Geotrichum: sounds like quite a fancy name, right? Well, you might be surprised to learn that you’ve most definitely been exposed to this yeast more than once! After all, we all breathe in Geotrichum spores on a daily basis. But don’t let this scare you: Geotrichum poses a serious threat to some individuals only in very rare cases. For most of us, this yeast is harmless and can actually be pretty useful. Check out this article to discover impressive facts about this yeast.
What is Geotrichum?
Our intestinal tract is inhabited by millions of bacteria and one of them is Geotrichum. This yeast, which belongs to the Endomyceteaceae family, exists as various species. It is considered a commensal yeast since it typically lives in the human body (from which it obtains foods and other benefits) but neither hurts nor helps it. In fact, many species of Geotrichum have been isolated from the stools and sputum (a mixture of saliva and mucus from the respiratory tract) of humans.
Did you know? Geotrichum can be found in approximately 30% of healthy individuals! This fungus likes to live on dead cells in the oral and intestinal mucous membrane.
Besides the human body, where can it be found?
Geotrichum is often called the ‘cosmopolitan fungus’ since this yeast feels ‘at home’ in a multitude of areas. In fact, this type of fungus can be found everywhere around the globe – from the soil to sewage pipes and on plants. Moreover, it also thrives in milk, on decaying meat and fruits as well as in rug dust and on damp walls.
Other places where Geotrichum can be found include:
- Rotting bread and vegetables
- Fruit juices
- Polluted water
- Paper pulp
How was it discovered?
In 1809, Johann Heinrich Friedrich Link, a German naturalist and botanist, discovered several species of yeast on rotting leaves. To facilitate the classification of these various species, he defined a new genus (class of organisms that share common characteristics). He then decided to call this genus ‘Geotrichum’. Since that time, more than 130 classification methods have been described to help identify organisms that belong to this genus.
What does it look like?
Geotrichum, which often appears as off-white and cream, has a butyrous (a tissue or bacterial growth of butter like consistency) texture as well as a silky look. This yeast forms colonies that grow rapidly in a fine pattern that looks like suede.
How does it grow?
When studying Geotrichum, scientists noticed that colonies of this yeast-like fungus tend to grow better at temperatures ranging from 25oC to 30oC. They also discovered that the growth of this yeast can be limited at 37oC.
What are the uses of Geotrichum?
Most of us probably consider fungus as a relatively disgusting nuisance. However, Geotrichum is not just another fungus: it actually plays a very important role in the production of some highly prized foods. Does this revolt you? Yes? Well, don’t be: I am sure you’ve enjoyed some of these foods at least once in your life. Keep scrolling – you’re in for a few surprises.
- Production of cheese
Next time you stop by the cheese shop, try to take a closer look at the available cheeses made from goat’s milk. I can assure you that you won’t be able to miss the many wrinkles on the surface of the cheese!
Well, guess what is behind the wrinkles and cream colored rinds on these cheeses? You’re right: the yeast Geotrichum. Or more specifically, the species Geotrichum candidum. The fungus Geotrichum candidum thrives on most cheeses in the very first stages of the ripening process. On soft cheeses such as Camembert and semi-hard cheeses such as St. Nectaire and Reblochon, the chemical processes occurring within this fungus are what influence the way cheese ripen.
And if you’re into natural cheese making, you can even buy Geotrichum candidum online!
Benjamin Wolfe, a famous microbiologist, said that these species of Geotrichum are “kind of a confused yeast. Geotrichum is an ancestral yeast. Yeasts are derived from mold so this is a type of yeast in transition.”
Did you know? The French owe part of their great success in cheese production to the amount of fungi that colonize their cheese during the ripening stage!
- Chocolate production
You probably love eating chocolate, don’t you? Well, let me ask you something: have you ever stopped to wonder how it is made?
As weird as this may sound, your favorite chocolate would never have come into existence without fungi! You see, although fungi are not considered as ingredients of chocolate, they are still of utter importance both in the growth of the cacao tree and in the production of chocolate.
Although it is unclear how humans came to eat the bitter seeds of the cacao tree, history suggests that early humans probably tried consuming some rotten cacao seeds and found them to be scrumptious!
To better understand how these bitter seeds can become so delicious, food scientists conducted extensive research and made an amazing discovery. They found out that the seeds from the cacao tree can become delicious in a very simple process, namely fermentation! When these little beans are fermented and have partly decayed, their unpleasant taste is naturally replaced by a most delightful one.
How does the fermentation process happen?
