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

Mucormycosis

Mucormycosis is an aggressive and frequently lethal disease. Most patients with mucormycosis have poorly controlled diabetes mellitus and rhino-orbito-cerebral disease. Patients with hematologic malignancy and transplant recipients mostly present with rhino-orbito-cerebral or pulmonary disease. Prompt recognition of clinical symptoms and radiographic features of mucormycosis is required to establish timely diagnosis and initiate targeted therapy. Diagnosis is, historically, made by direct microscopy, culture, and pathology of biopsy tissue, but molecular methods are increasingly playing a role in establishing an earlier diagnosis. Treatment is multidisciplinary, involving early surgical intervention, antifungal therapy, and correction of underlying immune compromising risk factors when possible.

Exploring the feasibility of utilizing universal primers in detecting mucormycosis pathogens: An in-silico analysis

This study aimed to design and evaluate a universal primer for Polymerase Chain Reaction (PCR)- based detection of mucormycosis-causing fungi by targeting their Internal Transcribed Spacer (ITS) sequences. In-silico analysis was conducted to assess primer suitability. Using Clustal Omega and Primer-BLAST, ITS sequences of 32 fungi species causing mucormycosis were aligned and subjected to primer design. Generated primers were sorted and in silico PCR simulations were performed to identify primers capable of amplifying all fungal species. Instead of identifying one pair of universal primer, in silico PCR analysis identified a panel of 14 primer pairs designed from full-length ITS sequences, and a panel of 12 primer pairs designed from conserved regions, that could detect 31 species. The study recommends a panel of 12 primers for multiplex-PCR to detect mucormycosis-causing fungi instead of a long list of PCR analyses for each fungus in diagnosing mucormycosis.

PCR diagnostic platforms for non-Aspergillus mold infections: ready for routine implementation in the clinic?

INTRODUCTION

While Aspergillus spp. remain the predominant cause of invasive mold infections, non-Aspergillus molds, such as the Mucorales or Fusarium spp., account for an increasing proportion of cases. The diagnosis of non-Aspergillus invasive mold infections (NAIMI) is challenging because of the low sensitivity and delay of conventional microbiological tests. Therefore, there is a particular interest to develop molecular tools for their early detection in blood or other clinical samples.

AREAS COVERED

This extensive review of the literature discusses the performance of Mucorales-specific PCR and other genus-specific or broad-range fungal PCR that can be used for the diagnosis of NAIMI in diverse clinical samples, with a focus on novel technologies.

EXPERT OPINION

PCR currently represents the most promising approach, combining good sensitivity/specificity and ability to detect NAIMI in clinical samples before diagnosis by conventional cultures and histopathology. Several PCR assays have been designed for the detection of Mucorales in particular, but also Fusarium spp. or Scedosporium/Lomentospora spp. Some commercial Mucorales PCRs are now available. While efforts are still needed for standardized protocols and the development of more rapid and simpler techniques, PCR is on the way to becoming an essential test for the early diagnosis of mucormycosis and possibly other NAIMIs.

Comparative genomics predict specific genes in potential mucorales identification

Mucoralean fungi could cause mucormycosis in humans, particularly in immunodeficient individuals and those with diabetes mellitus or trauma. With plenty of species and genera, their molecular identification and pathogenicity have a large deviation. Reported cases of mucormycosis showed frequent occurrence in Rhizopus species, Mucor species, and Lichtheimia species. We analyzed the whole genome sequences of 25 species of the top 10 Mucorales genera, along with another 22 important pathogenic non-Mucorales species, to dig the target genes for monitoring Mucorales species and identify potential genomic imprints of virulence in them. Mucorales-specific genes have been found in various orthogroups extracted by Python script, while genus-specific genes were annotated covering cellular structure, biochemistry metabolism, molecular processing, and signal transduction. Proteins related to the virulence of Mucorales species varied with distinct significance in copy numbers, in which Orthofinder was conducted. Based on our fresh retrospective analysis of mucormycosis, a comparative genomic analysis of pathogenic Mucorales was conducted in more frequent pathogens. Specific orthologs between Mucorales and non-Mucoralean pathogenic fungi were discussed in detail. Referring to the previously reported virulence proteins, we included more frequent pathogenic Mucorales and compared them in Mucorales species and non-Mucorales species. Besides, more samples are needed to further verify the potential target genes.

An update on current and novel molecular diagnostics for the diagnosis of invasive fungal infections

BACKGROUND

Invasive fungal infections cause millions of infections annually, but diagnosis remains challenging. There is an increased need for low-cost, easy to use, highly sensitive and specific molecular assays that can differentiate between colonized and pathogenic organisms from different clinical specimens.

AREAS COVERED

We reviewed the literature evaluating the current state of molecular diagnostics for invasive fungal infections, focusing on current and novel molecular tests such as polymerase chain reaction (PCR), digital PCR, high-resolution melt (HRM), and metagenomics/next generation sequencing (mNGS).

