Rhinocerebral zygomycosis caused by Saksenae vasiformis in a diabetic patient

Abstract

We report a rare case of invasive rhinocerebral Saksenae vasiformis infection in a 71-year-old man with type 2 diabetes mellitus ketoacidosis. Combined histological and microbiological examination of two biopsy specimens taken at four days' intervals showed broad non-septate hyphae on direct smears of biopsies and necrosis and angioinvasion by hyphae were seen in the tissue. S. vasiformis was cultured from both biopsies. The patient had a fatal outcome even though partial debridement, liposomal amphotericin B treatment and control of diabetes were instituted. Permission for necropsy was denied. Clinical, epidemiological and pathological features of the case and manifestations of S. vasiformis infections are discussed. Most cases involve cutaneous sites and only two cases of rhinocerebral infections (both with fatal outcome) have been described. The present case is the third documented case of involvement of the sinuses and the second case of S. vasiformis infection documented in Europe.

Mucormycosis Caused by Unusual Mucormycetes, Non-Rhizopus, -Mucor, and -Lichtheimia Species

“…In immunocompromised hosts, the most common underlying conditions are leukemia and other hematological diseases, solid neoplasms, splenectomy, uncontrolled diabetes, and treatment with adrenal corticosteroids (29,48,58,90,104,326,329). Therefore, S. vasiformis, like Apophysomyces elegans, is different from the typical opportunistic Mucormycetes because it affects mainly nonimmunocompromised patients (279).…”

“…Rhino-orbito-cerebral mucormycosis caused by S. vasiformis is clinically indistinguishable from similar infections caused by other Mucormycetes, even though the prognosis for rhino-orbito-cerebral S. vasiformis infection appears to be especially poor, with the majority of patients (83%) dying of the infection despite undergoing antifungal-based therapy and surgery (4,27,48,81,104,113,150). Nearly 50% of all reported patients with rhino-orbitocerebral mucormycosis caused by S. vasiformis were diabetics (48,104) or had a variety of malignancies, such as gastric adenocarcinoma (104) and ALL (113), which may explain the relatively poorer outcomes for these patients than for those with other clinical forms of S. vasiformis infection.…”

“…It was first isolated in 1953 from soil in India (295) and has been isolated from soil samples in Brazil, Honduras, Israel, Panama, and the United States (14,90,91,134,279). The ecology of S. vasiformis is not well known, and thus far, it has been found in soil and causing infection in human and veterinary patients (4,91,104,132,285). S. vasiformis and Apophysomyces elegans have been reported as causes of death in dolphins, and S. vasiformis caused cranial mucormycosis in a cow (132,285).…”

“…As with other causes of mucormycosis, S. vasiformis infection usually is characterized by angioinvasion and tissue necrosis (37,104,279,366).…”

Molecular Phylogeny and Proposal of Two New Species of the Emerging Pathogenic FungusSaksenaea

“…It is a thermotolerant fungus that grows between 25°C and 44°C (13,24,44) and is able to cause severe human infections in both immunocompromised and immunocompetent hosts. Mucormycosis caused by S. vasiformis most often occurs after traumatic implantation of the fungus but can also be due to inhalation of spores (18), spider bites, insect stings, and the use of indwelling catheters (11,22,28,31). Clinical cases seems to be more common in tropical and subtropical climates than elsewhere and have been reported from Australia (16,19,22,40,48), India (6,7,11,33), the United States (1,8,31,35,45), Thailand (44), Tunisia (28), the Middle East (2,25), and Central and South America (9,47).…”