Geotrichum and Candida krusei are the two fungi needed in the fermentation of the cacao seeds. As they are often present on these pods, fermentation occurs naturally. However, since natural fermentation occurs very slowly, another technique is used in the manufacturing of chocolate nowadays. Instead of letting these seeds decay on their own, specific strains of Geotrichum and Candida krusei are added to the cacao tree. These strains, which are carefully selected, are what give a unique flavor and aroma to the chocolate.
Now that you know what Geotrichum is and how it has impressive uses, let’s move to the not-so-nice aspects of this yeast.
What are the different types of Geotrichum that exist?
As mentioned earlier, the Geotrichum family is composed of various species. The most popular species are listed below:
- Geotrichum candidum
- Geotrichum clavatum
- Geotrichum fici
Does it cause infections?
Short answer: Yes. In fact, studies have shown a direct link between Geotrichum and several infections. Some of these include infections of:
- The intestinal tract
- The bronchi (the tubes which carry air to the lungs)
- The lungs
- The skin
- The mouth
- The vagina
Moreover, besides infectious complications, there are some cases where sensitive individuals reported allergic and asthmatic reactions after they were contaminated by Geotrichum.
Scientists have also reported that Geotrichum infection could lead to enteritis which involves the inflammation of the small intestine and usually causes diarrhea.
What is the link between Geotrichum and geotrichosis?
Geotrichum candidum, the most common species of the fungi Geotrichum, is the agent that is responsible for a rare disease known as geotrichosis. Yes, that’s the same fungi we can use to make cheese!
Geotrichosis can either be localized and affect a single organ or it can become a systemic disease affecting the entire body. This infection can occur in both humans and animals.
Who is particularly at risk of developing geotrichosis?
Geotrichosis mainly affects individuals who are immunocompromised such as those diagnosed with cancer, diabetes mellitus, leucosis, and HIV. People who undergo renal transplant may also be more vulnerable to geotrichosis.
How can I know if I have been infected with Geotrichum candidum? What are the symptoms to be wary of?
An infection with Geotrichum candidum can cause various symptoms depending on which part of your body is affected. As such, there are various forms of geotrichosis:
Pulmonary geotrichosis, the most frequent form of the disease, involves the lungs and can occur after a bout of tuberculosis, an infection that can significantly weaken the host’s immune system.
The symptoms include a cough with a clear or yellow sputum as well as light to medium rales – these are abnormal respiratory sounds which are heard with a stethoscope. Individuals who contract this infection may also produce light or thick, gray sputum that may be stained with blood. Pulmonary geotrichosis may also cause fever, a little debilitation, an increased heartbeat but no chest pain, a rise in the blood’s concentration of white blood cells as well as intermittent wheezing.
Bronchial geotrichosis, as the name suggests, affects the bronchi, the two tubes which branch off the windpipe and transport air to the lungs. The infection, which does not affect the lungs, is contained within the bronchi since, in this case, Geotrichum candidum will grow only inside these two tubes.
The symptoms, which resemble allergic reactions due to aspergillosis, include medium to coarse rales as well as a deep, chronic cough and gelatinous sputum. Individuals suffering from bronchial geotrichosis will usually present with a normal pulse, no breathing problems, and no fever – elevated pulse and respiratory issues are quite rare.
Candida albicans may also colonize the bronchi in cases of bronchial geotrichosis. This usually occurs in individuals diagnosed with chronic obstructive lung disease.
Cutaneous geotrichosis exists in two forms namely a superficial infection or a deep one. In the superficial form of the disease, the yeast will colonize skin folds such as those below the breasts, in the groin area, around the anus, and between the fingers. As you may have guessed, the deep form is more severe – in this case, the infection will cause nodules, tumors, and ulcers to grow on the infected person’s face, hands and legs. This type of infection may also lead to the formation of a cystic lesion on the skin.
Oral geotrichosis has, for a long time, been mistaken for thrush. This usually involves whitish plaques in the mouth, accompanied by a burning sensation.
Gastrointestinal geotrichosis involves enterocolitis, the medical term denoting an inflammation of both the small intestine and the colon. Common symptoms include diarrhea.
This condition usually occurs following a glutamic acid therapy and typically resolves once the therapy is stopped. It is possible that, in this condition, the glutamic acid therapy causes the yeast to produce toxins that cause symptoms.
Vaginal geotrichosis has also been mistaken for thrush, just like oral geotrichosis. Symptoms include a whitish plaque and burning sensation in the vaginal area. This infection mostly affects pregnant women and is often connected to vaginitis.