EXPERT OPINION

PCR is highly sensitive and specific, although performance can be impacted by prior/concurrent antifungal use. PCR assays can identify mutations associated with antifungal resistance, non-Aspergillus mold infections, and infections from endemic fungi. HRM is a rapid and highly sensitive diagnostic modality that can identify a wide range of fungal pathogens, including down to the species level, but multiplex assays are limited and HRM is currently unavailable in most healthcare settings, although universal HRM is working to overcome this limitation. mNGS offers a promising approach for rapid and hypothesis-free diagnosis of a wide range of fungal pathogens, although some drawbacks include limited access, variable performance across platforms, the expertise and costs associated with this method, and long turnaround times in real-world settings.

Novel Approaches in the Management of Mucormycosis

Purpose of Review

Invasive mucormycosis (IM), caused by fungi of the order Mucorales, is one of the deadliest fungal infection among hematologic cancer patients. Its incidence is also increasingly reported in immunocompetent individuals, notably with the COVID-19 pandemic. Therefore, there is an urgent need for novel diagnostic and therapeutic approaches of IM. This review discusses the current advances in this field.

Recent Findings

Early diagnosis of IM is crucial and can be improved by Mucorales-specific PCR and development of lateral-flow immunoassays for specific antigen detection. The spore coat proteins (CotH) are essential for virulence of the Mucorales and may represent a target for novel antifungal therapies. Adjuvant therapies boosting the immune response, such as interferon-γ, anti-PDR1 or fungal-specific chimeric antigen receptor (CAR) T-cells, are also considered.

Summary

The most promising perspectives for improved management of IM consist of a multilayered approach targeting both the pathogen and the host immune system.

Fungal Integrated Histomolecular Diagnosis Using Targeted Next-Generation Sequencing on Formalin-Fixed Paraffin-Embedded Tissues

Histopathology is the gold standard for fungal infection (FI) diagnosis, but it does not provide a genus and/or species identification. The objective of the present study was to develop targeted next-generation sequencing (NGS) on formalin-fixed tissue samples (FTs) to achieve a fungal integrated histomolecular diagnosis. Nucleic acid extraction was optimized on a first group of 30 FTs with Aspergillus fumigatus or Mucorales infection by macrodissecting the microscopically identified fungal-rich area and comparing Qiagen and Promega extraction methods through DNA amplification by A. fumigatus and Mucorales primers. Targeted NGS was developed on a second group of 74 FTs using three primer pairs (ITS-3/ITS-4, MITS-2A/MITS-2B, and 28S-12-F/28S-13-R) and two databases (UNITE and RefSeq). A prior fungal identification of this group was established on fresh tissues. Targeted NGS and Sanger sequencing results on FTs were compared. To be valid, the molecular identifications had to be compatible with the histopathological analysis. In the first group, the Qiagen method yielded a better extraction efficiency than the Promega method (100% and 86.7% of positive PCRs, respectively). In the second group, targeted NGS allowed fungal identification in 82.4% (61/74) of FTs using all primer pairs, in 73% (54/74) using ITS-3/ITS-4, in 68.9% (51/74) using MITS-2A/MITS-2B, and in 23% (17/74) using 28S-12-F/28S-13-R. The sensitivity varied according to the database used (81% [60/74] using UNITE compared to 50% [37/74] using RefSeq [P = 0.000002]). The sensitivity of targeted NGS (82.4%) was higher than that of Sanger sequencing (45.9%; P < 0.00001). To conclude, fungal integrated histomolecular diagnosis using targeted NGS is suitable on FTs and improves fungal detection and identification.

Molecular diagnostics of infectious disease: Detection and characterization of microbial agents in cytology samples

BACKGROUND

Cytology samples are widely used to diagnose various infectious diseases by detection and identification of causative infectious agents, including bacteria, fungi, and viruses. The role of cytopathology in infectious disease has expanded tremendously in the past decades with the advances in molecular techniques. Molecular diagnostic methods, compared to conventional methods, have shown improved patient outcome, reduction in cost, and shortened hospital stay times. The aim of this article is to review molecular testing in cytology samples for diagnosis of infectious diseases.

METHODS

The literature search for molecular testing in common cytology samples for diagnosis of infectious diseases was performed. The findings of the studies were summarized. The common cytology samples included in this article were gynecologic specimens, cerebrospinal fluid, bronchoalveolar lavage, and urine samples.

CONCLUSIONS

There are a number of molecular diagnostic tests that are available to be used in common cytology samples to detect infectious agents. Each test has its own advantages and limitations. It is our hope that upon reading this review article, the readers will have better understanding of molecular diagnostic testing of infectious diseases utilizing commonly sampled cytology specimens in daily practice.

