Schimmelcultures, Baarn and Delft, The Netherlands.

Kwon-Chung, K.J. and J.E. Bennett. 1992. Medical Mycology. Lea & Febiger, Philadelphia and London.

Fungi Species A-D 17

Aspergillus terreus

Culture of Aspergillus terreus

On Czapek dox agar, colonies are typically suede-like and cinnamon-buff to sand brown in color with a yellow to deep dirty brown reverse. Conidial heads are compact, columnar (up to 500 x 30-50 um in diameter) and biseriate. Conidiophores are hyaline and smooth-walled. Conidia are globose to ellipsoidal (1.5-2.5 um in diameter), hyaline to slightly yellow and smooth-walled.

Conidial head of A. terreus. Note: conidial heads are biseriate

Clinical significance Aspergillus terreus occurs commonly in soil and is occasionally reported as a pathogen of humans and animals. Clinical group: Opportunistic mycoses Mycosis: Aspergillosis

Further reading De Hoog G.S. and J Guarro. 1995. Atlas of clinical fungi. Centraalbureau voor Schimmelcultures, Baarn and Delft, The Netherlands.

Kwon-Chung, K.J. and J.E. Bennett. 1992. Medical Mycology. Lea & Febiger, Philadelphia and London.

Fungi Species A-D 18

Aureobasidium pullulans

A. pullulans showing chains of 1- to 2-celled, darkly pigmented arthroconidia representing the Scytalidium anamorph of Aureobasidium and the presence of numerous hyaline, single-celled, ovoid-shaped conidia (ameroconidia) which are produced on short denticles.

Colonies are fast growing, smooth, covered with slimy masses of conidia, cream or pink to brown or black. Hyphae are hyaline and septate, frequently becoming dark-brown with age and undergoing holothallic transformation to form chains of 1- to 2-celled, thick-walled, darkly pigmented arthroconidia commonly called chlamydoconidia. These arthroconidia actually represent the Scytalidium anamorph of Aureobasidium and are only of secondary importance in recognizing members of this genus. Conidia are produced synchronously in dense groups from indistinct scars or from short denticles on undifferentiated, hyaline to sub-hyaline hyphae. Conidia are hyaline, smooth-walled, single-celled (ameroconidia), ellipsoidal but of variable shape and size (8-12 x 4-6 um), often with an indistinct hilum (a mark or scar at the point of attachment). Temperature range for growth 2-35C; optimum 25C; maximum 35C (higher in some human pathogenic isolates).

This species has two varieties: A. pullulans var. pullulans, with a colony which remains pink, light brown, or yellow for at least three weeks, and A. pullulans var. melanogenum which soon becomes black or greenish-black due to dark hyphae which often fall apart into separate cells.

Clinical significance Aureobasidium pullulans has a world-wide distribution and it is usually isolated as a saprophyte, occasionally from skin and nails. However, it has also been reported as a rare causative agent of phaeohyphomycosis, mycotic keratitis and peritonitis in patients on continuous ambulatory peritoneal dialysis (CAPD).

Clinical group: Opportunistic mycoses Mycosis: Phaeohyphomycosis

Further reading De Hoog, G.S., and E.J. Hermanides-Nijhof. 1977. The black yeasts and allied hyphomycetes. Studies in Mycology No. 15. Centraalbureau voor Schimmelcultures, Baarn, The Netherlands.

Fungi Species A-D 19

Kwon-Chung, K.J. and J.E. Bennett. 1992. Medical Mycology. Lea & Febiger, Philadelphia and London.

Fungi Species A-D 20

Basidiobolus ranarum

Synonym: Basidiobolus meristosporus; Basidiobolus haptosporus; Basidiobolus heterosporus

Culture of Basidiololus ranarum.

Colonies are moderately fast growing at 30C, flat, yellowish-grey to creamy-grey, glabrous, becoming radially folded and covered by a fine, powdery, white surface mycelium. Note, satellite colonies are often formed by germinating conidia ejected from the primary colony.

Zygospores of Basidiobolus ranarum.

Microscopic examination usually shows the presence of large vegetative hyphae (8-20 um in diameter) forming numerous round (20-50 um in diameter), smooth, thick-walled zygospores that have two closely appressed beak-like appendages. Two types of asexual spores are formed: primary and secondary. Primary spores are globose, one-celled, solitary and are forcibly discharged from a sporophore. The sporophore has a distinct swollen area just below the spore that actively participates in the discharge of the spore. Secondary spores are clavate, one-celled and are passively released from a sporophore. These sporophores are not swollen at their bases. The apex of the passively released spore has a knob-like adhesive tip. These spores may function as sporangia, producing several sporangiospores. Note, isolates often lose their sporulating ability with subculture and special media incorporating glucosamine hydrochloride and casein hydrolsate may need to be used to stimulate sporulation.

Fungi Species A-D 21

Asexual spores of B. ranarum. Note typical swollen sporophore in lower right corner

Clinical significance Basidiobolus ranarum is commonly present in decaying fruit and vegetable matter, and as a commensal in the intestinal tract of frogs, toads and lizards. It has been reported from tropical Africa, India, Indonesia and South East Asia including the Northern Territory of Australia. Clinical group: Subcutaneous mycoses Mycosis: Zygomycosis

Further reading Rippon, J.W. 1988. Medical Mycology. 3rd Edition. W.B. Saunders Co., Philadelphia, USA.

Fungi Species A-D 22

Beauveria sp.

Beauvaria bassiana showing sympodial development of conidia on a geniculate or zig-zag rachis. Conidiogenous cells are flask-shaped, rachiform, proliferating sympodially and are often aggregated into sporodochia or synnemata. Conidia are hyaline and globose or ovoid in shape.

Colonies are usually slow growing, downy, at first white but later often becoming yellow to pinkish. The genus Beauveria is characterized by the sympodial development of single-celled conidia (ameroconidia) on a geniculate or zig-zag rachis. Conidiogenous cells are flask-shaped, rachiform, proliferating sympodially and are often aggregated into sporodochia or synnemata. Conidia are hyaline and globose or ovoid in shape.

Clinical significance Three species of Beauvaria are recognized, two of which are well known parasites of insects. B. bassiana is the most common species and is best known as the causal agent of the disastrous muscardine in silkworms. Beauveria species are occasionally isolated in the clinical laboratory as saprophytic contaminants.

Clinical group: Saprophytes Mycosis: Hyaline hyphomycetes

Further reading Domsch, K.H., W. Gams, and T.H. Anderson. 1980. Compendium of soil fungi. Volume 1. Academic Press, London, UK.

