Does Candida Know When To Attack

There is always a wealth of information coming forth that helps to provide greater clarity on how candida becomes problematic in the body. This recent study, as reported in Science Daily, provides some good information and some confusing information. I’ll add some editorial throughout the article – http://www.sciencedaily.com/releases/2012/07/120724153651.htm

The opportunistic fungal pathogen Candida albicans inconspicuously lives in our bodies until it senses that we are weak when it quickly adapts to go on the offensive. The fungus, known for causing yeast and other minor infections, also causes a sometimes-fatal infection known as candidemia in immunocompromised patients An in vivo study, published in mBio, demonstrates how C. albicanscan distinguish between a healthy and an unhealthy host and alter its physiology to attack. [There are several factors that cause the conversion of the normal yeast form of candida to its pathogenic, problematic fungal form – pH, temperature, antibiotics, bacterial cell wall components, etc., The phrase, “senses we are weak” isn’t something that I have ever seen in scientific studies, but it may be another way to state immunsuppression. Even so, I have yet to see that listed as a trigger for yeast-to-fungal conversion. Immunosuppression can play a role in the spread of candida, but some studies indicate that it isn’t a pre-requisite for this to happen. Candidemia is another term for fungal sepsis, or blood-borne fungal infection. Sepsis is one of the top 10 or 11 leading causes of death in the United States, depending on year of reference, and fungal candida causes over 50% of that].

“The ability of the fungus to sense the immune status of its host may be key to its ability to colonize harmlessly in some people but become a deadly pathogen in others,” said Jessica V. Pierce, BA, PhD student in the molecular microbiology program at the Sackler School of Graduate Biomedical Sciences at Tufts. [This is an interesting quote from an author in the study. It can be taken a couple of different ways. It might be interpreted that she is stating that it spreads throughout the body in its fungal form in the presence of an intact immune system, but doesn’t create any imbalances. That would be ignoring a lot of other research that demonstrates how the fungal form of candida creates many imbalances within the body. It has been shown to spread through the body without the immune system being compromised. A second interpretation and the one that I believe she is stating is that as a fungus, it colonizes the digestive tract harmlessly or pathogenically depending on the host immune status. That would ignore the fact that candida colonizes the intestinal tract in its yeast form. It may not be much of a differentiation, but it can be misleading as the fungal form is problematic and the yeast form isn’t.]

“Effective detection and treatment of disease in immunocompromised patients could potentially work by targeting the levels of a protein, Efg1p, that we found influenced the growth of Candida albicans inside the host,” she continued. [As stated before, there are several factors that cause the conversion of yeast-to-fungus. Efg1 has been identified previously as part of the internal mechanism that regulates the yeast-to-hyphal conversion and back again. It’s not the only part and its presence may not be a good indicator of fungal infections, as it can exist in the yeast form also.]

The researchers knew from previous research that Efg1p influences the expression of genes that regulate how harmful a fungal cell can become. Surprisingly, the investigators found that lower Efg1p levels allow the fungal cells to grow to high levels inside a host. Higher levels of the protein result in less growth. [Would the high levels be associated with it’s yeast form and the low levels with its fungal form. That can be a good reason for differentiating between yeast and fungus and not referring to both forms as though they were fungal.]

To examine how the immune status could affect the growth of C. albicans within a host, the researchers fed both healthy and immunocompromised mice equal amounts of two fungal strains containing two different levels of the Efg1p protein.

Fecal pellets from the mice were tested to determine which strain of fungi thrived. In a healthy host, the fungal cells with higher levels of the protein predominated.

In immunocompromised mice, the fungal cells with lower levels of the protein flourished. The researchers noted that lack of interactions with immune cells in the intestinal tract most likely caused the necessary environmental conditions favoring fungal cells that express lower levels of the protein, resulting in fungal overgrowth and setting the stage for systemic infection.

“By having a mixed population with some high Efg1p cells and some low Efg1p cells, the fungus can adjust its physiology to remain benign or become harmful when it colonizes hosts with varying immune statuses. These findings are important because they provide the first steps toward developing more effective methods for detecting and treating serious and stubborn infections caused by Candida albicans, such as candidemia,” said Carol A. Kumamoto, PhD, professor of molecular biology and microbiology at Tufts University School of Medicine and member of the molecular microbiology and genetics program faculties at the Sackler School of Graduate Biomedical Sciences.

The immune system and “good bacteria” within the body act to regulate the size of C. albicans fungal populations in healthy individuals. When the immune system is compromised, the fungus can spread throughout the body. Candidemia, i.e. blood-borne Candida, is the fourth most common blood infection among hospitalized patients in the United States and is found in immunocompromised patients such as babies, those with catheters, and the critically ill. [Here we see the authors state that it is the immune system and the “good bacteria” that help to regulate the candida populations. This would be a very strong statement against the use of antibiotics, as antibiotics destroy the “good bacteria” and suppress the immune system. With Sepsis being one of the top causes of death in the United States and over 50% of that being due to fungal candida, much of that can be prevented by not using antibiotics. That would eliminate sepsis as a leading cause of death and fungal candida as the 4th leading cause of hospital infections. Throughout this article I didn’t see any differentiation between the yeast and fungal forms of candida and I didn’t find it mentioned in the original abstract either. Many studies seem to be limited in the breadth of understanding of candida and the vast amount of past research. Through other studies, it has already been established that immunosuppression is not necessary for the spread of candida. For more research on this, view the Candida Facts Sheet article.  Tests can only serve as indicators, not absolute measures of function in the body. Targeting something like Efg1 doesn’t seem to be a promising advancement in the understanding or treatment of candida. If the purpose is to create another target for antifungal medications, it must be remembered that all medications contain far more harmful effects than beneficial effects. One common effect of antifungal medications  is immunosuppression.