Candida Guilliermondii: Infection, Transmission & Diseases

Candida guilliermondii are a species of unicellular yeast that live as saprophytes and are found worldwide as airborne microorganisms. Yeasts of this species colonize human skin as commensals but can become opportunistic pathogens in immunodeficiencies. They can cause mycoses of the skin, mucosa, and intestine, as well as Candida sepsis and consequent blood poisoning.

What is Candida guilliermondii?

Candida is a genus of yeast that belongs to the division of tubular fungi (Ascomycota) and within it to the subdivision of Saccharomycotina. The genus is classified in the class Saccharomycetes and falls under it in the order of true yeasts or Saccharomycetales and the family Inceratae sedis. Candida exists in the form of a total of about 150 different species. One of these is the species Candida guilliermondii. The fungal species is distributed worldwide and lives ubiquitously as an airborne germ. The fungus forms colonies of elongated or cylindrical shoot cells ranging in length from two to seven micrometers and width from two to five micrometers. In most cases, the yeast bears long and often coiled pseudohyphae. Along these pseudohyphae are numerous, clustered blastospores of small size, so especially at the septa. In addition, the species can form terminal chlamydospores. Growth resembles that of the related species Candida famata, thus appearing in white-gray to cream-colored colonies of smooth to matte finish. Candida guilliermondii are also called Pichia guilliermondii and belong to the saprophytes. The yeast species is a so-called opportunistic pathogen and can be pathogenic to humans. Like all yeasts, Candida species are unicellular eukaryotic microorganisms that reproduce by sprouting, division, or fission.

Occurrence, distribution, and characteristics

Representatives of the yeast species Candida guilliermondii are aerial germs. As saprophytes, representatives of the species do not perform chemo- or photosynthesis. All yeasts are chemo-organotrophic organisms that carry out their energy metabolism with energy sources from organic substances such as fructose, glucose, maltose or sucrose. They do not require sunlight for growth due to the lack of a requirement for photosynthesis. Yeasts thrive best in neutral to slightly acidic pH ranges. Saprophytes such as Candida guilliermondii feed exclusively heterotrophically. They therefore require dead organic matter, which they break down into energy-rich substances and finally convert into inorganic substances. The cells of all shoot fungi usually bear oval shape and are blastospores. Like all other yeast cells, the cells of Candida guilliermondii reproduce by means of sprouting. From the respective mother cell, a certain area protrudes from the cell wall, forming a bud. A cell nucleus copy migrates into the individual buds, which in the subsequent process separates completely from the mother cell. Shoot fungi can form cell associations when conditions are favorable. The individual cells of these associations do not communicate via septa and are therefore not true mycelia, but are referred to as pseudomycelia.

Meaning and function

The yeast species Candida guilliermondii is not normally a pathogen, but lives saprophytically with humans. As a harmless saprophyte or commensal, the yeast neither harms nor particularly benefits humans. Commensally, yeast usually colonizes the skin of humans, which it reaches through the air. Yeast can also colonize the mucous membranes, the gastrointestinal tract or the vagina without causing any symptoms. Accordingly, infection does not occur in people with a healthy immune system. Before the yeast can spread alarmingly, it is recognized by cells of the immune system as foreign to the body and attacked. The pathogenetic significance of Candida guilliermondii is accordingly low. However, since there are usually fluid boundaries between saprophytes and parasites, the harmless saprophyte can become pathogenic under certain circumstances and thus appear as a parasite. For this reason, Candida guilliermondii are referred to as opportunistic pathogens despite their widespread existence.

Diseases and symptoms

Immunodeficiency is a circumstance that can turn the actually harmless yeast species Candida guilliermondii into pathogens.Such immunodeficiency can be associated with diseases such as AIDS, but can also be due to a weakening of the immune system caused by diseases such as cancer or infections. In addition, immunodeficiency often presents itself due to the physiology of age. In addition, the therapeutic approaches of some diseases suppress the immune system, for example in autoimmune diseases. In immunodeficient patients, the yeast species may continue to spread without successful intervention by the immune system. Skin lesions in the sense of mycoses, nail defects and even intestinal mycoses can be the result. In the case of intestinal mycoses of the internal mucous membranes, there is a certain risk of the so-called Candida sepsis. This is a fungemia, i.e., blood poisoning caused by fungi or, in this case, yeasts. Sepsis is a systemic inflammatory reaction of the whole body that can be a life-threatening condition. Candida guilliermondii infections are endogenous in most cases, as they are usually caused by yeasts already established in the body. Lesions on the skin, nails, or hair are usually treated with antifungal agents. The complication of Candida sepsis is associated with unfavorable outcome and is treated with amphotericin B or alternatively liposomal amphotericin B. If these therapies fail, administration of caspofungin, voriconazole, posaconazole, or anidulafungin is necessary. Ideally, under certain conditions, the patient’s immune system recovers to be able to fight the pathogens on its own after all.