Review article

Zygomycosis

The number of nosocomial fungal infections is increasing due to several factors, but especially due to the higher number of immunocompromised patients, advances in medicine such as the increasing number of invasive procedures and treatments, and longer stays within healthcare facilities. Air and surfaces of those facilities, healthcare workers’ hands, and contaminated medical products are some of the main sources of fungi and associated with nosocomial infection. Aspergillus and Candida species are responsible for the majority of the cases of nosocomial fungal infections in immunocompromised patients. However, other fungi have emerged, namely Fusarium species, Pseudallescheria boydii, species belonging to the subphylum Mucormicotina, and yeasts like Malassezia or Saccharomyces. Some of these emerging pathogens are, in some cases, resistant to the available antifungals, potentiating the threat of novel fungal diseases. In this article, some of these etiological agents, associated infections, transmission routes, and potential sources of infection in healthcare facilities will be discussed. In addition, collection procedures and new methods of laboratory analysis will also be mentioned.

Cunninghamella bertholletiae although rarely causing mucormycosis, is responsible for the highest mortality among mucormycetes. The diagnosis of mucormycosis is challenged by the absence of specific biomarkers. Herein, we report a fatal case of C. bertholletiae infection and detection of its DNA in the serum by polymerase chain reaction (PCR).

A 23-year-old male with refractory osteosarcoma was admitted with multiple lung metastases. He was on oral voriconazole prophylaxis after pulmonary aspergillosis. He suffered from fever during temporary neutropenia following chemotherapy and showed several neurological and respiratory symptoms. Despite liposomal-amphotericin B administration, the symptoms rapidly progressed, and he died five days after the onset of neurological symptoms.

We retrospectively evaluated the filamentous fungus isolated after his death from gastric juices. Based on the sequence of the internal transcribed spacer (ITS) region we identified the fungal isolate as C. bertholletiae. A 146-bp portion of the D1/D2 region was quantified by quantitative-PCR using DNA extracted from the serum. C. bertholletiae DNA load in the serum was 18.0 copies/μL on the day of onset of neurological symptoms, with the highest (101.0 copies/μL) on the day of his death.

Detection of circulating DNA of mucormycetes in the blood would greatly enhance the diagnosis of mucormycosis. Rapid diagnosis might alleviate mortality due to mucormycosis.

The present case-report suggests that the quantification of C. bertholletiae DNA in the serum could be useful for the diagnosis and evaluation of mucormycosis pathogenesis in patients.

Mucormycosis is a life threatening fungal infection that occurs in immunocompromised patients.

A 36-year-old Saudi male with known case of Insulin-Dependent Diabetes Mellitus (IDDM), who was presented with productive cough and diarrhea. Computed tomography (CT) revealed a disseminated fungal invasion of the lungs and spleen with invading the fundus of the stomach. An aggressive surgical approach and amphotericin B treatment resolved his condition.

Disseminated Mucormycosis in one organ can spread hematogenously to other organs and can cause severe morbidity and mortality in high risk individuals. The diagnosis of mucormycosis is usually delayed, Antifungal therapy alone is insufficient for mucormycosis, and surgical debridement for all infected tissue is often required.

Mucormycosis is a life threating infection, and usually the diagnosis late because of non-specific clinical, radiological feature and need biopsy for confirmation of the organism. The cornerstone for the management and increase the survival rate remain on rapid diagnosis, treatment of the underlying predisposing condition, and urgent surgical debridement.