Mucormycosis co-infection in COVID-19 patients: An update

Mucormycosis (MCM) is a rare fungal disorder that has recently been increased in parallel with novel COVID-19 infection. MCM with COVID-19 is extremely lethal, particularly in immunocompromised individuals. The collection of available scientific information helps in the management of this co-infection, but still, the main question on COVID-19, whether it is occasional, participatory, concurrent, or coincidental needs to be addressed. Several case reports of these co-infections have been explained as causal associations, but the direct contribution in immunocompromised individuals remains to be explored completely. This review aims to provide an update that serves as a guide for the diagnosis and treatment of MCM patients' co-infection with COVID-19. The initial report has suggested that COVID-19 patients might be susceptible to developing invasive fungal infections by different species, including MCM as a co-infection. In spite of this, co-infection has been explored only in severe cases with common triangles: diabetes, diabetes ketoacidosis, and corticosteroids. Pathogenic mechanisms in the aggressiveness of MCM infection involves the reduction of phagocytic activity, attainable quantities of ferritin attributed with transferrin in diabetic ketoacidosis, and fungal heme oxygenase, which enhances iron absorption for its metabolism. Therefore, severe COVID-19 cases are associated with increased risk factors of invasive fungal co-infections. In addition, COVID-19 infection leads to reduction in cluster of differentiation, especially CD4+ and CD8+ T cell counts, which may be highly implicated in fungal co-infections. Thus, the progress in MCM management is dependent on a different strategy, including reduction or stopping of implicit predisposing factors, early intake of active antifungal drugs at appropriate doses, and complete elimination via surgical debridement of infected tissues.

Mucormycosis: risk factors, diagnosis, treatments, and challenges during COVID-19 pandemic

Mucormycosis is a deadly opportunistic disease caused by a group of fungus named mucormycetes. Fungal spores are normally present in the environment and the immune system of the body prevents them from causing disease in a healthy immunocompetent individual. But when the defense mechanism of the body is compromised such as in the patients of diabetes mellites, neustropenia, organ transplantation recipients, and other immune-compromised states, these fungal spores invade our defense mechanism easily causing a severe systemic infection with approximately 45-80% of case fatality. In the present scenario, during the COVID-19 pandemic, patients are on immunosuppressive drugs, glucocorticoids, thus are at high risk of mucormycosis. Patients with diabetes mellitus are further getting a high chance of infection. Usually, the spores gain entry through our respiratory tract affecting the lungs and paranasal sinuses. Besides, they can also enter through damage into the skin or through the gastrointestinal route. This review article presents the current statistics, the causes of this infection in the human body, and its diagnosis with available recent therapies through recent databases collected from several clinics and agencies. The diagnosis and identification of the infection were made possible through various latest medical techniques such as computed tomography scans, direct microscopic observations, MALDI-TOF mass spectrometry, serology, molecular assay, and histopathology. Mucormycosis is so uncommon, no randomized controlled treatment studies have been conducted. The newer triazoles, posaconazole (POSA) and isavuconazole (ISAV) (the active component of the prodrug isavuconazonium sulfate) may be beneficial in patients who are refractory to or intolerant of Liposomal Amphotericin B. but due to lack of early diagnosis and aggressive surgical debridement or excision, the mortality rate remains high. In the course of COVID-19 treatments, there must be more vigilance and alertness are required from clinicians to evaluate these invasive fungal infections.

Mucormycosis and COVID-19-Associated Mucormycosis: Insights of a Deadly but Neglected Mycosis

The ongoing COVID-19 pandemic has quickly become a health threat worldwide, with high mortality and morbidity among patients with comorbidities. This viral infection promotes the perfect setting in patients for the development of opportunistic infections, such as those caused by fungi. Mucormycosis, a rare but deadly fungal infection, has recently increased its incidence, especially in endemic areas, since the onset of the pandemic. COVID-19-associated mucormycosis is an important complication of the pandemic because it is a mycosis hard to diagnose and treat, causing concern among COVID-19-infected patients and even in the already recovered population. The risk factors for the development of mucormycosis in these patients are related to the damage caused by the SARS-CoV-2 itself, the patient's overstimulated immune response, and the therapy used to treat COVID-19, causing alterations such as hyperglycemia, acidosis, endothelial and lung damage, and immunosuppression. In this review, the molecular aspects of mucormycosis and the main risk factors for the development of COVID-19-associated mucormycosis are explained to understand this virus-fungi-host interaction and highlight the importance of this neglected mycosis.

