Tag Archives: bacteria

Do we get our genes from fish and mushrooms?!

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Simple figure of how HGT occurs.

We acquire all our genes from our ancestors, right? Hmmm, maybe not. Recently, came across an article in the news expressing that we may have more than 100 genes from other species. You are probably wondering what the heck I am talking about. When we think of transferring genes, we imagine a family tree with branches pertaining to different members of the family, with a direct transfer of genes from parent to offspring. What we don’t consider at all is Horizontal Gene Transfer. This phenomenon, shortened to HGT, refers to when DNA is transferred between species through bacteria-infected viruses, genes that “jump” around cells and various other methods. The YouTube video below provides a quick summary of HGT with animations.

It is common to see this in action in single-celled organisms such as bacteria, where the foreign genes enter and get embedded in the recipient’s cell. However, recently scientists have found that this process occurs in animal cells as well. In this scientific article, Alastair Crisp and his research team examined HGT in detail in 26 animal species, including primates. Many genes, including the ABO blood group gene, were transferred to humans through other vertebrates. This article discussed more of Crisp’s finding in detail. Crisp and his team inferred that HGT between primates did not happen in the most recent common ancestor of all primates, but way back when our common ancestors were fish. Crisp also identified some genes as emerging from fungi!

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We have genes from mushrooms……

 

What does this mean for us humans? Are we going to start growing gills like fish, or decomposing dead matter like fungi? This second scientific paper looks at the implications of HGT in evolution. The author, Michael Syvanen, discusses how how the origin of animal cells could be a form of HGT, and that structural genes that are fundamental to everyday life were adapted from genes of prokaryotes.

Don’t worry, we won’t be growing gills anytime soon. That already happened thousands of years ago when we evolved into vertebrates!

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A War Against Antibiotic Resistance

Ever since the discovery of penicillin, scientists have been in constant battle against the growing resistance of bacteria to antibiotics. How did the war start? According to APUC (Alliance for the Prudent Use of Antibiotics), bacteria develops resistance through genetic mutations or acquiring resistance genes from another bacterium. By treat bacterial infection with antibiotics, the bacteria without the resistance gene will be killed. However, bacteria with the resistance gene will survive and continue to multiply.

Here’s a more in-depth video:

So why do we care? At 2011, Coates et al. examined the existing antibiotics and concluded that the rate of new antibiotic discovery is much slower than the growing rate of antibiotic resistance. This means that in the near-future, we will run out of antibiotics to even treat a minor infection.

However, according to some of the recent articles, we seem to have the upper hand in this battle. Henry et al. discovered a new therapy of fighting bacterial infection without causing bacterial resistance. The therapy involves creating liposome (vesicles made of cell membranes) decoys in the body for bacterial toxin to bind to, preventing the toxin from damaging the host cells. This buys time for the immune system to get rid of harmful bacteria in the host.

Also, a new class of antibiotic is being developed by Ling et al., and the way they discover the antibiotic may possibly lead to a new ways of discovering new antibiotics.

Everything looks pretty good at this point. New ways of discovering antibiotics and new therapy that will not result in antibiotic resistance will likely lead to the solution of antibiotic resistance.

However, these discoveries may not necessarily lead to a solution of growing antibiotic resistance. The root of the problem remains untouched. For example, the general public should be better educated about the misuse of antibiotics. In an article by Jean Pechere, Jean conducted a survey on patients using antibiotics. The result shows significant misuse of antibiotics in the community Jean surveyed.

The discovery by Henry et al. may look really promising. Treating infections without using antibiotics will prevent the development of antibiotic resistance. However, what if the immune system cannot clear out the bacterial infection effectively, and the patient is required to use antibiotics? A follow-up study is required to test the effectiveness of the therapy on different strains of bacteria.

Overuse of Antibiotics. Source: Flickr Common. Credit to: Ian Weddell

Even though these are great discoveries, we should not view them as solutions to antibiotic resistance, but should keep in mind that great amount of effort is still required to solve the emerging antibiotic resistance. More effort should be put towards educating the public or preventing the overuse of antibiotics.

The Center for Disease Control (CDC) listed ways to prevent antibiotic resistance:

  • Practice Good Hygiene
  • Take exactly the amount doctors have prescribed. No more, no less.

 

Misuse of Antiobiotics can cause antibiotic resistance. Picture Obtained from Flickr, Credit to AJC1

-Daniel Hsiao

Drying your hands doing more harm than good?

