Table of Contents
- What is Candida tropicalis?
- Habitat of Candida tropicalis
- Morphological features of Candida tropicalis
- Cultural Characteristics of Candida tropicalis
- Pathogenesis of Candida tropicalis
- Clinical Features of Candida tropicalis infection
- Laboratory Diagnosis of Candida tropicalis
- Treatment of Candida tropicalis infections
- Candida tropicalis Antifungal resistance
- Prevention and Control of Candida tropicalis
What is Candida tropicalis?
Candida tropicalis is a yeast type of fungi that is pathogenic in neutropenic hosts and spreads to peripheral tissues via the bloodstream.
- In pathogenicity and clinical characteristics, it is very similar to Candida albicans.
- It is a prevalent systemic fungus that affects people with compromised or suppressed immune systems.
- Amphotericin B, echinocandins, and broad-spectrum triazole antifungals are common treatments for Candida tropicalis invasive infection.
- It is also known to induce infections when the human host's normal microbiota has been compromised by the use of antimicrobial agents such as antibiotics or when sugar levels in the system are elevated.
Habitat of Candida tropicalis
- Candida tropicalis is a fungal species found in saltwater, sea sediments, mudflats, marine fish intestines, mangrove plants, and marine algae, as well as shrimps.
- As a result, they are common in tropical and subtropical marine habitats.
- It is also found in high concentrations in the human gut, fruit surfaces, a range of foods, and soil.
Morphological features of Candida tropicalis
- Candida tropicalis is a round or oval-shaped vegetative cell with a width of 2-10um.
- These candida fungi are known to create coloured pigments on cultural media that are red, pink, or orange in colour.
- They are dimorphic and give rise to single-celled blastoconidia.
- They multiply by unipolar or bipolar budding.
- The blastoconidia buds are produced on needle-shaped stalks.
- The buds are pigmented and septate which form pseudohyphae.
Cultural Characteristics of Candida tropicalis
- Candida tropicalis thrives at temperatures ranging from 25 to 35 degrees Celsius (77 to 95 degrees Fahrenheit).
- Their growth flourishes in sugar and fat media.
- Sabourand dextrose agar or yeast potato dextrose agar yields cream-colored or off-white to grey, bland, smooth, soft, and creamy or wrinkled or rough results. This medium inhibits conidia development while promoting mycelium formation.
- Conidia flourish on cornmeal agar. (blastoconidia).
- They can also thrive in Potato Dextrose Agar, Potato-glucose, Potato-carrot, tomato juice, and lima bean media.
Pathogenesis of Candida tropicalis
Candida tropicalis is one of the most prevalent Candida species that colonise humans, causing pathogenic infections on the skin, gastrointestinal system, and female genitourinary tract.
Transmission of Candida tropicalis
- Nosocomial infection occurs most frequently between health-care employees and patients.
- The fungi, which is most commonly found in immunocompromised individuals with HIV/AIDS, cancer, leukemia, and organ transplantation, produces candidiasis in different organ systems of the body.
Virulence Factors of Candida tropicalis
- Blastoconidial spores are immune to a variety of environmental variables, allowing them to flourish in both natural and human host settings. As a result, they can live on the hands for more than 24 hours before being transferred to another host.
- Candida tropicalis colonisation skills have been related to the development of a biofilm on the exterior of the epithelial and endothelial cell lining.
- Adherence is caused by the secretion of enzymatic enzymes such as protease, which enables the fungi to infiltrate the epithelial lining.
- Protease enzymes aid in the hydrolysis of peptide bonds, allowing bacteria to adhere and colonise deep tissues, resulting in organ diseases.
- Phospholipids hydrolyze phospholipids, allowing them to pass through the hyphal ends into the epithelial cell membrane and into the cytosol.
- Other variables that contribute to fungus colonisation on epithelial and endothelial cell linings include
- immunocompromised system of the host
- long-term use of antimicrobial drugs such as medicines.
- The use of tubes for an extended length of time.
