Histopathologic diagnosis of fungal infections in the 21st century

Detection of fungal pathogens by a histomolecular approach using targeted-massive parallel sequencing on formalin-fixed tissues: a retrospective study

OBJECTIVES

Because fungal infections (FI) are frequently encountered by pathologists, it is crucial to improve fungal diagnosis on formalin-fixed paraffin-embedded tissues (FT). We aimed to investigate if a histomolecular approach using targeted-massive parallel sequencing (MPS) could help detect and identify fungi on FT when no mycological diagnosis is available on fresh tissue.

METHODS

Forty-nine FT from 48 patients with histopathological FI diagnosis but without mycological identification were retrospectively included. Histopathology defined the fungal pattern and the tissue injuries. Panfungal PCRs were performed using ITS-3/ITS-4 and MITS-2A/MITS-2B primers. Amplicons were sequenced using Sanger sequencing and targeted-MPS. Probabilities of fungal identification for both sequencing techniques and both primers were compared.

RESULTS

The median age was 57 years (Q1: 47; Q3: 64). Fungal cultures were performed in 22/49 (44.9%) samples but failed to identify the pathogenic fungi. Fungal identification by Sanger sequencing was successful in 17/49 (34.7%; [0.214-0.480]) FT; the probability of fungal identification was 32.7% (16/49; [0.195-0.458]) for ITS-3/ITS-4; and 22.4% (11/49; [0.108-0.341]) for MITS-2A/MITS-2B. Targeted-MPS was successful in 35/49 (71.4%; [0.588-0.841]) samples; the probability of fungal identification was 59.2% (29/49; [0.454-0.729]) for ITS-3/ITS-4 primers and 61.2% (30/49; [0.476-0.749]) for MITS-2A/MITS-2B. The probability of fungal identification by targeted-MPS (35/49 [71.4%]) was significantly higher than that of Sanger sequencing (17/49 [34.7%]; p < 0.0001). We assessed that this approach could have optimized care for 22/48 (45.8%) patients.

DISCUSSION

Integrated histomolecular diagnosis using targeted-MPS could secure diagnosis and help clinicians prescribe the most appropriate antifungal therapy in the absence of mycological identification.

Autonomous learning of pathologists' cancer grading rules

Deep learning (DL) algorithms have demonstrated remarkable proficiency in histopathology classification tasks, presenting an opportunity to discover disease-related features escaping visual inspection. However, the "black box" nature of DL obfuscates the basis of the classification. Here, we develop an algorithm for interpretable Deep Learning (IDL) that sheds light on the links between tissue morphology and cancer biology. We make use of a generative model trained to represent images via a combination of a semantic latent space and a noise vector to capture low level image details. We traversed the latent space so as to induce prototypical image changes associated with the disease state, which we identified via a second DL model. Applied to a dataset of clear cell renal cell carcinoma (ccRCC) tissue images the AI system pinpoints nuclear size and nucleolus density in tumor cells (but not other cell types) as the decisive features of tumor progression from grade 1 to grade 4 - mirroring the rules that have been used for decades in the clinic and are taught in textbooks. Moreover, the AI system posits a decrease in vasculature with increasing grade. While the association has been illustrated by some previous reports, the correlation is not part of currently implemented grading systems. These results indicate the potential of IDL to autonomously formalize the connection between the histopathological presentation of a disease and the underlying tissue architectural drivers.

Emerging Treatments in Neonatal Fungal Infections: Progress and Prospects

Fungal infections in neonates are potentially life threatening. The differential diagnosis for neonatal rashes is extensive, with common culprits including both bacteria and fungi. Candida albicans is the predominant fungal pathogen, causing infections that range from superficial disease to severe systemic conditions, including sepsis and meningitis. Neonates, especially those who are preterm, are particularly susceptible because of developmentally immature immune systems and the use of invasive procedures and devices in neonatal intensive care units. Congenital cutaneous candidiasis, acquired in utero or during delivery, can lead to disseminated infection with high mortality rates. Early diagnosis and prompt antifungal treatment are crucial but challenging because of subtle clinical presentations, making accurate identification of the offending organism essential for selecting the appropriate treatment. Candida species account for the majority of neonatal fungal infections, with different species necessitating distinct treatments because of varying susceptibility profiles. Aspergillus, another significant pathogen, poses high mortality risks and can present either cutaneously or systemically. Malassezia, though less common, primarily affects preterm infants with catheter-related fungemia. Other fungal species, including Zygomycetes, Trichosporon, and Cryptococcus, rarely produce neonatal infections but are noteworthy for consideration. Treatment of fungal infection is critical despite the relative paucity of information regarding the clinical pharmacology of many antifungal drugs in neonates. We review the major antifungal agents (e.g., amphotericin B, the echinocandins, the azoles) and provide pharmacologic and dosing information. Finally, preventive strategies, including the use of stringent aseptic techniques and careful clinical monitoring, are essential to mitigate both the incidence and severity of these infections in neonates and infants in the first months of life.

Cladosporium species novum Invasive Pulmonary Infection in a Patient with Post-COVID-19 Syndrome and AIDS

Background and Clinical Significance: Since the prevalence of fungal lung infections is increasing, certain agents, such as Cladosporium spp., have emerged as unexpected causes. Cladosporium spp. fungi are ubiquitous in environments such as soil, fruits, and wine corks; they are a part of the normal human skin flora; and they are known respiratory allergens. Case Presentation: A patient with a history of post-COVID-19 syndrome and AIDS presented with lung pathology indicative of an invasive fungal infection. The initial histopathological examination revealed numerous yeast-like cells with narrow-based budding, which led to a mistaken diagnosis of cryptococcosis. However, further detailed examination revealed sparse hyphae in the lung tissue, suggesting a more complex fungal infection. Molecular analyses and sequence BLAST alignment were performed, ultimately identifying the infectious agent as "Cladosporium species novum", a rare cause of invasive pulmonary cladosporiasis. Conclusions: Invasive pulmonary cladosporiasis is a rare condition, and the morphological features of the fungus alone were insufficient to establish a correct diagnosis. A comprehensive pathohistological and molecular approach with bioinformatics tools is essential for the correct identification of rare and potentially life-threatening fungal pathogens in immunocompromised patients.

Invasive bony destructive orbital aspergillosis in an immunocompetent child: a case report

PURPOSE

To report a case of invasive sino-orbital aspergillosis, a rare condition in a healthy child. The patient presented with orbital involvement and bone destruction, an exceedingly uncommon occurrence that mimics other invasive inflammatory or neoplastic orbital lesions.

CASE PRESENTATION

A 4-year-old female presented with an ill-defined, irregular, erythematous mass-like lesion measuring 8 × 10 mm on the left upper eyelid. Orbital computed tomography (CT) revealed an infiltrative soft tissue mass with bone erosions and destruction on the medial side of the frontal bone, extending toward the fronto-maxillary suture in the anterior orbit. Except for the left anterior ethmoidal sinus, the other paranasal sinuses were nearly clear. Magnetic resonance imaging (MRI) showed enhancement of the adjacent dura mater near the site of bony erosion and lesion expansion. The lesion was surgically excised, with drainage of mucopurulent discharge. Pathological examination revealed necrotizing granulomatous inflammation and fungal hyphae, with Aspergillus fumigatus growth confirmed by culture. The patient was diagnosed with invasive orbital aspergillosis. She was treated with intravenous and then oral voriconazole, and there was no recurrence of the disease.

CONCLUSIONS

Invasive orbital aspergillosis with bone destruction of the orbital walls can occur in immunocompetent individuals, including children, without any predisposing factors. It can mimic other invasive orbital diseases, leading to delayed diagnosis and treatment, which may result in life-threatening outcomes if intracranial spread occurs. Therefore, timely orbital biopsy of the lesions is crucial.

Aspergillosis in 41 wild bird species in the eastern United States: a 22-year retrospective review

Aspergillosis is the most commonly and widely reported fungal infection in birds. Disease development is often secondary to stressors that cause immunocompromise, and it is typically regarded as a disease of captivity. We retrospectively evaluated data from 133 birds diagnosed with aspergillosis at the Southeastern Cooperative Wildlife Disease Study from 2001-2023 to assess diversity and relative frequency across avian taxa, gross and histologic lesion patterns, and comorbidities. Of 10 taxonomic orders represented, Charadriiformes (shorebirds; n = 35) and Accipitriformes (raptors; n = 32) were most common. Among them, the laughing gull (Leucophaeus atricilla; n = 20) and bald eagle (Haliaeetus leucocephalus; n = 14) were infected most commonly. Gross lesions were most frequent in lung (n = 80), air sac (n = 71), or celomic cavity lining (n = 42). Four distinct gross lesion patterns were identified: 1) tan caseous plaques (n = 106), 2) hollow masses lined with mold (n = 26), 3) red pulmonary nodules (n = 15), and 4) necrotic brown plaques (n = 3). Histologically, fungal hyphae were most common in lung (n = 107) and air sac (n = 49). Comorbidities were diagnosed in 67 birds with a spectrum of viral (n = 19), bacterial (n = 11), parasitic (n = 6), other fungal (n = 4), and non-infectious (n = 50) causes. Six birds each were diagnosed with highly pathogenic avian influenza or salmonellosis. Twenty-two birds were emaciated. Free-ranging birds are susceptible to myriad stressors that can predispose them to the development of aspergillosis.

