Candida albicans is a type of fungus that naturally occurs in the human body.
When it overgrows, it can cause a wide range of health problems, including yeast infections, thrush, and even systemic candidiasis.
Culturing candida albicans is an important part of diagnosing and treating these infections.
In this article, we will explore the process of culturing candida albicans.
How to culture candida albicans
To culture candida albicans, a sample is taken from the affected area and then placed on a special type of agar, known as Sabouraud agar, chromogenic agar, or cornmeal agar.
The choice of cultural media may depend on the specific purpose of the culture, such as detection, enumeration, or differentiation.
Sabouraud agar contains a mixture of glucose and peptone, which provides the nutrients necessary for candida albicans to grow. The agar is then incubated at a temperature of 30-37°C for 24-48 hours.
Cultural characteristics of candida albicans
On Sabouraud agar, Candida albicans appear as creamy-white, moist colonies with a smooth surface, and may have a “yeasty” or “bready” odor.
In addition, Candida albicans are capable of producing pseudohyphae, which are elongated cells that appear as chains of cells.
These characteristics are useful for the identification of Candida albicans in clinical specimens.
Morphological characteristics of candida albicans
Candida albicans, an oval-shaped yeast, have the ability to form pseudohyphae, true hyphae, and chlamydospores.
Pseudohyphae are chains of elongated yeast cells that remain attached, whereas true hyphae are long, branched filaments that can penetrate tissues.
Chlamydospores are round or oval-shaped spores that are thick-walled and formed by the fungus in response to adverse environmental conditions.
The presence of these structures in clinical specimens strongly indicates Candida albicans infection.
On Sabouraud dextrose agar (SDA) or potato dextrose agar (PDA), Candida albicans colonies are creamy, white to beige-colored, with a smooth and glossy texture.
The colonies may become wrinkled with age, and yellow or brown pigments may accumulate in the center.
On chromogenic agar, such as CHROMagar Candida, Candida albicans colonies are pink to magenta-colored, making them distinguishable from other Candida species.
How to test for candida albicans
There are other ways to test for the presence of Candida albicans other than culturing, and they include:
- Microscopy: A direct microscopic examination of the clinical specimen can reveal the characteristic morphological features of Candida albicans, such as the presence of budding yeast cells, pseudohyphae, and true hyphae.
- Biochemical tests: Biochemical tests, such as the germ tube test, can be used to differentiate Candida albicans from other Candida species. The germ tube test involves incubating the yeast cells in human serum at 37°C for 2-3 hours. If germ tubes are observed under a microscope, the isolate is likely Candida albicans.
- Molecular methods: Molecular methods, such as polymerase chain reaction (PCR), can be used to detect the DNA of Candida albicans in clinical specimens.
What is the difference between candida spp and candida albicans
Candida albicans is a diploid fungus that can switch between two growth forms: the yeast form and the hyphal form, depending on the environmental conditions.
This ability to switch between these two forms is thought to play a key role in its ability to colonize and infect different parts of the human body, including the mouth, throat, gut, genitals, and bloodstream.
Candida albicans produce a wide range of virulence factors, including adhesins, proteases, phospholipases, lipases, and hydrolases, which enable them to adhere to and invade host tissues, evade immune surveillance, and cause tissue damage.
These virulence factors are also responsible for the various clinical manifestations of candidiasis, which range from superficial infections, such as thrush, to severe, life-threatening systemic infections, such as candidemia.
Other Candida species, such as Candida glabrata, Candida krusei, Candida parapsilosis, and Candida tropicalis, also have the ability to cause infections in humans, but they differ from Candida albicans in their genetic and biochemical characteristics.
For instance, Candida glabrata is often resistant to the antifungal drug fluconazole, while Candida krusei is naturally resistant to many antifungal drugs.
Candida parapsilosis is frequently associated with infections in premature infants, and Candida tropicalis is more commonly found in tropical and subtropical regions.
The clinical manifestations of these different species of Candida may vary depending on the host, underlying medical conditions, and the severity of the infection.
Proper identification of the candidal species is essential for accurate diagnosis and effective treatment of infections caused by these fungi.