My name is Desmond Osatuyi, I am a graduate student at Western Illinois University presently working with Dr Sue Hum-Musser. My focus is on Molecular Biology. I have never been fascinated about fungi until I took Medical Mycology, this class opened my eyes to the hidden facts about fungi and its applications. It's so much interesting and fun learning about the various forms of fungi  and its relative infections..I hope you enjoy my Blog on Sporotrichosis which is very unique because the Causative agent loves the Rose flower...........

Sporotrichosis

Taxonomy of Sporotrichosis

Phylum: Ascomycota

Class: Pyrenomycetes

Order: Ophiostomatales

Family: ophiostomataceae

General Description
Sporotrichosis is a skin infection caused by the fungus Sporothrix schenckii. This fungus is dimorphic, the fungus exists as a mold when found in the environment and  as yeast when found in the host. It usually colonizes plant materials, decaying vegetation, soil and woods. Sporothrix schenckii is found all over the world, most common in the tropical and subtropical America (Restrepo 1986 ). Sporotrichosis has also been referred to as "rose handler's disease” (Rapini 2007). This is due primarily to the fact that they found a high prevalence of the disease in individuals that grow roses. The infection can occur when these individuals get skin cuts from the rose thorns and the fungus present on these thorns infect the cuts on the skin. It is also possible that the soil for cultivating roses might be contaminated with the fungus and  individuals get infected when the fungus is in contact with the cuts from the rose thorns (Ryan 2004). Sporotrichosis has two clinical manifestations: 1. cutaneous sporotrichosis which is common and 2. pulmonary sporotrichosis which is probably acquired when the fungus spores are inhaled, this infection is more dangerous although it is rarely found in individuals that are immunocompetent (Restrepo 1986 ).

Natural Habitat

The natural habitat of the fungus is plant materials, rose thorns, decaying vegetation, woods, and soil (Volk 2007 ).

Figure 1. The Rose flower is a popular habitat for the fungus Sporothrix schenckii (image from www.saltworks.us)

Causes of Sporotrichosis

Sporotrichosis is majorly caused by direct contact of the inoculum with the skin through a small cut or abrasion, on few occasions, the infection can also be acquired from inhaling spores. This fungus infection is sometimes gotten through bites, stings and scratches from different kind of animals, birds and insects. The fungus infection is popular among horticulturists, farmers, plant nursery and gardeners. It is also common in people with a compromised immune system when they  inhale the spores (Kauffman 2011 ).

Growth and Colony identification

The fungus is known to survive optimally at temperatures ranging between 25-37 degrees Celsius. The fungus grows on brain heart infusion agar at an incubation temperature of around 37 degrees Celsius, the colony appears creamy and turns dark on further incubation, and at 25 degrees celsius, colonies are leathery and moist with surface appearing wrinkled (Fig 2). The culture normally takes between 1 to 3 weeks (Pappas 2000 ) .

Figure 2. Creamy colony of Sporothrix schenckii culture (Image from healthscience4_wikispace.com)

Symptoms of Sporotrichosis

Symptoms usually include presence of bumps in the skin, this may develop into a chronic ulcer if not managed in time (Ryan 2004 ). The lesion is usually found in the arm, fingers and hands (Fig 3). In occasions when the spores of the fungus are inhaled, symptoms may include coughing and swollen lymph nodes. In systemic cases it can spread to the nervous system causing lungs and breathing problems (Kevin 2011 ).

Epidemiology

Sporotrichosis often affects immunosuppressed and occasionally affects immunocompetent individuals. Causes of infection are usually traumatic implantation of the fungus on the skin and by inhaling spores into the lungs which happen in rare cases (Rapini 2007). The infection is  an occupational hazard for farmers, florists, nursery and forestry workers, gardeners and manual laborers. The disease is found worldwide and more prominent in tropical and subtropical America (Volk 2007).

Figure 3. ulceration and indurate nodules caused by traumatic implantation of Sporothrix schenckii fungus (Image from microbewikki.kenyon.edu)

Examples of Clinical Cases 

Case report 1 

This case was reported on the 2^nd of February 1981, at the bureau of community health and prevention in division of health in Wisconsin. They receive two brothers, high school students, who were recently employed at southeastern Wisconsin garden center as a part time worker, their age’s ranges between 16 and 17 years, both of them had actually develop  ulcerating lesion, the lesion was present on their wrist and hand, probably gotten while working in the garden. Initially they received antibiotics treatment and there was no improvement,l ymphangitis simultaneously developed, so they took swabs from the lesions of the two brothers and made a fungus culture at the hospital, results revealed that both cultures were positive for Sporothrix schenckii. The two brothers were quickly treated with antifungal drugs itraconazole and potassium iodide, and shortly they recovered (Gastineau et al. 1982 ).

