This page updated:
1/7/2007 12:49:00 PM
DoctorFungus - All Rights Reserved
© 2007 Copyright
Site built and designed for doctorfungus by Webillustrated
You are here:
> Descriptions >
(described by Link ex Gray in 1821)
Fusarium is a filamentous fungus widely distributed on plants and in the soil. It is found in normal mycoflora of commodities, such as rice, bean, soybean, and other crops . While most species are more common at tropical and subtropical areas, some inhabit in soil in cold climates. Some Fusarium species have a teleomorphic state [1295, 2202].
As well as being a common contaminant and a well-known plant pathogen, Fusarium spp. may cause various infections in humans. Fusarium is one of the emerging causes of opportunistic mycoses [63, 66, 531, 916, 1426, 1581, 1826, 1921, 2297, 2304].
The genus Fusarium currently contains over 20 species. The most common of these are Fusarium solani, Fusarium oxysporum, and Fusarium chlamydosporum . Please refer to the table of synonyms for a much more complete list of the currently recognized Fusarium spp.
See the summary of synonyms and teleomorph-anamorph relations for the Fusarium spp.
As well as being common plant pathogens, Fusarium spp. are causative agents of superficial and systemic infections in humans. Infections due to Fusarium spp. are collectively referred to as fusariosis. The most virulent Fusarium spp. is Fusarium solani . Trauma is the major predisposing factor for development of cutaneous infections due to Fusarium strains. Disseminated opportunistic infections, on the other hand, develop in immunosuppressed hosts, particularly in neutropenic and transplant patients [142, 306, 844, 2297, 2304]. Fusarium infections following solid organ transplantation tend to remain local and have a better outcome compared to those that develop in patients with hematological malignancies and bone marrow transplantation patients .
Keratitis [581, 1340, 1577, 1963, 2223], endophthalmitis [861, 1374], otitis media , onychomycosis [952, 1961], cutaneous infections  particularly of burn wounds, mycetoma, sinusitis , pulmonary infections , endocarditis, peritonitis, central venous catheter infections, septic arthritis, disseminated infections [63, 66, 531, 916, 1426, 1581, 1826, 1921, 2072], and fungemia [716, 918, 1241, 1248, 2471] due to Fusarium spp. have been reported .
Outbreaks of nosocomial fusariosis have also been reported. Existence of Fusarium in hospital water distribution systems may result in disseminated fusariosis in immunosuppressed patients . Fusarium may also exist in soil of potted plants in hospitals. These plants constitute a hazardous mycotic reservoir for nosocomial fusariosis .
Fusarium spp. produce mycotoxins. Ingestion of grains contaminated with these toxins may give rise to allergic symptoms or be carcinogenic in long-term consumption. Fumonisins are the mycotoxins produced by Fusarium moniliforme and Fusarium proliferatum in maize. They may cause oesophageal cancer . Another group of mycotoxins, zearalenones, may also be produced by some Fusarium spp. growing in grains . Studies on reduction or elimination of Fusarium mycotoxins from contaminated agricultural and food commodities are in progress .
Fusarium spp. grow rapidly on Sabouraud dextrose agar at 25°C and produce woolly to cottony, flat, spreading colonies. The only slow-growing species is Fusarium dimerum. From the front, the color of the colony may be white, cream, tan, salmon, cinnamon, yellow, red, violet, pink, or purple. From the reverse, it may be colorless, tan, red, dark purple, or brown.
A sclerotium, which is the organized mass of hyphae that remains dormant during unfavorable conditions, may be observed macroscopically and is usually dark blue in color. On the other hand, sporodochium, the cushion-like mat of hyphae bearing conidiophores over its surface, is usually absent in culture. When present, it may be observed in cream to tan or orange color, except for Fusarium solani, which gives rise to blue-green or blue sporodochia [531, 2202].
Hyaline septate hyphae, conidiophores, phialides, macroconidia, and microconidia are observed microscopically. In addition to these basic elements, chlamydospores are also produced by Fusarium chlamydosporum, Fusarium napiforme, Fusarium oxysporum, Fusarium semitectum, Fusarium solani, and Fusarium sporotrichoides[531, 1295, 2202].
