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Clinical Microbiology and Infection :... Oct 2009Zygomycetes are filamentous fungi with a worldwide distribution. This class of fungi encompasses two orders, i.e. the Mucorales and the Entomophthorales. Members of the... (Review)
Review
Zygomycetes are filamentous fungi with a worldwide distribution. This class of fungi encompasses two orders, i.e. the Mucorales and the Entomophthorales. Members of the latter are associated with chronic cutaneous and subcutaneous infections that are limited to the tropics and rarely disseminate to internal organs. The order Mucorales includes several species involved in rhinocerebral, pulmonary, cutaneous, gastrointestinal and other less frequent infections in immunocompetent and immunocompromised individuals, and is characterized by a tendency to disseminate. Portals of entry of zygomycetes are usually the lungs, skin, and gastrointestinal tract. A characteristic property of zygomycetes is their tendency to invade blood vessels and to cause thrombosis-processes that result in subsequent necrosis of involved tissues. Risk factors associated with zygomycosis include prolonged neutropenia and use of corticosteroids, solid organ or haematopoietic stem cell transplantation, AIDS, poorly controlled diabetes mellitus, iron chelation with deferoxamine, burns, wounds, malnutrition, extremes of age, and intravenous drug abuse. Recently, the widespread use of voriconazole for prophylaxis or treatment of aspergillosis in patients with haematological malignancies has been linked with a rise in the numbers of cases of invasive zygomycosis. As the symptoms, clinical signs and imaging findings of these infections are non-specific, a high index of suspicion is required for timely diagnosis. Early diagnosis, correction of the underlying predisposing factors, aggressive surgical debridement of all infected tissues and lengthy administration of antifungals are the only potentially curative options for this rare but emerging invasive fungal infection.
Topics: Antifungal Agents; Debridement; Entomophthorales; Humans; Mucorales; Risk Factors; Zygomycosis
PubMed: 19754751
DOI: 10.1111/j.1469-0691.2009.02974.x -
International Ophthalmology Jun 2023Mucormycosis is a severe fungal infection caused by species of the order Mucorales. Early and accurate diagnosis is a prerequisite in the management of the disease. In...
PURPOSE
Mucormycosis is a severe fungal infection caused by species of the order Mucorales. Early and accurate diagnosis is a prerequisite in the management of the disease. In the present study, we evaluated and compared two PCR-based techniques for the diagnosis and identification of mucormycosis in patients with rhino-orbital mucormycosis (ROM) post-COVID-19.
METHODS
Diagnosed clinically and radiologically, 25 patients of ROM were included in the study and endoscopically or blind collected nasal swabs or orbital tissues were submitted for microbiological evaluation (direct microscopy + culture) and PCR using primers targeting two different loci (ITS and 28S rDNA region) for diagnosis. All PCR products were further processed for species identification using Sanger sequencing whenever possible.
RESULT
Of the 25 samples included in the study, 16 samples were positive for presence of fungal filaments by Smear suggestive of Mucorales sp., but only 7/25 grew in culture. ITS-based PCR was able to identify mucormycosis in 7/25 (28%) samples and 28S rDNA PCR showed positivity for 19/25 (76%) samples. Rhizopus oryzae was found to be the predominant species in our study. The sensitivity and specificity of 28S rDNA PCR compared to culture were found to be 85.71% and 27.78%, respectively, while for ITS-based PCR, they were 42.86% and 77.78%, respectively.
CONCLUSIONS
28S rDNA-based PCR is a reliable and sensitive method for early diagnosis of mucormycosis. Molecular techniques have shown a promising future to provide quick and effective treatment by accurately identifying the aetiologic agent.
Topics: Humans; Mucormycosis; COVID-19; Mucorales; Mycoses; DNA, Ribosomal; Eye Diseases; COVID-19 Testing
PubMed: 36414852
DOI: 10.1007/s10792-022-02577-y -
Virulence Nov 2017Mucormycoses are life-threatening infections in immunocompromised patients. This study characterizes the response of human mononuclear cells to different Mucorales and...
Mucormycoses are life-threatening infections in immunocompromised patients. This study characterizes the response of human mononuclear cells to different Mucorales and Ascomycota. PBMC, monocytes, and monocyte derived dendritic cells (moDCs) from healthy donors were stimulated with resting and germinated stages of Mucorales and Ascomycota. Cytokine response and expression of activation markers were studied. Both inactivated germ tubes and resting spores of Rhizopus arrhizus and other human pathogenic Mucorales species significantly stimulated mRNA synthesis and secretion of proinflammatory cytokines. Moreover, R. arrhizus spores induced the upregulation of co-stimulatory molecules on moDCs and a specific T-helper cell response. Removal of rodlet hydrophobins by hydrofluoric acid treatment of A. fumigatus conidia resulted in enhanced immunogenicity, whereas the cytokine response of PBMCs to dormant R. arrhizus spores was not influenced by hydrofluoric acid. Scanning electron micrographs of Mucorales spores did not exhibit any morphological correlates of rodlet hydrophobins. Taken together, this study revealed striking differences in the response of human mononuclear cells to resting stages of Ascomycota and Mucorales, which may be explained by absence of an immunoprotective hydrophobin layer in Mucorales spores.
