''Candidozyma haemuli'' is a

yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom (biology), kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are est ...

fungal pathogen that is known to cause infections in humans. ''C. haemuli'' is an emerging opportunistic pathogen that is found in hospitals and healthcare settings. Infections are difficult to treat because the fungus has resistance to

antifungal An antifungal medication, also known as an antimycotic medication, is a pharmaceutical fungicide or fungistatic used to treat and prevent mycosis such as athlete's foot, ringworm, candidiasis (thrush), serious systemic infections such as ...

agents. Since its emergence, little research has been conducted on this fungus. However, in recent years, research has been conducted to help identify the various properties of ''C. haemuli''.

Taxonomy

The fungus was first classified as ''Torulopsis haemuli'' in 1962. In 1978, the fungus became classified as ''Candida haemulonii.''

Morphology

Oval cells are present at a microscopic level. The fungus has the ability to switch from a filamentous

phenotype In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology (physical form and structure), its developmental processes, its biochemical and physiological propert ...

to a yeast phenotype given temperature differences. This allows the fungus to survive within different environments at different temperatures.

Habitat

Since the fungus has yeast properties, it has the ability to survive in soil and water. The fungus has been present in various outbreaks around the globe, including in hospitals within patients where the fungus has increased resistance to antifungals. This indicates its ability to survive and reside in human bodies. As well, it is an indication it can survive on non-living surfaces. Due to the fungus's ability to switch phenotypes given the temperature, it is implied that the fungus can survive within a wide temperature range in order to adapt to the external environment and continue to survive.

Geographical distribution and outbreaks

There have been an increased number of global outbreaks where this strain of fungus was found. The original locations of the fungus is reported to have been the Atlantic Ocean. Researchers noted that they found traces of the fungus on the skin of dolphins and the seawater of the coast of Portugal. A study in 2001 reported that the fungus was associated with an epidemic in a laboratory maintained colony in the Czech Republic. A study in 2015 reported how the fungus was found in patients in Brazilian hospitals. This study reported antifungal multi-resistant properties. Recent studies around 2020 report ''C. haemuli'' as an opportunistic pathogen in hospitals across the United States. The fungus has been reported in diverse regions around the world. This would corroborate how the species has properties that allow it to adapt to different temperatures in different environments because each of the mentioned regions have climates that are distinct from one another.

Medical relevance

Amphotericin B Amphotericin B is an antifungal medication used for serious fungal infections and leishmaniasis. The fungal infections it is used to treat include mucormycosis, aspergillosis, blastomycosis, candidiasis, coccidioidomycosis, and cryptococ ...

fluconazole Fluconazole is an antifungal medication used for a number of fungal infections. These include candidiasis, blastomycosis, coccidioidomycosis, cryptococcosis, histoplasmosis, dermatophytosis, and tinea versicolor. It is also used to pr ...

, and

itraconazole Itraconazole, sometimes abbreviated ITZ, is an antifungal medication used to treat a number of fungal infections. This includes aspergillosis, blastomycosis, coccidioidomycosis, histoplasmosis, and paracoccidioidomycosis. It may be given ...

are antifungal agents that have been used against ''C. haemuli'' in immunocompromised patients. The fungus was reported to be resistant to these antifungal agents. In addition, the fungus is resistant to

azoles Azoles are a class of five-membered heterocyclic compounds containing a nitrogen atom and at least one other non-carbon atom (i.e. nitrogen, sulfur, or oxygen) as part of the ring. Their names originate from the Hantzsch–Widman nomenclature. T ...

and echinocandins, which are also antifungal drugs. The fungus is reported to have a tendency to cause chronic lower extremity wounds. The fungus is also more likely to negatively impact

diabetic Diabetes mellitus, commonly known as diabetes, is a group of common endocrine diseases characterized by sustained high blood sugar levels. Diabetes is due to either the pancreas not producing enough of the hormone insulin, or the cells of th ...

patients. The fungus has been isolated from the nails of diabetic patients. It has also been associated with toe

ulcers An ulcer is a discontinuity or break in a bodily membrane that impedes normal function of the affected organ. According to Robbins's pathology, "ulcer is the breach of the continuity of skin, epithelium or mucous membrane caused by sloughing ...

and

renal failure Kidney failure, also known as renal failure or end-stage renal disease (ESRD), is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney fa ...

. A study delved into how the case fatality rate of ''C. haemuli'' is 83.33%. Immunological studies showed that the species stimulated genes involved in

proinflammatory cytokine An inflammatory cytokine or proinflammatory cytokine is a type of signaling molecule (a cytokine) that is secreted from immune cells like helper T cells (Th) and macrophages, and certain other cell types that promote inflammation. They include int ...

group, indicating the species can impact the inflammatory pathway.

References

{{Taxonbar, from=Q118202949 Pathogenic microbes Fungal pathogens of humans Fungus species