Rhinocerebral zygomycosis in a diabetic patient

Management of Invasive Infections in Diabetes Mellitus: A Comprehensive Review

Patients with diabetes often have more invasive infections, which may lead to an increase in morbidity. The hyperglycaemic environment promotes immune dysfunction (such as the deterioration of neutrophil activity, antioxidant system suppression, and compromised innate immunity), micro- and microangiopathies, and neuropathy. A greater number of medical interventions leads to a higher frequency of infections in diabetic patients. Diabetic individuals are susceptible to certain conditions, such as rhino-cerebral mucormycosis or aspergillosis infection. Infections may either be the primary symptom of diabetes mellitus or act as triggers in the intrinsic effects of the disease, such as diabetic ketoacidosis and hypoglycaemia, in addition to increasing morbidity. A thorough diagnosis of the severity and origin of the infection is necessary for effective treatment, which often entails surgery and extensive antibiotic use. Examining the significant issue of infection in individuals with diabetes is crucial. Comprehensive research should examine why infections are more common amongst diabetics and what the preventive treatment strategies could be.

Development of a Monoclonal Antibody and a Serodiagnostic Lateral-Flow Device Specific to Rhizopus arrhizus (Syn. R. oryzae), the Principal Global Agent of Mucormycosis in Humans

Mucormycosis is a highly aggressive angio-invasive disease of humans caused by fungi in the zygomycete order, Mucorales. Though a number of different species can cause mucormycosis, the principal agent of the disease worldwide is Rhizopus arrhizus, which accounts for the majority of rhino-orbital-cerebral, pulmonary, and disseminated infections in immunocompromised individuals. It is also the main cause of life-threatening infections in patients with poorly controlled diabetes mellitus, and in corticosteroid-treated patients with SARS-CoV-2 infection, where it causes the newly described disease, COVID-19-associated mucormycosis (CAM). Diagnosis currently relies on non-specific CT, a lengthy and insensitive culture from invasive biopsy, and a time-consuming histopathology of tissue samples. At present, there are no rapid antigen tests for the disease that detect biomarkers of infection, and which allow point-of-care diagnosis. Here, we report the development of an IgG1 monoclonal antibody (mAb), KC9, which is specific to Rhizopus arrhizus var. arrhizus (syn. Rhizopus oryzae) and Rhizopus arrhizus var. delemar (Rhizopus delemar), and which binds to a 15 kDa extracellular polysaccharide (EPS) antigen secreted during hyphal growth of the pathogen. Using the mAb, we have developed a competitive lateral-flow device (LFD) that allows rapid (30 min) and sensitive (~50 ng/mL running buffer) detection of the EPS biomarker, and which is compatible with human serum (limit of detection of ~500 ng/mL) and bronchoalveolar lavage fluid (limit of detection of ~100 ng/mL). The LFD, therefore, provides a potential novel opportunity for the non-invasive detection of mucormycosis caused by Rhizopus arrhizus.

Epidemiology, clinical features, diagnosis and treatment of cerebral mucormycosis in diabetic patients: A systematic review of case reports and case series

BACKGROUND

Patients with diabetes are known as an important high-risk group for cerebral mucormycosis (CM).

METHOD

We conducted a structured search using PubMed/MEDLINE to collect both case reports and case series case (ie including at least two patients) onto CM in diabetic patient published between 2000 and March 2020.

RESULTS

Forty-five reports of individual cases and eighteen case series articles were included. India accounted for the largest share of reports with 37.7% and 38.8% of individual cases and case series, respectively. Mortality ranged from 0% to 100% in the case series. The overall mortality in the individual cases was 46.3%, and 64.2% of deaths were reported in patients with ketoacidosis diabetes. Facial swelling (53.3%), headache (44.4%), loss of vision (35.5%) and ophthalmoplegia (35.5%) were the most frequently reported clinical symptoms. In all patients except 4 (91.1%), CM was treated surgically; however, in many cases (42%), despite the use of surgery, death occurred. Amphotericin B deoxycholate (AMB) and lipid-based AMB (LAMB) were used as the first lines of treatment for all patients; however, posaconazole, echinocandins, hyperbaric oxygen therapy (HBOT) and deferasirox were used in combination for a number of patients. Posaconazole has been shown to have positive therapeutic effect; however, posaconazole, LAMB and HBOT are not commonly used in low-income and health-challenged countries.

CONCLUSION

Cerebral mucormycosis is a rapidly progressive infection in diabetic patients and carries immense morbidity despite early diagnosis and treatment. Low-income countries have had the highest number of reports of the disease in recent years, indicating the need to control diabetes in these countries.

Identification of Mucorales in patients with proven invasive mucormycosis by polymerase chain reaction in tissue samples

BACKGROUND

Accurate diagnosis of mucormycosis, a life-threatening fungal infection, remains a challenge for physicians.

OBJECTIVES

To identify the causative Mucorales in fresh clinical samples and formalin-fixed paraffin-embedded (FFPE) samples of patients with proven mucormycosis by molecular method.

PATIENTS/METHODS

Fresh clinical samples of patients with proven mucormycosis according to the EORTC/MSG criteria admitted between 2015 and 2017 and histopathologically proven FFPE archives collected during 2004-2007 and 2015-2017 from Mazandaran University-affiliated hospitals of northern Iran were included. Seminested PCR targeting the 18S rDNA of Mucorales and ITS region was performed, and PCR products were then sequenced.