Dematiaceous Molds

Dematiaceous molds are darkly pigmented environmental molds found worldwide, especially prevalent in tropical and subtropical regions. Common genera include Bipolaris, Cladophialophora, Exophiala, and Alternaria. They cause disease in both immunocompetent and immunocompromised individuals, presenting as cutaneous infections, allergic sinusitis, pneumonia, and, rarely, disseminated infections. Contaminated medical products have also led to fungal meningitis outbreaks. Treatment typically involves itraconazole, voriconazole, or posaconazole, along with source control and reduction in immunosuppression, if possible. Newer antifungals may have a role in treatment. Mortality is high in disseminated disease, especially with Lomentospora prolificans in immunocompromised individuals, prompting global efforts to improve diagnostics and treatments.

An unexpected guest: First report of Tintelnotia destructans as an agent of maxillary fungus ball

Fungal rhinosinusal infections comprise several nosological entities, including sinus fungus ball. Diagnosis of sinus fungus ball relies on patient interrogation and clinical and paraclinical findings. Mold species commonly involved include Aspergillus, as well as dematiaceous fungi. Nevertheless, thanks to improvements in fungal culture and species level identification in clinical settings, new species are continuously described as agents in rhinosinusal infections. We present the first report of Tintelnotia destructans causing maxillary sinus fungus ball in a female patient.

Cerebral thrombus analysis as a useful diagnostic tool for infective endocarditis in ischemic stroke patients

INTRODUCTION

Infective endocarditis (IE) is a life-threatening condition and a rare cause of ischemic stroke (IS). This study aimed to evaluate the utility of analyzing cerebral thrombi, obtained through endovascular thrombectomy in IS, for the pathological diagnosis of IE.

PATIENTS AND METHODS

Cerebral thrombi from three groups of IS patients were compared: definite IE (n = 10), cardioembolic stroke without and with concomitant infection (CE-I-: n = 30, CE-I+: n = 10). We performed histological examination, molecular biology, and microbiological tests on cerebral thrombi, to detect microorganisms and assess their composition.

RESULTS

Median age of included patients was 73 years and 50% were females. Hematoxylin & Eosin and Grocott-Gomori Methenamine Silver stains detected microorganisms in all IE cerebral thrombi, and none in the control groups. Thrombus PCR detected relevant microorganism in n = 2/7 IE. Compared to control groups, IE thrombi were characterized by significant lower content of red blood cells (median [IQR]: IE = 7.4 [4.2-26.7], CE-I- = 49.3 [17-62.6], CE-I+ = 57.5 [40.7-60.8], % over thrombus section area [%TSA], p = 0.001), increased von Willebrand Factor (IE = 23.9 [19.1-32], CE-I- = 11.2 [8.2-12.8], CE-I+ = 12.9 [10.7-18.3], %TSA, p = 0.001), cell-dominant pattern of Neutrophil Extracellular Traps (IE = 100%, CE-I- = 69%, CE-I+ = 70%, p ⩽ 0.001), and more frequent sub-acute or chronic thrombus age classification (p ⩽ 0.001). These latter thrombus features displayed good discriminative ability between IE and controls, with AUC values between 0.84 and 0.95.

DISCUSSION

Multimodal analysis of cerebral thrombi in IS with suspected IE supports early and definite pathological diagnosis by detecting pathogens and assessing changes in thrombus composition.

A Small Cut, a Big Challenge: Pediatric Mucormycosis in an Unexpected Host

Mucormycosis is an infrequent fungal infection commonly seen in immunocompromised individuals. However, it can also occur in immunocompetent patients, especially following trauma. We present a case of a 15-month-old girl with increasing swelling and redness in her left eye after a minor traumatic injury. Imaging showed sinusitis with orbital involvement. Histopathology validated the diagnosis of mucormycosis caused by Rhizopus species. The patient had emergency surgery, followed by antifungal and antibiotic therapy. Despite febrile reactions to the treatment, the infection was managed, and the patient was discharged after 2 months. This case highlights the importance of considering mucormycosis in immunocompetent patients with unexplained ocular symptoms after trauma. Early diagnosis and aggressive treatment are essential for improving outcomes, especially in pediatric patients.

Assessment of pathogenic yeast species in the oral cavity of dogs: Antifungal susceptibility and implications for human health

Companions' animals can present a risk for the transmission of opportunistic diseases to their owners, including those caused by yeasts of the Candida genus residing in their oral microbiota. This study aimed to isolate and identify yeasts from the oral cavity of dogs and assess their susceptibility to antifungals. Yeast species were identified using automated methods MALDI-TOF-MS and VITEK 2 from 50 dogs (aged 2-4 years, various breeds). Among the evaluated animals Candida albicans (37.5 %) and Candida parapsilosis (25 %) were predominant, followed by other species including C. haemuloni, C. tropicalis, C. krusei, and Trichosporon asahii (12.5 % each). In this study, antifungal susceptibility testing revealed a general susceptibility with limited resistance. Although most antifungals exhibited good efficacy, some Candida strains demonstrated resistance to fluconazole (FLC), caspofungin (CAS), and amphotericin B (AMPB). These findings highlight the importance of conducting fungal cultures and antifungigram testing for the effective management of fungal infections in humans and animals. Therefore, vigilant monitoring and control measures are essential to reduce the transmission of opportunistic diseases from pets to humans.

Histoplasma capsulatum in Bat Species in Portugal

Histoplasmosis, caused by the fungus Histoplasma capsulatum, poses health risks to various mammals, including humans. Bats are primary wild carriers of Histoplasma capsulatum, playing a crucial role in its epidemiology. However, fecal shedding in Europe remains poorly studied, with no data available for Portugal. This study analyzed 285 guano samples from 22 bat species, collected across Portuguese regions between 2014 and 2018, using a nested PCR assay. Despite using a sensitive method, no positive samples were detected. These results align with other European studies, suggesting that Histoplasma capsulatum circulates at low levels in European bat populations. However, they contrast with findings from regions like Brazil and Mexico, where the fungus is more prevalent due to differing geographic, climatic, and ecological factors. The absence of Histoplasma capsulatum in Portuguese bat guano highlights the importance of local environmental conditions and raises questions about its distribution in Europe. Although bats can harbor zoonotic pathogens, our findings suggest they do not shed Histoplasma capsulatum in Portugal. Continuous monitoring and research are essential in understanding infectious disease dynamics. Targeted surveillance in caves could improve early detection and management strategies for potential histoplasmosis outbreaks, contributing to public health efforts in these ecosystems.

Human inborn errors of immunity underlying Talaromyces marneffei infections: a multicenter, retrospective cohort study

Introduction

Talaromyces marneffei (T. marneffei) infections in children can occur secondary to inborn errors of immunity (IEIs). We aimed to investigate the clinical and genetic features of T. marneffei infection in Chinese pediatric patients.

Materials and methods

We retrospectively reviewed 18 pediatric patients with IEIs who were diagnosed with T. marneffei infections at five public hospitals in China from January 2015 to January 2023.

Results

The common clinical features among the patients were fever, cough, and hepatomegaly. The most common severe complications included septic shock, hemophagocytic lymphohistiocytosis (HLH), and acute respiratory distress syndrome (ARDS). Three cases presented with pan-hypogammaglobulinemia, while three other cases showed heightened levels of IgM. Elevated levels of IgE were detected in five cases, and six cases exhibited decreased T lymphocyte absolute counts. Four children were diagnosed with hyperimmunoglobulin M syndrome (HIGM) due to CD40LG mutations, three cases had severe combined immunodeficiency (SCID), and five were diagnosed with hyper-IgE syndrome (HIES). Gain-of-function (GOF) mutations in STAT1 led to STAT1 GOF in four cases. One patient was diagnosed with caspase-recruitment domain (CARD9) deficiency due to a compound mutation in the CARD9 gene, while another patient was confirmed with adenosine deaminase (ADA) deficiency.

