Candida albicans

How will you take a sample for Candida albicans?

1. Scrapings from the affected area.
2. Gram stain of the smear.
3. The culture of the material.
4. The patient’s serum is needed for an antibody test.
5. The serum or body fluid is needed for the presence of the antigens.

How will you define Candida albicans?

1. Candida organisms may be present as normal flora of the nasopharyngeal area or gastrointestinal tract (20% to 40%).
2. Positive culture of the vaginal secretions in asymptomatic women (10% to 15%)
3. Superficial infection is seen in the oral cavity or vagina.
4. It can be seen as a deep or disseminated infection.
5. The most common opportunistic infections are caused by:
   1. Candida.
   2. Aspergillosis.
   3. Mucormycosis.

How will you discuss the microbiology of Candida albicans?

1. The most common Candida infection in humans is caused by Candida albicans (90%), followed by Candida tropicalis.
2. These are oval budding yeast measuring 3 x 6 μm.
3. These are gram-positive.
4. Elongated filament cells joined end to end are called pseudohyphae in vivo.
   1. Candida albicans is the only species to produce hyphae and pseudohyphae in vivo.
   2. Spherical to budding oval cells (3 to 5  x 5 to 10 μm).
   3. Yeast is Y-form.
5. Other types are:
   1. C. stellatoidea (subtype is C.albicans).
   2.  C. tropicalis.
   3. C. krusei.
   4. C. guilliermondii.
   5. C. parapsilosis.
6. Candida is also known as moniliasis.

What are the characteristic features of Candida albicans?

1. Candida is a normal flora of the upper respiratory tract (nasopharyngeal area), gastrointestinal tract, and female genital tract (20% to 40%).

How will you culture Candida albicans?

1. These are aerobic and easy to cultivate.
2. Sabouraud’s medium may be made selective by adding the antibiotic (chloramphenicol) and is helpful for primary isolation when incubated at 37 °C for 48 hours.
   1. Other media, such as blood agar, show colonies around the antibiotic disc, indicating that bacterial growth has been inhibited.
   2. Colonies are cream to white, flat or hemispherical, and have a waxy appearance.

What is the pathogenicity of Candida albicans?

1. The most common areas affected are:
   1. Mucous membranes.
   2. Nails.
   3. Skin.
2. Candidiasis may be Superficial, where it involves:
   1. Mucocutaneous thrush.
   2. Skin in the form of red weeping areas, particularly in obese people.
   3. In chronic mucocutaneous lesions, involvement is typically seen in the face and scalp.
3. Candidiasis may be deep, where it involves:
   1. Lower respiratory system.
   2. Urinary tract.
   3. The eyes, meninges, bones, and kidneys are involved in septicemia.
4. It is a yeast-like fungus and is usually present in vaginal secretions.
   1. Candida albicans is present in the upper respiratory, female genital tract, and gastrointestinal tract.
5. Candida albicans is the causative agent in 90% of the cases.
6. The rapid growth of Candida occurs in:
   1. The patients are on long-term antibiotic therapy.
   2. The patients with diabetes mellitus.
   3. The patients are on corticosteroid therapy.
   4. The female during pregnancy.
   5. The ladies on oral contraceptives.
   6. Candida growth occurs in areas that are not well-ventilated, such as undergarments, and in infants, particularly in the diaper area.
   7. Candida infection has occurred in immune-compromised patients mainly due to T-lymphocyte depression and AIDS.
   8. It may be seen in premature babies.
   9. It is identified in malignancies like leukemia and lymphoma.
   10. It is seen in extensive surgery.

What are the clinical manifestations of Candida albicans?

1. The predisposing factors are:
   1. Aged.
   2. Cachectic or debilitated persons.
   3. People with diseases like AIDS or leukemia.
   4. Drugs are impairing the immune system.
   5. Oral antibiotic therapy.
2. Clinically, there may be mucosal candida infection characterized by laryngitis and esophagitis.
3. Female Patients may have vaginitis, cystitis, and thrush.
4. In the case of acute disease, it may involve the eyes, skin, and muscles when it spreads through the blood.
5. Chronic cases have been seen in a patient with neutropenia.
6. Clinically, one can see candidiasis as follows:
   1. Thrush.
   2. Diaper rash.
   3. Genital candidiasis.
7. Candida albicans lesions are:
   1. Superficial like thrush.
   2. The skin shows a red, weeping lesion.
   3. Chronic mucocutaneous candidiasis affects the face and scalp.
   4. Deep lesions are involved in both the respiratory and urinary systems.
   5. Septicemia shows eye, endocardium, meninges, kidneys, and bone lesions.