Mucormycosis and COVID-19 pandemic: Clinical and diagnostic approach

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is yet to be controlled worldwide, especially in India. The second wave of coronavirus disease 2019 (COVID-19) led to panic and confusion in India, owing to the overwhelming number of the population that fell prey to this highly infectious virus of recent times. In the second wave of COVID-19, the patients had to fight both the virus and opportunistic infections triggered by fungi and bacteria. Repeated use of steroids, antibiotics, and oxygen masks during the management of severely and critically ill COVID-19 patients nurtured opportunistic infections such as mucormycosis. Despite mucormycosis being a decades-old disease, it has gained notice of its widespread occurrence in COVID-19 patients throughout India. Instances of mucormycosis are usually unearthed in immunocompromised individuals and are caused by the inhalation of filamentous fungi, either from the natural environment or through supportive care units. In the recent outbreak during the second wave of COVID-19 in India, it has been seen to cause secondary infection as it grows along with the treatment of COVID-19. Furthermore, COVID-19 patients with comorbidities such as diabetes were more likely to have the mucormycosis co-infection because of their challenged immune systems' inability to fight it. Despite the hype, mucormycosis still remains neglected and least studied, which is predominantly due to all focus on diagnostics, vaccine, and therapeutic research. In this review, we emphasize mainly on the association of mucormycosis in COVID-19 patients. We also present the molecular mechanism of mucormycosis for a better understanding of the fungal infections in patients who have recently been infected with SARS-CoV-2. Better understanding of fungal pathogens, immediate diagnosis, and management of the infections are crucial in COVID-19 patients, as high mortalities have been recorded in co-infected patients despite recovery from COVID-19.

Evaluating a semi-nested PCR to support histopathology reports of fungal rhinosinusitis in formalin-fixed paraffin-embedded tissue samples

BACKGROUND

Fungal rhinosinusitis (FRS) encompasses a various spectrum of diseases. Histopathology is the "reference method" for diagnosing FRS, but it cannot determine the genus and species. Moreover, in more than 50% of the histopathologically proven cases, the culture elicited no reliable results. This study was an attempt to evaluate the diagnostic efficiency of semi-nested polymerase chain reaction (PCR) from formalin-fixed paraffin-embedded (FFPE) functional endoscopic sinus surgery (FESS) in FRS patients.

METHODS

One hundred ten specimens were subjected to DNA extraction and histopathology examination. The amplification of the β-globin gene by conventional PCR was used to confirm the quality of extracted DNA. The semi-nested PCR was performed using ITS1, ITS2, and ITS4 primers during two steps. Sequencing the internal transcribed spacer region (ITS1-5.8S-ITS2) to identify causative agents was performed on PCR products.

RESULTS

Sixty-four out of 110 samples were positive by histopathology evidence, of which 56 samples (87.5%) were positive by PCR. Out of 46 negative samples by histopathological methods, five samples (10.9%) yielded positive results by PCR. Sensitivity, specificity, positive predictive value, and negative predictive value of the semi-nested PCR method were reported 87.5%, 89.2%, 92.7%, and 85.2%, respectively. The kappa factor between PCR and histopathological methods was 0.76, indicating substantial agreements between these two tests.

CONCLUSION

Due to the acceptable sensitivity and specificity of the present method, it might be used to diagnose fungal sinusitis infections along with microscopic techniques. This method is recommended to confirm the diagnose of suspected fungal sinusitis with negative histopathology results.

Consensus guidelines for the diagnosis and management of invasive fungal disease due to moulds other than Aspergillus in the haematology/oncology setting, 2021

Invasive fungal disease (IFD) due to moulds other than Aspergillus is a significant cause of mortality in patients with malignancies or post haemopoietic stem cell transplantation. The current guidelines focus on the diagnosis and management of the common non-Aspergillus moulds (NAM), such as Mucorales, Scedosporium species (spp.), Lomentospora prolificans and Fusarium spp. Rare but emerging NAM including Paecilomyces variotii, Purpureocillium lilacinum and Scopulariopsis spp. are also reviewed. Culture and histological examination of tissue biopsy specimens remain the mainstay of diagnosis, but molecular methods are increasingly being used. As NAM frequently disseminate, blood cultures and skin examination with biopsy of any suspicious lesions are critically important. Treatment requires a multidisciplinary approach with surgical debridement as a central component. Other management strategies include control of the underlying disease/predisposing factors, augmentation of the host response and the reduction of immunosuppression. Carefully selected antifungal therapy, guided by susceptibility testing, is critical to cure. We also outline novel antifungal agents still in clinical trial which offer substantial potential for improved outcomes in the future. Paediatric recommendations follow those of adults. Ongoing epidemiological research, improvement in diagnostics and the development of new antifungal agents will continue to improve the poor outcomes that have been traditionally associated with IFD due to NAM.

The use of combined PCR, fluorescence in situ hybridisation and immunohistochemical staining to diagnose mucormycosis from formalin-fixed paraffin-embedded tissues

OBJECTIVE

To develop a comprehensive diagnostic system for mucormycosis from formalin-fixed paraffin-embedded tissues, consisting of own-designed real-time polymerase chain reaction (PCR) assays, fluorescence in situ hybridisation, and immunohistochemical staining.