If you suspect an infection or notice any of the above-mentioned symptoms, please make sure to contact your healthcare provider immediately.
Are there any differences between symptoms of geotrichosis and those of candidiasis?
Interestingly, scientists have reported that symptoms of geotrichosis may look like those of candida yeast overgrowth. Some of these symptoms are:
- Chronic fatigue
- Mood swings
- Regular vaginal and urinary infections
- Oral infections
- Infections of the sinuses
- Skin and nail infections
- Intestinal complications
- Inability to concentrate properly
- Hormonal imbalance
What are the tests available to diagnose geotrichosis?
If you, or your physician, suspect that you may be suffering from geotrichosis, your physician will usually request that you do the following tests.
- Laboratory culture
Without using culture or doing microscopic evaluations, it is not possible to diagnose geotrichosis since, as you might have noticed from the information described above, symptoms are very similar to those of other infections.
As such, to diagnose geotrichosis, a sample of the fungi causing the infection will be collected from the infected areas and sent to a laboratory for analysis. For instance, if oral geotrichosis is suspected, lesions or ulcers in the mouth will be gently scraped. Otherwise, pus and mucus samples from the stools will be collected. The person’s sputum may also be collected – laboratory technicians will look for white flakes that will be further examined.
In cases of oral lesions, culturing Geotrichum in great numbers often proves to be a good indicator for the presence of geotrichosis in a patient. When analyzed under a microscope, this fungus looks similar to yeast. Its branching is divided into slender threads and can be broken down into chains or separate rectangular cells with flat or rounded ends known as arthrospores.
- Selective isolation method
Geotrichum candidum can also be identified using the selective isolation method which is based on how the fungi react to carbon dioxide and novobiocin (an antibiotic also known as albamycin or cathomycin).
- Diagnostic imaging
This test is usually reserved for cases of pulmonary geotrichosis and bronchial geotrichosis. However, while X-rays can be utilized to inspect the lung tissue and the interior of the bronchi, they will not provide a clear-cut diagnosis for geotrichosis.
If a patient suffers from pulmonary geotrichosis, an X-ray can indicate the presence of cavities as well as smooth, dense patchy infiltrations in the lungs. Moreover, the lung tissue may indicate changes that are similar to those found in lungs affected by tuberculosis.
In cases where patients suffer from bronchial geotrichosis, an X-ray will reveal the thickening of the bronchial tissues. Moreover, the middle or the base of the patient’s lungs may be marked with spots.
This test can be performed by Genova Diagnostics: for this test, the patient will have to send stool samples to the lab where they will be analyzed. If the culture reveals the presence of Geotrichum, your physician may request to assess how permeable your intestines are (this is to rule out leaky gut).
Based on the test’s results, your physician will be able to determine which remedy would be the most effective in eradicating the organisms identified.
- Comprehensive Parasitology Stool test
Using a very powerful microscope, this innovative diagnostic tool analyzes stool samples for the presence of yeasts such as Geotrichum and Candida albicans as well as various parasites and bacteria. This test can be used to detect the presence of yeast overgrowth (including an overgrowth of Geotrichum candidum) which can contribute to irritable bowel syndrome (IBS). Based on the test’s results, the most effective remedies will be listed.
Can this condition be treated? What are the available treatments?
Generally, geotrichosis has a good prognosis and, in most cases, patients successfully recover from this illness. However, you should know that no standard treatment is available for this disease. As such, two individuals suffering from geotrichosis may be offered two completely different treatments. This being said, the treatment of pulmonary geotrichosis will typically include potassium iodine, sulfonamides (antibacterial drugs) or the antibiotic colistin.
This being said geotrichosis can be treated using different antimicrobial and antifungal compounds. Your physician will also recommend proper bed rest so as to allow your immune system to strengthen. The most common treatments for geotrichosis are outlined below.
- Miconazole and ketoconazole
These two compounds are antifungal agents that can kill the fungus Geotrichum by acting on the fungus’ cell membrane, causing the contents of the fungal cells to spill out. These substances also prevent the fungus from growing and multiplying. As such, they can help prevent recurrent infections with Geotrichum. Studies have shown that miconazole and ketoconazole can improve cutaneous, bronchopulmonary, intestinal and even joint conditions.
Miconazole can be obtained as a spray liquid, a cream, a lotion, a powder and even as a suppository to be inserted into the vagina. Ketoconazole is usually prescribed as an oral treatment to treat serious yeast or fungi infections.
