Rhinocerebral zygomycosis caused by Saksenae vasiformis in a diabetic patient

Cutaneous Invasive Fungal Infections with Saksenaea Species in Immunocompetent Patients in Europe: A Systematic Review and Case Report

Invasive fungal infections from Saksenaea, a fungus belonging to the Mucorales, have been rarely reported in central European climate zones. This study aims to raise awareness of invasive cutaneous infections with Saksenaea species. The first case of a cutaneous infection was diagnosed in Switzerland in an immunocompetent 79-year-old patient. A minor skin trauma of her left lower leg led to a fulminant infection causing necrosis and extensive loss of tissue. The combination of surgical debridement and administration of antifungal agents averted a prolonged course with a possible worse outcome. A pedicled hemisoleus muscle flap was used to reconstruct the defect and treatment was continued for 63 days.

Saksenaea infection masquerading as a brain tumor in an immunocompetent child

Saksenaea species are a rare cause of mucormycosis, the majority associated with cutaneous and subcutaneous infections resulting from trauma in both immunocompromised and immunocompetent individuals. Unlike other causative agents of mucormycosis, cerebral infections are exceptionally rare. We describe the first case of isolated cerebral infection by Saksenaea in a 4-year-old previously healthy male child who presented with headaches. He had no past medical history other than an episode of febrile seizures. In addition to raising the awareness of an unusual presentation of infection by Saksenaea, this case highlights the importance of pathologic examination for the prompt diagnosis of mucormycosis as well as the specific fungal identification for treatment as Saksenaea spp. may be more susceptible to posaconazole and less susceptible to amphotericin B compared to more common causes of mucormycosis.

kMucormicosys due to Saksenaea vasiformis in a dog

A 2-year-old female Border collie was examined for dermatitis with a partial alopecic zone around her left front member. Six months later the lesion became swollen, alopecic with ulcerated areas. Microscopy analysis of samples showed numerous non-septate, branching, thin-walled and irregular shaped hyphal elements. Fungal cultures and molecular studies identified Saksenaea vasiformis. Treatments with griseofulvin, itraconazole and surgical debridement were used, however, fourteen months later the dog was euthanatized because of the unfavorable clinical outcome.

Emerging infections caused by non-Aspergillus filamentous fungi

There are three broad groups of non-Aspergillus moulds: the mucormycetes, the hyalohyphomycetes and the phaeohyphomycetes. Infections with these pathogens are increasingly reported, particularly in the context of increasing use of immunosuppressant agents and improved diagnostics. The epidemiology of non-Aspergillus mould infections varies with geography, climate and level of immunosuppression. Skin and soft-tissue infections are the predominant presentation in the immunocompetent host and pulmonary and other invasive infections in the immunocompromised host. The more common non-Aspergillus moulds include Rhizopus, Mucor, Fusarium and Scedosporium species; however, other emerging pathogens are Rasamsonia and Verruconis species, which are discussed in this article. Outbreaks of non-Aspergillus mould infections have been increasingly reported, with contaminated medical supplies and natural disasters as common sources. Currently culture and other conventional diagnostic methods are the cornerstone of diagnosis. Molecular methods to directly detect and identify mould pathogens in tissue and body fluids are increasingly used.

Saksenaea erythrospora infection following a serious sailing accident

Saksenaea erythrospora is a species of the order Mucorales recently described and reported as a cause of human mucormycosis. We report a case of S. erythrospora in a man involved in a serious sailing accident causing deep skin and soft tissue contamination with soil and water. Direct microscopic examination of the clinical sample with Giemsa stains showed hyaline and non-septate hyphae belonging to the order Mucorales. Fungal identification was performed by culture of biopsy material on SDA, and identification of species by floating an agar block containing the fungus in a nutritionally deficient medium consisting of sterile distilled water supplemented with 0.05 % yeast extract; and by sequencing the ITS region of the rDNA. This is the first report to our knowledge of infection with S. erythrospora in Argentina, confirming the presence of this fungus in this country.