Phialides are cylindrical, with a small collarette, solitary or produced as a component of a complex branching system. Monophialides and polyphialides (in heads or in chains) may be observed. Macroconidia (3-8 x 11-70 µm) are produced from phialides on unbranched or branched conidiophores. They are 2- or more celled, thick-walled, smooth, and cylindrical or sickle- (canoe-)shaped. Macroconidia have a distinct basal foot cell and pointed distal ends. They tend to accumulate in balls or rafts. Microconidia (2-4 x4-8 µm), on the other hand, are formed on long or short simple conidiophores. They are 1-celled (occasionally 2- or 3-celled), smooth, hyaline, ovoid to cylindrical, and arranged in balls (occasionally occurring in chains). Chlamydospores, when present, are sparse, in pairs, clumps or chains. They are thick-walled, hyaline, intercalary or terminal [531, 1295, 2202].
Macroscopic and microscopic features, such as, color of the colony, length and shape of the macroconidia, the number, shape and arrangement of microconidia, and presence or absence of chlamydospores are key features for the differentiation of Fusarium species . Molecular methods, such as 28S rRNA gene sequencing, may be used for rapid identification of Fusarium strains to species level .
See our histopathology page.
Fusarium differs from Acremonium, Lecythophora, and Phialemonium by having macroconidia. It differs from Cylindrocarpon by having macroconidia with foot cells and pointed distal ends .
No special precautions other than general laboratory precautions are required.
Fusarium is one of the most drug-resistant fungi. Among the Fusarium spp., Fusarium solani in general tends to be most resistant of all. Fusarium strains yield quite high MICs for flucytosine, ketoconazole, miconazole, fluconazole, itraconazole, and posaconazole [119, 1434, 1854, 1899, 2282, 2283]. The novel triazole, Syn-2869, has no activity against Fusarium . Fusarium spp. are intrinsically resistant to the novel glucan synthesis inhibitors, caspofungin, anidulafungin, and micafungin [120, 558, 683, 1780, 2226]. Despite the lack of its activity alone, the combination of caspofungin with amphotericin B appears synergistic against some Fusarium isolates .
The only antifungal drugs that yield relatively low MICs for Fusarium are amphotericin B [65, 1899, 1973], voriconazole [446, 687, 1152, 1433, 1494, 1864, 2432], and natamycin [1899, 1973]. Compared to itraconazole, voriconazole yields notably lower MICs [119, 1130]. Terbinafine may show good in vitro activity against some isolates .
For MICs of various antifungal drugs for Fusarium, see our susceptibility database.
Fusarium infections are difficult to treat and the invasive forms are often fatal. Amphotericin B alone or in combination with flucytosine or rifampin is the most commonly used antifungal drug for treatment of systemic fusariosis . Lipid formulations of amphotericin B, such as liposomal amphotericin B  and amphotericin B lipid complex [2370, 2452] are also used. However, most cases remain resistant and fail to respond to amphotericin B treatment. Granulocyte and GM-CSF transfusions concommitant to amphotericin B therapy may be life-saving in some immunosuppressed patients with disseminated fusariosis . Despite its limited in vitro activity, posaconazole appears effective in murine fusariosis . Human data are awaited for verification of this finding.
Topical natamycin is used for treatment of keratitis due to Fusarium . In addition to antifungal therapy, keratoplasty is required for several patients . Patients with mycetoma due to Fusarium may respond to itraconazole . Onychomycosis due to Fusarium, on the other hand, may be treated with itraconazole and ciclopirox nail lacquer.
63. Anaissie, E., H. Kantarjian, J. Ro, R. Hopfer, K. Rolston, V. Fainstein, and G. Bodey. 1988. The emerging role of Fusarium infections in patients with cancer. Medicine (Baltimore). 67:77-83.
65. Anaissie, E., V. Paetznick, R. Proffitt, M. J. Adler, and G. P. Bodey. 1991. Comparison of the in vitro antifungal activity of free and liposome-encapsulated amphotericin B. Eur. J. Clin. Microbiol. Infect. Dis. 10:665-668.
66. Anaissie, E. J., G. P. Bodey, and M. G. Rinaldi. 1989. Emerging fungal pathogens. Eur. J. Clin. Microbiol. Infect. Dis. 8:323-330.