RESULTS

While culture was positive only in 5 of 9 (56%) of fresh specimen cases, PCR was positive in all 9 (100%) histologically proven mucormycosis. Ten of 18 (56%) FFPE samples were PCR-positive. Overall, Mucorales PCR was positive in 19 of 27 (70%) samples. Mucorales species were Rhizopus arrhizus in 16 (84%) cases, R. arrhizus/Amylomyces rouxii in 2 (10.5%) cases and Rhizopus stolonifer in one case (5.5%). Among 27 mucormycosis cases, 25 (93%) cases were rhinocerebral, and 2 (7%) cases were disseminated. Diabetes mellitus (74%) and neutropaenia (63%) were the main risk factors.

CONCLUSIONS

Seminested PCR targeting 18S rDNA region of Mucorales is useful for identification of the causative agents of mucormycosis.

Clinical features, diagnosis, and outcomes of rhino-orbito-cerebral mucormycosis- A retrospective analysis

Background and Purpose:

Rhino-orbito-cerebral mucormycosis (ROCM) is a rare disease with acute and fulminant manifestation. This infection is associated with high morbidity and mortality rates. Herein, we reviewed the manifestations, underlying conditions, medical treatments, and surgical interventions in ROCM patients admitted to a tertiary referral center in northern Iran over a seven-year period.

Materials and Methods:

In a retrospective analysis, 15 cases of ROCM were identified from 2007 to 2013 in Bu Ali Sina Hospital, Sari, Iran. All the ROCM cases were clinically diagnosed and confirmed by histopathological and/or mycological examination. The relevant demographic data, clinical, ophthalmic, and neurologic manifestations, underlying conditions, medical treatments, and surgical interventions were recorded and analyzed.

Results:

The mean age of the patients was 54±11 years (age range: 28–70 years); 26.7% of the patients were male and 73.3% female (male: female ratio of 1: 2.7). Uncontrolled diabetes was noted in at least 86.7% (13/15) of the cases. The maxillary sinuses were the most frequently involved sites (66.7% of the cases) followed by the ethmoid sinus. Amphotericin B in combination with surgical debridement was used in the treatment of 80% of the cases. Furthermore, 73.3% of the patients who were diagnosed early and underwent medical and extensive surgical debridement of the infected tissues survived.

Conclusion:

Uncontrolled diabetes mellitus is considered to be the main predisposing factor for ROCM. To prevent and reduce mortality rate of this acute disease, early diagnosis based on clinical findings and biopsy is recommended.

Evaluation of disinfectants for elimination of fungal contamination of patient beds in a reference hospital in Piauí, Brazil

This quantitative and qualitative study aimed to identify fungi isolated from patient beds at a reference hospital in Teresina, Piauí, Brazil, and evaluate the efficacy of 70 % ethanol and 1 % hypochlorite for removing the contamination. Thirty-eight beds were chosen at random and the collection was carried out in three situations: before and after disinfection with 70 % alcohol or hypochlorite 1 %. Each sample was inoculated onto Sabouraud dextrose agar containing chloramphenicol and incubated at room temperature to allow fungal growth. We identified 13 species belonging to the genera Aspergillus, Cladosporium, Alternaria, Rhizopus, Penicillium, and Candida. All of these species are pathogenic and can worsen the clinical condition of patients. The 1 % hypochlorite solution proved to be an efficient disinfectant against the fungi, but the same was not observed using 70 % ethanol. Based on these findings, we recommended that the use of 1 % hypochlorite during bed disinfection be added to the hospital biosafety protocol to reduce cross contamination and contribute to patient recovery.

Mucormycosis in Iran: a systematic review

Fungi in the order Mucorales cause acute, invasive and frequently fatal infections in susceptible patients. This study aimed to perform a systematic review of all reported mucormycosis cases during the last 25 years in Iran. After a comprehensive literature search, we identified 98 cases in Iran from 1990-2015. The mean patient age was 39.8 ± 19.2 years. Diabetes was the most common underlying condition (47.9%), and 22.4% of the patients underwent solid organ or bone marrow transplantation. The most common clinical forms of mucormycosis were rhinocerebral (48.9%), pulmonary (9.2%) and cutaneous (9.2%). Eight cases of disseminated disease were identified. Overall mortality in the identified cases was 40.8%, with the highest mortality rate in patients diagnosed with disseminated infection (75%). The mortality rate in rhinocerebral infection patients was significantly lower (45.8%). Rhinocerebral infection was the most common clinical manifestation in diabetes patients (72.9%). Patients were diagnosed using various methods including histopathology (85.7%), microscopy (12.3%) and culture (2.0%). Rhizopus species were the most prevalent (51.7%), followed by Mucor species (17.2%). Sixty-nine patients were treated with a combination of surgery and antifungal therapy (resulting survival rate, 66.7%). Owing to the high mortality rate of advanced mucormycosis, early diagnosis and treatment may significantly improve survival rates. Therefore, increased monitoring and awareness of this life-threatening disease is critical.

Rhinocerebral mucormycosis due to Rhizopus oryzae in a diabetic patient: a case report

Mucormycosis is an opportunistic fulminant fungal infection, which affects nose and paranasal sinuses by direct invasion or through the blood vessels mainly in diabetic and immunocompromised patients. In the present study, a rhino-orbito-cerebral mucormycosis in a 24-year-old female with diabetes mellitus as underlying disease was reported. Computed tomography (CT scan) demonstrated an increase in the soft tissue densities in the left nasal cavity, maxillary and ethmoid sinuses and destruction of the antral wall with soft tissue densities in the pterygopalatine fossa and retromaxillary fissure. In histopathology, wide ribbon-shape non-septate hyphae were seen in tissue sections stained with hematoxylin-eosin (H&E). The etiologic fungus isolated from tissue biopsy on mycological media was identified by the amplification and sequencing of the 5.8S RNA gene and of the adjacent internal transcriber spacer domains, ITS1/ITS4, as Rhizopous oryzae. Recognition of the unique patterns of this high mortality rhinocerebral fungal infection in patients with diabetes is a key to early diagnosis and successful treatment.