Penicillium marneffei Infection in AIDS

Abstract

Penicillium marneffei is a dimorphic fungus which is endemic in Southeast Asia. It is an opportunistic pathogen which has emerged to become an AIDS-defining illness in the endemic areas. Early diagnosis with prompt initiation of treatment is crucial for its management. Prompt diagnosis can often be established through careful cytological and histological examination of clinical specimens although microbiological culture remains the gold standard for its diagnosis. Standard antifungal treatment for AIDS patients with penicilliosis is well established. Highly active antiretroviral therapy should be started early together with the antifungal treatment. Special attention should be paid to potential drug interaction between antiretroviral and antifungal treatments. Secondary prophylaxis may be discontinued with a low risk of relapse of the infection once the immune dysfunction has improved.

Figure 1

Granular colony of P. marneffei with a characteristic red diffusible pigment on Sabouraud's dextrose agar after 7 days incubation at 25°C.

Figure 2

Yeast-like colony of P. marneffei without red diffusible pigment on Sabouranud's dextrose agar after 7 days of incubation at 35°C.

Figure 3

Microscopy of the mold form of P. marneffei showing septated hyaline hypae and fruiting structures composing of branching metulae and philiades with spherical condidia in chains (lactophenol cotton blue ×400).

Figure 4

Molluscum-contagiosum-like skin lesions associated with P. marneffei infection.

Figure 5

Chest X-ray showing diffuse mottling of both lungs simulating military tuberculosis.

Figure 6

Peripheral blood monocytes with ingested yeast cells (May Grünwald Giemsa ×1000).

Figure 7

Lymph node biopsy showing histiocytic proliferation with numerous round to oblong yeast cells (haematoxylin and eosin ×400).

Figure 8

(a) Marrow aspirate showing a histiocyte engorged with yeast cells with reddish pink inclusions (May Grünwald Giemsa ×1000). (b) Trephine biopsy showing histiocytic proliferation with vague granuloma formation and ingested yeast cells. Some yeast cells have transverse septum (arrow) (haematoxylin and eosin ×400).

Figure 9

Silver methenamine stain showing colonies of P. marneffei. Some yeast cells are oval to oblong in shape with a transverse septum (silver methenamine ×1000).

Figure 10

Septated hyphae-like structures but not yeast forms are demonstrated in the initial gram smear taken from a positive blood culture (Gram ×1000).