METHODS

We designed 11 primers and probes for specific real-time PCR assays based on genome sequences, and validated the specificity by Aspergillus, Fusarium, Scedosporium, Lomentospora, Cryptococcus and Candida species. Formalin-fixed paraffin-embedded (FFPE) tissues from forty-four mouse model infected by above fungi were collected and extracted DNA by laser capture microdissection (LCM) and direct extraction methods for real-time PCR assays. In addition, seventeen clinical specimens histopathologically proven for mucormycosis were included for specific detection with the new diagnostic system.

RESULTS

The real-time PCR assays allowed detection of a minimum of 10 CFU/ml equivalent gDNA of each species. No cross-reaction with gDNA among species was noted. From mouse model specimens, the sensitivity of real-time PCR in samples extracted with LCM versus direct extraction method was 100% versus 91.43% at Mucorales level and 80% versus 45.71% at species level, respectively. The specificity was 100%. From clinical samples, LCM combined with real-time PCR can test 88.24% (15/17) of Mucorales. Sensitivities of fluorescence in situ hybridisation (FISH) and immunohistochemical staining (IHC) were 70.59% and 41.18%, respectively. Combined LCM-RT-PCR, FISH and IHC yielded positive results in all samples.

CONCLUSIONS

The combination diagnostic system we developed is a culture-independent and robust method which enables rapid species identification from FFPE tissues for timely diagnosis of mucormycosis.

Diagnostic Utility of Polymerase Chain Reaction for Paraffin-embedded Sinus Specimens for Rhinocerebral Mucormycosis Complicated by Internal Carotid Artery Thrombosis and Cerebral Infarction

We herein report a 73-year-old man who experienced cerebral infarction caused by infection with a Mucromycocetes species. A delay in anti-fungal treatment might result in a lethal clinical outcome. We were unable to establish an accurate diagnosis based on histological findings and cerebrospinal fluid culture. Therefore, we performed polymerase chain reaction (PCR) using paraffin-embedded specimens, and based on the findings, successfully started administering anti-fungal treatment. We suggest that PCR using sinus specimens be applied when mucormycosis is suspected as an etiology of cerebral infarction and a confirmative diagnosis cannot be established based on the results of pathological examinations or cerebrospinal fluid culture.

Microbiological and Molecular Diagnosis of Mucormycosis: From Old to New

Members of the order Mucorales may cause severe invasive fungal infections (mucormycosis) in immune-compromised and otherwise ill patients. Diagnosis of Mucorales infections and discrimination from other filamentous fungi are crucial for correct management. Here, we present an overview of current state-of-the-art mucormycosis diagnoses, with a focus on recent developments in the molecular field. Classical diagnostic methods comprise histology/microscopy as well as culture and are still the gold standard. Newer molecular methods are evolving quickly and display great potential in early diagnosis, although standardization is still missing. Among them, quantitative PCR assays with or without melt curve analysis are most widely used to detect fungal DNA in clinical samples. Depending on the respective assay, sequencing of the resulting PCR product can be necessary for genus or even species identification. Further, DNA-based methods include microarrays and PCR-ESI-MS. However, general laboratory standards are still in development, meaning that molecular methods are currently limited to add-on analytics to culture and microscopy.

Performance evaluation of fungal DNA PCR amplification from formalin-fixed paraffin-embedded tissue for diagnosis: Experience of a tertiary reference laboratory

BACKGROUND

Diagnosis of invasive fungal infections from formalin-fixed paraffin-embedded (FFPE) tissues by PCR amplification is a developing technology. One of the difficulties of establishing a validated protocol for this testing is that the gold standard, culture, is much less sensitive than the test being validated.

OBJECTIVES

To validate FFPE PCR as a refence laboratory identification methodology in the absence of abundant gold standard specimens.

METHODS

In this validation, PCR from FFPE tissue was compared to other diagnostic methods for genus/species identification. Four different groups of correlative data from FFPE tissues were used to validate this procedure. Thirteen specimens had culture or serology results and FFPE PCR results, 49 specimens had both immunohistochemistry (IHC) identification and FFPE PCR results, 118 specimens had histological evidence of fungal elements, 64 of which also had FFPE PCR results, and 36 fungal mock tissues or fungal negative tissues were used.

RESULTS

The sensitivity determined from the tissues with positive fungal histopathology was 54%. The specificity of the cases for which there were both culture and FFPE PCR results was 100%. For the correlation with IHC, the specificity was 98%. For the mock tissues and fungal negative tissues, the calculated analytical sensitivity was 94%, specificity was 95%, and accuracy was 94%.

CONCLUSIONS

By uniquely combining various data sources, this study provides a comprehensive framework for how validation can be achieved in the absence of a gold standard and outlines the excellent performance of PCR from FFPE tissue, despite relatively the low sensitivity when compared to histopathology.