Topics: Cytokines; Dendritic Cells; Fungal Proteins; Humans; Leukocytes, Mononuclear; Mucorales; Mucormycosis; Phagocytes; Spores, Fungal; Th1 Cells
PubMed: 28783439
DOI: 10.1080/21505594.2017.1342920 -
Frontiers in Cellular and Infection... 2023Mucoromycosis is a highly aggressive angio-invasive disease of humans caused by fungi in the zygomycete order, Mucorales. While is the principal agent of mucoromycosis,...
Mucoromycosis is a highly aggressive angio-invasive disease of humans caused by fungi in the zygomycete order, Mucorales. While is the principal agent of mucoromycosis, other Mucorales fungi including , , , , and are able to cause life-threatening rhino-orbital-cerebral, pulmonary, gastro-intestinal and necrotising cutaneous infections in humans. Diagnosis of the disease currently relies on non-specific CT, lengthy and insensitive culture from invasive biopsy, and time-consuming histopathology of tissue samples. At present, there are no rapid antigen tests that detect Mucorales-specific biomarkers of infection, and which allow point-of-care diagnosis of mucoromycosis. Here, we report the development of an IgG2b monoclonal antibody (mAb), TG11, which binds to extracellular polysaccharide (EPS) antigens of between 20 kDa and 250 kDa secreted during hyphal growth of Mucorales fungi. The mAb is Mucorales-specific and does not cross-react with other yeasts and molds of clinical importance including , , , , and species. Using the mAb, we have developed a Competitive lateral-flow device that allows rapid (30 min) detection of the EPS biomarker in human serum and bronchoalveolar lavage (BAL), with a limit of detection (LOD) in human serum of ~100 ng/mL serum (~224.7 pmol/L serum). The LFD therefore provides a potential novel opportunity for detection of mucoromycosis caused by different Mucorales species.
Topics: Humans; Mucorales; Antibodies, Monoclonal; Aspergillus; Fusarium; Biomarkers
PubMed: 38145040
DOI: 10.3389/fcimb.2023.1305662 -
Pathology, Research and Practice Aug 2022Due to Corona Virus disease -19, India saw a surge of mucormycosis cases, associated with high death rate. India, during the month of May to July 2021 saw a surge of...
INTRODUCTION
Due to Corona Virus disease -19, India saw a surge of mucormycosis cases, associated with high death rate. India, during the month of May to July 2021 saw a surge of mucormycosis from all states, with close to 50,000 cases just in a span of 3 months.
OBJECTIVE
To examine the histopathological appearances of rhino-orbital/rhino-maxillary/sino-nasal mucormycosis in the backdrop of the ongoing COVID 19 pandemic.
MATERIAL AND METHODS
The study involved analysis of 60 biopsy samples of suspected rhino-maxillary /rhino-orbital mucormycosis received from post-COVID-19 patients. A preliminary review of the slides showing hyphal forms of fungal organisms with un-doubtful tissue / mucosal invasion was included. All samples were examined under Hematoxylin and Eosin stains along with special fungal stains. Data thus obtained were analyzed statistically. Special stains for fungus namely Periodic Acidic Schiff (PAS) and Gomori Methenamine silver (GMS) were utilized to confirm and/or to differentiate the fungal organisms and to highlight the cell wall of the fungus.
RESULTS
The mean age of the patients with mucormycosis was 51.68 years and 72 (83.33%) of them were males. Acute type of inflammation was noted in 44 (73.33%), granulomatous inflammation in 14 (23.33%) of cases. Bony invasion and perineural invasion was observed in 5 (8.33%) and 55 (91.67%) cases, respectively. The dominant fungus were mucorales in 58 (96.67%), aspergillous, along with mucorales in 12 (20%) and combination of mucorales and candida identified in 8 (13.33%) cases.
CONCLUSION
Besides all the histological appearance of angioinvasion, bone, and soft tissue invasion, a notable aspect was the shift in inflammatory pattern, which was more granulomatous in nature, with a decrease in fungal load correlating with the drop of COVID second wave. This proves that as immunity develops, the host's response to secondary opportunistic infections changes.
Topics: COVID-19; Female; Humans; Male; Middle Aged; Mucorales; Mucormycosis; Pandemics; Retrospective Studies
PubMed: 35749915
DOI: 10.1016/j.prp.2022.153981 -
BMC Veterinary Research Jun 2022Host-associated gut microbial communities are key players in shaping the fitness and health of animals. However, most current studies have focused on the gut bacteria,...