119. Arikan, S., M. Lozano-Chiu, V. Paetznick, S. Nangia, and J. H. Rex. 1999. Microdilution susceptibility testing of amphotericin B, itraconazole, and voriconazole against clinical isolates of Aspergillus and Fusarium species. J Clin Microbiol. 37:3946-3951.
120. Arikan, S., M. Lozano-Chiu, V. Paetznick, and J. H. Rex. 2001. In vitro susceptibility testing methods for caspofungin against Aspergillus and Fusarium isolates. Antimicrob. Agents Chemother. 45:327-330.
121. Arikan, S., M. Lozano-Chiu, V. Paetznick, and J. H. Rex. 2000. In vitro synergy studies with caspofungin and amphotericin B against Aspergillus and Fusarium. 40th Interscience Conference on Antimicrobial Agents and Chemotherapy, Abstract No. J-932.
142. Austen, B., H. McCarthy, B. Wilkins, A. Smith, and A. Duncombe. 2001. Fatal disseminated fusarium infection in acute lymphoblastic leukaemia in complete remission. J Clin Pathol. 54:488-490.
306. Boutati, E. I., and E. J. Anaissie. 1997. Fusarium, a significant emerging pathogen in patients with hematologic malignancy: Ten years' experience at a cancer center and implications for management. Blood. 90:999-1008.
446. Clancy, C. J., and M. H. Nguyen. 1998. In vitro efficacy and fungicidal activity of voriconazole against Aspergillus and Fusarium species. Eur. J. Clin. Microbiol. Infect. Dis. 17:573-575.
455. Cofrancesco, E., C. Boschetti, M. A. Viviani, C. Bargiggia, A. M. Tortorano, M. Cortellaro, and C. Zanussi. 1992. Efficacy of liposomal amphotericin B (AmBisome) in the eradication of Fusarium infection in a leukaemic patient. Haematologica. 77:280-3.
531. de Hoog, G. S., J. Guarro, J. Gene, and M. J. Figueras. 2000. Atlas of Clinical Fungi, 2nd ed, vol. 1. Centraalbureau voor Schimmelcultures, Utrecht, The Netherlands.
558. Del Poeta, M., W. A. Schell, and J. R. Perfect. 1997. In vitro antifungal activity of pneumocandin L-743,872 against a variety of clinically important molds. Antimicrob. Agents Chemother. 41:1835-1836.
581. Deshpande, S. D., and G. V. Koppikar. 1999. A study of mycotic keratitis in Mumbai. Indian J Pathol Microbiol. 42:81-7.
683. Espinel-Ingroff, A. 1998. Comparison of in vitro activities of the new triazole SCH56592 and the echinocandins MK-0991 (L-743,872) and LY303366 against opportunistic filamentous and dimorphic fungi and yeasts. J Clin Microbiol. 36:2950-2956.
687. Espinel-Ingroff, A. 2001. In vitro fungicidal activities of voriconazole, itraconazole, and amphotericin B against opportunistic moniliaceous and dematiaceous fungi. J Clin Microbiol. 39:954-958.
716. Farina, C., F. Vailati, A. Manisco, and A. Goglio. 1999. Fungaemia survey: a 10-year experience in Bergamo, Italy. Mycoses. 42:543-548.
844. Girmenia, C., A. P. Lori, F. Boecklin, A. Torosantucci, P. Chiani, P. De Fabritiis, F. Taglietti, A. Cassone, and P. Martino. 1999. Fusarium infections in patients with severe aplastic anemia: review and implications for management. Haematologica. 84:114-118.
861. Goldblum, D., B. E. Frueh, S. Zimmerli, and M. Bohnke. 2000. Treatment of postkeratitis fusarium endophthalmitis with amphotericin B lipid complex [In Process Citation]. Cornea. 19:853-6.
916. Guarro, J., and J. Gene. 1995. Opportunistic fusarial infections in humans. Eur. J. Clin. Microbiol. Infect. Dis. 14:741-754.
918. Guarro, J., M. Nucci, T. Akiti, J. Gene, M. D. C. Barreiro, and R. T. Goncalves. 2000. Fungemia due to Fusarium sacchari in an immunosuppressed patient. J Clin Microbiol. 38:419-421.
952. Gupta, A. K., and R. C. Summerbell. 1999. Combined distal and lateral subungual and white superficial onychomycosis in the toenails. J Am Acad Dermatol. 41:938-44.
