Tag Archives: bacteria

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The Resurrection of the Antibiotic?

Posted on March 13, 2016 by | 2 comments

Antibiotics?

Antibiotics are bacteria-killing drugs that either inhibit the growth of bacterial cell walls (the protective wall surrounding the bacteria) or stop bacteria from replicating by manipulating bacterial DNA. Evidence of the use of antibiotics such as tetracycline

tetracycline, Source: wikimedia commons

tetracycline, Source: Wikimedia Commons

have been found in fossils dating back to 350 Common Era and has since evolved alongside human technology to become more effective and accessible to the everyday consumer. Common uses of antibiotics include disinfecting wounds, mediating safe child birth and curing food poisoning. Using antibiotics, countless lives have been saved in human history especially in major historical events such as World War II. The following link demonstrates the effects of the drug Penicillin on the outcome of World War II which was discovered by Alexander Fleming in 1928 (http://classroom.synonym.com/did-invention-penicillin-affect-world-war-ii-8709.html).

Bacteria vs. Antibiotic?

But, antibiotics are double-edged swords. Bacteria has been slowly adapting to various antibiotics and evolved so that some antibiotics are no longer effective. This is due to mainly two reasons:

  1. People have been misusing and overusing antibiotics for the last couple of decades which allowed bacteria to have an easier time adapting and building resistance to the antibiotics.
  2. Bacteria is a very flexible life from in the aspect that it adapts quickly and have quick mutation cycles.

Dangerous cases have resulted where Super Bugs which are bacteria resistant to antibiotics have started to grow in hospitals infecting patients receiving various treatments. These cases have often resulted in mortality in these patients. The following illustration demonstrates the quick adaptability of a bacteria cell to an antibiotic.

512px-Artificial_Bacterial_Transformation.svg

Bacteria/ Antibiotics, Source: Wikimedia Commons

The Battle is Won?

The information presented above must be shocking to some but rest assured because scientists believe that they have found an antibiotic that does not induce bacterial resistance. Teixobactin

Teixobactin, Source: Wikimedia Commons

Teixobactin, Source: Wikimedia Commons

discovered  earlier last year appears to successfully combat the development of bacterial resistance. The key in why this antibiotic is so effective in prohibiting bacterial resistance is the fact that it is able to inhibit bacterial growth in two methods as opposed to the normal one method attack of alternative antibiotics. Teixobactin prohibits the formation of both lipid II and lipid III in a bacteria which are detrimental in the formation of bacteria cells walls. Even if the bacteria is able to adapt by restoring the ability to produce of one of these lipids, the other lipid would still be inhibited.

The following is a YouTube video provided by Newsy Science which outlines the basics of what this new antibiotic can do and the mechanism behind it.

Hopefully, this new antibiotic marks the oncoming of a new age of drug use where antibiotic will no longer induce bacterial resistance.

By: Ming Lun (Allan) Zhu

 

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Posted in Biological Sciences, Issues in Science, Science in the News, Uncategorized

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Organisms Inside Us

Posted on February 29, 2016 by | 2 comments

Have you ever wondered how many micro organisms are living inside us? Micro organisms are living organisms that cannot be seen with our naked eyes. They may be multicellular (made out of more than one cell) or unicellular (made out of one cell). Our human body is packed with trillions of microbes (or micro organisms). In fact, our own body cells are out numbered with a ratio of 1:10. So, we are technically 90% germs and 10% human. Microbes are found in all parts of our body in different proportions. Our lung has approximately 1000x less microbes than our mouth and has approximately 1 billion times less microbes than our intestines. Although most microbes are harmless to us, some may cause bacterial infections in humans.

The Human Body = 90% Germs + 10% Human

Top three functions microbes in our body:

  1. Defense mechanism: Microbes in our lungs, intestines and our skin provide the first line of defense against harmful bacteria that enters our body. Good microbes found in these areas play an essential role in preventing the spread of harmful microbes by occupying space so less space are available for harmful microbes to settle down inside us. Thus, preventing us from bacterial infections that may cause fever, diarrhea or other problems. Other than that, researchers have found evidence that microbes that live inside us help promote our immune system cells to grow and replicate.
  2. Keeping us in shape: The trillions of microbe colonies in our intestines help digest fats and carbohydrates, facilitating the absorption of nutrients in cells. Our intestinal microbes also ferment food that we consume. The fermentation process produces chemicals that speeds up our metabolic processes. As a result, the microbes in our gut helps us keep in shape by increasing our metabolism.
  3. Detoxifies us: Microbes living in us are also capable of digesting toxins that we accidently ingest into less harmful substances. Therefore, preventing us from being poisoned. For example, the microbe Lacrobacillus probiotics found in food help the human body detoxify heavy toxic metals such as aluminum.