Disseminated infection due to Saksenaea vasiformis secondary to cutaneous mucormycosis

Mucormycosis is an uncommon opportunistic fungal infection caused by Zygomycetes. It usually affects immunocompromised, diabetic and trauma patients with infected wounds. We report a case of disseminated infection secondary to facial cutaneous mucormycosis caused by Saksenaea vasiformis in a diabetic patient who had a farming accident causing him severe head injury. The patient was treated with a combination of surgical debridement and antifungal therapy with liposomal amphotericin B, but he had a slow and fatal outcome. In cases of tissue necrosis following trauma involving wound contact with soil (i.e., potential fungal contamination), testing for the presence of Zygomycetes fungi such as S. vasiformis in both immunocompetent and immunocompromised patients is crucial. The reason is that this infection usually has a rapid progression and may be fatal if appropriate treatment is not administered.

[Necrotising fasciitis caused by Saksenaea vasiformis in an immunocompetent patient after a car accident]

BACKGROUND

Cutaneous mucormycosis (zygomycosis), with subcutaneous spreading and dissemination, in immunocompetent patients is an uncommon disease caused by species belonging to the fungal genera Apophysomyces, Rhizopus and Saksenaea, among others.

CASE REPORT

A case of necrotising fasciitis by Saksenaea vasiformis in an immunocompetent woman is described. The infection was acquired through a car accident resulting in multiple injuries affecting mainly her right arm. After the surgical reduction of fractures, skin lesions worsened and led to necrosis. The patient quickly developed a severe necrotising fasciitis with negative cultures at first. Despite the extensive surgical debridement and the aggressive antifungal treatment, the patient died. The histopathological study showed a fungal infection due to a fungus belonging to the Mucorales order, which was confirmed by culturing the clinical sample on Sabouraud agar, and identifying the species by cultures on Czapek-Dox agar, and sequencing of the ITS region of the ribosomal DNA.

CONCLUSIONS

This case confirm the presence of this fungus in Spain, the value of histopathology for the mucormycosis diagnosis, as well as the need to perform special cultures to facilitate their isolation and identification to the species level by the combined use of Czapek-Dox agar and sequencing of the ITS region.

Mucormycosis caused by unusual mucormycetes, non-Rhizopus, -Mucor, and -Lichtheimia species

Rhizopus, Mucor, and Lichtheimia (formerly Absidia) species are the most common members of the order Mucorales that cause mucormycosis, accounting for 70 to 80% of all cases. In contrast, Cunninghamella, Apophysomyces, Saksenaea, Rhizomucor, Cokeromyces, Actinomucor, and Syncephalastrum species individually are responsible for fewer than 1 to 5% of reported cases of mucormycosis. In this review, we provide an overview of the epidemiology, clinical manifestations, diagnosis of, treatment of, and prognosis for unusual Mucormycetes infections (non-Rhizopus, -Mucor, and -Lichtheimia species). The infections caused by these less frequent members of the order Mucorales frequently differ in their epidemiology, geographic distribution, and disease manifestations. Cunninghamella bertholletiae and Rhizomucor pusillus affect primarily immunocompromised hosts, mostly resulting from spore inhalation, causing pulmonary and disseminated infections with high mortality rates. R. pusillus infections are nosocomial or health care related in a large proportion of cases. While Apophysomyces elegans and Saksenaea vasiformis are occasionally responsible for infections in immunocompromised individuals, most cases are encountered in immunocompetent individuals as a result of trauma, leading to soft tissue infections with relatively low mortality rates. Increased knowledge of the epidemiology and clinical presentations of these unusual Mucormycetes infections may improve early diagnosis and treatment.

Molecular phylogeny and proposal of two new species of the emerging pathogenic fungus Saksenaea

Saksenaea is a monotypic genus belonging to the order Mucorales and capable of producing severe human infections. Through a polyphasic study based on analysis of the sequences of the internal transcribed spacer (ITS) region, domains D1 and D2 of the 28S rRNA gene, and the elongation factor 1α (EF-1α) gene, as well as by evaluation of relevant morphological and physiological characteristics of a set of clinical and environmental strains, we have demonstrated that Saksenaea vasiformis is a complex of species. We propose as new species Saksenaea oblongispora, characterized by oblong sporangiospores and unable to grow at 42°C, and Saksenaea erythrospora, characterized by large sporangiophores and sporangia and by ellipsoid sporangiospores, biconcave in the lateral view. Itraconazole, posaconazole, and terbinafine were active against all isolates included in the study, while amphotericin B, voriconazole, and the echinocandins showed low activity.