Kwon-Chung, K.J. and J.E. Bennett. 1992. Medical Mycology. Lea & Febiger, Philadelphia and London.

Fungi Species A-D 23

Bipolaris sp.

Teleomorph: Cochliobolus sp.

Bipolaris australiensisshowing sympodial development of pale brown, fusiform to ellipsoidal, pseudoseptate, poroconidia on a geniculate or zig-zag rachis.

Colonies are moderately fast growing, effuse, grey to blackish brown, suede-like to floccose with a black reverse. Microscopic morphology shows sympodial development of pale brown pigmented, pseudoseptate conidia on a geniculate or zig-zag rachis. Conidia are produced through pores in the conidiophore wall (poroconidia) and are straight, fusiform to ellipsoidal, rounded at both ends, smooth to finely roughened and germinating only from the ends (bipolar).

Drechslera, Bipolaris, Curvularia and Exserohilum are all closely related and differentiation of the genera relies upon a combination of characters including conidial shape, the presence or absence of a protruding hilum, the contour of the basal portion of the conidium and its hilum, the point at which the germ tube originates from the basal cell and, to a lesser degree, the sequence and location of the first three conidial septa. The table below is modified from Domsch et al. (1980).

Anamorph Main characters Teleomorph Drechslera Conidia cylindrical, Pyrenophora germinating from any cell, hilum not protuberant. Bipolaris Conidia fusiform- Cochliobolus ellipsoidal, central cells not much darker and broader than the distal

Fungi Species A-D 24

ones, hilum not protuberant, germination bipolar. Curvularia Conidia with 2-3 broader Cochliobolus and darker central cells, often curved, with or without a prominent hilum, germination bipolar. Exserohilum Conidia fusiform- Setosphaeria cylindrical to obclavate, with a protuberant hilum, germination bipolar.

Clinical significance The genus Bipolaris contains about 45 species which are mostly subtropical and tropical plant parasites. However, several species notably B. australiensis, B. hawaiiensis and B. spicifera, are well documented human pathogens. Clinical manifestations include mycotic keratitis, subcutaneous phaeohyphomycosis, sinusitis, peritonitis in patients on continuous ambulatory peritoneal dialysis (CAPD), and cerebral and disseminated infections. Phaeohyphomycosis caused by Bipolaris species has been reported in both normal and immunosuppressed patients.

Clinical group: Opportunistic mycoses, Mycosis: Phaeohyphomycosis Subcutaneous mycoses

Further reading Domsch, K.H., W. Gams, and T.H. Anderson. 1980. Compendium of soil fungi. Volume 1. Academic Press, London, UK.

Kwon-Chung, K.J. and J.E. Bennett. 1992. Medical Mycology. Lea & Febiger, Philadelphia and London.

McGinnis, M.R., M.G. Rinaldi and R.E. Winn. 1986. Emerging agents of Phaeohyphomycosis: pathogenic species of Bipolaris and Exserohilum. J. Clin. Microbiol. 24:250-259.

Fungi Species A-D 25

Blastomyces dermatitidis

Tissue section showing large, broad-base, unipolar budding yeast-like cells of Blastomyces dermatitidis.

On Sabouraud's dextrose agar at 25C, colonies are variable in both morphology and rate of growth. They may grow rapidly, producing a fluffy white mycelium, or slowly as glabrous, tan, non-sporulating colonies. Growth and sporulation are enhanced by nitrogenous substances found in starling dung and yeast extract. Most strains become pleomorphic with age. Microscopically, hyaline, ovoid to pyriform, one-celled, smooth-walled conidia (2-10 um in diameter) of the Chrysosporium type, are borne on short lateral or terminal hyphal branches.

On blood agar at 37C, colonies are wrinkled and folded, glabrous and yeast-like. Microscopically, the organism produces the characteristic yeast phase as seen in tissue pathology. B. dermatitidis can be described as a dimorphic fungus because it has both a mould and yeast phase.

WARNING: Cultures of B. dermatiditis represent a severe biohazard to laboratory personnel and must be handled with extreme caution in an appropriate pathogen handling cabinet. In the past, conversion from the mould form to the yeast form was necessary to positively identify this dimorphic pathogen from species of Chrysosporium or Sepedonium. However, culture identification by the exoantigen test is now the method of choice.

Clinical significance Blastomycosis is a chronic granulomatous and suppurative disease having a primary pulmonary stage that is frequently followed by dissemination to other body sites, chiefly the skin and bone. Although the disease was long thought to be restricted to the North American continent, in recent years autochthonous cases have been diagnosed in Africa, Asia and Europe. All available clinical and epidemiological evidence indicates that humans and lower animals contract blastomycosis from some source in nature. However, the natural habitat of B. dermatitidis has yet to be clearly delineated, despite some reports of its isolation from soil.

Fungi Species A-D 26

Clinical group: Dimorphic systemic Mycosis: Blastomycosis mycoses

Further reading Rippon, J.W. 1988. Medical Mycology. 3rd Edition. W.B. Saunders Co., Philadelphia, USA.

Fungi Species A-D 27

Blastoschizomyces capitatis

Synonym: Trichosporon capitatis On Sabouraud's dextrose agar colonies are white to cream colored, wrinkled and dull in appearance with a mycelial fringe. Microscopic morphology showing oval to long-oval blastoconidia 3.5-6.7 x 7.4-12.3 um in size.

India Ink Preparation: Negative - no capsules present.

Dalmau Plate Culture on Cornmeal and Tween 80 Agar: True mycelium and arthroconidia are abundant. The blastoconidia usually form clusters along or at the end of the hyphae.

Physiological Tests:

Germ Tube test is Negative Hydrolysis of Urea is Negative Growth on Cycloheximide medium is Positive Growth at 37C is Positive

Fermentation Reactions: Where fermentation means the production of gas and is independent of pH changes.

Negative: Glucose; Sucrose; Lactose; Galactose; Maltose; Trehalose.

Assimilation Tests:

Positive: Glucose; Galactose (Weak); L-Sorbose (Delayed); Citric acid; Glycerol; L-Arabinose; DL-Lactic acid; Succinic acid. Negative: Potassium nitrate; Lactose; Ribitol; Maltose; Cellobiose; D-Ribose; Raffinose; Sucrose; Melibiose; Galactitol; Trehalose; Erythritol; D-Mannitol; D- Xylose; Inositol; D-Glucitol; Soluble Starch; L-Rhamnose; Salicin; Melezitose; D- Arabinose.