Conclusion

T. marneffei infections in children with IEIs induced severe systemic complications. These children commonly exhibited abnormal immunoglobulin levels in peripheral blood, and underlying IEIs associated with T. marneffei infections have enhanced our understanding of the disease.

Fungal Infections in Kidney Transplant Recipients: A Comprehensive Narrative Review

BACKGROUND

Despite kidney transplantation being a life-saving procedure, patients experience a high risk of developing fungal infections (FIs), with an increased risk of both morbidity and mortality, especially during the first year after transplant.

METHODS

We herein conducted a narrative review of the most common FIs in kidney transplant recipients (KTRs), with a focus on prevalence, risk factors, mortality, and prevention strategies.

RESULTS

The most common fungal pathogens in KTRs include Candida species (up to 70% of the overall FIs), Aspergillus species, Pneumocystis jiroveci, and Cryptococcus species. Fungal colonization, diabetes mellitus, chronic liver disease, malnutrition, and pre-existing lung conditions should all be acknowledged as possible predisposing risk factors. The mortality rate can vary from 25 to 50% and according to different settings and the types of FIs. Preventive strategies are critical for reducing the incidence of FIs in this population. These include antifungal prophylaxis, environmental precautions, and infection control measures. The use of novel tools (such as PCR-based molecular assays and NGS) for rapid and accurate diagnosis may play an important role.

CONCLUSIONS

Early recognition, the appropriate use of antifungal therapy, and preventive strategies are essential for improving graft loss and fatal outcomes in this vulnerable population. Future research is needed to optimize diagnostic tools, identify novel antifungal agents, and develop better prophylactic strategies for high-risk transplant recipients.

Invasive Aspergillosis in the Intensive Care Unit

Invasive aspergillosis (IA) is a fungal infection, which has traditionally been associated with neutropenia and immunosuppressive therapies. Our understanding of invasive aspergillosis has been evolving and, in the past few decades, IA among ICU patients has been recognized as a common infection and has become more widely recognized. The diagnosis and management of invasive aspergillosis in the ICU is particularly challenging, due to the unstable clinical condition of the patients, lack of diagnostic markers, increased risk of further clinical deterioration, multiple comorbidities, and a need for early assessment and treatment. In this article, we will discuss the challenges and pitfalls of the diagnosis and management of invasive aspergillosis in an ICU setting, along with a review of the current literature that is pertinent and specific to this population.

Novel Curvularia species causing disseminated phaeohyphomycosis in a dog

Phaeohyphomycosis is an uncommon disease caused by dematiaceous fungi that is almost exclusively found in immunocompromised dogs. Here we describe the case of a dog treated with prednisone (1.1 mg/kg/day) and cyclosporine (11.2 mg/kg/day) for immune thrombocytopenia that developed cutaneous/subcutaneous lesions affecting both forelimbs 29 days after initiation of immunosuppression. The owner elected conservative outpatient treatment that consisted of wound care, antibiotics, mirtazapine, maropitant, and a dose reduction of prednisone (0.3 mg/kg/day) in lieu of biopsies or cultures. The dog was subsequently euthanized 13 days later because of an acute onset of increased respiratory rate and effort, obtunded mentation, and an inability to ambulate. Postmortem examination revealed widespread fungal dissemination in the heart, pericardium, intercostal muscles, lymph nodes, skin, subcutis, kidneys, lungs, pleura, and nasal cavity. Histopathology of the widespread plaques and nodules revealed fungal hyphae that were 4-8 µm in diameter, pigmented, variably septate, non-parallel, and toruloid with acute branching and occasional terminal bulbous dilations up to 20 µm in diameter, resembling chlamydoconidia. Yeast-like cells had a thick, variably pigmented wall and internal, foamy to granular, pale amphophilic contents. Fungal culture of swabs from the right elbow subcutaneous granulomas and from the left lateral pleural nodules yielded pure growth of Curvularia sp. Genomic DNA was extracted from harvested mycelia and molecular sequencing confirmed the presence of a novel Curvularia sp., C. arizonensis.

Impact of COVID-19 on the prevalence of oral and maxillofacial disorders: A retrospective cohort study

ObjectiveThe COVID-19 pandemic has impacted various health conditions. Emerging evidence suggests that COVID-19 may trigger or exacerbate oral and maxillofacial conditions, yet data from Iraq and the broader Middle East remain limited. This retrospective cohort study, conducted at the Laboratory of Oral Pathology, College of Dentistry, University of Baghdad, explores potential links between COVID-19 infection and maxillofacial disorders.MethodsThis was a retrospective cohort study using data from the Laboratory of Oral Pathology, College of Dentistry, University of Baghdad. Cases were divided into pre-COVID-19 and post-COVID-19 periods. Chi-square tests assessed differences in oral pathologies incidence, while logistic regression analyzed associations with COVID-19 status and corticosteroid use.ResultsMucormycosis cases demonstrated a significant increase from 3 (pre-COVID-19) to 23 (post-COVID-19), with 65.22% of post-COVID-19 patients testing COVID-19-positive. A significant increase in mucormycosis severity was observed after COVID-19 (χ² = 14.24, p = 0.0026). Logistic regression identified age (coefficient 0.8738) as having a significant association with severe mucormycosis, while COVID-19 status (coefficient 0.1272) exerted a lesser effect. Sjögren's syndrome increased from 15 to 25 cases, with a model area under the curve of 0.8, indicating substantial ability to distinguish symptom changes pre- vs. post-COVID-19.ConclusionThe findings suggest that the pandemic has considerably impacted the incidence and severity of mucormycosis and Sjögren's syndrome. Older age and COVID-19 positivity may be key drivers of severe mucormycosis, whereas COVID-19 infection appeared to exacerbate Sjögren's syndrome symptoms. These results underscore the importance of vigilant monitoring and targeted therapeutic strategies for managing oral and maxillofacial conditions during and after viral pandemics.

Cryptococcus neoformans/gattii and Histoplasma capsulatum var. capsulatum infections on tissue sections: Diagnostic pitfalls and relevance of an integrated histomolecular diagnosis

Cryptococcus neoformans/gattii and Histoplasma capsulatum var. capsulatum may present atypical histopathological features inducing diagnostic errors. We aimed to estimate the frequency of these atypical features in formalin-fixed tissue (FT) samples and to assess the relevance of an integrated histomolecular diagnosis using specific H. capsulatum PCR and panfungal PCR followed by Sanger sequencing and/or targeted massive parallel sequencing (MPS). A total of 27 FT from 23 patients with a histopathological diagnosis of cryptococcosis (n = 16 FT from 13 patients) or histoplasmosis (n = 11 FT from 10 patients) were retrospectively included. All FT were consultation cases. Mycological identifications on equivalent fresh tissue were available for 11/23 (47.8%) patients. The expert pathologist review modified the diagnosis suggested by the initial pathologist in 7/27 (25.9%) FT. Fungal morphology and tissue inflammation were compared between both mycoses. The most discriminant atypical criterion was the presence of dented-looking yeasts, observed in 68.75% (11/16) of C. neoformans/gattii and none (0/11) of H. capsulatum var. capsulatum (P = .002). For the 12/23 (52.2%) patients without mycological identification on fresh tissue, an integrated histomolecular diagnosis on FT using specific PCR or panfungal PCR followed by Sanger sequencing and/or MPS led to fungal identification in 9/12 (75%) cases; for cryptococcosis, the targeted MPS sensitivity was higher than that of Sanger sequencing (P = .041). Thus, because atypical histopathological features may be tricky, integrated histomolecular diagnosis is essential for optimal patient care.

