Candida tropicalis is a yeast in the genus Candida. It is a common pathogen in those with lower numbers of white blood cells (neutrophils). In those with severe infections, it may spread through the bloodstream to peripheral organs. For strong disease, treatments include amphotericin B, echinocandins, or extended-spectrum triazole antifungals.
History and taxonomy
The name of genus Candida, comes from the family Debaryomycetaceae, Candida comes from the Latin term "candidus". This means “glowing white” and also refers to it as smooth and shiny. There are 200 species identified in this genus, The older genera Oidium and Monilia were used to describe the genus Candida.
There are other species that are similar to Candida tropicalis. Candida albicans is very similiar to C. tropicalis sharing many harmful traits.
Habitat and ecology
Candida species are very common yeasts. They are more likely to be found in the tropical climate. The temperature and humidity increases makes C. tropicalis stronger. Candida species can be found in food such as sauerkraut, molasses, miso, fruit, baker’s yeast and some fruits. They are commonly found on plants and in the digestive system of mammals.
Human diseases
Chromogenic agar can help in indicating Candida tropicalis infection versus some similar fungi. (CHROMAgar shown)
Types of disease caused by C. tropicalis will vary depending on the location on or in the body. With an infection in the mucous membrane, subject will experience oropharyngeal candidiasis, angular cheilitis, balanoposthitis, oral thrush and vulvovaginal candidiasis. The human body has the ability to fight C.tropicalis with oral cavity defenses such as epithelial cells, saliva, salivary immunoglobin (IgA), lysozyme, lactoferrin, histidine-rich polypeptide and lactoperoxidase. This is to lessen C. tropicalis’ overgrowth. Infections are mostly reported with a higher risk factor when combined with other diseases found in a patient. Patients with C. tropicalis infections are also seen with denture, HIV infection or irradiation for malignancies. 38% of AIDS patients with recurrent disease are more likely to get infected by C. tropicalis. They can get oral thrush and oropharyngeal candidiasis. Only filamentous growth of C. tropicalis have the ability to invade and colonize orally in the epithelium, This is commonly seen in cancer patients and higher risk for someone who develops disseminated invasive disease. Candiduria is referred to as urinary tract infections caused by C. tropicalis. Up to 2% of patients are asymptomatic, those with diabetes mellitus and with leukemia are more likely to be infected.
Treatment and prevention
The most important way to prevent infection is washing the hands. There are many kinds of treatment for a C. tropicalis infection. Amphotericin B deoxycholate is the common treatment medication. The medicine comes in 3 forms: oral liquid, ointment and powder. Oral liquid is mainly used to treat a C. tropicalis infection. Ointment is applied onto the infected skin. Nystatin is a type of antifungal agent used because it is not absorbed by the gastrointestinal tract. These types of agents will function to lower candida species’ phospholipases activities. Flucytosine (5FC) is another type of therapy treatment including 3 agents used; caspofungin, micafungin and anidulafungin. Usage of caspofungin will efficiently target against oropharyngeal and oesophageal candidiasis and invasive candidiasis. Micafungin, compared to amphotericin B, it is more efficient. Anidulafungin results are similar to Caspofungin and Micafungin. echinocandin are a type of non-competitive inhibitors of cell wall 1,3-b-D-glucan synthase complex mainly used to treat fungal infections.
Azoles are agents that can deplete ergosterol, the main component of the fungus cell wall membrane, in order to inhibit fungal growth. fluconazole is water-soluble, ready to be taken orally. C. tropicalis can rapidly develop resistance towards fluconazole therefore it's not recommended to retreat fluconazole-treated patients with recurrent candidiasis. Other azoles that are highly active against C. tropicalis are itraconazole, voriconazole, posaconazole, ravuconazole and isavuconazole. Voriconazole is a new generation from fluconazole with a higher potential of broad spectrum activity. All of the mentioned treatments and drug therapies can also be applied onto neonates and premature newborns taking into account the amount of recommended dose. Although there are several ways to treat the different types of C. tropicalis’ infections, the best way to improve treatments results is to improve host immune system.
References
↑"Bacterial vaginosis: a review on clinical trials with probiotics". New Microbiologica.
↑Wilson, C. B.; Nizet, V.; Maldonado, Y.; Remington, J. S.; Klein, J. O. (2015). Remington and Klein's Infectious diseases of the Fetus and Newborn Infant. Philadelphia, US: Saunders. ISBN9780323241472.
