Disseminated Invasive Infection Due to Metarrhizium anisopliae in an Immunocompromised Child

Abstract

The first reported human case of possible disseminated infection with the insect pathogen Metarrhizium anisopliae var.anisopliae, a fungus which has been used commercially for biocontrol of insects, is described. The patient, a 9-year-old boy, had a 5-year history of pre-B-cell acute lymphoblastic leukemia and had been on chemotherapy throughout this period. After 10 days of profound neutropenia, lesions consistent with ecthyma gangrenosum appeared on his arms and legs. M. anisopliae was grown from specimens from three separate sites, collected at different times over a period of 1 month: a skin biopsy, a swab from the base of a lesion, and the core of another skin lesion which spontaneously discharged. The initial skin biopsy also showed histological evidence of epidermal necrosis and dermal invasion with fungal hyphae. A computed-tomography (CT) scan of the chest demonstrated a lesion in the superior segment of the lower lobe of the left lung. A CT scan of the brain revealed a lesion in the left temporoparietal region of the brain, consistent with an abscess. Despite antifungal treatment including liposomal amphotericin and 5-flucytosine, the patient eventually died. The initial portal of entry is unknown, but hematogenous dissemination to the skin appears likely because of the multiple ecthymic lesions, and the appearances of the brain lesion on the CT scan are consistent with a hematogenous fungal abscess.

Species of Metarhizium anisopliae complex implicated in human infections: retrospective sequencing study

“…Metarhizium tropism for eyes and skin may be explained by an optimal growth temperature range of 25e32 C, because the temperature of the ocular surface is slightly less than 35 C, contrary to the internal temperature of mammals that is beyond the maximum temperature for growth of M. anisopliae complex [26,27]. Among our cases, although immune status does not seem to influence the occurrence of non-ocular infections, the only suspected fatal invasive infection occurred in an immunocompromised patient presenting with skin lesions and probable secondary brain abscess for which the fungus was not isolated, but Metarhizium caused severe morbidity and contributed to his death (Table 1) [10]. The other deep localization occurred in an intravenous drug user who probably self-inoculated Metarhizium with contaminated devices (Table 1).…”

“…This suggests that the ocular barrier must be impaired and followed by exposure to an environmental source contaminated by Metarhizium [25]. Non-ocular infection presentations are mainly divided between nasal/sinusal and skin lesions [10,17,19,20] (Table 1). Metarhizium tropism for eyes and skin may be explained by an optimal growth temperature range of 25e32 C, because the temperature of the ocular surface is slightly less than 35 C, contrary to the internal temperature of mammals that is beyond the maximum temperature for growth of M. anisopliae complex [26,27].…”

“…The terms 'Metarhizium/Metarrhizium human infection' or 'Metarhizium/Metarrhizium mammalian infection' were submitted to PubMed. We collected three strains from already published cases, two from humans and one from cat [7,10,11]. Furthermore, we report eight new human cases from France (three patients) and Australia (five patients).…”

“…We identified 12 previously published cases (11 humans and one cat), the first one being reported in 1995 [7,10,11,16e23]. Among them, we collected three strains: two isolated from humans (strains NAN01 from France and AUS00 from Australia) and one from an Australian cat (strain AUS01) [7,10,11]. Furthermore, we included eight additional strains from new human cases, four from France (strains CFD01, LYO01, STR01 and STR02) and four from Australia (strains AUS02, AUS03, AUS04, AUS05).…”

Infectious Causes of Vasculitis

“…Similar lesions may be seen in immunocompromised patients with disseminated Pseudomonas, Nocardia, Aspergillus, Mucor, Curvularia, Pseudallescheria, Fusarium, Morganella, Metarrhizium, Xanthomonas, Klebsiella, E coli, and Aeromonas infections. [87][88][89][90][91][92][93][94][95][96][97][98][99].…”