BACKGROUND
Host-associated gut microbial communities are key players in shaping the fitness and health of animals. However, most current studies have focused on the gut bacteria, neglecting important gut fungal and archaeal components of these communities. Here, we investigated the gut fungi and archaea community composition in Large White piglets using shotgun metagenomic sequencing, and systematically evaluated how community composition association with gut microbiome, functional capacity, and serum metabolites varied across three weaning periods.
RESULTS
We found that Mucoromycota, Ascomycota and Basidiomycota were the most common fungi phyla and Euryarchaeota was the most common archaea phyla across individuals. We identified that Methanosarcina siciliae was the most significantly different archaea species among three weaning periods, while Parasitella parasitica, the only differential fungi species, was significantly and positively correlated with Methanosarcina siciliae enriched in day 28 group. The random forest analysis also identified Methanosarcina siciliae and Parasitella parasitica as weaning-biased archaea and fungi at the species level. Additionally, Methanosarcina siciliae was significantly correlated with P. copri and the shifts of functional capacities of the gut microbiome and several CAZymes in day 28 group. Furthermore, characteristic successional alterations in gut archaea, fungi, bacteria, and serum metabolites with each weaning step revealed a weaning transition coexpression network, e.g., Methanosarcina siciliae and P. copri were positively and significantly correlated with 15-HEPE, 8-O-Methyloblongine, and Troxilin B3.
CONCLUSION
Our findings provide a deep insight into the interactions among gut archaea, fungi, bacteria, and serum metabolites and will present a theoretical framework for understanding gut bacterial colonization and succession association with archaea during piglet weaning transitions.
Topics: Animals; Archaea; Bacteria; Mucorales; Physical Conditioning, Animal; Swine; Weaning
PubMed: 35751084
DOI: 10.1186/s12917-022-03330-4 -
Journal of Clinical Microbiology Jan 2023There has been significant increase in the use of molecular tools for the diagnosis of invasive aspergillosis (IA) and mucormycosis. However, their range of detection...
There has been significant increase in the use of molecular tools for the diagnosis of invasive aspergillosis (IA) and mucormycosis. However, their range of detection may be too limited as species diversity and coinfections are increasing. Here, we aimed to evaluate a molecular workflow based on a new multiplex PCR assay detecting the whole Aspergillus genus and the Mucorales order followed by a species-specific PCR or a DNA-sequencing approach for IA and/or mucormycosis diagnosis and species identification on serum. Performances of the MycoGENIE Aspergillus spp./Mucorales spp. duplex PCR kit were analyzed on a broad range of fungal strains and on sera from high-risk patients prospectively over a 12-month period. The kit allowed the detection of nine Aspergillus species and 10 Mucorales (eight genera) strains assessed. No cross-reactions between the two targets were observed. Sera from 744 patients were prospectively analyzed, including 35 IA, 16 mucormycosis, and four coinfections. Sensitivity varies from 85.7% (18/21) in probable/proven IA to 28.6% (4/14) in COVID-19-associated pulmonary aspergillosis. PCR-positive samples corresponded to 21 A. fumigatus, one A. flavus, and one A. nidulans infections. All the disseminated mucormycosis were positive in serum (14/14), including the four Aspergillus coinfections, but sensitivity fell to 33.3% (2/6) in localized forms. DNA sequencing allowed Mucorales identification in serum in 15 patients. Remarkably, the most frequent species identified was (eight cases), whereas it is barely found in fungal culture. This molecular workflow is a promising approach to improve IA and mucormycosis diagnosis and epidemiology.
Topics: Humans; Mucormycosis; Multiplex Polymerase Chain Reaction; Coinfection; Workflow; COVID-19; Aspergillosis; Mucorales; Invasive Fungal Infections; Aspergillus; Sequence Analysis, DNA; DNA; DNA, Fungal; COVID-19 Testing
PubMed: 36533925
DOI: 10.1128/jcm.01409-22 -
The Journal of Infection Aug 2020We aimed to assess the clinical relevance of the marketed pan-mucorales real-time PCR assay MucorGenius® (Pathonostics) on pulmonary specimens relative to that of...
OBJECTIVES
We aimed to assess the clinical relevance of the marketed pan-mucorales real-time PCR assay MucorGenius® (Pathonostics) on pulmonary specimens relative to that of in-house PCR assays and conventional mycology for the diagnosis of mucormycosis.
METHODS
In total, 319 pulmonary samples from severely immunosuppressed patients at risk for invasive mold disease (IMD) were retrospectively included. Direct examination, mycological culture, and PCR testing were performed using three genus-specific in-house mucorales real-time PCR assays and MucorGenius®PCR. Results from Aspergillus testing, including galactomannan and PCR, were also collected.