Blastoschizomyces capitatum is distinguished from Trichosporon beigelii by being lactose negative.

Clinical significance Blastoschizomyces capitatis is a common environmental fungus and transient component of the normal skin flora, it is frequently isolated from sputum. Disseminated infections involving the spleen, liver, kidney, lung and brain have been reported in neutropenic patients with leukemia or from those undergoing bone marrow transplantation. Blood cultures are often positive and skin lesions similar to disseminated candidiasis may also be present.

Fungi Species A-D 28

Clinical group: Opportunistic mycoses Mycosis: Miscellaneous Yeast Infections

Further reading Kreger-Van Rij, N.J.W. (ed) 1984. The Yeasts: a taxonomic study. 3rd Edition. Elsevier Science Publishers B.V., Amsterdam, The Netherlands.

Rippon, J.W. 1988. Medical Mycology. 3rd Edition. W.B. Saunders Co., Philadelphia, USA

Fungi Species A-D 29

Candida albicans

Synonym: Candida stellatoidea

Culture of Candida albicans.

On Sabouraud's dextrose agar colonies are white to cream colored, smooth, glabrous and yeast-like in appearance. Microscopic morphology shows spherical to subspherical budding yeast-like cells or blastoconidia, 2.0-7.0 x 3.0-8.5 um in size.

Bubbing yeast cells of Candida albicans

India Ink Preparation: Negative - no capsules present.

Dalmau Plate Culture on Cornmeal and Tween 80 Agar: Pseudohyphae with blastoconidia and terminal vesicles (chlamydoconidia).

Physiological Tests:

Germ Tube test is Positive within 3 hours Hydrolysis of Urea is Negative Growth on Cycloheximide medium is Positive Growth at 37C is Positive

Fungi Species A-D 30

Germ-tubes of Candida albicans

Fermentation Reactions: Where fermentation means the production of gas and is independent of pH changes.

Positive: Glucose; Maltose. Variable: Galactose; Trehalose. Negative: Sucrose (some strains positive); Lactose.

Assimilation Tests:

Positive: Glucose; Maltose; Galactose; Trehalose; Sucrose (some negative);D- Xylose; Soluble Starch; D-Mannitol; D-Glucitol (Delayed). Variable: Melezitose; Glycerol; Succinic acid; L-Arabinose; L-Sorbose; D-Ribose (some positive); Citric acid; DL-Lactic acid. Negative: Potassium nitrate; Lactose; Ribitol (some positive); Raffinose; Cellobiose; Melibiose; Erythritol; Inositol; L-Rhamnose; D-Arabinose; Galactitol; Salicin.

Clinical significance Candida albicans occurs naturally as a commensal of mucous membranes and in the digestive tract of humans and animals. It accounts for up to 70% of Candida species isolated from sites of infection and has been reported as a causative agent of all types of candidiasis. Environmental isolations are usually from sources contaminated by human or animal excreta, such as polluted water, soil, air and plants.

Clinical group: Cutaneous mycoses, Mycosis: Candidiasis Opportunistic mycoses

Further reading Kreger-Van Rij, N.J.W. (ed) 1984. The Yeasts: a taxonomic study. 3rd Edition. Elsevier Science Publishers B.V., Amsterdam, The Netherlands.

Fungi Species A-D 31

Rippon, J.W. 1988. Medical Mycology. 3rd Edition. W.B. Saunders Co., Philadelphia, USA.

Fungi Species A-D 32

Candida dubliniensis

On Sabouraud's dextrose agar colonies are white to cream coloured, smooth, glabrous yeast-like in appearance [and are indistinguishable from those of C. albicans] . Microscopic morphology shows numerous ovoid, budding yeast-like cells or blastoconidia, 2.0-7.0 x 3.0-8.5 um in size.

However, C. dubliniensis may be distinguished from C. albicans when grown on CHROMagar Candida. On this medium, C. albicans colonies are light blue-green in colour, while those of C. dubliniensis are a much darker green colour.

India Ink Preparation: Negative - no capsules present.

Dalmau Plate Culture on Cornmeal and Tween 80 Agar: Pseudohyphae with blastoconidia and terminal vesicles (chlamydoconidia) are produced usually in abundance [similar to C. albicans].

Physiological Tests:

Germ Tube test is Positive within 3 hours [as in C. albicans]. Hydrolysis of Urea is Negative Growth on Cycloheximide medium is Positive Growth at 37C is Positive [However, unlike C. albicans growth at 42C is very poor or absent].

Assimilation Tests: [Note the databases supplied by commercial systems like API 20C and ID32C do not contain profiles for C. dubliniensis, so often the first hint is a germ tube positive yeast with an unusual carbohydrate assimilation profile].

Positive: Glucose, Galactose, Maltose, Sucrose, D-Mannitol, Sorbitol, 2-Keto- gluconate, N-Acetylglucosamine, Glucosamine.

Variable: Trehalose, Palatinose.

Negative: L-Arabinose, D-Xylose, D-Ribose, L-Sorbose, L-Rhamnose, Cellobiose, Lactose, Melibiose, Melezitose, Raffinose, Glycerol, Erythritol, Inositol, DL-Lactic acid, Glucuronate, DL-Lactate, Gluconate, Esculin hydrolysis.

Clinical significance Candida dubliniensis has recently been recognised from the oral cavity of HIV- infected patients and are most frequently implicated in cases of recurrent infection following antifungal drug treatment. Phenotypically, isolates are very similar to C.

Fungi Species A-D 33 albicans in that isolates produce both germ-tubes and chlamydoconidia, however, they have unusual carbohydrate assimilation patterns and grow poorly or not at all at 42C.

Clinical group: Cutaneous mycoses, Mycosis: Candidiasis Opportunistic mycoses

Further reading Sullivan D. et al. Widespread geographic distribution of oral Candida dubliniensis strains in human immunodificiency virus-infected individuals. J. Clin. Micro. 1997 35:960-964. Sullivan D. and D. Coleman. Candida dubliniensis: an emerging opportunistic pathogen. Current Topics in medical Mycology. 1997; 8:15-25. Sullivan D and D. Coleman. Minireview. Candida dubliniensis: characteristics and identification. J. Clin. Micro. 1998; 36:329-334

Fungi Species A-D 34

Candida famata

Synonym: Torulopsis candida On Sabouraud's dextrose agar colonies are white to cream colored, smooth, glabrous yeast-like in appearance. Microscopic morphology shows numerous ovoid, budding yeast-like cells or blastoconidia, 2.0-3.5 x 3.5-5.0 um in size. No pseudohyphae produced.

