Weekly Fungal Diagnostics Update – 28 September 2026
This week’s fungal diagnostics literature has a particularly clear theme: getting to an accurate fungal identification faster. New studies explore rapid rRNA-based identification, point-of-care LAMP for dermatophytes and antifungal resistance, faster MALDI-TOF identification of moulds, and metagenomic sequencing for pulmonary infections.
Other papers remind us that diagnostic technology is only part of the problem. Rare mould outbreaks, unusual presentations of histoplasmosis and sporotrichosis, and fungal infections of the lacrimal drainage system can still be missed unless clinicians first consider a fungal diagnosis.
Rapid rRNA-based identification of fungal pathogens
Yee EA, Burt BJ, Sephton-Clark PCS, et al.
An rRNA hybridization-based approach for rapid and accurate identification of diverse fungal pathogens.
Microbiology Spectrum. Published 25 September 2026.
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Researchers have developed a multiplexed hybridisation assay targeting fungal ribosomal RNA (rRNA) to rapidly identify a wide range of clinically important fungi.
The system uses a panel of probes designed to recognise fungal rRNA signatures. In an independent validation set, the approach achieved approximately 91% species-level, 94% genus-level and 98% family-level identification.
The assay requires relatively little hands-on time and can provide results within hours rather than the days that may be required for conventional identification. The researchers also demonstrated its potential for identifying fungi in formalin-fixed paraffin-embedded tissue.
Why this matters
Slow identification remains an important problem in medical mycology, particularly with unusual moulds and yeasts. A method capable of identifying many different fungal pathogens using a single rapid platform could help laboratories move from a broad suspicion of fungal infection towards organism-level identification much sooner.
The technology still needs further clinical validation and implementation studies, but this is one of the more interesting broad-spectrum fungal identification approaches reported recently.
Faster MALDI-TOF identification of filamentous fungi
Bagga R, Delport J.
Validation of the Mycelium Transfer Method Coupled with MALDI-TOF MS for Rapid Identification of Filamentous Fungi.
Pathogens. 2026;15(9):992.
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MALDI-TOF mass spectrometry has transformed bacterial and yeast identification, but moulds remain more difficult because sample preparation and growth characteristics can delay testing.
This study evaluated a Mycelium Transfer Method in which actively growing mycelium is sampled from routine solid culture and prepared for MALDI-TOF MS identification.
The aim is to shorten the route between visible mould growth and a useful species identification while avoiding some of the more cumbersome preparation procedures traditionally used for filamentous fungi.
Why this matters
Rapid identification is particularly important for invasive mould infections because different fungi can have very different antifungal susceptibility patterns. Improving how existing MALDI-TOF equipment handles moulds could potentially be easier for laboratories to implement than introducing an entirely new diagnostic platform.
Point-of-care LAMP test for dermatophytes and antifungal resistance
Wunderlich G, Butterly S, Johnson M, Tatian A, Baum J.
Development of a rapid LAMP assay toward point-of-care detection of dermatophyte infections and antifungal resistance.
Microbiology Spectrum. Published 24 September 2026.
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A new loop-mediated isothermal amplification (LAMP) assay has been developed to rapidly detect dermatophyte infection while also addressing the increasingly important problem of antifungal resistance.
LAMP amplifies DNA at a constant temperature, avoiding the thermal cycling required for conventional PCR. This makes the technology potentially suitable for relatively simple and portable diagnostic systems.
The researchers envisage the assay being particularly useful in settings where access to conventional molecular laboratories is limited.
Why this matters
Antifungal-resistant dermatophytes, including resistant Trichophyton infections, are an emerging international problem. Rapidly establishing both that a dermatophyte is present and whether resistance may affect treatment could reduce inappropriate antifungal use and support antifungal stewardship.
Metagenomic sequencing of bronchoalveolar lavage fluid
Song Y, Xu C, Zu F, Dong R, Yang H.
Diagnostic Performance of Bronchoalveolar Lavage Fluid Metagenomic Next-generation Sequencing versus Conventional Microbiological Tests in Immunocompromised and Immunocompetent Patients with Pulmonary Infection.
Infection and Drug Resistance. 2026;19:632502.
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This study compared metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid with conventional microbiological testing in patients being investigated for pulmonary infection.
One attraction of mNGS is that it does not require clinicians to decide in advance exactly which organism they are looking for. DNA from many potential pathogens can be detected simultaneously, which may be particularly valuable in immunocompromised patients with complex or mixed infections.
The study included analysis of fungal detection as part of its comparison between mNGS and conventional diagnostic methods.
Why this matters
mNGS has enormous potential, but detecting microbial DNA is not automatically the same as diagnosing disease. Results must still be interpreted alongside clinical findings, imaging and conventional microbiology.
Studies directly comparing mNGS with established tests are therefore important in determining where this technology genuinely improves patient diagnosis rather than simply detecting more organisms.
Investigating hospital acquisition of rare and emerging moulds
Marek A, Carlesse F, Bagrade L, et al.
A Pragmatic Approach to Investigating Nosocomial Acquisition of Rare and Emerging Molds.
Medical Mycology. Published 22 September 2026.
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Rare mould infections can present a difficult question for hospitals: did the patient acquire the fungus in the community, or was exposure associated with the healthcare environment?
This paper discusses a practical approach to investigating possible hospital acquisition of rare and emerging moulds, including environmental investigation, surveillance and molecular approaches that can help determine relationships between isolates.
Organisms of concern include uncommon opportunistic moulds such as Fusarium, Scedosporium and Lomentospora.
