Micro Eclectics

Two compounds derived from garlic may help contaminants in baby formula, says a UBC study. Photo: Rüdiger Wölk, Münster/Wikimedia Commons. Garlic may be bad for your breath, but it’s good for your baby, according to a new study from the University of British Columbia. The study, recently published in Applied and Environmental Microbiology , is the first to identify two compounds derived from garlic – diallyl sulfide and ajoene – that significantly reduce the contamination risk of Cronobacter sakazakii in the production of dry infant formula powder. The discovery could make the product safer to consume, easing the minds of new mothers who can’t or opt not to breastfeed. “A trace dose of these two compounds is extremely effective in killing C. sakazakii in the food manufacturing process,” says Xiaonan Lu, corresponding author and assistant professor of food safety engineering in the Faculty of Land and Food Systems. “They have the potential to eliminate the path

The more we look, the more we realise just how important intact ecosystems are for our own well-being - and it really doesn’t matter at which scale we are looking. When Alan Cooper , Director of the Australian Centre for Ancient DNA , asked me (Corey) for a bit of help with a cool paper he and some of his colleagues were working on, I was initially sceptical. Why would an ecologist be even remotely interested in dentistry? I mean seriously - oral hygiene? Then he went into detail, and I couldn’t refuse. Before we get into that detail, we have to tell a story about a colleague of ours (name withheld, but true story) who recently went to the dentist to have some routine cleaning done. There was nothing particularly special about his visit - no local anaesthetic, no extractions, no caps, and certainly no surgery. Two weeks later he was in the hospital getting his chest cracked open for open-heart surgery. What happened was a microscopic bit of his dental plaque had di

Chemicals are all around us. They are crucial in all manner of industries, from agriculture to food to cosmetics. Most people give little thought to how these chemicals are made – and certainly very few would consider the chemical industry as a contributor to our society’s dependence on oil. But it is. Historically petroleum has been used to develop the chemicals needed for products such as pesticides, food supplements and make-up. Although many of the building blocks required to make these chemicals occur naturally, trying to take those natural materials and use them in large-scale industrial processes has proved difficult and costly. So petroleum is used instead. Until recently, oil was seen as a cheap commodity which was available in abundance, so petroleum was perfect for use in the chemical industry. However, the world has changed. We now recognise the need to reduce our reliance on oil in order to protect the environment and maintain our national security.

We invariably imagine electronic devices to be made from silicon chips, with which computers store and process information as binary digits (zeros and ones) represented by tiny electrical charges. But it need not be this way: among the alternatives to silicon are organic mediums such as DNA. DNA computing was first demonstrated in 1994 by Leonard Adleman who encoded and solved the travelling salesman problem , a maths problem to find the most efficient route for a salesman to take between hypothetical cities, entirely in DNA. Deoxyribonucleaic acid, DNA, can store vast amounts of information encoded as sequences of the molecules, known as nucleotides, cytosine (C), guanine (G), adenine (A), or thymine (T). The complexity and enormous variance of different species’ genetic codes demonstrates how much information can be stored within DNA encoded using CGAT, and this capacity can be put to use in computing. DNA molecules can be used to process information, using a b

Bacteria are single-celled microorganisms abundant in nature that can’t be seen with the naked eye. In fact, there are approximately five multiplied by 10³¹ bacteria on the earth, constituting 90% of its biomass. These microorganisms are found everywhere in our environment and are vitally important to maintaining a balanced ecosystem. They cycle carbon, nitrogen, sulphur, hydrogen and oxygen, regulate and affect the growth of plants and animals, and are at the base of most food chains. Microorganisms also play a pivotal role in human health, as most areas of our body that come in contact with the outside environment, such as the skin and gastrointestinal tract, harbour resident (colonising) bacteria. In fact, there are about ten times as many bacterial cells inside and on you than there are human cells. These colonising bacteria don’t cause disease under normal conditions. They actually protect us by preventing the growth of harmful bacteria. But sometimes colonisin

Antibiotics are compounds that can kill bacteria. Many antibiotics are produced naturally by bacteria themselves as they compete for food or living space with other bacterial species. Over time, bacteria that are always exposed to antibiotics will be under selective pressure to evolve resistance to them; the members of the population that are more resistant will be the ones to reproduce more often. Bacterial species reproduce incredibly rapidly compared to human beings, leading to rapid evolution within species. Under the right conditions, for instance, the common gut bacterium Escherichia coli can reproduce in just thirty minutes. Bacteria can also swap antibiotic resistance genes via a process known as horizontal gene transfer . That means that if antibiotic resistance develops in one bacterial species in an environment, there’s a good chance other bacteria can pick up that resistance as well. It’s a problem for human beings if bacterial pathogens, through this