India Ink Preparation: Negative - no capsules present.

Dalmau Plate Culture on Cornmeal and Tween 80 Agar: Spherical to ovoid, budding yeast-like cells only. No pseudohyphae produced.

Physiological Tests:

Germ Tube test is Negative Hydrolysis of Urea is Negative Growth on Cycloheximide medium is Variable Growth at 37C is Variable

Fermentation Reactions: Where fermentation means the production of gas and is independent of pH changes.

Variable: Glucose; Sucrose; Maltose; Trehalose. Negative: Lactose; Galactose.

Assimilation Tests:

Positive: Glucose; Galactose; Maltose; Sucrose; Trehalose; D-Xylose; Melezitose; Glycerol; Raffinose; Cellobiose; L-Arabinose; D-Mannitol; D-Glucitol; Ribitol; Salicin; DL-Lactic acid; Succinic acid. Variable: Lactose; Melibiose; Erythritol; Soluble Starch; L-Rhamnose; D- Arabinose; L-Sorbose; D-Ribose; Galactitol; Citric acid. Negative: Potassium nitrate; Inositol.

Clinical significance Candida famata is a common environmental isolate, however it is only rarely recovered from clinical specimens, usually associated with skin.

Clinical group: Opportunistic mycoses Mycosis: Candidiasis

Further reading Kreger-Van Rij, N.J.W. (ed) 1984. The Yeasts: a taxonomic study. 3rd Edition. Elsevier Science Publishers B.V., Amsterdam, The Netherlands.

Fungi Species A-D 35

Rippon, J.W. 1988. Medical Mycology. 3rd Edition. W.B. Saunders Co., Philadelphia, USA.

Fungi Species A-D 36

Candida glabrata

Synonym: Torulopsis glabrata On Sabouraud's dextrose agar colonies are white to cream colored, smooth and glabrous yeast-like in appearrance. Microscopic morphology shows numerous ovoid, budding yeast-like cells or blastoconidia, 2.0-4.0 x 3.0-5.5 um in size. No pse udohyphae produced.

India Ink Preparation: Negative - no capsules present.

Dalmau Plate Culture on Cornmeal and Tween 80 Agar: Ovoid budding yeast- like cells only. No pseudohyphae produced.

Physiological Tests:

Germ Tube test is Negative Hydrolysis of Urea is Negative Growth on Cycloheximide medium is Negative Growth at 37C is Positive

Fermentation Reactions: Where fermentation means the production of gas and is independent of pH changes.

Positive: Glucose. Variable: Trehalose. Negative: Latose; Maltose; Sucrose; Galactose.

Assimilation Tests:

Positive: Glucose; Trehalose. Variable: Glycerol; DL-Lactic acid. Negative: Potassium nitrate; Lactose; Galactose; Maltose; D-Xylose; Soluble Starch; Melezitose; Sucrose; Raffinose; Cellobiose; Erythritol; Inositol; L- Rhamnose; D-Arabinose; L-Arabinose; Ribitol; L-Sorbose; D-Ribose; Galactitol; D- Mannitol; D-Glucitol; Salicin; Citric acid; Succinic acid.

Clinical significance Candida (Torulopsis) glabrata is one of the most common yeast species to be found on the body surface and is often isolated as an incidental finding from skin and urine. It has been implicated as an "opportunistic" cause of both superficial and systemic infections, especially in immunocompromised patients, and it has been isolated from patients with septicemia, pyelonephritis, pulmonary infections, endocarditis and hyperalimentation.

Fungi Species A-D 37

Clinical group: Cutaneous mycoses, Mycosis: Candidiasis Opportunistic mycoses

Further reading Kreger-Van Rij, N.J.W. (ed) 1984. The Yeasts: a taxonomic study. 3rd Edition. Elsevier Science Publishers B.V., Amsterdam, The Netherlands.

Rippon, J.W. 1988. Medical Mycology. 3rd Edition. W.B. Saunders Co., Philadelphia, USA.

Fungi Species A-D 38

Candida guilliermondii

India Ink Preparation: Negative - no capsules present.

Dalmau Plate Culture on Cornmeal and Tween 80 Agar: Branched pseudohyphae with dense verticils of blastoconidia.

Physiological Tests:

Germ Tube test is Negative Hydrolysis of Urea is Negative Growth on Cycloheximide medium is Positive Growth at 37C is Positive

Fermentation Reactions: Where fermentation means the production of gas and is independent of pH changes.

Positive: Glucose; Sucrose; Variable: Galactose. Negative: Lactose; Maltose; Trehalose.

Assimilation Tests:

Positive: Glucose; Sucrose; Galactose; Maltose; Trehalose; D-Xylose; Melezitose; Glycerol; Raffinose; Cellobiose; Melibiose; L-Rhamnose; D-Arabinose (delayed); L- Arabinose; Ribitol; L-Sorbose (delayed); Galactitol (delayed); D-Mannitol; D- Glucitol; Salicin; Citric acid; Succinic acid. Variable: D-Ribose; DL-Lactic acid. Negative: Potassium nitrate; Lactose; Erythritol ; Inositol; Soluble Starch .

Clinical significance Candida guilliermondii has been isolated from numerous human infections, mostly of cutaneous origin. Systemic infections are rare, although one has been reported in a patient with aplastic anemia. C. guilliermondii has also been isolated from normal skin and in sea water, faeces of animals, fig wasps, buttermilk, leather, fish and beer.

Clinical group: Cutaneous mycoses Mycosis: Candidiasis

Fungi Species A-D 39

Further reading Kreger-Van Rij, N.J.W. (ed) 1984. The Yeasts: a taxonomic study. 3rd Edition. Elsevier Science Publishers B.V., Amsterdam, The Netherlands.

Rippon, J.W. 1988. Medical Mycology. 3rd Edition. W.B. Saunders Co., Philadelphia, USA.

Fungi Species A-D 40

Candida haemulonii

Synonym: Torulopsis haemulonii On Sabouraud's dextrose agar colonies are white to cream colored, smooth, glabrous and yeast-like in appearance. Microscopic morphology shows numerous ovoid to globose, budding yeast-like cells or blastoconidia, 3.0-5.0 x 3.0-6.5 um in size. No pseudohyphae produced.

India Ink Preparation: Negative - no capsules present.