Conventional PCR as a reliable method for diagnosing invasive mucormycosis in resource-limited settings

Introduction. Invasive mucormycosis (IM) is a life-threatening infection caused by fungi belonging to the order Mucorales. Histopathology, culture and radiology are the mainstay of diagnosis but lack sensitivity, leading to a delay in timely diagnosis and intervention. Recently, PCR-based approaches have been shown to be a promising method in diagnosing IM.Hypothesis/Gap Statement. Molecular-based approaches may be a valuable adjunct to standard conventional methods for diagnosing IM, especially among culture negatives and patients on antifungal therapy.Aim. In the present study we aimed to evaluate the clinical utility of panfungal and Mucorales-specific PCR for diagnosing IM from various clinical specimens.Methodology. This was a prospective study in which 239 clinically suspected cases of IM attending our tertiary care hospital from August 2015 to March 2018 were enrolled. All the cases were defined as 'proven', 'probable' or 'possible' based on EORTC/MSGERC guidelines. In addition to conventional diagnostics (KOH-calcofluor stain and culture), panfungal and Mucorales-specific PCR assays were also performed. The amplified products were sequenced for species identification. In vitro antifungal susceptibility was performed on all the culture-positive isolates.Results. Among 239 clinically suspected cases of IM, only 140 cases were diagnosed by the demonstration of aseptate ribbon-like hyphae on direct microscopy. Culture was positive in 35.7 % (54/140) of direct microscopy-positive samples. Among the proven cases (n=11), the sensitivity for both Mucorales-specific nested PCR and panfungal PCR was 100 %, but specificity was 91.9 and 73.7% respectively. In probable cases (n=129), the sensitivity of both the PCRs was 98.5 % and specificity for panfungal PCR was 73.7 and 91.9 % for Mucorales-specific PCR.Conclusion. Pan fungal PCR in combination with Mucorales-specific PCR, followed by sequencing, may play a significant role in IM diagnosis especially among those negative for both direct microscopy and culture.

Frequency of occurrence, seasonal variation and antifungal susceptibility of opportunistic Mucorales isolated from hospital soils in Iran

BACKGROUND

Mucorales are opportunistic pathogens that can cause life-threatening diseases predominantly in immunocompromised patients.

OBJECTIVES

This study aimed to investigate the frequency, seasonal variation and antifungal susceptibility of pathogenic Mucorales in the soil collected from seven hospitals in Urmia, Iran, between November 2017 and July 2018 in four different seasons.

METHODS

Mucorales isolates obtained from soil were characterised based on conventional and molecular assays. In addition, in vitro antifungal susceptibility was performed using the CLSI M38Ed3 procedure.

RESULTS

Out of 196 tested soil samples, 80 (40.8%) samples were positive for mucoralean fungi. Rhizopus arrhizus var. arrhizus (n = 47) was the most frequent species followed by Mucor circinelloides (n = 21) and Cunninghamella echinulata (n = 6). A seasonal variation in the frequency of Mucorales in soil was detected with a maximum of culture-positive soil samples detected in wet autumn (43.2%) followed by winter (23.4%), summer (19.7%) and spring (13.6%). In vitro antifungal susceptibility testing for 80 environmental isolates exhibited MIC of ≤2 μg/ml for amphotericin B indicating the smallest range of MIC variation among the tested Mucorales (range: 0.125-2 μg/ml). Among the azoles, posaconazole was the most effective antifungals (GM MIC, 0.724 μg/ml).

CONCLUSIONS

We considered associations of species and seasonal frequencies between soil mucoralean fungi and mucormycosis. The effect of opportunistic Mucorales dominating in the soil and prevalent causative agents of mucormycosis in Iran reported in the literatures but more comprehensive studies are needed to confirm this conclusion.

Molecular Techniques for Genus and Species Determination of Fungi From Fresh and Paraffin-Embedded Formalin-Fixed Tissue in the Revised EORTC/MSGERC Definitions of Invasive Fungal Infection

The EORTC/MSGERC have revised the definitions for proven, probable, and possible fungal diseases. The tissue diagnosis subcommittee was tasked with determining how and when species can be determined from tissue in the absence of culture. The subcommittee reached a consensus decision that polymerase chain reaction (PCR) from tissue, but not immunohistochemistry or in situ hybridization, can be used for genus or species determination under the new EORTC/MSGERC guidelines, but only when fungal elements are identified by histology. Fungal elements seen in tissue samples by histopathology and identified by PCR followed by sequencing should fulfill the definition of a proven fungal infection, identified to genus/species, even in the absence of culture. This summary discusses the issues that were deliberated by the subcommittee to reach the consensus decision and outlines the criteria a laboratory should follow in order to produce data that meet the EORTC/MSGERC definitions.