Unexpected Discrepancies in the Histopathological and Microbiological Diagnoses of Suspected Mucormycosis Cases at a South Indian Tertiary Care Center During the COVID-19 Pandemic

Introduction Mucormycosis is an uncommon fungal infection caused by filamentous fungi of the Mucorales order, namely Rhizopus, Lichthemia, andMucor species. The incidence and prevalence of mucormycosis reached an all-time high during the COVID-19 pandemic due to excessive steroid use and other factors, leading to the coining of the term CAM (COVID Associated Mucormycosis). The diagnosis of mucormycosis is by a combination of histopathology and microbiological techniques, such as KOH mount and culture. Although microbiological and histopathological findings usually correlate, certain discrepancies are known to occur and are discussed in our study. The aim of our research is to study the correlation between histopathology and microbiology findings, as well as their respective merits and limitations, in suspected mucormycosis cases in COVID-19 patients at a tertiary healthcare center in South India. Methods It is a retrospective study, where data from 74 COVID-19 patients admitted in the ENT ward between June 2021 and August 2021 with a suspicion of mucormycosis was collected. Samples from these patients were sent to the pathology and microbiology departments of Rangaraya Medical College. KOH mount, culture on Saboraud's Dextrose Agar (SDA), and histopathology findings were analyzed. Results Histopathology and culture findings of Mucormycosis were correlated in 64 isolates (86.5%), including five cases (6.7%) of mixed infections, where the culture was positive for only a single type of fungus. In the remaining 10 isolates, discrepancies were observed, accounting for 13.5% of the total sample size. Pearson's correlation coefficient test did not reveal any statistically significant correlation in the case of histopathology and microbiology culture or KOH mount, further highlighting the presence of discrepancies. The high correlation between KOH mount and culture isolates (100%) in our study is attributable to the processing of the same sample by the microbiology department. On the other hand, the correlation between histopathology and culture in our study is 86.5%, and the expected correlation as suggested by previous studies is only 50%. These discrepancies between culture and histopathology could be due to different samples being sent to the two departments. Conclusion  Although fungal cultures are considered the gold standard, they have drawbacks such as slow growth, and the potential for both false positives and false negatives. KOH mount is a rapid and cost-effective method, but it lacks specificity and sensitivity. Histopathology offers the advantage of specific species identification and assessment of tissue inflammation; however, it is an invasive procedure and poses challenges in accurately identifying the fungus. A multidisciplinary approach, with coordination between physicians, surgeons, pathologists, clinical microbiologists, and radiologists, is essential for timely diagnosis and management. For accurate identification of the causative organism, it is recommended to send the same sample for histopathological examination, KOH mount, and culture.

Challenges in Management of Uncommon Otologic Fungal Disease - a Case Series and Review of Literature

The purpose of this study is to describe challenges in diagnosis and treatment of otologic fungal infections.; 2) Methods: Case series and literature review 3) Results: Three patients treated at Louisiana State University Health Sciences Center - Shreveport between November 2020 - November 2023 were identified with complicated fungal otitis externa requiring detailed radiologic and histopathologic workup to aid in diagnosis and management. 4) Conclusion: Diagnosis of otologic fungal infection is often complex due to similar presentation of more common pathogens, overlapping features among common fungal specimens, and limitations of available diagnostic methods. Patient factors, including diabetes with poor glycemic control, may further complicate this challenging disease. High index of clinical suspicion, collaboration between multidisciplinary teams is essential to differentiate between common and uncommon fungal ear infections. A combination of mechanical debridement, topical and/or systemic therapy, and longitudinal follow-up with otolaryngology and infectious disease teams is required for successful treatment.

Treatment of mycotic rhinitis caused by aspergillus fumigatus in a quarter horse mare using topical clotrimazole and oral potassium iodide

Fungal rhinitis in horses is rare, although severe, due to the progressive nasal obstruction. Aspergillus is one of the fungi most often involved in these cases. A 7-year-old Quarter Horse mare weighing 325 kg was admitted with a history of recurrent nasal discharge and bleeding, foul smell, reluctance to exercise, and abortion. Laboratory and imaging examinations revealed eosinophilia, scarring and erosion areas in the nasal mucosa, purulent and bloody secretions, and remarkable yellowish plaques. Histopathological examination revealed fungal rhinitis and bacterial culture revealed the presence of β-hemolytic Streptococcus and Staphylococcus sp. Fungal culture and molecular diagnosis confirmed Aspergillus fumigatus as the etiological agent. A tracheostomy was necessary due to the patient's dyspnea. For the treatment, topical application of clotrimazole ointment was carried out in the rostral portion of the nasal cavity once a day and in the caudal portion of the nasal cavity, endoscopic guided every 48 h. In the fifth endoscopy-guided application, a significant improvement was noticed; however, the animal exhibited a hypersensitivity reaction, and the treatment was discontinued. Thus, potassium iodide therapy was initiated (67 mg/kg, PO, SID, 14 days). The patient demonstrated favorable clinical improvement, achieved resolution of the fungal infection, and was discharged after 25 days of hospitalization. Topical clotrimazole demonstrated a probable efficacy as a standalone treatment, although its use had to be prematurely discontinued due to the emergence of a hypersensitivity reaction. The combination of clotrimazole and potassium iodide effectively treated fungal rhinitis in a shorter time than previously reported. This report provides useful guidance for other cases of fungal rhinitis, although further studies are needed.

The first report of rhinosinusitis by Rhizopus delemar in a patient with severe COVID-19 in Iran: a case report

BACKGROUND

Mucormycosis is a severe and fatal fungal infection in patients with coronavirus disease 2019 caused by Mucorales. Here we present a case of a 63-year-old man with coronavirus disease 2019 infection, along with rhinosinusitis mucormycosis caused by Rhizopus delemar.

CASE PRESENTATION

A 63-year-old Iranian man suffering from a coronavirus disease 2019 infection with symptoms of cough, shortness of breath, and generalized body pain. On the basis of the clinical manifestations, such as headache, a history of black nasal discharge, nasal hypoesthesia, facial swelling, numbness, nasal obstruction, presence of necrotic lesions on the nasal passages on physical examination, and abnormal computed tomography scans of paranasal sinuses, the patient underwent surgical debridement. Direct microscopy of specimens obtained from the paranasal sinuses, and subsequent isolation and identification, revealed a rhinosinusitis mucormycosis caused by R. delemar. Despite therapeutic measures, such as sinus debridement surgery and antifungal therapy with amphotericin B injection (50 mg/day), the patient died after 35 days of hospitalization.

CONCLUSION

In this report, we present the first documented case of human infection with R. delemar in a patient with coronavirus disease 2019 infection, who also exhibited rhinosinusitis mucormycosis. R. delemar appears to be an emerging agent of rhinosinusitis mucormycosis in this region. Furthermore, prompt diagnosis and the exploration of alternative antifungal treatments, beyond amphotericin B, may be crucial for effectively managing patients with R. delemar infections.

Deep Fungal Infections of Skin and Role of Histopathology in Diagnosis

Introduction

Deep mycoses acquired by penetrating trauma to the skin can have varied and sometimes atypical morphological presentations resulting in diagnostic dilemmas and delay in treatment onset. Histopathology can be a useful tool in not only diagnosing but also differentiating various deep mycoses.

Aims and Objectives

To observe various morphological presentations and histopathological features of deep fungal infections.

Materials and Methods

A retrospective multi-centric study was conducted from 2010 to 2020 at 16 centres. The cases with diagnoses of various deep mycoses were included in the study. The patients presenting with cutaneous manifestations were included in the study. Their demographic details, history, presenting signs and symptoms, morphological presentations, histopathological features and treatment details were collected from the case sheets.

Results

A total of 124 cases were found from the case records. The most common type was chromoblastomycosis (42) followed by mycetoma (28) and rhinosporidiosis (17). The mean age was 43.76 ± 5.44 years. The average duration of symptoms before presentation was between 2 months to 10 years (average 2.5 ± 1.33 years). Male to female ratio was 1:0.7. Prior history of trauma was recorded in 36% of cases. Chromoblastomycosis cases presented with verrucous to atrophic plaques with black dots on the surface and histopathology findings included pesudoepitheliomatous hyperplasia, epithelioid cell granulomas, copper penny bodies within granulomas and abscesses. Rhinosporidiosis cases had polypoid grape-like lesions in the nose and eyes most commonly with histopathology findings of abundant thick-walled sporangia in dermis packed with thousands of spores. Eumycetoma patients had pigmented, indurated swelling with multiple sinuses discharging black granules and histopathology showed dermal abscesses and foreign body granulomatous reaction with PAS-positive hyphae. Histoplasmosis patients presented with few to multiple nodulo-pustular lesions on skin and palatal ulcers while small basophilic bodies packed in the cytoplasm of histiocytes were noted in histopathology. Phaeohyphomycosis cases presented as deep-seated cystic lesions and biopsy revealed deepithelialized cysts in the dermis or hypodermis with lumen showing necro inflammatory debris and fungal hyphae. Sporotrichosis cases had erythematous, tender nodules and papules either as single lesions or as multiple lesions arranged in a linear fashion and histopathology showed pseudoepitheliomatous hyperplasia of epidermis, loose to well-defined epithelioid cell granulomas and microabscesses. Spores were found in two cases. Cryptococcosis patient had multiple umbilicated lesions resembling giant molluscum contagiosum loose epithelioid cell granulomas and medium-sized spores lying in both intra and extracellularly on histopathology. Penicilliosis patients had nodulo-pustular lesions and histopathology showed an admixture of histiocytes, epithelioid cells, plasma cells, lymphocytes and polymorphs in the dermis with the presence of yeast-like spores in the cytoplasm of histiocytes and epithelioid cells. Entomophthoromycosis cases presented with asymptomatic subcutaneous firm swelling with loss of skin pinchability.