This is another type of anti-fungal medication used to treat infections of the mouth, intestinal tract, and vagina. This drug can be purchased as a tablet, capsule or liquid to be taken orally. Soft lozenges are also available.
If you suffer from vaginal geotrichosis, your physician may recommend a vaginal cream. Powders, ointments, and creams are available for cutaneous geotrichosis.
- Iodine therapy
This type of therapy is used to kill various types of organisms including molds, yeasts, and fungi. Not only is this treatment effective but it also has very few side effects and does not cause bacterial or yeast resistance. It is usually given as a tincture which is a preparation involving alcohol, water, potassium iodide or sodium iodide and elemental iodine.
- Azole drugs
Isoconazole and clotrimazole are two types of azole drugs with antifungal properties. Both have proven to be very effective in the treatment of geotrichosis.
- Amphotericin B
Amphotericin B comes in the form of an injection and is used in the treatment of fungal infections that may be lethal. Although it is effective, Amphotericin B also causes numerous side effects and, as such, should not be used to treat mild fungal infections (such as those of the throat, mouth or vagina) in individuals with a normal immune system.
If your physician decides to opt for this treatment, make sure to ask her/him about the health risks associated with Amphotericin B before agreeing to the injection.
As you can see, Geotrichum is a yeast that can be considered as a double-edged sword. While it has some pretty unique, and useful, properties, Geotrichum can cause serious infections especially in individuals with a weakened immune system. If you suspect that you, or a closed one, suffers from geotrichosis, an infection caused by Geotrichum candidum, contact your health care provider immediately. And do not attempt to auto-medicate as this could be very dangerous.
- William J D.; Berger, G Timothy G.; et al. (2006). Andrews’ Diseases of the Skin: clinical Dermatology., Saunders Elsevier. ISBN 0-7216-2921-0.
- Tubitak, 2010, Intestinal geotrichosis in a German shepherd, Turk. J. Vet. Anim. Sci., 34(5): 481-484, doi: 10.3906/vet-0906-56.
- Gente S, N, Desmasures, C. Jacopin C,et al.(June 2002). “Intra-species chromosome length polymorphism in Geotrichum candidum revealed by pulsed field gel electrophoresis”. Int.J. Food Microbiol.76 (1-2): 127–34. doi: 10.1016/S0168-1605(02)00023-5. PMID 12038569.
- MahendraPl,S. Sunita, S.Anand, S.Tesfaye,2013,Geotrichosis-An OpportunisticMycosis of Humans And Animals,Int. J. Livest. Res..2013; 3(2):38-44.
- T C Chagas-Neto, Chaves GM, AL Columbo, .Sept 2008; 166:121-132. Update on genus Trichosporon.Mycopathologica.
- Etienne A, A. Datry A, Gaspar N,et al.(May 2008). “Successful treatment of disseminated Geotrichum capitatum infection with a combination of caspofungin and voriconazole in an immunocompromised patient”. Mycoses 51(3): 270–2. doi:10.1111/j.1439 0507.2007.01484.x. PMID 18399909.
- Huamin H. Li, M. A Kaliner, more… Jul 1, 2013, Angioedema, Medscape.
- Nemet C, 2006, Parazitoze Umane, Epidemiologie, Clinica, Tratament, Editura University Press – Targu Mures, ISBN (10), 973-7788-71-0; ISBN(13) 978-973-7788-71-9., pag.18-65.
- Bonifaz A, D.Vázquez-González ,B.Macías , F.Paredes-Farrera , MA.Hernández,, J.Araiza , RM,Ponce , sep 2010,Oral geotrichosis: report of 12 cases, Department ofMycology, General Hospital of Mexico, Col. Doctores, Mexico, D.F., J Oral Sci. 52(3):477-83.
- Bouakline A, Lacroix C, Roux N, Gangneux JP, Derouin F. Fungal contamination of food in hematology units. J Clin Microbiol 2000; 38: 4272 4273.
- Sutton DA, Fothergill AW, Rinaldi MG (eds). Guide to Clinically Significant Fungi, 1st edn. Baltimore: Wilkins & Wilkins, 1998.
- Kassamali H, Anaissie E, Ro J, et al. Disseminated Geotrichum candidum infection. J Clin Microb 1987; 25: 1782 1783.
- Sheklakov ND, Milich MV (eds). Mycoses in Man, 1st edn. Moscow: MIR Publishers, 1974.