Entomophthoramycosis: a neglected tropical mycosis

Abstract

The term 'entomophthoramycosis' classically refers to infections caused by members of the order Entomophthorales. A new subphylum, Entomophthoramycota, has been created to include Basidiobolomycetes, Neozygitomycetes and Entomophthoramycetes. Basidiobolomycetes encompass Basidiobolus spp., while the Entomophthoramycetes include Conidiobolus spp. Conidiobolus spp. characteristically cause rhinofacial entomophthoramycosis in apparently immunocompetent hosts. Conidiobolus spp. may also cause disseminated infection in immunocompromised patients. Basidiobolus spp. more typically cause subcutaneous entomophthoramycosis of the limbs, buttocks, back and thorax in immunocompetent patients. While once considered to be rare, there is an increasing number of reported cases of gastrointestinal infection caused by Basidiobolus spp. worldwide in countries such as United States, Thailand, Australia, Iran, Egypt and Saudi Arabia. These cases have clinical presentations similar to those of inflammatory bowel diseases, particularly Crohn's disease. Retroperitoneal, pulmonary, nasal and disseminated basidiobolomycosis have also been reported. Histology of entomophthoramycosis may reveal the Splendore-Hoeppli phenomenon. Culture of infected tissue remains the definitive method of laboratory diagnosis. However, molecular methods with specific DNA probes and panfungal primers, as well as real time PCR, are increasingly used to detect and identify these organisms in tissue. Treatment largely consists of therapy with antifungal triazoles. Surgery plays a selective role in the management of entomophthoramycosis, depending upon location, organism and extent of the infection.

First‐time isolation and quantification of Basidiobolus spp. from reptile faeces in KwaZulu‐Natal (South Africa) using selective media

“…can enter the body through cuts, via ingestion or insect bites, although the transmission causing infection is mostly unknown. [21][22][23][24][25]28,32 However, a recent review suggests that hydrolytic enzymes released by the fungus are involved in invasion. 49 If accidentally ingested via contaminated food, Basidiobolus spp.…”

“…could be protected against gastric acid within food vesicles/matrix and its bile tolerance 12 22,31,32 However, recent sequencing data suggest that different pathogenic (and saprophytic) Basidiobolus species exist, highlighting that the former use of synonyms was problematic and that additional phylogenetic studies are necessary to clarify if pathogenic species differ from saprophytic species of this genus. [51][52][53] Diagnostic confirmation of basidiobolomycosis relies currently on histological examination and cultural methods (considered as the "gold standard"), but noncultural methods such as serology and PCR are considered as promising additions.…”

Contribution of Ultra Deep Sequencing in the Clinical Diagnosis of a New Fungal Pathogen Species: Basidiobolus meristosporus

“…Basidiobolus spp. cannot be isolated if sample is stored at 4°C or if Sabouraud agar media contain antibiotics (Al-Naemi et al, 2015; Geramizadeh et al, 2015; Shaikh et al, 2016). Futhermore, hyphae of Basidiobolus spp.…”

Use of potassium iodide in deep mycosis

“…Entomophthoramycosis is a subcutaneous fungal infection caused by members of the order entomophthorales. The two genera pathogenetic to humans include conidiobolus and basidiobolus species (El‐Shabrawi, Arnaout, Madkour, & Kamal, ; Raveenthiran et al, ; Shaikh, Hussain, Petraitiene, Schuetz, & Walsh, ). Basidiobololus ranarum is the species pathogenic to humans and classically presents as an indurated plaque over the perineum and thighs in children.…”

“…These plaques are well circumscribed and can easily be lifted up from the underlying structures while being firmly attached to the overlying skin described as the finger insinuation test. Diagnosis is primarily based on demonstration of the broad sparsely septate hyphae and characteristic colonies on culture (Atadokpédé et al, ; Shaikh et al, ).…”