Fungal Diagnostics Research Update – 12 October 2026

This week’s fungal diagnostics research highlights the growing role of DNA sequencing in identifying difficult infections, hospital screening for drug-resistant fungi, and new ways of understanding the severity of fungal disease.

One important theme connects these studies: detecting a fungus is only part of the diagnostic process. Laboratories and clinicians must also establish whether it is causing disease, how it may have spread and which treatments are likely to work.

1. Can DNA sequencing identify an eye infection when routine tests fail?

Infections of the cornea, known as microbial keratitis, can threaten sight. Rapid identification of the responsible microorganism is important because bacterial, fungal and other infections may require very different treatments.

Passaro and colleagues reported a difficult case involving a contact lens wearer with rapidly worsening keratitis. Conventional cultures and targeted molecular investigations had not established a diagnosis.

The report examines the role of broad-range sequencing of the internal transcribed spacer (ITS) region, a genetic region commonly used to identify fungi.

Unlike a targeted PCR test, which looks for a particular organism, broad-range sequencing can help investigate a wider range of possible pathogens.

Why this matters: When an infection continues to worsen despite treatment and routine tests remain negative, broader molecular investigations may provide valuable additional information.

Important limitation: This is a case report, not a large diagnostic accuracy study. It illustrates a potential use for sequencing but does not establish how often the method will succeed or whether it should be used routinely.

Research: Passaro et al., BMJ Case Reports (2026).

2. Hospital screening can help identify Candida auris before it spreads

Candida auris, now also classified as Candidozyma auris, is an important healthcare-associated fungus because it can persist in hospital environments, spread between patients and show resistance to antifungal medicines.

Some people carry the organism on their skin without becoming ill. This is called colonisation, and it is different from an active infection.

Guran and colleagues evaluated active surveillance testing for C. auris in an acute healthcare system.

Active surveillance means testing selected patients even when they have no symptoms of fungal infection. The study also examined how screening programmes influence infection prevention practices.

The researchers reported that surveillance supported earlier identification of colonised or infected patients and contributed to infection control activities.

Why this matters: Detecting C. auris before transmission occurs can help hospitals introduce appropriate precautions, protect vulnerable patients and investigate possible outbreaks.

Screening does not necessarily mean a patient needs antifungal treatment. A positive result must be interpreted according to whether the fungus is colonising the body or causing an infection.

Research: Guran et al., American Journal of Infection Control (2026).

3. Genome sequencing helps investigate suspected Candida auris outbreaks

When several patients in a hospital test positive for the same fungus, an important question is whether their infections are connected.

Traditional laboratory identification may show that patients have the same fungal species, but it cannot always establish how closely related the individual strains are.

Tan and colleagues investigated suspected Candida auris outbreaks in Malaysia using an integrated approach combining genome sequencing, clinical information and antifungal susceptibility testing.

Whole-genome sequencing examines much more of an organism’s genetic material than routine species identification. Comparing genomes can help researchers understand relationships between isolates and investigate possible patterns of transmission.

Why this matters: Genomic information can strengthen hospital outbreak investigations and help infection prevention teams interpret how resistant fungi may be spreading.

However, genetically similar isolates do not, by themselves, prove direct transmission between particular patients. Clinical and epidemiological evidence remains essential.

Research: Tan et al., Medical Mycology (2026).

4. Tracking the spread of drug-resistant Candida tropicalis

Candida tropicalis can cause serious bloodstream and other invasive infections, particularly in people whose immune systems are weakened.

Antifungal resistance makes these infections more difficult to manage and increases the importance of reliable laboratory identification and susceptibility testing.

Zhu and colleagues conducted a retrospective multicentre genomic investigation of multidrug-resistant C. tropicalis in China.

The study examined the regional expansion and genetic evolution of resistant isolates, using genomic methods to investigate how resistance and persistence may develop in healthcare settings.

Why this matters: Genome sequencing can help researchers understand the emergence and distribution of resistant fungal strains. This information may support surveillance and guide future infection prevention strategies.

For individual patients, laboratory antifungal susceptibility testing remains important when clinicians need to select an appropriate medicine. Genomic findings do not automatically replace those tests.

Research: Zhu et al., The Lancet Microbe (2026).

5. Can fungal burden and immune biomarkers predict outcomes in Pneumocystis pneumonia?

Pneumocystis jirovecii pneumonia (PCP or PJP) is a potentially life-threatening lung infection, especially in people with advanced HIV or other forms of immune suppression.

Diagnostic tests can help establish whether Pneumocystis is present, but doctors also need to assess how seriously the infection is affecting the patient.

Rossi-Smith and colleagues used a multi-omics approach to investigate biological factors associated with mortality in HIV-associated Pneumocystis pneumonia.

Multi-omics combines different kinds of biological measurements, including information about genes, proteins and metabolites. The researchers examined fungal burden alongside immune and metabolic responses.

Why this matters: Better understanding of these biological patterns could eventually help clinicians identify patients at particularly high risk and understand why outcomes differ.

Important limitation: These findings concern potential prognostic biomarkers rather than a new routine diagnostic test. Further validation would be needed before such measurements could guide everyday clinical decisions.

Research: Rossi-Smith et al., JCI Insight (2026).

Also in fungal diagnostics this week

Urine tests for invasive aspergillosis: Two studies investigated non-invasive testing using urinary fungal markers, including the MycoMEIA assay and urinary triacetylfusarinine C combined with blood biomarkers. These are promising approaches, but their performance in routine clinical practice requires further evaluation.

Read the studies: Baburina et al. and Patil et al..

Understanding Candida auris genetic groups: A new commentary considers the clinical implications of distinguishing different C. auris clades, or genetically related groups. This may be relevant to surveillance and laboratory interpretation. Lee, Annals of Laboratory Medicine (2026).

What can we learn from this week’s research?

• Broader molecular testing: DNA sequencing may help investigate infections that conventional laboratory methods cannot identify.
• Screening and infection prevention: Detecting drug-resistant fungi in people without symptoms can help hospitals reduce transmission risks.
• Genomic surveillance: Comparing fungal genomes provides information about relatedness, outbreaks and resistance patterns.
• Interpreting positive results: Finding a fungus does not always mean that it is causing an active infection.
• Predicting outcomes: Researchers are investigating whether combinations of fungal, immune and metabolic biomarkers can improve assessment of disease severity.

Although molecular technologies are becoming increasingly powerful, the most reliable diagnoses still depend on combining laboratory findings with symptoms, imaging, clinical history and other relevant investigations.

This article summarises recently published research for educational purposes. Investigational tests and biomarkers should not be regarded as established clinical practice unless appropriately validated and recommended.