Table 11.

Features distinguishing the Mucorales from the Entomophthorales

Geographic distribution of organismsMost but not all species distributed worldwideWorldwide distribution, but endemic in tropical climates
Geographic distribution of casesMost species cause infections worldwidePredominantly seen in tropical and subtropical regions
Mode of transmissionMajority of infections result from inhalation of spores or traumatic implantationMajority of infections result from inhalation of spores, traumatic implantation, bug bites, or other percutaneous mechanisms
Host immune statusPredominantly immunocompromised, but some competent hosts also seenPredominantly immunocompetent, only a few compromised hosts
Most common disease manifestationsPulmonary disease most common; rhinocerebral, cutaneous/subcutaneous, gastric, and other forms also seenSinusitis disease predominates for Conidiobolus coronatus, while subcutaneous mycosis predominates for Basidiobolus ranarum
Invasive qualitiesPrimarily angioinvasiveMost infections are localized, demonstrating no angioinvasion
Organism colony morphologyFloccose aerial mycelium; often seen as “lid lifters”Waxy, folded, and compact mycelium
Organism mycelium morphologyCoenocytic hyphae, predominantly aseptate; Splendore-Hoeppli phenomenon rarely seenCoenocytic hyphae, becoming moderately septate with age; Splendore-Hoeppli phenomenon characteristically seen in tissue sections