Rhinocerebral mucormycosis to the rise? The impact of the worldwide diabetes epidemic

The authors present seven cases of rhinocerebral mucormycosis associated to diabetes mellitus, which is a disease with epidemic proportions affecting individuals worldwide, particularly in developing countries, and which poses significant morbidity and mortality. Mucormycosis is an opportunistic fungal infection with high mortality and requires an invasive therapeutic approach to save the patient’s life with significant morbidity and sequelae, thus prevention is crucial.

Identification of pathogens causing invasive fungal rhinosinusitis in surgical biopsies using polymerase chain reaction

BACKGROUND

Invasive fungal rhinosinusitis is associated with high morbidity and mortality. Rapid pathogen identification is mandatory, but fresh tissue is not always available. A polymerase chain reaction method was designed in order to detect fungi in formalin-fixed paraffin-embedded samples. This was applied to a retrospective series of tissue biopsies from Thai patients with invasive fungal rhinosinusitis.

METHODS

Tissue blocks from 64 cases yielded adequate DNA. Three sequential polymerase chain reaction were performed: ZP3 (housekeeping gene) and panfungal polymerase chain reactions, and a differentiating polymerase chain reaction based on the 5.8s ribosomal RNA and internal transcribed spacer 2 regions. The polymerase chain reaction products were then sequenced.

RESULTS

Polymerase chain reaction identified a fungal pathogen in 20 of 64 cases (31 per cent). Aspergillus species was the most common cause of invasive fungal rhinosinusitis (nine cases). Other causes included candida (n = 4), cladosporium (n = 4), mucor (n = 1), alternaria (n = 1) and dendryphiella (n = 1) species.

CONCLUSION

Polymerase chain reaction can provide rapid identification of fungal pathogens in paraffin-embedded tissue, enabling prompt treatment of invasive fungal rhinosinusitis.

A New Age in Molecular Diagnostics for Invasive Fungal Disease: Are We Ready?

Invasive fungal diseases (IFDs) present an increasing global burden in immunocompromised and other seriously ill populations, including those caused by pathogens which are inherently resistant or less susceptible to antifungal drugs. Early diagnosis encompassing accurate detection and identification of the causative agent and of antifungal resistance is critical for optimum patient outcomes. Many molecular-based diagnostic approaches have good clinical utility although interpretation of results should be according to clinical context. Where an IFD is in the differential diagnosis, panfungal PCR assays allow the rapid detection/identification of fungal species directly from clinical specimens with good specificity; sensitivity is also high when hyphae are seen in the specimen including in paraffin-embedded tissue. Aspergillus PCR assays on blood fractions have good utility in the screening of high risk hematology patients with high negative predictive value (NPV) and positive predictive value (PPV) of 94 and 70%, respectively, when two positive PCR results are obtained. The standardization, and commercialization of Aspergillus PCR assays has now enabled direct comparison of results between laboratories with commercial assays also offering the simultaneous detection of common azole resistance mutations. Candida PCR assays are not as well standardized with the only FDA-approved commercial system (T2Candida) detecting only the five most common species; while the T2Candida outperforms blood culture in patients with candidemia, its role in routine Candida diagnostics is not well defined. There is growing use of Mucorales-specific PCR assays to detect selected genera in blood fractions. Quantitative real-time Pneumocystis jirovecii PCRs have replaced microscopy and immunofluorescent stains in many diagnostic laboratories although distinguishing infection may be problematic in non-HIV-infected patients. For species identification of isolates, DNA barcoding with dual loci (ITS and TEF1α) offer optimal accuracy while next generation sequencing (NGS) technologies offer highly discriminatory analysis of genetic diversity including for outbreak investigation and for drug resistance characterization. Advances in molecular technologies will further enhance routine fungal diagnostics.

Global guideline for the diagnosis and management of mucormycosis: an initiative of the European Confederation of Medical Mycology in cooperation with the Mycoses Study Group Education and Research Consortium

Mucormycosis is a difficult to diagnose rare disease with high morbidity and mortality. Diagnosis is often delayed, and disease tends to progress rapidly. Urgent surgical and medical intervention is lifesaving. Guidance on the complex multidisciplinary management has potential to improve prognosis, but approaches differ between health-care settings. From January, 2018, authors from 33 countries in all United Nations regions analysed the published evidence on mucormycosis management and provided consensus recommendations addressing differences between the regions of the world as part of the "One World One Guideline" initiative of the European Confederation of Medical Mycology (ECMM). Diagnostic management does not differ greatly between world regions. Upon suspicion of mucormycosis appropriate imaging is strongly recommended to document extent of disease and is followed by strongly recommended surgical intervention. First-line treatment with high-dose liposomal amphotericin B is strongly recommended, while intravenous isavuconazole and intravenous or delayed release tablet posaconazole are recommended with moderate strength. Both triazoles are strongly recommended salvage treatments. Amphotericin B deoxycholate is recommended against, because of substantial toxicity, but may be the only option in resource limited settings. Management of mucormycosis depends on recognising disease patterns and on early diagnosis. Limited availability of contemporary treatments burdens patients in low and middle income settings. Areas of uncertainty were identified and future research directions specified.

