• View in gallery

    Multiple erythematous plaques are accompanied by papules, shallow ulcers, and crusts on his right upper limb and left lower limb.

  • View in gallery

    Gram stain of blood culture reveals spherical Gram-positive organisms of various sizes resembling yeast. Magnification, × 1,000.

  • View in gallery

    Milky white yeast-like colonies are observed on blood agar plate after incubation at 35°C for 3 days.

  • View in gallery

    Wet-mount preparation with lactophenol cotton blue discloses spherical sporangia containing multiple endospores with symmetrical arrangement. Magnification, × 1,000.

  • 1.

    Lass-Flörl C, Mayr A, 2007. Human protothecosis. Clin Microbiol Rev 20: 230242.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Prototheca wickerhamii Cutaneous and Systemic Infections

View More View Less
  • Department of Internal Medicine, Tainan Municipal Hospital, Tainan City, Taiwan; Department of Clinical Laboratory, Tainan Municipal Hospital, Tainan City, Taiwan

Prototheca wickerhamii, an environmental alga, rarely causes human infections. We present a case of Prototheca wickerhamii cutaneous and systemic infections in an 85-year-old male with adrenal insufficiency. This organism was identified by morphological features and microbiological tests. The patient was successfully treated with ketoconazole.

An 85-year-old male presented with a fever lasting for 2 days. He had a history of adrenal insufficiency with prednisolone use for 2 years. Pruritic erythematous maculopapules on his lower extremities appeared 1 year ago. On examination, he was febrile, tachycardic, and tachypneic. Multiple erythematous plaques were accompanied by papules, shallow ulcers, and crusts on his four limbs (Figure 1). Empirical piperacillin/tazobactam therapy was initiated. Blood cultures obtained on admission were positive after 3 days of incubation. Gram stain revealed spherical Gram-positive organisms of various sizes (Figure 2). A subculture on a blood agar plate showed milky white yeast-like colonies (Figure 3). A lactophenol cotton blue wet mount preparation disclosed characteristic endosporulating sporangia (Figure 4). The organisms isolated from both blood and cutaneous wound cultures were identified as Prototheca wickerhamii using the API 20C identification system (bioMérieux, Marcy l’Etoile, France). Ketoconazole therapy was started on hospital Day 6. His clinical condition and cutaneous lesions improved with ketoconazole for a total of 4 weeks.

Figure 1.
Figure 1.

Multiple erythematous plaques are accompanied by papules, shallow ulcers, and crusts on his right upper limb and left lower limb.

Citation: The American Society of Tropical Medicine and Hygiene 91, 4; 10.4269/ajtmh.14-0082

Figure 2.
Figure 2.

Gram stain of blood culture reveals spherical Gram-positive organisms of various sizes resembling yeast. Magnification, × 1,000.

Citation: The American Society of Tropical Medicine and Hygiene 91, 4; 10.4269/ajtmh.14-0082

Figure 3.
Figure 3.

Milky white yeast-like colonies are observed on blood agar plate after incubation at 35°C for 3 days.

Citation: The American Society of Tropical Medicine and Hygiene 91, 4; 10.4269/ajtmh.14-0082

Figure 4.
Figure 4.

Wet-mount preparation with lactophenol cotton blue discloses spherical sporangia containing multiple endospores with symmetrical arrangement. Magnification, × 1,000.

Citation: The American Society of Tropical Medicine and Hygiene 91, 4; 10.4269/ajtmh.14-0082

Prototheca wickerhamii is an achlorophyllic alga and is ubiquitous in nature, which can cause human infections. The definite diagnosis usually depends on morphological identification of the organisms in wet slide preparations of cultures and/or direct identification in tissue specimens.1

1.

Lass-Flörl C, Mayr A, 2007. Human protothecosis. Clin Microbiol Rev 20: 230242.

Author Notes

* Address correspondence to Kuo-Mou Chung, Department of Internal Medicine, Tainan Municipal Hospital, 670 Chung-Te Road, East District, Tainan City, Taiwan. E-mail: Kuomou_chung@yahoo.com.tw

Authors' addresses: Deng-Wei Chou and Kuo-Mou Chung, Department of Internal Medicine, Tainan Municipal Hospital, Tainan City, Taiwan, E-mails: choudw@gmail.com and Kuomou_chung@yahoo.com.tw. Chao-Tai Lee, Department of Clinical Laboratory, Tainan Municipal Hospital, Tainan City, Taiwan, E-mail: chaotai2010@yahoo.com.tw.

Save