Conclusion

Though clinical findings of deep fungal infections are characteristic similar morphology and atypical presentations can be sometimes confusing. Histopathology is useful for confirming the diagnosis.

Recent Advances in Diagnostic Approaches for Mucormycosis

Mucormycosis, an invasive fungal infection caused by members of the order Mucorales, often progresses fulminantly if not recognized in a timely manner. This comprehensive review discusses the latest developments in diagnostic approaches for mucormycosis, from traditional histopathology and culture-based methods to advanced and emerging techniques such as molecular assays, imaging, serology, and metabolomics. We discuss challenges in the diagnosis of mucormycosis and emphasize the importance of rapid and accurate identification of this life-threatening infection.

Invasive Fungal Rhinosinusitis: The First Histopathological Study in Vietnam

BACKGROUND

Invasive fungal rhinosinusitis (IRFS) is a rare but highly fatal disease. The two primary groups of pathogens, Mucorales and Aspergillus, require different treatments and have distinct prognoses.

PURPOSE

This study aimed to analyze the histopathological features of IFRS.

METHODS

We conducted a retrospective study involving 57 IFRS cases. Demographic and comorbid characteristics were obtained from clinical records. Two pathologists independently examined the histopathological features using H&E, PAS, and GMS-stained slides. Fungal groups were identified with PCR under the guidance of histopathology.

RESULTS

The mean age of IFRS was 58.9 ± 13.4. The male-to-female ratio was 1.4:1. 100% of cases had diabetes comorbidity. Mucorales, Aspergillus, and other fungi were found in 61.4%, 33.3%, and 5.3% of cases, respectively. No Aspergillus and Mucorales co-infections were detected. Histopathology and PCR results were strongly concordant in classifying pathogens (Cohen's kappa = 84.2%, 95% CI 60.1% - 100%, p < 0.001). Mucormycosis exhibited higher rates of extensive necrosis and vascular invasion, and lower rates of pigment and spore presence than the non-Mucormycosis group (p < 0.001, p = 0.01, p = 0.02, p = 0.03, respectively). Extensive necrosis and vascular invasion were statistically significantly correlative (OR = 13.03, 95% CI 2.62-64.75, p = 0.002).

CONCLUSIONS

IFRS predominantly affects older adults and males. Histopathology is a reliable method for differentiating between Mucorales and Aspergillus. When extensive necrosis is detected, it is critical to investigate for vascular invasion carefully. The vascular invasion, degree of necrosis, pigments, and spores are valuable factors for distinguishing fungal agents of IFRS.

An old unknown: 40 years of crayfish plague monitoring in Switzerland, the water tower of Europe

The oomycete Aphanomyces astaci is the causative agent of crayfish plague, a disease threatening susceptible freshwater crayfish species in Europe. To detect its spatiotemporal occurrence in Switzerland, we reviewed (1) the literature regarding occurrence of crayfish plague and North American crayfish carrier species and (2) the necropsy report archive of the Institute for Fish and Wildlife Health (FIWI) from 1968 to 2020. In the past, crayfish plague was diagnosed through several methods: conventional PCR, culture, and histology. When available, we re-evaluated archived Bouin's or formalin-fixed, paraffin-embedded samples collected during necropsies (1991-2020) with a recently published quantitative PCR. Literature research revealed putative reports of crayfish plague in Switzerland between the 1870s and 1910s and the first occurrence of three North American crayfish species between the late 1970s and 1990s. Finally, 54 (28.1%) cases were classified as positive and 9 (4.7%) cases as suspicious. The total number of positive cases increased by 14 (14.7%) after re-evaluation of samples. The earliest diagnosis of crayfish plague was performed in 1980 and the earliest biomolecular confirmation of A. astaci DNA dated 1991. Between 1980-1990, 1991-2000 and 2001-2010 crayfish plague spread from one to two and finally three catchment basins, respectively. Similar to other European countries, crayfish plague has occurred in Switzerland in two waves: the first at the end of the 19th and the second at the end of the 20th century in association with the first occurrence of North American crayfish species. The spread from one catchment basin to another suggests a human-mediated pathogen dispersal.

A Case Report on Invasive Mucormycosis Involving the Maxillary Region, Brain, and Chest

The maxilla is a facial bone with a dense blood supply. Although rare, infections, trauma, and certain metabolic disorders can lead to necrosis of the maxillary bone. The maxilla, a vital bone forming the roof of the oral cavity, is particularly susceptible to mucormycosis, a prevalent fungal infection, especially in individuals with diabetes and compromised immune systems. Here, we discuss mucormycosis-associated maxillary necrosis in a patient with uncontrolled diabetes. Early identification and treatment of this lethal fungal infection can significantly reduce its mortality and morbidity rates. Due to the maxilla's high vascularity, necrosis is uncommon. However, various infections, including bacterial, viral, and fungal, can lead to maxillary necrosis. Other potential causes include trauma, radiation, prolonged corticosteroid use, and lipid metabolism disorders (like Gaucher disease). Early diagnosis and timely treatment are crucial to significantly reducing the mortality and morbidity associated with this life-threatening fungal infection.

Invasive candidiasis in dogs: A case report and review of the literature

Invasive candidiasis is characterized by the systemic dissemination of Candida spp. and colonization of multiple organs. We are reporting a case of invasive candidiasis in a 3.5-year-old female mixed-breed dog with a history of limb injury. After clinical evaluation and complementary examinations a sepsis diagnose was established. The patient remained hospitalized under antibiotic therapy, dying three days later. Necropsy revealed white, nodular (pyogranulomas), and multifocal areas on the liver, button ulcers in the stomach and intestines, and a random lung consolidation. Impression smears were made from the liver and lung surface lesions during necropsy showing yeast and pseudohyphae structures. Fragments of these organs were sent for fungal culture and subsequent molecular etiologic characterization, identifying it as Candida albicans. Histological examination of different organs showed pyogranulomatous inflammation surrounding the necrosis areas, which were full of yeast and pseudohyphae, as evidenced by periodic acid Schiff and immunohistochemistry. Neutropenia, as a consequence of sepsis, associated with the use of antibiotics may have allowed yeast invasion and proliferation in the mucosa of the gastrointestinal tract, reaching the liver and lungs through hematogenous route. Invasive candidiasis is a rare canine disease, and no other cases of neutropenia associated with antibiotic therapy, as a predisposing factors, have been reported.

Coccidioidomycosis and Histoplasmosis in Immunocompetent Individuals: A Comprehensive Review of Clinical Features, Diagnosis, and Management

Coccidioidomycosis and histoplasmosis are endemic mycoses caused by the Coccidioides species and Histoplasma capsulatum, respectively. While these fungal infections are often associated with immunocompromised individuals, they pose significant risks to immunocompetent hosts. This review comprehensively analyzes these infections in immunocompetent individuals, focusing on clinical features, diagnostic approaches, and management strategies. The current understanding of coccidioidomycosis and histoplasmosis in immunocompetent individuals includes their clinical presentations, diagnostic methodologies, and treatment options. A literature review encompassed recent studies, clinical guidelines, and expert opinions. Data were analyzed to highlight critical aspects of the clinical manifestations, diagnostic processes, and management of these infections in immunocompetent patients. Coccidioidomycosis typically presents with pulmonary symptoms that may range from mild to severe and can include chronic and disseminated forms. Histoplasmosis also presents a spectrum of pulmonary symptoms with the potential for extrapulmonary dissemination. Diagnostic approaches for both infections involve clinical evaluation, serological tests, culture, and imaging studies. Management strategies include antifungal therapies such as fluconazole and itraconazole for coccidioidomycosis and itraconazole and amphotericin B for histoplasmosis, with treatment duration and monitoring tailored to the severity of the infection. Coccidioidomycosis and histoplasmosis can significantly affect immunocompetent individuals, with clinical presentations varying widely from mild to severe. Accurate diagnosis and appropriate management are crucial for optimal outcomes. This review underscores the importance of awareness and timely intervention in managing these endemic mycoses and highlights the need for continued research into better diagnostic and therapeutic approaches.