Dalmau Plate Culture on Cornmeal and Tween 80 Agar: Spherical to ovoid, budding yeast-like cells only. No pseudohyphae produced.

Physiological Tests:

Germ Tube test is Negative Hydrolysis of Urea is Negative Growth on Cycloheximide medium is Positive Growth at 37C is Positive

Fermentation Reactions: Where fermentation means the production of gas and is independent of pH changes.

Positive: Glucose; Sucrose; Trehalose. Variable: Maltose. Negative: Lactose; Galactose.

Assimilation Tests:

Positive: Glucose; Galactose; Maltose; Sucrose; Trehalose; D-Xylose; Melezitose; Glycerol; Raffinose (delayed); L-Arabinose (delayed); Ribitol (delayed); Galactitol (delayed); D-Mannitol; L-Rhamnose; D-Glucitol; Citric acid; Succinic acid. Negative: Potassium nitrate; Lactose; L-Sorbose; Cellobiose; D-Ribose; Melibiose; Erythritol; Inositol; Soluble Starch; Salicin; D-Arabinose; DL-Lactic acid.

Clinical significance Candida haemulonii has been reported from a few cases of fungemia but clinical isolations remain rare. It has also been isolated from fish and a dolphin. C. haemulonii may be difficult to distinguish from C. famata using some commercial yeast identification systems due to data base limitations.

Clinical group: Opportunistic mycoses Mycosis: Candidiasis

Fungi Species A-D 41

Further reading Kreger-Van Rij, N.J.W. (ed) 1984. The Yeasts: a taxonomic study. 3rd Edition. Elsevier Science Publishers B.V., Amsterdam, The Netherlands.

Rippon, J.W. 1988. Medical Mycology. 3rd Edition. W.B. Saunders Co., Philadelphia, USA.

Fungi Species A-D 42

Candida kefyr

Synonym: Candida pseudotropicalis On Sabouraud's dextrose agar colonies are white to cream colored, smooth, glabrous and yeast-like in appearance. Microscopic morphology shows numerous short-ovoid to long-ovoid, budding yeast-like cells or blastoconidia, 3.0-6.5 x 5.5- 11.0 um, sometimes becoming elongate (up to 16.0 um) in size.

India Ink Preparation: Negative - no capsules present.

Dalmau Plate Culture on Cornmeal and Tween 80 Agar: Abundant, long, wavy, branched pseudohyphae is usually formed, with ovoid blastoconidia, budding off singly, in pairs or chains, often in a verticillated position. Note, in some strains pseudohyphae may be scarce or almost absent.

Physiological Tests:

Germ Tube test is Negative Hydrolysis of Urea is Negative Growth on Cycloheximide medium is Positive Growth at 37C is Variable

Fermentation Reactions: Where fermentation means the production of gas and is independent of pH changes.

Positive: Galactose (delayed). Variable: Glucose; Sucrose; Lactose; Maltose. Negative: Trehalose.

Assimilation Tests:

Positive: Glucose; Galactose; Sucrose; Lactose; Raffinose; DL-Lactic acid. Variable: Trehalose; D-Xylose; Glycerol; L-Arabinose; Cellobiose; L-Sorbose; D- Ribose; D-Mannitol; Salicin; Citric acid; Succinic acid. Negative: Potassium nitrate; Ribito; Maltose; Melibiose; Galactitol; Erythritol; Inositol; D-Glucitol; Soluble Starch; L-Rhamnose; Melezitose; D-Arabinose.

Clinical significance Candida kefyr is a rare cause of candidiasis and is usually associated with superficial cutaneous manifestations rather than systemic disease. It has been isolated from nails and lung infections. Environmental isolations have been made from cheese and dairy products.

Clinical group: Cutaneous mycoses, Mycosis: Candidiasis

Fungi Species A-D 43

Opportunistic mycoses

Further reading Kreger-Van Rij, N.J.W. (ed) 1984. The Yeasts: a taxonomic study. 3rd Edition. Elsevier Science Publishers B.V., Amsterdam, The Netherlands.

Rippon, J.W. 1988. Medical Mycology. 3rd Edition. W.B. Saunders Co., Philadelphia, USA.

Fungi Species A-D 44

Candida krusei

On Sabouraud's dextrose agar colonies are white to cream colored, smooth, glabrous yeast-like colonies. Microscopic morphology shows predominantly small, elongated to ovoid budding yeast-like cells or blastoconidia, 2.0-5.5 x 4.0-15.0 um in size.

India Ink Preparation: Negative - no capsules present.

Dalmau Plate Culture on Cornmeal and Tween 80 Agar: Abundant long, wavy, branched pseudohyphae with elongated to ovoid blastoconidia, budding off in verticillate branches.

Physiological Tests:

Germ Tube test is Negative Hydrolysis of Urea is Variable Growth on Cycloheximide medium is Negative Growth at 37C is Positive

Fermentation Reactions: Where fermentation means the production of gas and is independent of pH changes.

Positive: Glucose. Negative: Sucrose; Lactose; Galactose; Maltose; Trehalose.

Assimilation Tests:

Positive: Glucose; Glycerol (delayed); DL-Lactic acid; Succinic acid. Variable: L-Sorbose; Citric acid. Negative: Potassium nitrate; Lactose; Ribitol; Galactose; Raffinose; Maltose; Cellobiose; D-Ribose (some positive); Sucrose; Melibiose; Galactitol; Trehalose; Erythritol; D-Mannitol; D-Xylose; Inositol; D-Glucitol; Soluble Starch; L- Rhamnose; Salicin; Melezitose; D-Arabinose; Arabinose.

Clinical significance Candida krusei is regularly associated with some forms of infant diarrhoea and occasionally with systemic disease. It has also been reported to colonize the gastrointestinal, respiratory and urinary tracts of patients with granulocytopenia. Environmental isolations have been made from beer, milk products, skin, faeces of animals and birds and pickle brine

Clinical group: Opportunistic mycoses Mycosis: Candidiasis

Fungi Species A-D 45

Further reading Kreger-Van Rij, N.J.W. (ed) 1984. The Yeasts: a taxonomic study. 3rd Edition. Elsevier Science Publishers B.V., Amsterdam, The Netherlands.

Rippon, J.W. 1988. Medical Mycology. 3rd Edition. W.B. Saunders Co., Philadelphia, USA.

Fungi Species A-D 46

Candida lusitaniae

On Sabouraud's dextrose agar colonies are white to cream colored, smooth, glabrous and yeast-like in appearance. Microscopic morphology shows numerous subglobose, ovoid, or elliptical budding yeast-like cells or blastoconidia, 1.5-6.0 x 2.5-10.0 um in size.

