Successful treatment of cutaneous protothecosis with liposomal amphotericin and oral itraconazole

Abstract

Protothecosis is a rare algal infection, affecting primarily immunocompromised hosts. Optimal management is unclear: in-vitro antimicrobial breakpoints are not established and therapeutic decisions are primarily based on case reports. We present a case of cutaneous Prototheca wickerhamii infection in an immunosuppressed 63 year old male, successfully treated with liposomal amphotericin and prolonged itraconazole. Inoculation may have been through frequent hot-tub use, highlighting hot-tub exposure as an infection risk for the immunocompromised host.

Successful treatment of multifocal pedal Prototheca wickerhamii infection in a feline immunodeficiency virus-positive cat with multiple Bowenoid in situ carcinomas containing papillomaviral DNA sequences

“…Perhaps co-administration of terbinafine, amphotericin B (systemically or intralesionally) or all three might have represented a more aggressive and effective approach to the medical management of this patient. In human patients, using a combination of itraconazole and amphotericin B is usually more effective, 24 , 25 but use of amphotericin B in cats requires twice-weekly subcutaneous infusions, although intralesional therapy is also possible. 26 Indeed, one could make a strong case that early surgical intervention while lesions are small represents the most cost-effective therapy for most feline patients and the cornerstone for therapy with the goal of curative intent, although consolidation therapy itraconazole and/or amphotericin B may still be important to prevent recurrence of infection due to persistence of algal elements in portions of the wound margin.…”

Case Report: Olecranon Bursitis due to Prototheca wickerhamii in an Immunocompromised Patient

“…A review of present literature suggests that intravenous liposomal amphotericin B has the highest success rate to treat all clinical types of protothecosis either alone (77%) or in combination with other agents such as tetracyclines (86%). 6,10 Overall, treatment success rates are higher for cutaneous and olecranon bursitis (73% and 83%, respectively) compared with disseminated protothecosis (33%). Because of the paucity of susceptibility information of Prototheca species infection, it is recommended to perform susceptibility testing on these algae when identified as a source of infection.…”

Unusual ulcerative keratitis caused by Prototheca wickerhamii in a diabetic patient

“…[ 4 ] The speciation of Prototheca ultimately depends on carbohydrate assimilation tests or using the API strip series (bioM'erieux, Marcy l'Etoile, Paris, France) applicable for yeasts, the Vitek yeast identification database (bioM'erieux, Marcy l'Etoile, Paris, France), the Vitek 2 test (bioM'erieux, Marcy l'Etoile, Paris), and the RapidID Yeast Plus test (Remel, Santa Fe, NM, USA), but several clues can be found in tissue staining. [ 4 ] Reports on molecular techniques[ 8 ] and mass spectrometry[ 9 ] for the identification of Prototheca are available.…”

“…This is due to the presence of ergosterol in neutral lipid fraction of cell membrane, and voriconazole shows superior activity against wickerhamii having 4% ergosterol. [ 8 14 ] Phospholipid components of Prototheca enable them to be susceptible to polymyxin B. Imidazole susceptibility is due to free fatty acid fraction of their cell membrane. [ 4 ] Variable sensitivities are also noted to tetracycline, gentamycin, and amikacin, with synergistic activity between amphotericin B and tetracycline combination in vitro .…”