Why this matters
Identifying the fungus is sometimes only the beginning of the investigation. When an unusual mould infection occurs in a vulnerable patient, determining where it came from can be important for protecting other patients and identifying environmental sources that need remediation.
Fungal infections of the lacrimal drainage system
Juniat V, Ali MJ.
A Major Review of Fungal Lacrimal Drainage Infections.
International Ophthalmology Clinics. Published online 24 September 2026.
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Fungal infections involving the lacrimal drainage system are uncommon and consequently may not immediately be considered when patients develop persistent epiphora, dacryocystitis or canaliculitis.
This review brings together the published experience of these unusual infections. Candida and Aspergillus are among the organisms reported.
Clinical suspicion, examination of material such as casts or dacryoliths, and microbiological investigation all contribute to diagnosis.
Why this matters
Rare fungal infections illustrate an important principle of diagnosis: even an excellent laboratory test cannot detect an infection if the possibility of fungal disease is never considered and an appropriate specimen is not collected.
Imaging in acute invasive fungal rhino-orbital sinusitis
Dave TV, Doctor S, Bhopatkar S, Sinha P, Rootman D, Vagefi MR.
Acute Invasive Fungal Rhino Orbital Sinusitis: Imaging-Driven Stratification and Orbit-Sparing Therapeutic Paradigms.
International Ophthalmology Clinics. Published online 24 September 2026.
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This review examines the role of imaging in assessing acute invasive fungal rhino-orbital sinusitis.
Imaging does more than simply demonstrate that disease is present. The pattern and extent of involvement can help clinicians assess disease progression and guide decisions about surgical and medical management.
Why this matters
In rapidly progressive invasive fungal disease, diagnosis, anatomical assessment and treatment decisions are closely connected. Imaging can therefore be an essential component of the diagnostic pathway rather than simply confirmation after microbiological diagnosis.
Could fluconazole heteroresistance help predict cryptococcosis relapse?
Moreira IMB, Silva IB, Dias do Val Bisneto JF, et al.
Baseline fluconazole heteroresistance and risk of relapse within six months among patients with neurocryptococcosis in the Brazilian Amazon.
Medical Mycology. Published 21 September 2026.
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This retrospective cohort study examined isolates from 70 patients with neurocryptococcosis and investigated whether baseline fluconazole minimum inhibitory concentrations (MICs) and fluconazole heteroresistance were associated with relapse during the following six months.
Heteroresistance occurs when a small subpopulation within an apparently susceptible fungal population can tolerate higher concentrations of an antifungal drug.
Why this matters
Fungal susceptibility testing is traditionally used to help determine whether an organism is likely to respond to an antifungal. Research into heteroresistance raises a broader possibility: characteristics hidden within the original diagnostic isolate might eventually provide information about the patient’s risk of subsequent treatment failure or relapse.
This is not yet a routine clinical test, but it is an interesting example of fungal diagnostics moving beyond simple species identification.
Sporotrichosis identified using metagenomic sequencing
Wang X, Bian J, Xu J, et al.
Lymphocutaneous sporotrichosis: A case report from southeastern China and review of the literature.
Medicine. 2026;105(39):e50812.
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A patient with lymphocutaneous sporotrichosis was investigated using molecular methods alongside conventional fungal culture.
The case illustrates the potential for sequencing-based methods to accelerate recognition of an infection that can otherwise be confused with other chronic skin and lymphatic conditions.
Why this matters
This is a case report rather than evidence that sequencing should replace fungal culture. However, it demonstrates how broad molecular testing can sometimes provide an early clue when the diagnosis is uncertain, with conventional microbiology subsequently providing confirmation.
Gastric histoplasmosis mimicking other gastrointestinal disease
Yousef M, Almasaid S, Chaar A, et al.
Gastric Involvement With Disseminated Histoplasmosis in an Immunocompetent Patient From a Nonendemic Region.
ACG Case Reports Journal. 2026;13(9):e02315.
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Gastrointestinal histoplasmosis can resemble more common gastrointestinal disease, including ulceration and malignancy.
This case involved gastric disease in an immunocompetent patient from a non-endemic region, illustrating how both an unusual site of infection and geographical expectations can complicate recognition of histoplasmosis.
Why this matters
Diagnostic tests only work when clinicians consider the diagnosis. Travel and exposure history, previous fungal disease and histopathological examination can become particularly important when fungal infections appear in unexpected patients or anatomical sites.
This week in fungal diagnostics
The strongest message from this week’s research is that speed is becoming a central target for fungal diagnostics.
Three quite different technologies illustrate this particularly well: rRNA hybridisation aims to identify a broad range of fungal pathogens within hours; LAMP could bring rapid dermatophyte and resistance testing closer to the point of care; and improved MALDI-TOF workflows could shorten identification using equipment already present in many microbiology laboratories.
Metagenomic sequencing provides another route towards broad pathogen detection, particularly when clinicians do not know exactly what they are looking for. But its growing sensitivity also reinforces the importance of interpreting molecular detection in the context of the patient, imaging and conventional microbiology.
Finally, this week’s reports of fungal lacrimal infection, gastric histoplasmosis and sporotrichosis illustrate a more fundamental diagnostic challenge: before a fungus can be identified quickly, somebody first has to suspect that a fungal infection might be present.
This weekly research update highlights recently published studies of potential interest in fungal diagnostics. Inclusion does not mean that a diagnostic method has been clinically validated or is recommended for routine use. New diagnostic tests require appropriate validation and interpretation within the clinical context.