With the growing need to constantly be efficient in almost every aspect of our lives we could be doing more harm than good. Hand washing is considered the most simple and important procedure to prevent sickness but the method we dry our hands may be counterproductive. According to the Malaysian Journal of Pathology, electric hand dryers dispersed bacteria at a radius of 3 feet from the dryer. In the experiment by the department of Microbiology in Kuala Lumpur, Serratia marcescens (bacteria) was placed under the dryer to stimulate someone drying their hands (in a hospital setting) and the results indicated that the bacteria was blown an average of 3 feet. A more recent study done by the University of Leeds also found that electric hand dryers spread bacteria in a bathroom setting. Using paper towels does consume trees but is the trade-off worth the risk?

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Picture of bacteria obtained from Flickr – credit to Cesar H.

Using an air dryer, it takes longer to dry hands relative to paper towels which means that people may not completely dry their hands. This being said, it may be possible that bacteria could grow on surface skin. Skin flora can then be transmitted from one person to another in a variety of ways such as the casual hand shake or simply by touching objects after hand washing. Someone could wash their hands and then dry them using an electric hand dryer and have bacteria blown onto their hands that will spread with contact. In other words a non-contaminated surface can become contaminated with skin flora even if the contact surface is not immediately under the dryer. Electric dryers may not only spread bacteria, it may provide an environment for growth.

Head Dryer

Picture obtained from Flickr courtesy of Walter J.

The environment that is in the inside structure of an electric hand dryer provides conditions suitable for growth of bacteria according to Dailymail. Bacteria can multiply in the electric dryer in between uses and then spread by becoming airborne when the dryer is turned on. By using electric air dryers to ultimately reduce the amount of trees that are cut down every year according to the Slate. Paper towels do not cause bacteria to become airborne but they do cause many trees every year to be cut down and are inefficient in terms of the environment. Electric air dryers do provide a good alternative to paper towels but they cause the spread of bacteria. As technology and science continue to improve hopefully a solution to this problem will be in the near future where we can protect the environment as well as ourselves at the same time. It may seem like a small part of our lives – washing and drying hands – but the consequences can potentially be severe. In the end, using electric hand dryers saves millions of trees worldwide and is worth the risk in my opinion. Below is an example video of the efficiency of electric hand dryers.

Kevin Nand

Friendly Fecals

Poop pills may be the solution for thousands of people suffering from recurring Clostridium difficile infection. C. difficile is a bacteria in the lower gut that causes colon inflammation, resulting in symptoms such as watery diarrhea, nausea, fever, abdominal pain and loss of appetite.

Image Source: Flickr Commons

Clostridium difficile   Image Source: AJC1 on Flickr

C. difficile may account for up to 14 000 deaths out of the 300 000 cases reported each year in the United States alone. Over the last decade, the number of infections has reached epidemic proportions. The major issue is that anyone taking broad-spectrum antibiotics is susceptible to this infection; antibiotics eliminate both harmful and healthy bacteria in the gut, leaving a patient vulnerable to contamination. The bacteria survive and are transmitted through feces, making outbreaks in hospitals common.

Numerous treatments have been proposed and tested, including vaccinations, antibiotics and fecal transplants. Fecal microbiota transplantation (FMT) has been the most effective method in reducing the recurrence of infection, but the process is costly and complex. The idea is to replace healthy gut flora in infected patients by using the gut bacteria from another person. First, screening for a healthy donor must take place. It is essential that donor testing is thorough, to reduce the spread of infection. The feces are then transplanted into the recipient’s lower gut, either by colonoscopy, enema or through the nose using a nasogastric tube. As a result of extremely high costs of these procedures, some patients have opted for the “do-it-yourself” method of transplantation. Most people who decide to do it themselves at home are not professionals, nor are they being held to the same standards as a hospital would be. Although there are many success stories, there has not been any research into the effectiveness or risks associated with the DIY method.

Some research shows over 90% of patients have been cured by FMT procedures conducted in hospitals. It is probably for this reason, along with the fact that there is a very low chance of patients experiencing any serious side effects during or after the procedure, that so many are turning to FMT as a long-term solution.

Here is a brief animation by MinuteEarth about fecal transplants:

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A slightly more appealing technique may be the new poop pills, which can be taken orally like any other medication. The effects of these frozen fecal pills were monitored in a recent study conducted at Massachusetts General Hospital. The results were very positive, and reinforced the conclusion that the fecal pills could be a viable option for patients. Since it has been shown that frozen and fresh fecal matter perform equally well, screenings and donations can be made before a patient actually needs it.

Image Source: e-Magine Art on Flickr

Variety of Pills  Image Source: e-Magine Art on Flickr

Many turn to antibiotics and medication to treat infection, but in this case, the cure may be all natural.

You can now say that you have been informed about the power of your poop!

– Anne Persson