Molecular Diagnostics of Mucormycosis in Hematological Patients: A Literature Review

OBJECTIVES

to analyze the results of molecular methods applying for the diagnosis of mucormycosis in hematologic patients based on a literature review.

DATA SOURCES

A systematic search in databases PubMed, Google Scholar for August 2019. Review eligibility criteria: original articles published in English, studies of molecular methods for the diagnosis of mucormycosis in hematologic patients.

RESULTS

We analyzed the research data from 116 hematological patients with mucormycosis, including children (6%). Patients with localized forms of mucormycosis prevailed (72%), and lung involvement was diagnosed in 58% of these cases. For molecular verification of the causative agent of mucormycosis, blood serum was most often used, less commonly postoperative and autopsy material, biopsy specimens, formalin-fixed paraffin-embedded samples and bronchoalveolar lavage, pleural fluid and sputum. The sensitivity of molecular diagnostics of mucormycosis in a cohort of hematological patients was 88.2%.

CONCLUSION

The use of molecular techniques along with standard mycological methods will improve the diagnostics of mucormycosis in hematologic patients. However, prospective studies of the effectiveness of molecular methods for the diagnosis of mucormycosis of various etiologies in hematological patients, including children, using bronchoalveolar lavage (BAL) and cerebrospinal fluid (CSF) are needed.

Diagnosis and Treatment of Acute Invasive Fungal Sinusitis in Cancer and Transplant Patients

PURPOSE OF REVIEW

Modern advances in oncologic and end-organ therapies have led to an increase in immunocompromised patients and a corresponding rise in acute invasive fungal sinusitis (AIFS). Here, we present a comprehensive medical and surgical approach to the diagnosis and management of immunocompromised cancer and transplant patients with AIFS.

RECENT FINDINGS

Aspergillus and Mucorales are the most common fungi to cause AIFS, though atypical fungal pathogens have been implicated particularly among patients on azole prophylaxis. Symptoms present in the majority of AIFS cases include fever, nasal congestion, and facial swelling. Nasal endoscopy and radiology are adjuncts to clinical exam with the gold standard diagnostic test still being histopathology, though molecular testing such as panfungal PCR is playing a larger role. The treatment of AIFS requires surgery, antifungal therapy, and reversal of immunosuppression. We recommend initiation of liposomal amphotericin B as an empiric therapy for AIFS, transitioned to targeted therapy when/if a fungal pathogen is identified. Goals of surgery include diagnostic sampling and debridement of necrotic tissue. Equally, if not more important, is reversal of underlying immune suppression. Immune-stimulating therapies hold promise for reducing mortality, but require additional study. Despite improvements in medical and surgical management of AIFS, mortality continues to approach 50%. Early diagnosis of this disease entity followed by aggressive surgical and medical management are important, including reversal of the underlying immunosuppression.

A Guide to Investigating Suspected Outbreaks of Mucormycosis in Healthcare

This report serves as a guide for investigating mucormycosis infections in healthcare. We describe lessons learned from previous outbreaks and offer methods and tools that can aid in these investigations. We also offer suggestions for conducting environmental assessments, implementing infection control measures, and initiating surveillance to ensure that interventions were effective. While not all investigations of mucormycosis infections will identify a single source, all can potentially lead to improvements in infection control.

Fatal rhinocerebral mucormycosis in a patient with ulcerative colitis receiving azathioprine and corticosteroid

Background and Purpose:

Rhinocerebral mucormycosis is a rare fatal fungal infection which is on a growing trend, particularly among immunocompromised patients. Immunosuppressive drugs, including corticosteroids and antimetabolites, increase the risk of this infection. Herein, we reported the case of fulminant rhinocerebral mucormycosis in a patient with ulcerative colitis receiving azathioprine and corticosteroid.

Case report:

A 58-year-old woman was admitted to the hospital in a state of coma with an extensive necrosis in her nose. She was afflicted with intestinal bleeding after 1 month of fasting and was treated with azathioprine and a high dose of prednisolone for ulcerative colitis 2 months prior to hospital admission. The direct microscopic examination of the necrotic tissues of the paranasal sinuses showed several non-septate hyphae consistent with Mucorales. Culture media yielded Rhizopus species, which was identified as Rhizopus oryzae by internal transcribed spacer polymerase chain reaction sequencing. Despite the implementation of surgical and pharmaceutical (liposomal amphotericin B) treatments, the patient expired after 2 weeks of admission.

Conclusion:

The gastroenterologists should be aware of the adverse effect of immunosuppressive drugs they prescribe for the treatment of inflammatory bowel disease.