India Ink Preparation: Negative - no capsules present.

Dalmau Plate Culture on Cornmeal and Tween 80 Agar: Abundant pseudohyphae with short chains of blastoconidia.

Physiological Tests:

Germ Tube test is Negative Hydrolysis of Urea is Negative Growth on Cycloheximide medium is Negative Growth at 37C is Positive

Fermentation Reactions: Where fermentation means the production of gas and is independent of pH changes.

Positive: Glucose; Sucrose (delayed); Trehalose (delayed). Variable: Galactose; Maltose. Negative: Lactose.

Assimilation Tests:

Positive: Glucose; Maltose; Sucrose; Trehalose; D-Xylose; Glycerol; Cellobiose; L- Rhamnose; D-Ribose (delayed); D-Mannitol; Ribitol; D-Glucitol; Salicin; DL- Lactic acid; Succinic acid. Variable: Galactose; Melezitose; D-Arabinose; L-Arabinose; L-Sorbose; Citric acid. Negative: Potassium nitrate; Lactose; Raffinose; Melibiose; Galactitol; Erythritol; Inositol; Soluble Starch.

Clinical significance Candida lusitaniae has been isolated from several cases of disseminated candidiasis, including septicemia and pyelonephritis. It has also been reported to colonize the human respiratory, gastrointestinal and urinary tracts and many strains have proven to be resistant to amphotericin B. C. lusitaniae was first isolated from the alimentary tract of warm blooded animals and environmental isolations have been made from cornmeal, citrus peel, fruit juices, and milk from cows with mastitis. C. lusitaniae may also be difficult to distinguish from C. tropicalis using some yeast identification systems.

Fungi Species A-D 47

Clinical group: Opportunistic mycoses Mycosis: Candidiasis

Further reading Kreger-Van Rij, N.J.W. (ed) 1984. The Yeasts: a taxonomic study. 3rd Edition. Elsevier Science Publishers B.V., Amsterdam, The Netherlands.

Rippon, J.W. 1988. Medical Mycology. 3rd Edition. W.B. Saunders Co., Philadelphia, USA

Fungi Species A-D 48

Candida norvegensis

Synonym: Torulopsis norvegica On Sabouraud's dextrose agar colonies are white to cream colored, smooth, glabrous and yeast-like in appearance. Microscopic morphology shows numerous ovoid, budding yeast-like cells or blastoconidia, 2.0-3.5 x 3.5-5.0 um in size. No pseudohyphae produced.

India Ink Preparation: Negative - no capsules present.

Dalmau Plate Culture on Cornmeal and Tween 80 Agar: Spherical to ovoid, budding yeast-like cells only. No pseudohyphae produced.

Physiological Tests:

Germ Tube test is Negative Hydrolysis of Urea is Negative Growth on Cycloheximide medium is Negative Growth at 37C is Positive

Fermentation Reactions: Where fermentation means the production of gas and is independent of pH changes.

Positive: Glucose (delayed). Negative: Sucrose; Lactose; Galactose; Maltose; Trehalose.

Assimilation Tests:

Positive: Glucose; Cellobiose; Citric acid; Succinic acid. Variable: Soluble Starch. Negative: Potassium nitrate; Lactose; Ribitol; Galactose; Raffinose; L-Sorbose; Maltose; D-Ribose; Sucrose; Melibiose; Galactitol; Trehalose; Erythritol; D- Mannitol; D-Xylose; Inositol; D-Glucitol; L-Rhamnose; Salicin; Melezitose; D- Arabinose; Glycerol; L-Arabinose; DL-Lactic acid.

Clinical significance Candida norvegensis is a very rare clinical isolate that has been reported as a causative agent of peritonitis and disseminated candidiasis in a patient on CAPD.

Clinical group: Opportunistic mycoses Mycosis: Candidiasis

Further reading Kreger-Van Rij, N.J.W. (ed) 1984. The Yeasts: a taxonomic study. 3rd Edition. Elsevier Science Publishers B.V., Amsterdam, The Netherlands.

Fungi Species A-D 49

Rippon, J.W. 1988. Medical Mycology. 3rd Edition. W.B. Saunders Co., Philadelphia, USA

Fungi Species A-D 50

Candida parapsilosis

On Sabouraud's dextrose agar colonies are white to cream colored, smooth, glabrous and yeast-like in appearance. Microscopic morphology shows predominantly small, globose to ovoid budding yeast-like cells or blastoconidia, 2.0-3.5 x 3.0-4.5 um in size, with some larger elongated forms present.

India Ink Preparation: Negative - no capsules present.

Dalmau Plate Culture on Cornmeal and Tween 80 Agar: Abundant, much- branched pseudohyphae in a delicate tree-like pattern with 2-3 blastoconidia in small clusters at intervals along the pseudohyphae.

Physiological Tests:

Germ Tube test is Negative Hydrolysis of Urea is Negative Growth on Cycloheximide medium is Negative Growth at 37C is Positive

Fermentation Reactions: Where fermentation means the production of gas and is independent of pH changes.

Positive: Glucose. Variable: Galactose. Negative: Lactose; Sucrose (some positive); Maltose (some positive); Trehalose (some positive).

Assimilation Tests:

Positive: Glucose; Galactose; Maltose; Trehalose; D-Xylose; Glycerol; L-Arabinose; Ribitol (delayed); D-Mannitol; Sucrose; D-Glucitol. Variable: D-Ribose; L-Sorbose; Succinic acid; Citric acid; DL-Lactic acid. Negative: Potassium nitrate; Cellobiose; Lactose; Raffinose; Melibiose; Galactitol; Erythritol; Inositol; Soluble Starch; L-Rhamnose; Salicin; Melezitose; D-Arabinose.

Clinical significance Candida parapsilosis is an opportunistic human pathogen which may cause both superficial cutaneous infections, especially of the nail and systemic disease, especially endocarditis. Other clinical manifestations include endophthalmitis and fungemia. Environmental isolations have been made from intertidal and oceanic waters, pickle brine, cured meats, olives and normal skin, and faeces.

Clinical group: Opportunistic mycoses Mycosis: Candidiasis

Fungi Species A-D 51

Further reading Kreger-Van Rij, N.J.W. (ed) 1984. The Yeasts: a taxonomic study. 3rd Edition. Elsevier Science Publishers B.V., Amsterdam, The Netherlands.