Good microbes that keep us healthy

Where do we get microbes that live in our body? Most of our microbes that inhabit our intestines comes from the food we ingest. Our skin and lung microbes come from the air we are exposed to. Recently, researchers discovered that newborn infants get their microbes from their mother’s breast milk and vagina. Researchers found that the method of delivery may have an effect on the diversity of intestinal microbes in newborns. They discovered that infants born vaginally and infants born by caesarean section have different intestinal microbe composition. This indicates that we start to develop our microbe colonies from the day we were born.

Microbes inside our body

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Benefits of Breastfeeding: Breast Milk Contains Sugars that Contribute to Healthy Infant Growth

Posted on February 22, 2016 by | 3 comments

Were you aware that the thousands of bacteria residing in our gastrointestinal tract (gut) and their interactions with the dietary foods we consume actually have a great impact on human health?

Two 25-milliliter samples of human breast milk. The lefthand sample is first milk produced and the righthand sample is milk produced later during the same pumping.

Two 25-milliliter samples of human breast milk. Source: Wikipedia Commons

Inspired by this discovery, a team of researchers led by Jeffrey Gordon from the Washington University School of Medicine in St.Louis found that the interactions of gut bacteria with the sugars in breast milk promote healthy infant growth.

Why is healthy infant growth a topic of discussion?
Every year, childhood malnutrition causes over 3 million deaths, leads to stunted growth and is associated with impaired cognitive ability.

Branched Oligosaccharide Structure

Branched Oligosaccharide Structure.                  Source: Wikipedia Commons

In Malawai, Africa, almost 50% of children under the age of 5 showed stunted growth. The researchers collected samples of human breast milk from those mothers with healthy babies or stunted babies. They discovered that the amount of oligosaccharides (sugar) in the breast milk containing sialic acid, an essential nutrient for brain development and cognition, were much greater in the mothers with healthy, relative to stunted growth babies.

This finding suggests that the sugars in the breast milk contribute to healthy infant growth. To analyze whether this was the case, the researchers created animal models, ensuring that both the bacteria in the gut and the diet could be manipulated. Gordon and his team began by isolating bacterial strains from fecal matter of the undernourished babies and inserted it into mice or piglets. Then, the researchers fed the mice or the piglets a typical Malawian diet, consisting of legumes, corn, vegetables, and fruit, a diet itself which is insufficient for healthy growth.

Whey

Whey, a by-product of cheesemaking. Source: Wikipedia Commons

With the mice and the piglets mimicking the undernourished Malawian infants, Gordon and his team then began testing effects of the sialic acid-containing sugars. They used cow milk as an alternative because of the difficulty to purify large amounts of sugars from human breast milk. They were able to obtain sialic acid-containing sugars from whey, a by-product of cheesemaking, and fed it to the animals. The mice and piglets showed significant improvements in growth, in both muscle mass and in bone volume. The mice and piglets also showed improved brain development and metabolic activities in the liver.

Because the bacteria in the gut was allowed to be manipulated, the researchers were able to pinpoint which bacterial strains were affected by sialic acid-containing sugars and how the different strains interacted with one another. They found that one strain of bacteria fed on the sialic acid-containing sugars and another strain fed on the digested products of sialic acid-containing sugars. This revealed a possible food web within the bacterial gut community.These two strains of bacteria alone were not sufficient enough to explain healthy growth in the mice and piglets, signifying that more complex interactions among different bacteria in the gut were necessary for growth.

The results of their study were recently published in Cell and serves as the foundation for future studies on the benefits of the components of breast milk on healthy infant growth and its interaction with gut bacteria.

 

Posted on February 22, 2016 By Jenny U

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Posted in Biological Sciences, Issues in Science, Science Communication, Science Communicators, Science in the News, Uncategorized

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Can First Nation’s clay be used in hospitals to kill antibiotic resistant bacteria?

Posted on January 30, 2016 by | 3 comments

As more empowerment and resources comes to First Nations group, new discoveries and technology may soon become available for use in a variety of settings.