Wound infections can occur when bacteria from the skin or from the environment are introduced into damaged tissues. Crucially, all wounds are colonised by bacteria but under certain conditions these bacteria can multiply unchecked, growing to reach numbers that overwhelm the immune system . Most wound infections can easily be treated with topical antimicrobials, or in more serious cases, by a course of antibiotics. They are also most commonly seen in clinical environments where, for example, infection-causing bacteria are inadvertently introduced into surgical incision sites after surgery. Despite rigorous cleaning and hygiene regimens, infections are often unavoidable because of the prevalence of bacteria in the environment and as part of normal human flora. When you add in that antibiotic resistant bacteria are rife within clinical environments, this can make these wound infections exceptionally difficult to treat. Chronic, inflammed s

On hearing the word “fungi” most people will probably think of pizza al funghi or a portobello mushroom burger. Incidentally, roughly half of the people salivating about these dishes will also carry a fungus called Candida albicans in their mouths or digestive tracts where it lives quietly, invisibly to the human eye, without causing disruptions or symptoms. But Candida albicans does not always go unnoticed. While most people carrying the fungus will go through life without ever learning the scientific name of their innocuous tenant, also called a “commensal”, some do encounter it as the common cause of oral thrush, nappy rush or vaginal yeast infections. Indeed, 75% of women will experience at least one episode of yeast infection throughout their lifetime. It gets worse. Changes to a person’s immune defences can help Candida albicans cause life-threatening infections of the blood stream and the inner organs. Patients suffering HIV/AIDS or those undergoing canc

When you’re sick, you want the most effective treatment to help get you back on your feet. But what if that involved bugs? Maggots and leeches have been used for decades and are still supplied to hospitals for speciality treatments. Researchers are now investigating whether hookworms can allow people with coeliac disease to safely consume wheat. Leeches and maggots Creepy crawlies have long been used for various types of treatment. Historical references from ancient Greece show that leeches were used as far back as 270 BC, probably for bloodletting. Over the years , leeches have been used for many purposes. With their potent secretions, leeches make microsurgery or plastic surgery more successful by preventing venous blood from collecting. Maggots secrete a host of factors to dissolve dying tissue.   The modern story of the maggot in wound healing is that one fortunate solder in the First World War was found to have

The discovery of unusual foraging activity in bacteria species populating our gut may explain how conditions like Inflammatory Bowel Disease (IBD) link to changes in the populations of bacteria in our gut. IBD affects 1 in every 250 people but its causes are unknown. Studies have shown that IBD patients have a different profile of gut microbes, which is called dysbiosis. All of us have trillions of beneficial bacteria in our gut, but the combination of different species, known as the microbiome, varies. A crucial question has been whether IBD causes our microbiome to change, or whether an imbalanced microbiome could be triggering IBD. And exactly how does one affect the other? We need to study these interactions to define new targets for therapeutics. Nathalie Juge and colleagues at the Institute of Food Research (IFR) have been trying to answer these questions by looking at the environment in which gut bacteria grow mucus. Mucus covers the lining of our gut and pro

Your intestines are home to many different kinds of bacteria (and some non-bacterial organisms as well). Together they’re called the “gut microbiome.” They come from the food you eat – and whatever else gets into your mouth. Bacteria start colonizing your gut at birth. Your gut microbiome aids in digestion and produces vitamins and other compounds that affect your health. It seems to play a role in many other health-related functions, including metabolism, cardiac health and mood. New evidence shows that the bacteria in our gut also interact with our immune systems, and might even influence the body’s immune reaction to vaccines. How can bacteria in your gut interact with your immune system? We are still learning how gut bacteria and the immune system interact. Research suggests that the interaction evolved over time to manage the balance between reacting to harmful pathogens and tolerating non-harmful organisms. You want your immune system to react to the pathogens that ca

The immune system protects us from the constant onslaught of viruses, bacteria and other types of pathogens we encounter throughout life. It also remembers past infections so it can fight them off more easily the next time we encounter them. But the immune system can sometimes misbehave. It can start attacking its own proteins, rather than the infection, causing autoimmunity. Or, it can effectively respond to one variant of a virus, but then is unable to stop another variant of the virus. This is termed the original antigenic sin (OAS). OAS occurs when the initial successful immune response blocks an effective response when the person is next exposed to the virus. This can have potentially devastating consequences for illnesses such as the mosquito-borne dengue . There are around 400 million dengue infections worldwide each year and no vaccine is available. Reinfection of someone who has been exposed to dengue previously can result in life-threatening hemorrhagic