Rippon, J.W. 1988. Medical Mycology. 3rd Edition. W.B. Saunders Co., Philadelphia, USA

Fungi Species A-D 52

Candida tropicalis

India Ink Preparation: Negative - no capsules present.

Cornmeal and Tween 80 Agar Plate: Abundant long, wavy, branched pseudohyphae with numerous ovoid blastoconidia budding off. Terminal vesicles (chlamydoconidia) are not produced.

Physiological Tests:

Germ Tube test is Negative Hydrolysis of Urea is Negative Growth on Cycloheximide medium is Positive Growth at 37C is Positive

Fermentation Reactions: Where fermentation means the production of gas and is independent of pH changes.

Positive: Glucose; Maltose; Galactose; Trehalose (delayed). Variable: Sucrose. Negative: Lactose.

Assimilation Tests:

Positive: Glucose; Galactose; Maltose; Trehalose; D-Xylose; Soluble Starch; Succinic acid; D-Mannitol; L-Arabinose (weak); D-Glucitol. Variable: Sucrose; Salicin; Melezitose; Glycerol; Cellobiose; D-Ribose; Ribitol; L- Sorbose; Citric acid; DL-Lactic acid. Negative: Potassium nitrate; L-Rhamnose; Lactose; Raffinose; Melibiose; Galactitol; Erythritol; Inositol; D-Arabinose.

Clinical significance Candida tropicalis is a major cause of septicemia and disseminated candidiasis, especially in patients with lymphoma, leukemia and diabetes. It is the second most frequently encountered medical pathogen, next to C. albicans, and is also found as part of the normal human mucocutaneous flora. Sucrose negative variants of C. tropicalis have also been increasingly found in cases of disseminated candidiasis. Environmental isolations have been made from faeces, shrimp, kefir, and soil.

Fungi Species A-D 53

Clinical group: Opportunistic mycoses Mycosis: Candidiasis

Further reading Kreger-Van Rij, N.J.W. (ed) 1984. The Yeasts: a taxonomic study. 3rd Edition. Elsevier Science Publishers B.V., Amsterdam, The Netherlands.

Rippon, J.W. 1988. Medical Mycology. 3rd Edition. W.B. Saunders Co., Philadelphia, USA

Fungi Species A-D 54

Candida viswanathii

On Sabouraud's dextrose agar colonies are white to cream colored, smooth, glabrous and yeast-like in appearance. Microscopic morphology shows numerous globose, ovoid, or cylindrical budding yeast-like cells or blastoconidia, 2.5-7.0 x 4.0-12.0 um in size.

India Ink Preparation: Negative - no capsules present.

Dalmau Plate Culture on Cornmeal and Tween 80 Agar: Abundant wavy pseudohyphae with verticillated branched chains of blastoconidia.

Physiological Tests:

Germ Tube test is Negative Hydrolysis of Urea is Negative Growth on Cycloheximide medium is Positive Growth at 37C is Positive

Fermentation Reactions: Where fermentation means the production of gas and is independent of pH changes.

Positive: Glucose; Galactose; Maltose; Trehalos (delayed). Variable: Sucrose; Negative: Lactose.

Assimilation Tests:

Positive: Glucose; Galactose; Maltose; Sucrose; Trehalose; D-Xylose; Soluble Starch; Melezitose; Glycerol; L-Arabinose (delayed); D-Mannitol; Ribitol; Salicin; Citric acid; Succinic acid. Negative: Potassium nitrate; Lactose; Raffinose; L-Sorbose; Cellobiose; D-Ribose; Melibiose; Galactitol; Erythritol; Inositol; D-Glucitol; L-Rhamnose; DL-Lactic acid; D-Arabinose.

Clinical significance Candida viswanathii is only rarely isolated from clinical specimens.

Clinical group: Opportunistic mycoses Mycosis: Candidiasis

Further reading Kreger-Van Rij, N.J.W. (ed) 1984. The Yeasts: a taxonomic study. 3rd Edition. Elsevier Science Publishers B.V., Amsterdam, The Netherlands.

Fungi Species A-D 55

Rippon, J.W. 1988. Medical Mycology. 3rd Edition. W.B. Saunders Co., Philadelphia, USA

Fungi Species A-D 56

Chrysosporium tropicum

Culture of Chrysosporium tropicum.

Colonies are moderately fast growing, flat, white to tan to beige in colour, often with a powdery or granular surface texture. Reverse pigment absent or pale brownish-yellow with age. Hyaline, one-celled (ameroconidia) are produced directly on vegetative hyphae by non-specialized conidiogenous cells. Conidia are typically pyriform to clavate with truncate bases (6 to 7 by 3.5 to 4 um) and are formed either intercalary (arthroconidia), laterally (often on pedicels) or terminally. No macroconidia or hyphal spirals are seen.

Chrysosporium tropicum showing typical pyriform to clavate shaped conidia with truncated bases which may be formed either intercalary, laterally or terminally.

Clinical significance Species of Chrysosporium are occasionally isolated from skin and nail scrapings, especially from feet, but because they are common soil saprophytes they are usually considered as contaminants. There are about 22 species of Chrysosporium, several are keratinophilic with some also being thermotolerant, and cultures may closely resemble some dermatophytes, especially Trichophyton mentagrophytes, and some strains may also resemble cultures of Histoplasma and Blastomyces. Clinical group: Saprophytes Mycosis: Hyaline hyphomycetes

Further reading Domsch, K.H., W. Gams, and T.H. Anderson. 1980. Compendium of soil fungi. Volume 1. Academic Press, London, UK.

Fungi Species A-D 57

McGinnis, M.R. 1980. Laboratory handbook of medical mycology. Academic Press, London, UK.

Fungi Species A-D 58

Cladophialophora bantiana

Synonym: Xylohyphae bantiana; Cladosporium bantianum; Cladosporium trichoides.

Conidiophore and conidia of Cladophialophora bantiana.

Colonies are moderately fast growing, olivaceous-grey, suede-like to floccose and grow at temperatures up to 42-43C. Conidia are formed in long, sparsely branched, flexuous, acropetal chains from undifferentiated conidiophores. Conidia are one-celled (very occasionally two-celled), pale brown, smooth-walled, ellipsoid to oblong-ellipsoid and are 2-3 x 4-7 um in size.

Cladophialophora bantiana may be distinguished from Cladosporium species by the absence of conidia with distinctly pigmented hila, the absence of characteristic shield cells and by growth at 42C (compared with Cladophialophora carrionii which has a maximum growth temperature of 35-36C.