1024. Hennequin, C., E. Abachin, F. Symoens, V. Lavarde, C. Reboux, N. Nolard, and P. Berche. 1999. Identification of Fusarium species involved in human infections by 28S rRNA gene sequencing. J Clin Microbiol. 37:3586-3589.
1130. Johnson, E. M., A. Szekely, and D. W. Warnock. 1998. In-vitro activity of voriconazole, itraconazole and amphotericin B against filamentous fungi. J Antimicrob Chemother. 42:741-745.
1131. Johnson, E. M., A. Szekely, and D. W. Warnock. 1999. In vitro activity of Syn-2869, a novel triazole agent, against emerging and less common mold pathogens. Antimicrob. Agents Chemother. 43:1260-1263.
1152. Kappe, R. 1999. Antifungal activity of the new azole UK-109, 496 (voriconazole). Mycoses. 42:83-86.
1241. Kovacicova, G., S. Spanik, A. Kunova, J. Trupl, A. Sabo, P. Koren, M. Sulcova, F. Mateicka, J. Novotny, E. Pichnova, L. Jurga, B. Chmelik, T. Obertik, D. West, and V. Krcmery, Jr. 2001. Prospective study of fungaemia in a single cancer institution over a 10-y period: Aetiology, risk factors, consumption of antifungals and outcome in 140 patients. Scand J Infec Dis. 33:367-374.
1248. Krcmery, V., Jr., and G. Kovacicova. 2000. Longitudinal 10-year prospective survey of fungaemia in Slovak Republic: trends in etiology in 310 episodes. Diagn Microbiol Infect Dis. 36:7-11.
1295. Larone, D. H. 1995. Medically Important Fungi - A Guide to Identification, 3rd ed. ASM Press, Washington, D.C.
1340. Liesegang, T. J., and R. K. Forster. 1980. Spectrum of microbial keratitis in South Florida. Am J Ophthalmol. 90:38-47.
1374. Louie, T., F. el Baba, M. Shulman, and V. Jimenez-Lucho. 1994. Endogenous endophthalmitis due to Fusarium: case report and review. Clin Infect Dis. 18:585-8.
1380. Lozano-Chiu, M., S. Arikan, V. L. Paetznick, E. J. Anaissie, D. Loebenberg, and J. H. Rex. 1999. Treatment of murine fusariosis with SCH 56592. Antimicrob. Agents Chemother. 43:589-591.
1426. Manfredini, L., A. Garaventa, E. Castagnola, C. Viscoli, C. Moroni, G. Dini, M. L. Garre, G. Manno, C. Savioli, Z. Kotitsa, and et al. 1995. [Fungal infections in pediatric oncology]. Pediatr Med Chir. 17:435-41.
1433. Marco, F., M. A. Pfaller, S. A. Messer, and R. N. Jones. 1998. Antifungal activity of a new triazole, voriconazole (UK- 109,496), compared with three other antifungal agents tested against clinical isolates of filamentous fungi. Med Mycol. 36:433-436.
1434. Marco, F., M. A. Pfaller, S. A. Messer, and R. N. Jones. 1998. In vitro activity of a new triazole antifungal agent, Sch 56592, against clinical isolates of filamentous fungi. Mycopathologia. 141:73-77.
1473. Mayayo, E., I. Pujol, and J. Guarro. 1999. Experimental pathogenicity of four opportunist Fusarium species in a murine model. J Med Microbiol. 48:363-366.
1494. McGinnis, M. R., L. Pasarell, D. A. Sutton, A. W. Fothergill, C. R. Cooper, and M. G. Rinaldi. 1998. In vitro activity of voriconazole against selected fungi. Med Mycol. 36:239-242.
1577. Moriarty, A. P., G. J. Crawford, I. L. McAllister, and I. J. Constable. 1993. Severe corneoscleral infection. A complication of beta irradiation scleral necrosis following pterygium excision. Arch Ophthalmol. 111:947-51.
1581. Morrison, V. A., R. J. Haake, and D. J. Weisdorf. 1993. The spectrum of non-Candida fungal infections following bone marrow transplantation. Medicine (Baltimore). 72:78-89.