Identification of causative fungus from sterile abscess using metagenomics followed by in situ hybridization

Introduction. Invasive fungal infections require early diagnosis for treatment. Microscopic observation of biopsy and blood culture is the gold standard for the identification of the causative fungus, but it is difficult to identify the causative pathogen by a sterile abscess biopsy. Case Presentation. We present a case report of breakthrough invasive trichosporonosis in a 65-year-old Japanese male with acute myeloid leukaemia receiving antifungal prophylaxis. Blood cultures showed no fungal growth, and a liver biopsy and a removed spleen with abscess showed fragmented fungi, but no fungal identification was possible. This report demonstrates that retrospective analyses were able to identify the causative fungus. Conclusion. We narrowed down the candidate fungi by deep sequencing of the ITS1 region of fungal genome and confirmed that the fungus observed in the specimen was Trichosporon asahii by in situ hybridization using a DNA probe targeting 26S rRNA.

Rhinocerebral mucormycosis: A clinicopathological analysis of COVID-19-associated mucormycosis

Background

During the coronavirus disease 2019 (COVD-19) pandemic, the incidence of mucormycosis also increased, especially affecting individuals who have had the COVID-19 infection in the past.

Aims

The aim of the study is to assess risk factors and clinical and histopathological features of mucormycosis in post-COVID-19 cases.

Methods

This is a retrospective study conducted in a tertiary care COVID-19-dedicated hospital, Dehradun, Uttarakhand, India, over a period of 2 months during the COVID-19 pandemic. All surgical specimens submitted for histopathology with a suspected diagnosis of mucormycosis were included. Histopathology was considered the gold standard. All histopathologically confirmed cases were studied in detail with respect to histopathology, clinico-radiological features, and microbiological results.

Results

Of 25 cases with clinical diagnosis of mucormycosis, nine were histopathologically confirmed as mucormycosis. Seven patients had diabetes, while two did not have any co-morbidity. The fungal load was heavy in 50% cases, and the proportion of necrosis was higher with diabetes mellitus, as compared to non-diabetic and non-co-morbidity patients. Angioinvasion (33.3% cases), soft-tissue invasion (44.4%), Splendor-Hoeppli phenomenon (44.4%), and neural invasion (11.1%) were also present. Mixed infection (Mucormycosis and Aspergillus species) was present in three of the cases who also had diabetes. The microbiological investigations were positive in only 55.5% cases.

Conclusion

Post-COVID Mucormycosis has fatal outcomes. Early diagnosis and treatment are the key to successful treatment. Early and reliable diagnosis can be offered by histopathological examination.

ISCCM Position Statement on the Management of Invasive Fungal Infections in the Intensive Care Unit

Rationale

Invasive fungal infections (IFI) in the intensive care unit (ICU) are an emerging problem owing to the use of broad-spectrum antibiotics, immunosuppressive agents, and frequency of indwelling catheters. Timely diagnosis which is imperative to improve outcomes can be challenging. This position statement is aimed at understanding risk factors, providing a rational diagnostic approach, and guiding clinicians to optimize antifungal therapy.

Objectives

To update evidence on epidemiology, risk factors, diagnostic approach, antifungal initiation strategy, therapeutic interventions including site-specific infections and role of therapeutic drug monitoring in IFI in ICU and focus on some practice points relevant to these domains.

Methodology

A committee comprising critical care specialists across the country was formed and specific aspects of fungal infections and antifungal treatment were assigned to each member. They extensively reviewed the literature including the electronic databases and the international guidelines and cross-references. The information was shared and discussed over several meetings and position statements were framed to ensure their reliability and relevance in critical practice. The draft document was prepared after obtaining inputs and consensus from all the members and was reviewed by an expert in this field.

Results

The existing evidence on the management of IFI was updated and practice points were prepared under each subheading to enable critical care practitioners to streamline diagnosis and treatment strategies for patients in the ICU with additional detail on site-specific infections therapeutic drug monitoring.

Conclusion

This position statement attempts to address the management of IFI in immunocompetent and non-neutropenic ICU patients. The practice points should guide in optimization of the management of critically ill patients with suspected or proven fungal infections.

How to cite this article

Bhattacharya PK, Chakrabarti A, Sinha S, Pande R, Gupta S, Kumar AAK, et al. ISCCM Position Statement on the Management of Invasive Fungal Infections in the Intensive Care Unit. Indian J Crit Care Med 2024;28(S2):S20-S41.

Powering the Future Green Buildings: Multifunctional Ultraviolet-Shielding Transparent Wood

Indoor UV damage is a serious problem that is often ignored. Common glasses cannot filter UV rays well and have fragility and environmental issues. UV-shielding transparent wood (TW) holds promise, yet striking the right balance between blocking UV rays and allowing sufficient visible-light transmission poses a challenge. The pronounced capillary force, fueled by persistent moisture and extractives in wood, alongside the existence of multiphase interfaces, collectively hinder the uniform penetration of polymers and the effective dispersion of nanomaterials within the wood skeleton. Here, we incorporate high-pressure supercritical CO2 fluid-assisted impregnation (HSCFI) into fabricating UV-shielding TW. The supercritical CO2 pretreatment efficiently eliminates moisture and refines wood structure by extracting polar substances, resulting in a prominent 52.4% increase in average water permeability. Subsequently, this HSCFI method facilitates the infiltration of methyl methacrylate (MMA) monomer and Ce-ZnO nanorods (NRDs) into the refined anhydrous wood, leveraging the excellent solvency of supercritical CO2 for MMA. The impregnation rate of PMMA undergoes a substantial increase from 34.5 to 59.1%. With the robust UV-blocking capability of Ce-ZnO NRDs, thanks to dual-valence Ce doping widening the ZnO energy gap via the Burstein-Moss effect and their unique photoactive microstructure featuring a solid prism with a sharp hexahedral pyramidal tip, along with intrinsic physical scattering/reflection actions, Ce-ZnO NRDs@TW achieves an impressive 99.6% UVA radiation blockage (the highest for TW) and maintains high visible-light transmission (83.2%). Furthermore, Ce-ZnO NRDs@TW presents favorable energy-saving, sound absorption, and antifungal abilities, making it a promising candidate for future green buildings.

What are the 100 most cited fungal genera?

The global diversity of fungi has been estimated between 2 to 11 million species, of which only about 155 000 have been named. Most fungi are invisible to the unaided eye, but they represent a major component of biodiversity on our planet, and play essential ecological roles, supporting life as we know it. Although approximately 20 000 fungal genera are presently recognised, the ecology of most remains undetermined. Despite all this diversity, the mycological community actively researches some fungal genera more commonly than others. This poses an interesting question: why have some fungal genera impacted mycology and related fields more than others? To address this issue, we conducted a bibliometric analysis to identify the top 100 most cited fungal genera. A thorough database search of the Web of Science, Google Scholar, and PubMed was performed to establish which genera are most cited. The most cited 10 genera are Saccharomyces, Candida, Aspergillus, Fusarium, Penicillium, Trichoderma, Botrytis, Pichia, Cryptococcus and Alternaria. Case studies are presented for the 100 most cited genera with general background, notes on their ecology and economic significance and important research advances. This paper provides a historic overview of scientific research of these genera and the prospect for further research. Citation: Bhunjun CS, Chen YJ, Phukhamsakda C, Boekhout T, Groenewald JZ, McKenzie EHC, Francisco EC, Frisvad JC, Groenewald M, Hurdeal VG, Luangsa-ard J, Perrone G, Visagie CM, Bai FY, Błaszkowski J, Braun U, de Souza FA, de Queiroz MB, Dutta AK, Gonkhom D, Goto BT, Guarnaccia V, Hagen F, Houbraken J, Lachance MA, Li JJ, Luo KY, Magurno F, Mongkolsamrit S, Robert V, Roy N, Tibpromma S, Wanasinghe DN, Wang DQ, Wei DP, Zhao CL, Aiphuk W, Ajayi-Oyetunde O, Arantes TD, Araujo JC, Begerow D, Bakhshi M, Barbosa RN, Behrens FH, Bensch K, Bezerra JDP, Bilański P, Bradley CA, Bubner B, Burgess TI, Buyck B, Čadež N, Cai L, Calaça FJS, Campbell LJ, Chaverri P, Chen YY, Chethana KWT, Coetzee B, Costa MM, Chen Q, Custódio FA, Dai YC, Damm U, de Azevedo Santiago ALCM, De Miccolis Angelini RM, Dijksterhuis J, Dissanayake AJ, Doilom M, Dong W, Alvarez-Duarte E, Fischer M, Gajanayake AJ, Gené J, Gomdola D, Gomes AAM, Hausner G, He MQ, Hou L, Iturrieta-González I, Jami F, Jankowiak R, Jayawardena RS, Kandemir H, Kiss L, Kobmoo N, Kowalski T, Landi L, Lin CG, Liu JK, Liu XB, Loizides M, Luangharn T, Maharachchikumbura SSN, Makhathini Mkhwanazi GJ, Manawasinghe IS, Marin-Felix Y, McTaggart AR, Moreau PA, Morozova OV, Mostert L, Osiewacz HD, Pem D, Phookamsak R, Pollastro S, Pordel A, Poyntner C, Phillips AJL, Phonemany M, Promputtha I, Rathnayaka AR, Rodrigues AM, Romanazzi G, Rothmann L, Salgado-Salazar C, Sandoval-Denis M, Saupe SJ, Scholler M, Scott P, Shivas RG, Silar P, Souza-Motta CM, Silva-Filho AGS, Spies CFJ, Stchigel AM, Sterflinger K, Summerbell RC, Svetasheva TY, Takamatsu S, Theelen B, Theodoro RC, Thines M, Thongklang N, Torres R, Turchetti B, van den Brule T, Wang XW, Wartchow F, Welti S, Wijesinghe SN, Wu F, Xu R, Yang ZL, Yilmaz N, Yurkov A, Zhao L, Zhao RL, Zhou N, Hyde KD, Crous PW (2024). What are the 100 most cited fungal genera? Studies in Mycology 108: 1-411. doi: 10.3114/sim.2024.108.01.

