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

Abstract

SUMMARY 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.

Central Nervous System Mucormycosis Caused by Cunninghamella Bertholletiae in a Bottlenose Dolphin (Tursiops truncatus)

“…Similar to other members of the order Mucorales, the pathogenicity of C. bertholletiae consists of its ability to invade blood vessels resulting in thrombosis and infarction. Vascular dissemination and rhino-orbito-cerebral infections are the two major routes of spreading (Gomes et al 2011). Entry through via aerosol to the laryngeal tonsillar tissue and hematogenous dissemination to the CNS is suspected in the present case, based on the severe involvement of arterioles at the basal arteriolar network of the brain.…”

“…They usually occur in immunocompromised patients (Gomes et al 2011). Infection by this fungal species has been described in two domestic cats (Mayayo et al 2011).…”

Adaptation to thermotolerance inRhizopuscoincides with virulence as revealed by avian and invertebrate infection models, phylogeny, physiological and metabolic flexibility

“…All three genera being responsible for 70 to 80 % of the reported infections, predominantly as rhinocerebral, pulmonary or disseminated manifestations; associated with high mortality rates. [18][19][20] From the mesophilic species of the genus Rhizopus, only R. stolonifer can be found in clinical settings, but is seen rarely; mostly as agents of allergic alveolitis or superficial infections but being predominantly non-invasive. 16,40,41 For the thermotolerant species R. arrhizus and R. microsporus are reported more frequently in severe infections than any other species from the Rhizopodaceae.…”

“…[16][17][18][19] These infections often develop rapidly, predominately as rhinocerebral and pulmonary manifestations; and are often associated with dissemination and high mortality rates. [16][17][18][19][20] Although mucormycoses are uncommon fungal infections compared to aspergillosis or candidiasis, their incidence is increasing in clinical settings. 17,21 Major risk factors for mucormycoses are diabetic ketoacidosis, immunosuppression and malignancies.…”

Seasonal monitoring of microbiological air contamination from a museum - a case study

“…; Penicillium spp., Cladosporium spp., Alternaria spp, Rhizopus nigricans; these are also known as an etiological factor of several allergic diseases [14][15].…”