Clinical significance Cladophialophora bantianahas been isolated from soil and is a recognized agent of cerebral phaeohyphomycosis. The fungus is neurotropic and may cause brain abscess in both normal and immunosuppressed patients.

Clinical group: Opportunistic mycoses Mycosis: Phaeohyphomycosis

Further reading De Hoog G.S. and J Guarro. 1995. Atlas of clinical fungi. Centraalbureau voor Schimmelcultures, Baarn and Delft, The Netherlands.

Kwon-Chung, K.J. and J.E. Bennett. 1992. Medical Mycology. Lea & Febiger, Philadelphia and London.

Fungi Species A-D 59

Cladophialophora carrionii

Synonym: Cladosporium carrionii

Culture of Cladophialophora carrionii

On Sabouraud's dextrose agar, colonies are slow growing, reaching 3-4 cm in diameter after one month, with a compact suede-like to downy surface. Colonies are olivaceous-black in color and have well defined margins. Microscopic morphology shows the typical Cladosporium type conidial ontogeny with elongate conidiophores producing branched acropetal chains of smooth-walled conidia, 1.5- 3.0 x 2.0-7.0 um in size. Maximum growth temperature 35-37C.

Conidiophores and conidia of C. carrionii

Clinical significance Cladophialophora carrionii is a recognized agent of chromoblastomycosis and it has been isolated from soil and fence posts made from Eucalyptus sp. Cases of chromoblastomycosis caused by C. carrionii are commonly found in Australia, Venezuela, Madagascar and South America. Isolates from phaeomycotic cysts and opportunistic infections have also been reported. Clinical group: Subcutaneous mycoses Mycosis: Chromoblastomycosis

Further reading De Hoog G.S. and J Guarro. 1995. Atlas of clinical fungi. Centraalbureau voor Schimmelcultures, Baarn and Delft, The Netherlands.

Fungi Species A-D 60

Kwon-Chung, K.J. and J.E. Bennett. 1992. Medical Mycology. Lea & Febiger, Philadelphia and London.

Fungi Species A-D 61

Cladosporium sp.

Culture of Cladsporium cladosporioides.

Colonies are rather slow growing, mostly olivaceous-brown to blackish brown but also sometimes grey, buff or brown, suede-like to floccose, often becoming powdery due to the production of abundant conidia. Vegetative hyphae, conidiophores and conidia are equally pigmented. Conidiophores are more or less distinct from the vegetative hyphae, are erect, straight or flexuous, unbranched or branched only in the apical region, with geniculate sympodial elongation in some species. Conidia are 1- to 4-celled, smooth, verrucose or echinulate, with a distinct dark hilum and are produced in branched acropetal chains. The term blastocatenate is often used to describe chains of conidia where the youngest conidium is at the apical or distal end of the chain. Note, the conidia closest to the conidiophore and where the chains branch, are usually "shield-shaped". The presence of shield-shaped conidia, a distinct hilum, and chains of conidia that readily disarticulate, are diagnostic for the genus Cladosporium.

Conidiophores and conidia of Cladosporium cladosporioides

For identification, isolates are best grown on potato dextrose agar or 2% malt extract agar at 20-25C. Microscopic mounts are best made using a cellotape flag or slide culture preparation mounted in lactophenol cotton blue. A drop of alcohol is usually needed to detach the cellotape flag from the stick, and to act as a wetting agent.

Clinical significance Cladosporium species have a world-wide distribution and are among the most

Fungi Species A-D 62 common air-borne fungi. Some 500 species have been described. Cladosporium species are frequently isolated as contaminants.

Clinical group: Saprophytes Mycosis: Dematiaceous hyphomycetes

Further reading Domsch, K.H., W. Gams, and T.H. Anderson. 1980. Compendium of soil fungi. Volume 1. Academic Press, London, UK.

Fungi Species A-D 63

Coccidioides immitis

Culture of Coccidioides immitis

On Sabouraud's dextrose agar at 25C, colonies are initially moist and glabrous, but rapidly become suede-like to downy, greyish white in color with a tan to brown reverse. However, considerable variation in both growth rate and culture morphology has been noted (Rippon, 1988). Microscopic morphology shows typical single-celled, hyaline, rectangular to barrel-shaped, alternate arthroconidia, 2.5-4.0 x 3.0-6.0 um in size, separated from each other by a disjunctor cell. This arthroconidial state has been classified in the genus Malbranchea and is similar to that produced by many non-pathogenic soil fungi such as Gymnoascus species.

WARNING: Cultures of Coccidioides immitis represent a severe biohazard to laboratory personnel and must be handled with extreme caution in an appropriate pathogen handling cabinet. C. immitis is a dimorphic fungus, existing in living tissue as spherules and endospores, and in soil or culture in a mycelial form. Culture identification by the exoantigen test is now the method of choice.

Arthroconidia of C. immitis.

Clinical significance Coccidioidomycosis is initially, a respiratory infection, resulting from the inhalation of conidia, that typically resolves rapidly leaving the patient with a strong specific immunity to re-infection. However, in some individuals the disease may progress to a chronic pulmonary condition or to a systemic disease involving the meninges, bones, joints and subcutaneous and cutaneous tissues. Coccidioides

Fungi Species A-D 64 immitis is a soil inhabiting fungus endemic in south-western U.S.A., northern Mexico and various centers in South America. Several cases have now been diagnosed in Australia, all in patients with a history of travel to endemic areas. Clinical group: Dimorphic systemic Mycosis: Coccidioidomycosis mycoses

Further reading Rippon, J.W. 1988. Medical Mycology. 3rd Edition. W.B. Saunders Co., Philadelphia, USA.

Fungi Species A-D 65

Colletotrichum coccodes

Culture of Colletotrichum coccodes.

Colonies usually darkly pigmented with white aerial mycelium, consisting of numerous black sclerotia and light brown coloured conidial masses, reverse is dark brown. Sclerotia are usually abundant, setose, spherical and are often confluent. Conidia are straight, fusiform, attenuated at the ends, 16-22 X 3-4 um. Appressoria are common, clavate, brown, 11-16.5 X6-9.5.

Sclerotia with setae of C. coccodes.

Fungi Species A-D 66

Conidia of C. coccodes.

Appressoria of C. coccodes.

Clinical significance Plant fungus reported from a case of mycotic keratitis.

Clinical group: Opportunistic mycoses Mycosis: Mycotic Keratitis