Fusarium and Neocosmospora: fungal priority pathogens in laboratory diagnosis

Fusarium and Neocosmospora are two fungal genera recently recognized in the list of fungal priority pathogens. They cause a wide range of diseases that affect humans, animals, and plants. In clinical laboratories, there is increasing concern about diagnosis due to limitations in sample collection and morphological identification. Despite the advances in molecular diagnosis, due to the cost, some countries cannot implement these methodologies. However, recent changes in taxonomy and intrinsic resistance to antifungals reveal the necessity of accurate species-level identification. In this review, we discuss the current phenotypic and molecular tools available for diagnosis in clinical laboratory settings and their advantages and disadvantages.

Incidence and Risk Factors for Acid-fast Bacillus/Fungal Culture Positivity in Primary, Conversion, and Revision Hip and Knee Arthroplasty

INTRODUCTION

Previous literature has reported minimal incidences of positive fungal/AFB cultures, questioning the routine use of these tests. With growing concern for excessive use, predictive factors for patients at higher risk for intraoperative AFB/fungal infections would help surgeons limit unnecessary testing. This study evaluates the positivity rate and predictive factors of positive fungal and/or acid-fast bacillus (AFB) cultures after primary, conversion, or revision hip and knee arthroplasty.

METHOD

Two hundred thirty-eight knee and hip procedures were done between January 2007 and 2022 where intraoperative AFB/fungal cultures were obtained. Procedures included primary total knee arthroplasty, primary total hip arthroplasty, conversion, first of two-stage, second of two-stage, irrigation and débridement polyexchange, and aseptic revision. Positivity rates of intraoperative AFB/fungal cultures were calculated as binomial exact proportions with 95% confidence intervals and are displayed as percentages. Univariable generalized linear mixed models estimated the unadjusted effects of demographics, individual comorbid conditions, and procedural characteristics on the logit of positive AFB/fungal cultures.

RESULTS

Two hundred thirty-eight knee and hip procedures recorded an overall positivity rate of 5.8% for intraoperative AFB/fungal cultures. Aseptic revisions showed the lowest rates of positivity at 3.6%, while conversions showed the highest rates of positivity at 14.3%. The positivity rates are highest among patients who are male (9.0%), of Hispanic origin (12.0%), with body mass index <30 (6.4%), and a Charlson Comorbidity Index <5 (6.1%). History of a prior infection in the same surgical joint showed statistically significant influence of odds of culture positivity with an odds ratio of 3.47 ( P -value: 0.039). Other demographic factors that we investigated including age, sex, race, ethnicity, body mass index, and Charlson Comorbidity Index did not show any notable influence on AFB/fungal positivity rates.

CONCLUSION

These results suggest utility in obtaining routine intraoperative AFB/fungal cultures, given the relatively high positivity and poor predictive factors.

Scedosporiosis and lomentosporiosis: modern perspectives on these difficult-to-treat rare mold infections

SUMMARYAlthough Scedosporium species and Lomentospora prolificans are uncommon causes of invasive fungal diseases (IFDs), these infections are associated with high mortality and are costly to treat with a limited armamentarium of antifungal drugs. In light of recent advances, including in the area of new antifungals, the present review provides a timely and updated overview of these IFDs, with a focus on the taxonomy, clinical epidemiology, pathogenesis and host immune response, disease manifestations, diagnosis, antifungal susceptibility, and treatment. An expansion of hosts at risk for these difficult-to-treat infections has emerged over the last two decades given the increased use of, and broader population treated with, immunomodulatory and targeted molecular agents as well as wider adoption of antifungal prophylaxis. Clinical presentations differ not only between genera but also across the different Scedosporium species. L. prolificans is intrinsically resistant to most currently available antifungal agents, and the prognosis of immunocompromised patients with lomentosporiosis is poor. Development of, and improved access to, diagnostic modalities for early detection of these rare mold infections is paramount for timely targeted antifungal therapy and surgery if indicated. New antifungal agents (e.g., olorofim, fosmanogepix) with novel mechanisms of action and less cross-resistance to existing classes, availability of formulations for oral administration, and fewer drug-drug interactions are now in late-stage clinical trials, and soon, could extend options to treat scedosporiosis/lomentosporiosis. Much work remains to increase our understanding of these infections, especially in the pediatric setting. Knowledge gaps for future research are highlighted in the review.

Endogenous fungal endophthalmitis caused by Cladophialophora devriesii: report of a case and literature review

PURPOSE

To report a case of endogenous endophthalmitis caused by the dematiaceous fungus Cladophialophora devriesii.

METHODS

Observational case report and literature review.

CASE PRESENTATION

A 73-year-old female with a history of chronic obstructive pulmonary disease presented with a red and painful left eye. Examination revealed anterior segment inflammation and vitritis, indicative of endophthalmitis. She underwent core vitrectomy and intravitreal injection of vancomycin and amphotericin B. The vitreous sample showed inflammatory cells and fungal hyphae, and systemic amphotericin B and itraconazole were commenced for fungal endophthalmitis. Targeted amplification of the sample for bacterial DNA (V2-V3 region of 16 S rDNA) was negative, but fungal DNA targets (ITS1 and ITS2) were present, and their sequences were consistent with Cladophialophora devriesii. Phenotypic characterisation and sequencing of ITS1 and ITS2, carried out on cultured fungus from the sample, also revealed Cladophialophora devriesii. She received repeated intravitreal injections of voriconazole, and based on the antifungal susceptibility results, her systemic medication was changed to posaconazole. After 12 months, the eye showed no signs of inflammation, and posaconazole therapy was discontinued. After 3 months without antifungal medication, the inflammation recurred, and she was restarted on antifungal therapy for an additional 20 months. Another recurrence occurred 3 months after discontinuation of treatment, and a repeat vitreous sample confirmed the presence of Cladophialophora devriesii. She was started on isavuconazole, but developed seclusio pupillae and painful secondary glaucoma. Due to the duration and severity of the infection, the eye was enucleated. Histopathology revealed persistent fungal elements at the ciliary processes and the posterior lens surface.

CONCLUSIONS

This second reported case of endogenous endophthalmitis caused by Cladophialophora devriesii illustrates the role of vitreous sampling and molecular methods in diagnosis and treatment of fungal endophthalmitis. Despite early diagnosis and prolonged local and systemic antifungal therapy, it was not possible to achieve long-term control of the fungal infection.

Mucormycosis during COVID-19 era: A retrospective assessment

In a retrospective view, this review examines the impact of mucormycosis on health workers and researchers during the COVID era. The diagnostic and treatment challenges arising from unestablished underlying pathology and limited case studies add strain to healthcare systems. Mucormycosis, caused by environmental molds, poses a significant threat to COVID-19 patients, particularly those with comorbidities and compromised immune systems. Due to a variety of infectious Mucorales causes and regionally related risk factors, the disease's incidence is rising globally. Data on mucormycosis remains scarce in many countries, highlighting the urgent need for more extensive research on its epidemiology and prevalence. This review explores the associations between COVID-19 disease and mucormycosis pathology, shedding light on potential future diagnostic techniques based on the fungal agent's biochemical components. Medications used in ICUs and for life support in ventilated patients have been reported, revealing the challenge of managing this dual onslaught. To develop more effective treatment strategies, it is crucial to identify novel pharmacological targets through "pragmatic" multicenter trials and registries. In the absence of positive mycology culture data, early clinical detection, prompt treatment, and tissue biopsy are essential to confirm the specific morphologic features of the fungal agent. This review delves into the history, pathogens, and pathogenesis of mucormycosis, its opportunistic nature in COVID or immunocompromised individuals, and the latest advancements in therapeutics. Additionally, it offers a forward-looking perspective on potential pharmacological targets for future drug development.

