Candida species is very common in affecting humans with weakened immunity to a large extent. There are several Candida species which are components of natural microbiota and act as the commensal organisms residing in humans. Belonging to the ‘flavinogenic yeasts’ group, Candida famata has the ability to over synthesize riboflavin in an iron-constrained environment. Candida famata or Debaryomyces hansenii is the industrial yeast which can be found in cheese and other dairy products. Candida famata, which is found in several food items, was thought to be nonpathogenic for the human body. However, with the advent of technology and curious minds, it was found that this yeast was causing nervous infections, ocular endopthalmitis and so on. After surveying, it was found that this yeast species was responsible for most fungemia.
A study in 2004 was set to isolate famata species of genus Candida from a patient with acute zonal occult. Since the etiology of AZOOR (Acute Zonal Occult Outer Retinopathy) could not be determined, the famata species were isolated from the conjunctival exudates of the patient. Immunological tests resulted in proving the presence of Candida famata with the activation of T- Lymphocyte which were antigen specific and no other fungi or pathogen were found to be present. Even with treatment of fluconazole and Iitraconazole, its presence was observed in the exudates.
This study proved to us that Candida famata cannot be treated with ease as in the case of Candida albicans. It has to be treated with a better antifungal medicine like voriconazole. Its presence even after treatment is definitely very alarming which indicates that it needs immediate treatment upon diagnosis.
What Does Candida Famata Look Like?
Candida flareri appears like a whitish to creamy colored yeast, which forms uncovered and smooth colonies on YPD colonies. When studied under microscope, this yeast appears like an egg-shaped with an approximate size of 3.5 to 5.0 µm. In this, pseudo hyphae are not produced and Candida famata is acquired from clinical experiments mostly related with skin. When carbon assimilation experiments are conducted, Candida famata is observed to be positive in case of glucose, maltose, galactose, trehalose, glycerol, raffinose, and salicin and so on. The experiment found this yeast to be changeable in case of lactose, erythritol, melibiose, and galactitol and negative in case of inositol and potassium nitrate.
Identifying Candida Famata?
Insertional mutagenesis is a technique which is utilized for identifying MET2 and SEF1 (homoserine O-acetyltransferase and putative transcription factor) which are Candida famata genes. These genes helped in the positive circulation of the synthesis of riboflavin. Powerful markers are required for the assimilation of the commercial riboflavin makers. It has been rather difficult to find drug resistances for Candida famata to be identified. The reason behind this is that Candida famata uses codon system which is non-conventional.
In 2013 a series of case studies and reviews were done to find the treatment of blood stream infections caused by the presence of Candida famata. The clinical course for two patients suffering from C. famata fungal diseases were reviewed and it was found that liposomal amphotericin B therapy should be initiated immediately upon removal of central venous catheters in case of immunocompromised patients.
These studies open up a lot of doorways in treating C. famata more systematically. It shows that upon regular check-ups for antifungal susceptibility, patients suffering from Candidaemia can go through successful antifungal treatments. It also shows that treatment with amphotericin B post removal of central venous catheters is extremely important in patients with a compromised immunity system to prevent any fungal activity and Candidaemia as well.
Candida Famata in Biotechnology
In biotechnology, production of Riboflavin is the most important factor of Candida famata. Candida famata has the highest flavinogenic potential. By combining several metabolic engineering and mutagenesis, Candida famata riboflavin overproducer was separated. Initially the AF-4 which is a riboflavin overproducer was secluded from VKMY-9 following six steps of mutagenesis. AF-4 was, however stable and when compared with the industrial strain, it did not return to riboflavin non-overproducing system.
Characteristics of Candida Famata
It has the strength to produce riboflavin in excess in iron constrained environment.
Increases riboflavin production to several hundred folds.
Besides Candida famata, there are Schwanniomyces occidentalis, Pichia guilliermondii, and Candida albicans and so on.
Candida famata has high osmotolerance. This yeast has the ability to grow in high NaCl conditions.
famata has a higher salt endurance capacity.
Due to its osmotolerance, proves to be advantageous in several biotechnological applications.
This yeast helps in quasi-non-sterile manufacturing and yields products with high concentrations; which help in decreasing production cost.
The risk factors of C. famata constitutes of exposure to antifungals, antibiotics, existence of CVC, and rupture of the skin flora. Although the species is quite pathogenic in nature it can surely be treated with good antifungal drugs upon diagnosis.
Candida famata (Candida flareri) – Researchgate – 2012
Isolation of Candida famata – Journal of Clinical Microbiology – 2005 – By Luis Carrasco, Marta Ramos and Rebeca Galisteo
Treatment of Candida famata bloodstream infections – Journal of Antimicrobial Chemotherapy – 2013 – By Nicholas D. Beyda, Shen Hui Chuang and M. Jahangir Alam
The Yeasts: A Taxonomic Study – Book by Cletus Kurtzman, J.W. Fell and Teun Boekhout – 2011