In this article, a clay from Kisameet Bay, British Columbia, used by First Nations for centuries for its healing properties have been used in lab tests to kill antibiotic-resistant bacteria.

Antibiotic-resistance bacteria has proven resilient and a danger to the population, particularly in hospital settings where there is a growing problem due to overuse of antiobiotics. This video highlights the microbiology of antibiotic resistance in bacteria.

The research was published in the American Society for Microbiology’s mBio journal. Rare mineral clay is recommended to be studied as a treatment for serious infections caused by the so-called ESKAPE pathogens, which cause the majority of hospital infections and the effects of antibacterial drugs.

The acronym ESKAPE comes from the scientific names of the bacteria themselves:

  • Enterococcus faecium.
  • Staphylococcus aureus (also known as as the methacillin-resistant superbug MRSA).
  • Klebsiella pneumoniae.
  • Acinetobacter baumannii.
  • Pseudomonas aeruginosa.
  • Enterobacter species.

However, further studies and testing will be required before this clay can be made for hospital use.

I think this is an interesting breakthrough, not only for science/technology/healthcare, but for Canadian-First Nations relations. Reconciliation can take on many different forms, but with combined effort on both sides, something wonderful can be achieved.

 

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Posted in Biological Sciences

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Biocatalysts for the production of hydrogen fuel

Posted on January 17, 2016 by | Leave a comment

Hydrogen fuel cells can be used to provide electricity for numerous applications, such as electric motors. They are conceptually similar to batteries, but the contents are not self-contained. A supply of hydrogen gas and molecular oxygen is needed to produce electricity. These cells have several advantages, for example, they are non-polluting, low maintenance, silent, safe and have a high energy efficiency in comparison to gas engines. However, the majority of hydrogen gas is produced from petroleum cracking and reforming reactions. Thus, finding alternatives to generate hydrogen gas, without depending on petroleum is crucial. Existing alternative processes or technologies that generate hydrogen gas include photoelectrochemical cells, electrolysis of sodium chloride and gasification.

Hydrogen fuel cell: How it works Source: Wikimedia Commons

In an article published by Nature Chemistry, scientists from Indiana University have created an efficient biomaterial that catalyzes the production of hydrogen. In the study, the [NiFe]-hydrogenases from the bacteria E.Coli were used as the target for the hydrogen-producing catalysts due to their oxygen-tolerant nature and ability to be incorporated into biomaterials. Hydrogenases are enzymes that catalyze the reduction of protons to form hydrogen gas. The hydrogenase enzyme of E.Coli is encoded in a six-gene operon (a unit regulating the expression of the protein), of which the first two genes, hyaA and hyaB encode for the small and large subunits of the enzyme, respectively. One plasmid (circular DNA strand of a bacterium) was engineered to contain the two genes of the hydrogenase enzyme, hyaA and hyaB, both fused to a scaffold protein. On a separate plasmid, the coat protein gene was present with a different promotor. The scientists induced expression of the hyaA and hyaB genes and expression of the coat protein gene followed resulting in the self-assembly of a shell surrounding the matured hydrogenase enzyme.

The ‘viral shell’. Source: Wikimedia Commons

The viral shell was shown to provide protection from protease (an enzyme that breaks down proteins), thermal denaturation and air exposure. The encapsulated hydrogenase enzyme is 100 times more active than the free enzyme and the coat protein offers protection to its cargo. Utilizing the enzyme’s remarkable capability to produce hydrogen gas, paired with the virus’ ability to self-assemble has resulted in a renewable, efficient and environmentally friendly biomaterial that could be utilized as an alternative fuel source in the future.

As mentioned, roughly 95% of hydrogen gas is generated from fossil fuels and the other 5% is generated from alternative processes. The conclusion of this research is indeed exciting and offers another potential alternative aimed to decrease our dependence on fossil fuels for hydrogen gas production. Hopefully, this process could reduce the operation costs of hydrogen fuel cells, given that conventional methods rely on using complex and expensive infrastructure for the production of hydrogen gas. It is uncertain however, how or if this process will be used to produce hydrogen gas on an industrial scale, given that the article does not mention how much hydrogen gas is produced from these nano-catalysts. The leading professor of the study, says the next step is to “[incorporate] this material into a solar-powered system”.

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Video by: Gregor Scott

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