- Antifungal overuse
Clinical Features of Candida tropicalis infection
Candida tropicalis infections differ depending on where the fungus are found. Among the symptomatic symptoms are:
1. Superficial and mucosal candidiasis
- It is linked to oropharyngeal candidiasis, angular cheilitis, and vulvovaginal candidiasis.
- Oral thrush, also known as oropharyngeal candidiasis, is the colonisation of the tongue and oral area by Candida albicans.
- Candida tropicalis colonises by secreted enzymes that enable it to escape the host's immune system and colonise the epithelial lining.
- It can also induce superficial skin and nail diseases. (onychomycosis).
- Diabetes, catheterization, and leukaemia patients are all at risk for candiduria.
- C. tropicalis causes widespread superficial illnesses such as interdigital candidiasis and diaper rash.
2. Systemic Candidiasis
- Disseminated candidiasis
- Gastrointestinal candidiasis – C. tropicalis colonises the gastrointestinal system in individuals who are at high risk of developing invasive candidiasis.
- Candidemia – Candidemia is the growth and impact of C. tropicalis on the human host's internal systems. It is prevalent in cancer patients suffering from leukaemia or neutropenia. This illness can be contracted in the hospital.
3. Chronic Disseminated Candidiasis
- This is a serious case of candidiasis spread in leukemic and secondary neutropenic individuals.
- They have an impact on the liver, pancreas, and kidney.
Laboratory Diagnosis of Candida tropicalis
Specimen: Skin scarring, sublingual and genital samples, tissue biopsies, blood, cerebrospinal fluid (CSF), or pee are all procedures that may be used.
Microscopic Examination
- Pseudohyphae detection using a 10% KOH moist mount from skin scrapings or tissue samples
- Differential stains such as Haematoxylin and eosin, periodic acid-Schiff, and Gomori-Grocott methenamine silver stains are used to differentiate fungal infection in tissue slices obtained from biopsy or autopsy tissues.
Cultural Identification
- To create smooth, shiny colonies with the development of small blastoconidial spores held by a hyphal stalk structure, use Saboraud Dextrose Agar and/or Yeast Extract Agar. (mycelium).
- Smooth blastoconidia spores are grown on cornmeal agar.
Biochemical Characterisation
- The purpose of this test is to identify the generation of acetic acid.
- Fermentation on different sugars and inositol element synthesis in carbon sources.
- Urease production is prevalent among C. tropicalis families.
Molecular Detection
- Polymerase Chain Reaction for detection of genotyping
Treatment of Candida tropicalis infections
- Antifungal drugs are used to treat Candida tropicalis infestations.
- Amphotericin B is most frequently used to treat Candida infestations.
- Topical antifungals are antifungals that are taken directly or applied locally.
- Topical antifungals, like nystatin, are used to address superficial skin and nail diseases.
- mouth antifungals are prescribed to address mouth candidiasis and gastric candidiasis.
- Flucytosine-based medications, such as caspofungin, micafungin, and anidulafungin, are used to treat oropharyngeal, esophagus, and invasive candidiasis.
- Amphotericin B and/or reduced fluconazole dosages are used to manage systemic candidiasis.
- Voriconazole, a new generation broad-spectrum fluconazole, is used to treat recurrent candidiasis in HIV/AIDS patients who have acquired fluconazole tolerance.
Candida tropicalis Antifungal resistance
- Fluconazole has acquired tolerance in Candida tropicalis over time, so it is no longer suggested for the treatment of recurrent candidiasis. Fluconazole inhibits the phospholipase connection to host epithelium cells, which aids in adhesion.
- If its mechanism of action is ineffective, itraconazole, voriconazole, posaconazole, ravuconazole, and isavuconazole are extremely active drugs.
- Voriconazole, a new generation broad-spectrum antifungal fluconazole medication, was designed to combat Candida tropicalis resistance.
Prevention and Control of Candida tropicalis
- Hand cleaning in order to remove fungal spores from the palms and avoid the spread of the fungi.
- Using water and ethyls to clean affected areas.
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