1780. Pfaller, M. A., F. Marco, S. A. Messer, and R. N. Jones. 1998. In vitro activity of two echinocandin derivatives, LY303366 and MK-0991 (L-743,792), against clinical isolates of Aspergillus, Fusarium, Rhizopus, and other filamentous fungi. Diagn. Microbiol. Infect. Dis. 30:251-255.
1804. Pitt, J. I. 2000. Toxigenic fungi: which are important? Med Mycol. 38:17-22.
1806. Pitt, J. I., A. D. Hocking, K. Bhudhasamai, B. F. Miscamble, K. A. Wheeler, and P. Tanboon-Ek. 1994. The normal mycoflora of commodities from Thailand. 2. Beans, rice, small grains and other commodities. International Journal of Food Microbiology. 23:35-43.
1826. Ponton, J., R. Ruchel, K. V. Clemons, D. C. Coleman, R. Grillot, J. Guarro, D. Aldebert, P. Ambroise-Thomas, J. Cano, A. J. Carrillo-Munoz, J. Gene, C. Pinel, D. A. Stevens, and D. J. Sullivan. 2000. Emerging pathogens. Med Mycol. 38:225-236.
1854. Pujol, I., J. Guarro, J. Gene, and J. Sala. 1997. In vitro antifungal susceptibility of clinical and environmental Fusarium spp. strains. J. Antimicrob. Chemother. 39:163-167.
1864. Radford, S. A., E. M. Johnson, and D. W. Warnock. 1997. In vitro studies of activity of voriconazole (UK-104,496), a new triazole antifungal agent, against emerging and less-common mold pathogens. Antimicrob. Agents Chemother. 41:841-843.
1866. Rahman, M. R., G. J. Johnson, R. Husain, S. A. Howlader, and D. C. Minassian. 1998. Randomised trial of 0.2% chlorhexidine gluconate and 2.5% natamycin for fungal keratitis in Bangladesh. Br J Ophthalmol. 82:919-25.
1895. Restrepo, A. 1994. Treatment of tropical mycoses. J. Amer. Acad. Dermatol. 31:S91-102.
1899. Reuben, A., E. Anaissie, P. E. Nelson, R. Hashem, C. Legrand, D. H. Ho, and G. P. Bodey. 1989. Antifungal susceptibility of 44 clinical isolates of Fusarium species determined by using a broth microdilution method. Antimicrob. Agents Chemother. 33:1647-1649.
1921. Richardson, S. E., R. M. Bannatyne, R. C. Summerbell, J. Milliken, R. Gold, and S. S. Weitzman. 1988. Disseminated fusarial infection in the immunocompromised host. Rev. Infect. Dis. 10:1171-1181.
1955. Rolston, K. V. I. 2001. The spectrum of pulmonary infections in cancer patients. Curr Opin Oncol. 13:218-223.
1961. Romano, C., C. Miracco, and E. M. Difonzo. 1998. Skin and nail infections due to Fusarium oxysporum in Tuscany, Italy. Mycoses. 41:433-437.
1963. Rosa, R. H., Jr., D. Miller, and E. C. Alfonso. 1994. The changing spectrum of fungal keratitis in south Florida. Ophthalmology. 101:1005-13.
1973. Rotowa, N. A., H. J. Shadomy, and S. Shadomy. 1990. In vitro activities of polyene and imidazole antifungal agents against unusual opportunistic fungal pathogens. Mycoses. 33:203-11.
2015. Sampathkumar, P., and C. V. Paya. 2001. Fusarium infection after solid-organ transplantation. Clin Infect Dis. 32:1237-1240.
2039. Schaafsma, A. W., R. W. Nicol, M. E. Savard, R. C. Sinha, L. M. Reid, and G. Rottinghaus. 1998. Analysis of Fusarium toxins in maize and wheat using thin layer chromatography. Mycopathologia. 142:107-13.
2041. Schell, W. A. 2000. Histopathology of fungal rhinosinusitis. Otolaryngol Clin N Amer. 33:251-276,VII,VIII,NIL_5.
2072. Segal, B. H., T. J. Walsh, J. M. Liu, J. D. Wilson, and K. J. Kwon-Chung. 1998. Invasive infection with Fusarium chlamydosporum in a patient with aplastic anemia. J Clin Microbiol. 36:1772-1776.