A Seminested PCR Method for the Diagnosis of Invasive Fungal Infections in Combat Injured

Background

Among combat injured, invasive fungal infections (IFIs) result in significant morbidity. Cultures and histopathology are the primary diagnostic methods for IFIs, but they have limitations. We previously evaluated a panfungal polymerase chain reaction assay, which was 83% sensitive and 99% specific for angioinvasive IFIs. Here, we evaluated 3 less resource-intensive seminested assays targeting clinically relevant fungi in the order Mucorales and genera Aspergillus and Fusarium.

Methods

Formalin-fixed paraffin-embedded tissue specimens from a multicenter trauma IFI cohort (2009-2014) were used. Cases were US military personnel injured in Afghanistan with histopathologic IFI evidence. Controls were patients with similar injury patterns and no laboratory IFI evidence (negative culture and histopathology). Seminested assays specific to Mucorales (V4/V5 regions of 18S rDNA), Aspergillus (mitochondrial tRNA), and Fusarium (internal transcribed spacer [ITS]/28A regions of DNA) were compared with a panfungal assay amplifying the internal transcribed spacer 2 region of rDNA and to histopathology.

Results

Specimens from 92 injury sites (62 subjects) were compared with control specimens from 117 injuries (101 subjects). We observed substantial agreement between the seminested and panfungal assays overall, especially for the order Mucorales. Moderate agreement was observed at the genus level for Aspergillus and Fusarium. When compared with histopathology, sensitivity and specificity of seminested assays were 67.4% and 96.6%, respectively (sensitivity increased to 91.7% when restricted to sites with angioinvasion).

Conclusions

Prior studies of seminested molecular diagnostics have focused on culture-negative samples from immunocompromised patients. Our findings underscore the utility of the seminested approach in diagnosing soft-tissue IFIs using formalin-fixed paraffin-embedded tissue samples, especially with angioinvasion.

Humans vs. Fungi: An Overview of Fungal Pathogens against Humans

Human fungal diseases are infections caused by any fungus that invades human tissues, causing superficial, subcutaneous, or systemic diseases. Fungal infections that enter various human tissues and organs pose a significant threat to millions of individuals with weakened immune systems globally. Over recent decades, the reported cases of invasive fungal infections have increased substantially and research progress in this field has also been rapidly boosted. This review provides a comprehensive list of human fungal pathogens extracted from over 850 recent case reports, and a summary of the relevant disease conditions and their origins. Details of 281 human fungal pathogens belonging to 12 classes and 104 genera in the divisions ascomycota, basidiomycota, entomophthoromycota, and mucoromycota are listed. Among these, Aspergillus stands out as the genus with the greatest potential of infecting humans, comprising 16 species known to infect humans. Additionally, three other genera, Curvularia, Exophiala, and Trichophyton, are recognized as significant genera, each comprising 10 or more known human pathogenic species. A phylogenetic analysis based on partial sequences of the 28S nrRNA gene (LSU) of human fungal pathogens was performed to show their phylogenetic relationships and clarify their taxonomies. In addition, this review summarizes the recent advancements in fungal disease diagnosis and therapeutics.

Granulomas in Pediatric Liver Biopsies: Single Center Experience

BACKGROUND

Granulomas in pediatric liver biopsies (GPLB) are rare with the largest pediatric cohort reported over 25 years ago.

METHODS

Single-center retrospective study of GPLB.

RESULTS

Seventeen liver biopsies from 16 patients with granulomas were identified (9 boys, 56%) with a median age of 13 years (range: 1-18) for which the most common indication was the presence of a nodule/mass (47%). Significant comorbidities were seen in 13 patients (81%) and included: liver transplant (25%), history of a neoplasm (25%), autoimmune hepatitis (6%), Crohn disease (6%), bipolar disorder (6%), severe combined immunodeficiency (6%), and sickle cell disease (6%). Eleven patients were taking multiple medications at the time of biopsy. Granulomas were more commonly pan-acinar (11 cases) followed by subcapsular (4 cases), portal (1 case), and periportal (1 case). Necrosis was seen in 10 cases (59%). GMS stain was positive in 2 cases for Histoplasma-like yeast; microbiological cultures were negative in all cases (no: 4). A 18S and 16S rRNA gene sequencing performed in 15 cases revealed only 1 with a pathogenic microorganism, Mycobacterium angelicum.

CONCLUSION

In our experience, GPLB are heterogenous with only 3 cases having an identifiable infectious etiology and many of the remaining cases being associated to multiple medications, suggesting drug-induced liver injury as possible etiology.

Review of immunohistochemistry techniques: Applications, current status, and future perspectives

The Hematoxylin and Eosin stain is a cornerstone in histopathology that facilitates the microscopic examination of tissue samples for identifying infections and tumors. However, challenges arise from the similar appearances of diseases and cells, prompting the emergence of Immunohistochemistry (IHC) as an important technique. This review summarizes the principles, procedures, and applications and future perspectives of IHC, a prevalent immunostaining method allowing the detection of specific proteins in tissue sections. The multistep IHC process involves fixation, embedding, sectioning, antigen retrieval, blocking, detection, counterstaining, mounting, and visualization, with interpretation relying on factors such as microanatomic distribution and staining intensity. Common errors in IHC such as non-specific staining, tissue artifacts, inadequately inactivation of endogenous peroxidase activity and cross-reactivity, can substantially affect the accuracy and reliability of results, thereby impacting the interpretation of biological findings. Serving diagnostic, prognostic, predictive, and therapeutic roles in various conditions, including tumors, infectious diseases, neurodegenerative disorders, and muscle diseases, IHC remains pivotal despite its intricate nature. The adoption of digital pathology emerges as a progressive enhancement, addressing limitations and ensuring more accurate analyses in histopathology.

Novel B-DNA dermatophyte assay for demonstration of canonical DNA in dermatophytes: Histopathologic characterization by artificial intelligence

We describe a novel assay and artificial intelligence-driven histopathologic approach identifying dermatophytes in human skin tissue sections (ie, B-DNA dermatophyte assay) and demonstrate, for the first time, the presence of dermatophytes in tissue using immunohistochemistry to detect canonical right-handed double-stranded (ds) B-DNA. Immunohistochemistry was performed using anti-ds-B-DNA monoclonal antibodies with formalin-fixed paraffin-embedded tissues to determine the presence of dermatophytes. The B-DNA assay resulted in a more accurate identification of dermatophytes, nuclear morphology, dimensions, and gene expression of dermatophytes (ie, optical density values) than periodic acid-Schiff (PAS), Grocott methenamine silver (GMS), or hematoxylin and eosin (H&E) stains. The novel assay guided by artificial intelligence allowed for efficient identification of different types of dermatophytes (eg, hyphae, microconidia, macroconidia, and arthroconidia). Using the B-DNA dermatophyte assay as a clinical tool for diagnosing dermatophytes is an alternative to PAS, GMS, and H&E as a fast and inexpensive way to accurately detect dermatophytosis and reduce the number of false negatives. Our assay resulted in superior identification, sensitivity, life cycle stages, and morphology compared to H&E, PAS, and GMS stains. This method detects a specific structural marker (ie, ds-B-DNA), which can assist with diagnosis of dermatophytes. It represents a significant advantage over methods currently in use.

Dematiaceous fungal infections: clinical and pathologic conundrums

Dematiaceous fungi are defined by pigment within their cell walls. They are increasingly recognised human pathogens, causing a wide range of clinical presentations, from localised subcutaneous infections to disseminated disease in rare cases. We report our institutional experience with diagnosis of dematiaceous fungal infections from 2005 to 2022 and highlight four instructive cases that clinically and pathologically mimicked other diseases for which the diagnosis was confirmed by fungal culture (one case) or supported by PCR with 28S rRNA and internal transcribed spacer primers (three cases). Two patients were immunocompromised and two had presumed exposure to the organism. In each highlighted case, fungal infection was not clinically suspected, and the pathologist was critical in making the diagnosis and ensuring appropriate clinical management, which was supplemented by fungal stains and novel molecular methods.