Case report 2      

This case was reported in 2002, it’s about a 30 year male Caucasian, he was reported to be an agricultural worker and lived in the rural area of Brazil, he usually cut down trees for woods when at work. He  got cut and had a lesion in his upper arms and wrist, later he developed nodules on his upper arms and he was immunocompetent. Laboratory test using KOH examining the pus from the lesion shows a negative result, another culture media using corn meal agar on the scrapings from the cuts reveal large number of spores that were identified as Sporothrix schenckii. He was then treated with itraconazole and responded well to treatment ( Alves et al., 2004 ).

Diagnosis

Sporotrichosis do share similar symptoms with other common infections such as the dermatophytes, that make it a bit difficult in its diagnosis, It is recommended to make a culture of the fungus from the infected part like the skin and also culture from the cerebrospinal fluid and sputum for confirmation (Kauffman 2011).

Prevention of Sporotrichosis

Vaccines for this infection has not been discovered so far, but a good means of prevention is to wear protective clothing’s like gloves and long sleeves when dealing with risk factors such as plants (e.g. roses plants, hay, pine seedlings) and other objects that can lead to a cut or puncture on the skin and also since people at risk are mostly people working at places where there is high thorny plants and other inhabitants of the fungus, much care should be taken when handling such materials.

Treatments

The treatments for sporotrichosis involves the use of anti fungal drugs which includes amphotericin B, itraconazole, ketoconazole, flucytosine and saperconazole, sporotrichosis has also been treated with potassium and sodium iodide. Cutaneous sporotrichosis mostly shows a positive response to treatments like amphotericin B, however  pulmonary sporotrichosis may need surgery in addition to the antifungal drugs (Hogan 2010 ).

References

Restrepo, A., J. Robledo, I. Gomez, A. M. Tabares, and R. Gutierrez. 1986. Itraconazole therapy in lymphangitic and cutaneous sporotrichosis. Arch. Dermatol. 122:413-417.
Kauffman CA. Sporotrichosis. In: Goldman L, Schafer AI, eds.Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 345.

Pappas, P. G., I. Tellez, A. E. Deep, D. Nolasco, W. Holgado, and B. Bustamante. 2000. Sporotrichosis in Peru: Description of an area of hyperendemicity. Clin. Infect. Dis. 30: 65–70.

Volk T. "Sporothrix schenckii, cause of Rose-picker's Disease". Tom Volk's Fungus of the Month. Retrieved 2007-06-16.

Hogan BK, Hospenthal DR. Update on the therapy for sporotrichosis. Drug Benefit Trends. 2010;22:49-52.

Rex JH, Okhuysen PC. Sporothrix schenckii. In: Mandell GL,Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap 260

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Al-Tawfiq, J.A., and K.K. Wools. 1998. Disseminated sporotrichosis and Sporothrix schenckii fungemia as the initial presentation of human immunodeficiency virus infection. Clin Infect Dis. 26:1403-1406.

Gastineau FM, Spolyar LW, Haynes E. Sporotrichosis: report of six cases among florists. JAMA 1941;117:1074-7

Grotte M, Younger B. Sporotrichosis associated with sphagnum moss exposure. Arch Pathol Lab Med 1981;105:50-1

Kevin T Merrell, MD, PhD, Staff Physician, Department of Emergency Medicine, Denver Health Medical Center, University of Colorado 2011.

http://www.cdc.gov/fungal//sporotrichosis/risk-prevention.html

Powell KE, Taylor A, Phillips BJ, et al. Cutaneous sporotrichosis in forestry workers. Epidemic due to contaminated sphagnum moss. JAMA 1978;240:232-5.

Ryan KJ,Ray CG (2004) . Sherris Medical Microbiology (4th ed.). McGraw Hill pp.654-6.ISBN 0-83858529-9

Topley and Wilson’s Microbiology and Microbrial Infections, 10^th edition. 2005. Vol. 3. Medical Mycology. Hodder Arnold

www.doctorfungus.com

Clinical Mycology. 2003. William E. Dismukes, Peter G. Pappas, Jack D. Sobel, eds. Oxford University Press