Thrush:

1. This condition is a very common finding.
2. It is oropharyngeal candidiasis.
3. There are white or yellow patches on the tongue or oral cavity with a reddish base covering the mucous membranes.
4. There is a red area that may involve the throat.
5. It is difficult to scrape off.

Candida albicans leading to thrush.

Diaper rash:

2. It is seen in infants.
3. It occurs when a wet diaper is left for an extended period.
4. It is seen in the warm, moist areas under diapers and in adults between skin folds (under the breast in females).

Genitalcandidiasis:

1. It is more common in females than in men. It involves the vagina (monilia).
2. In females, it leads to candida vaginitis and is common during:
   1. Antibiotic therapy.
   2. Oral contraceptives.
   3. During menses.
   4. During pregnancy.

What are the S/S of vaginitis?

1.  There is severe itching in the vagina.
2. There is vaginal discharge, thick, copious secretion, wetting the undergarments.
3. On examination, the vagina is inflamed.
4. Cottage cheese patches appear in white clumps attached to the vaginal wall.
5. Imidazole suppository helps to treat the disease.

How will you discuss the Invasive candidiasis?

1. It occurs through the I/V or catheter when it is left in the body.
2. It can enter the brain, heart, and eyes.
3. It may involve nails and look like onychomycosis.
4. Candida albicans and Candida tropicalis are also seen in conditions like:
   1. Bone marrow transplantation.
   2. Leukemias.
   3. Lymphomas.

What is the mode of the spread of Candida albicans?

1. It is usually endogenous, but cross-infection may occur, such as from a mother to a baby or a baby in the nursery.
2. Infections are more common in premature babies.
3. Infection is also more common in debilitated patients and patients with diabetes mellitus.
4. Infection is more common in immunocompromised patients with AIDS, malignancy, leukemia, and lymphoma.
5. It is commonly observed in patients undergoing long-term treatment with antibiotics, immunosuppressive drugs, or cytotoxic agents.

How will you diagnose Candida albicans?

1. Wet film from the affected area can be Gram-stained.
2. Culture is diagnostic, and the culture media used are:
   1. Sabouraud’s medium.
   2. Incubation is done at 37 °C  for 48 hours.
   3. Agar and blood agar.
3. An indirect hemagglutination test may be helpful, but these tests lack sensitivity and specificity.
4. Antigen tests like EIA are available.
   1. A titer greater than 1:8 indicates systemic infection.
   2. A positive test may be observed in mucocutaneous candidiasis or in severe vaginal infections.
5. The skin test based on type VI sensitivity is a good diagnostic indicator.
6. Scrapings with KOH preparation may show Candida.
   1. It will detect around 60% to 70%of vaginal secretion smears.

What are the diagnostic features of Candida albicans?

1. Germ tubes are observed when grown in serum for 3 hours at 37 °C and then made into a wet film.
   1. There are filamentous outgrowths, such as germ tubes.
2. Chlamydospores are seen when grown on a nutrient-poor medium (cornmeal agar) for 24 hours at 28 °C.
   1. There are round, thick-walled resting structures – chlamydospores, usually found at the ends of pseudohyphae deep in the agar.

3. Biochemical activity is a result of fermentation.
4. Antigenic structure: This falls into two groups:
   1. Serotype A.
   2. Serotype B.
5. Antibodies are detected in most of the human sera.
6. A positive skin test is common due to a delayed hypersensitivity (type IV) reaction. This is almost universal in normal adults.
7. How will you summarize the diagnosis of Candida infection?
   1. Wet-mount or stained slide preparation.
   2. KOH (potassium hydroxide) can diagnose in 60% to 70% of the cases.
   3. The use of fluorescent stain (Calcofluor white) increases the detection possibility.
   4. Papanicolaou-stained slides are positive in 45% to 50% of the cases.
   5. Culture.
      1. The isolation of Candida from blood and urine is suggestive of disseminated candidiasis.
   6. Serologic tests.
      1. Latex agglutination tests are available. These are easy to perform.
      2. IgG EIA procedure is positive in about 82% of the cases for sensitivity.

How will you treat Candida infection?

1. Candida is resistant to all antibacterial drugs because it is an eukaryotic microorganism.
2. Amphotericin B is the drug of choice.
3. For topical use, Imidazole  (miconazole, clotrimazole) can be used.
4. Thrush is treated with nystatin, amphotericin B, and miconazole.
5. Systemic lesion needs I/V amphotericin B, either given alone or with 5-fluorocytosine.

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