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Aspergillosis and Mucormycosis
Published in Rebecca A. Cox, Immunology of the Fungal Diseases, 2020
Alayn R. Waldorf, Richard D. Diamond
Diabetes mellitus, especially with ketoacidosis, has been the most commonly recognized underlying disease associated with mucormycosis.37 Animal models of mucormycosis in diabetic mice and rabbits have been used to determine the influence of diabetes in predisposition to mucormycosis, as well as host defense mechanisms against the Mucorales in general.50–57 The models of mucormycosis provide an opportunity for evaluation of the relative importance of different cell populations in the pathogenesis of mucormycosis. Diabetic animals have rapidly fatal infection with Rhizopus oryzae, Rhizomucor pusillus, R. arrhizus, R. microsporus, Rhizopodiformis,53 or Absidia corymbifera.57 Intranasal or intrasinus inoculation of Rhizopus oryzae into streptozotocin-induced diabetic mice results in mucormycotic infections with pathology closely resembling pulmonary or rhinocerebral infections in humans: extensive tissue necrosis in the vicinity of hyphae and the penetration of hyphae into vascular structures.48,51 Unlike other models of mucormycosis,56–59 these diabetes models lead to induction of specific enhanced susceptibility to infection by Rhizopus, resembling the predisposition to mucormycosis which occurs in uncontrolled human diabetic patients. Thus, in these diabetic animals, susceptibility to aspergillosis does not occur.
Mucor and Mucormycosis
Published in Dongyou Liu, Handbook of Foodborne Diseases, 2018
The family Rhizopodaceae includes (1) a thermotolerant Rhizopus microsporus clade (R. microsporus, R. caespitosus, R. homothallicus, and R. schipperae, growing at up to 45°C); (2) a sub-thermotolerant R. arrhizus group (growing at 37°C–40°C); and (3) a mesophilic group (R. stolonifer, Sporodiniella, and Syzygites). Although several members of the genus Rhizopus are infective to humans (e.g., Rhizopus oryzae [synonyms: Rhizopus arrhizus, Rhizopus arrhizus var. arrhizus], Rhizopus microsporus var. rhizopodiformis), R. oryzae predominates human mucormycosis cases. Occurring in soil, on decaying fruits, on dung, and on moist fresh organic matter in contact with soil, Rhizopus may be occasionally involved in spoilage of bread and other food, and thus is called “black bread mold” or “pin-head mold” (a name shared with Mucor) [4].
Isavuconazole
Published in M. Lindsay Grayson, Sara E. Cosgrove, Suzanne M. Crowe, M. Lindsay Grayson, William Hope, James S. McCarthy, John Mills, Johan W. Mouton, David L. Paterson, Kucers’ The Use of Antibiotics, 2017
Michelle R. Ananda-Rajah, Christina C. Chang, Monica A. Slavin
Several case reports have described the successful use of isavuconazole as salvage therapy for mucormycosis (Peixoto et al., 2014; Ervens et al., 2014; Knoll, 2014). In one case of rhinocerebral mucromycosis due to Rhizopus oryzae, a durable clinical response with follow-up at 2 years was achieved, despite elevated MIC values of 8 to >16 mg/l (Ervens et al., 2014). Subsequent sterol analysis demonstrated accumulation of ergosterol precursors with elevated levels of squalene (17.06 vs. 9.95% in the control susceptible strain) and zymosterol (68.70 vs. 0.00%), with corresponding reductions seen in ergosterol levels (2.3 vs. 76.93% in the control susceptible strain) suggestive of azole resistance (Ervens et al., 2014). In all reports (Ervens et al., 2014; Peixoto et al., 2014; Knoll, 2014) isavuconazole was well tolerated despite prolonged treatment, with mild adverse events such as skin rash, nausea, transient elevations in liver enzymes, and an absence of QTc abnormalities.
Mucormycosis experience through the eyes of the laboratory
Published in Infectious Diseases, 2019
Pınar Sağıroğlu, Ayşe Nedret Koç, Mustafa Altay Atalay, Gülşen Altinkanat Gelmez, Özlem Canöz, Fatma Mutlu Sarıgüzel
Mucormycosis is caused by fungi within the order Mucorales and Entomophthorales. The Rhizopus, Mucor, Lichtheimia (formerly Absidia) and Cunninghamella generas are most closely associated with disease in the Mucorales order. Of all these agents, the most frequently identified pathogen is Rhizopus arrhizus (formerly Rhizopus oryzae) [4].
A Rare Case of Rhizopus Oryzae Keratitis following Orbital Cellulitis in a Diabetic Patient
Published in Ocular Immunology and Inflammation, 2022
Rama Rajagopal, Nikhil Navneet Toshniwal, Kirthi Koka, Janani Madhuravasal Krishnan, Sumathi Veluswamy
Rhizopus Oryzae is one of the generic pathogens belonging to the class of zygomycetes, order Mucorales that infrequently infects the eye. Chronic steroid use, immunosuppression and acidosis in poorly controlled diabetics are considered systemic risk factors.8