RESULTS
The 319 patients were graded according to modified EORTC-MSG criteria as proven/probable mucormycosis (n=6), proven/probable invasive aspergillosis (IA) (n=63), Aspergillus-mucorales co-infections (n=4), possible IMD (n=152), and excluded IMD (n=94). The in-house and MucorGenius®PCR assays were positive for 33 (10.3%) and 27 (8.5%) samples, respectively, whereas culture was positive for only 10 (3.1%). The in-house and MucorGenius®PCR assays showed a sensitivity of 100% (10/10) and 90% (9/10) and a specificity of 95.7% and 97.9%, respectively. Both PCR assays allowed the detection of mucorales DNA in samples from 10 possible cases and six IA, all missed by culture.
CONCLUSIONS
MucorGenius® showed good performance, despite missing some low fungal burden. Combining mucorales PCR with EORTC-MSG criteria greatly improved the diagnosis of mucormycosis.
Topics: DNA, Fungal; Humans; Invasive Fungal Infections; Mucorales; Mucormycosis; Retrospective Studies; Sensitivity and Specificity
PubMed: 32474046
DOI: 10.1016/j.jinf.2020.05.051 -
Clinical Microbiology and Infection :... Oct 2009Iron is an essential element for cell growth and development, contributing to DNA synthesis and regulating the G(1)-phase to S-phase transition. Moreover, iron is... (Review)
Review
Iron is an essential element for cell growth and development, contributing to DNA synthesis and regulating the G(1)-phase to S-phase transition. Moreover, iron is important for the virulence of the majority of microorganisms, and the function of the genes regulating iron uptake is coupled with the manifestations of the virulence phenotype. All fungi elaborate specific uptake mechanisms to sequester iron, and most commonly produce small molecules with high affinity for iron, the siderophores. The importance of iron appears to be particularly high for Zygomycetes, which grow abundantly in iron-rich media, and all the known predisposing factors for zygomycosis have, as a common feature, the increased availability of free iron. Among the known iron chelators, deferoxamine supports the growth of Zygomycetes because it acts as xenosiderophore, delivering iron to iron-uptaking molecules of these species. Conversely, the newer iron chelators deferiprone and deferasirox do not exhibit similar activity, apparently because they share higher affinity constants for iron and, as a result, deprive the fungi of iron, inhibiting their growth. This activity has been documented in various culture systems and in many animal models of zygomycosis, and therefore suggests that these drugs might be used as adjuvant treatment for systemic zygomycosis. There are few case reports in which the newer iron chelators have been used as antifungals, and their possible benefit must be verified in a prospective randomized trial.
Topics: Antifungal Agents; Chelating Agents; Entomophthorales; Iron; Mucorales; Virulence; Zygomycosis
PubMed: 19754753
DOI: 10.1111/j.1469-0691.2009.02976.x -
PLoS Pathogens Jan 2020Fungal pathogens represent a major human threat affecting more than a billion people worldwide. Invasive infections are on the rise, which is of considerable concern... (Review)
Review
Fungal pathogens represent a major human threat affecting more than a billion people worldwide. Invasive infections are on the rise, which is of considerable concern because they are accompanied by an escalation of antifungal resistance. Deciphering the mechanisms underlying virulence traits and drug resistance strongly relies on genetic manipulation techniques such as generating mutant strains carrying specific mutations, or gene deletions. However, these processes have often been time-consuming and cumbersome in fungi due to a number of complications, depending on the species (e.g., diploid genomes, lack of a sexual cycle, low efficiency of transformation and/or homologous recombination, lack of cloning vectors, nonconventional codon usage, and paucity of dominant selectable markers). These issues are increasingly being addressed by applying clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 mediated genetic manipulation to medically relevant fungi. Here, we summarize the state of the art of CRISPR-Cas9 applications in four major human fungal pathogen lineages: Candida spp., Cryptococcus neoformans, Aspergillus fumigatus, and Mucorales. We highlight the different ways in which CRISPR has been customized to address the critical issues in different species, including different strategies to deliver the CRISPR-Cas9 elements, their transient or permanent expression, use of codon-optimized CAS9, and methods of marker recycling and scarless editing. Some approaches facilitate a more efficient use of homology-directed repair in fungi in which nonhomologous end joining is more commonly used to repair double-strand breaks (DSBs). Moreover, we highlight the most promising future perspectives, including gene drives, programmable base editors, and nonediting applications, some of which are currently available only in model fungi but may be adapted for future applications in pathogenic species. Finally, this review discusses how the further evolution of CRISPR technology will allow mycologists to tackle the multifaceted issue of fungal pathogenesis.
Topics: Aspergillus fumigatus; CRISPR-Cas Systems; Cryptococcus neoformans; Forecasting; Gene Editing; Humans; Mucorales; Mycology
PubMed: 31945142
DOI: 10.1371/journal.ppat.1008201