2111. Singh, G., and S. R. Malik. 1972. Therapeutic keratoplasty in fungal corneal ulcers. Br J Ophthalmol. 56:41-5.
2136. Speeleveld, E., B. Gordts, H. W. Van Landuyt, C. De Vroey, and C. Raes-Wuytack. 1996. Susceptibility of clinical isolates of Fusarium to antifungal drugs. Mycoses. 39:37-40.
2137. Spielberger, R. T., M. J. Falleroni, A. J. Coene, and R. A. Larson. 1993. Concomitant amphotericin B therapy, granulocyte transfusions, and GM-CSF administration for disseminated infection with Fusarium in a granulocytopenic patient. Clin. Infect. Dis. 16:528-30.
2141. Squier, C., V. L. Yu, and J. E. Stout. 2000. Waterborne Nosocomial Infections. Curr Infect Dis Rep. 2:490-496.
2194. Summerbell, R. C., S. Krajden, and J. Kane. 1989. Potted plants in hospitals as reservoirs of pathogenic fungi. Mycopathologia. 106:13-22.
2202. Sutton, D. A., A. W. Fothergill, and M. G. Rinaldi (ed.). 1998. Guide to Clinically Significant Fungi, 1st ed. Williams & Wilkins, Baltimore.
2223. Tanure, M. A., E. J. Cohen, S. Sudesh, C. J. Rapuano, and P. R. Laibson. 2000. Spectrum of fungal keratitis at Wills Eye Hospital, Philadelphia, Pennsylvania. Cornea. 19:307-12.
2226. Tawara, S., F. Ikeda, K. Maki, Y. Morishita, K. Otomo, N. Teratani, T. Goto, M. Tomishima, H. Ohki, A. Yamada, K. Kawabata, H. Takasugi, K. Sakane, H. Tanaka, F. Matsumo, and S. Kuwahara. 2000. In vitro activities of a new lipopeptide antifungal agent, FK463, against a variety of clinically important fungi. Antimicrob. Agents Chemother. 44:57-62.
2282. Van Cutsem, J. 1989. The in-vitro antifungal spectrum of itraconazole. Mycoses. 32:7-13.
2283. Van Cutsem, J. 1992. In vitro antifungal spectrum of itraconazole and treatment of systemic mycoses with old and new antimycotic agents. Chemotherapy. 1:3-11.
2297. Vartivarian, S. E., E. J. Anaissie, and G. P. Bodey. 1993. Emerging fungal pathogens in immunocompromised patients: classification, diagnosis, and management. Clin. Infect. Dis. 17:S487-91.
2304. Venditti, M., A. Micozzi, G. Gentile, L. Polonelli, G. Morace, P. Bianco, G. Avvisati, G. Papa, and P. Martino. 1988. Invasive Fusarium solani infections in patients with acute leukemia. Rev. Infect. Dis. 10:653-660.
2334. Visconti, A., M. Solfrizzo, G. Avantaggiato, and A. De Girolamo. 2000. Strategies for detoxification of Fusarium mycotoxins and assessing in vivo the relevant effectiveness. BCPC Conference: Pests & Diseases:721-728.
2345. Wadhwani, K., and A. K. Srivastava. 1984. Fungi from otitis media of agricultural field workers. Mycopathologia. 88:155-9.
2370. Walsh, T. J., N. L. Seibel, C. Arndt, R. E. Harris, M. J. Dinubile, A. Reboli, J. Hiemenz, and S. J. Chanock. 1999. Amphotericin B lipid complex in pediatric patients with invasive fungal infections. Pediat Inf Dis J. 18:702-708.
2432. Wildfeuer, A., H. P. Seidl, I. Paule, and A. Haberreiter. 1998. In vitro evaluation of voriconazole against clinical isolates of yeasts, moulds and dermatophytes in comparison with itraconazole, ketoconazole, amphotericin B and griseofulvin. Mycoses. 41:309-319.
2452. Wolff, M. A., and R. Ramphal. 1995. Use of amphotericin B lipid complex for treatment of disseminated cutaneous Fusarium infection in a neutropenic patient. Clin. Infect. Dis. 20:1568-1569.
2471. Yildiran, S. T., S. Komurcu, M. A. Saracli, A. Gonlum, C. Beyan, H. Gun, and A. Yalcin. 1998. Fusarium fungaemia in severely neutropenic patients. Mycoses. 41:467-469.