Tag Archives: superbugs

Science or snake oil: is manuka honey really a ‘superfood’ for treating colds, allergies and infections?

The Conversation

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Sure it tastes nice, but what else can it do? from http://www.shutterstock.com.au

Nural Cokcetin, University of Technology Sydney and Shona Blair

Manuka honey is often touted as a “superfood” that treats many ailments, including allergies, colds and flus, gingivitis, sore throats, staph infections, and numerous types of wounds.

Manuka can apparently also boost energy, “detox” your system, lower cholesterol, stave off diabetes, improve sleep, increase skin tone, reduce hair loss and even prevent frizz and split ends.

Some of these claims are nonsense, but some have good evidence behind them.

Honey has been used therapeutically throughout history, with records of its cultural, religious and medicinal importance shown in rock paintings, carvings and sacred texts from many diverse ancient cultures.


Read more: Honey could be a potent medicine as well as a tasty treat


Honey was used to treat a wide range of ailments from eye and throat infections to gastroenteritis and respiratory ailments, but it was persistently popular as a treatment for numerous types of wounds and skin infections.

Medicinal honey largely fell from favour with the advent of modern antibiotics in the mid-20th century. Western medicine largely dismissed it as a “worthless but harmless substance”. But the emergence of superbugs (pathogens resistant to some, many or even all of our antibiotics) means alternative approaches to dealing with pathogens are being scientifically investigated.

We now understand the traditional popularity of honey as a wound dressing is almost certainly due to its antimicrobial properties. High sugar content and low pH mean honey inhibits microbial growth, but certain honeys still retain their antimicrobial activity when these are diluted to negligible levels.

Many different types of honey also produce microbe-killing levels of hydrogen peroxide when glucose oxidase (an enzyme incorporated into honey by bees) reacts with glucose and oxygen molecules in water. So, when honey is used as a wound dressing it draws moisture from the tissues, and this reacts to produce hydrogen peroxide, clearing the wound of infection.

The antimicrobial activity of different honeys varies greatly, depending on which flowers the bees visit to collect the nectar they turn into honey. While all honeys possess some level of antimicrobial activity, certain ones are up to 100 times more active than others.

How is manuka different to other honey?

Manuka honey is derived from the nectar of manuka (Leptospermum scoparium) trees, and it has an additional component to its potent antimicrobial activity. This unusual activity was discovered by Professor Peter Molan, in New Zealand in the 1980s, when he realised the action of manuka honey remained even after hydrogen peroxide was removed.

The cause of this activity remained elusive for many years, until two laboratories independently identified methylglyoxal (MGO) as a key active component in manuka honey in 2008. MGO is a substance that occurs naturally in many foods, plants and animal cells and it has antimicrobial activity.

Australia has more than 80 species of native Leptospermum, while New Zealand has one, but the “manuka” honeys from each country have similar properties. There is currently a great deal of debate between the two countries over the rights to use the name “manuka”, but for simplicity in this article we use the term to describe active Leptospermum honeys from either country.


Read more: Manuka honey may help prevent life-threatening urinary infections


Can manuka honey kill superbugs?

The activity of manuka honey has been tested against a diverse range of microbes, particularly those that cause wound infections, and it inhibits problematic bacterial pathogens, including superbugs that are resistant to multiple antibiotics.

Manuka honey can also disperse and kill bacteria living in biofilms (communities of microbes notoriously resistant to antibiotics), including ones of Streptococcus (the cause of strep throat) and Staphylococcus (the cause of Golden staph infections).

Crucially, there are no reported cases of bacteria developing resistance to honey, nor can manuka or other honey resistance be generated in the laboratory.

There is good evidence manuka honey kills bacteria. Ryan Merce/Flickr, CC BY

It’s important to note that the amount of MGO in different manuka honeys varies, and not all manuka honeys necessarily have high levels of antimicrobial activity.

Manuka honey and wound healing

Honey has ideal wound dressing properties, and there have been numerous studies looking at the efficacy of manuka as a wound dressing. Apart from its broad-spectrum antimicrobial activity, honey is also non-toxic to mammalian cells, helps to maintain a moist wound environment (which is beneficial for healing), has anti-inflammatory activity, reduces healing time and scarring, has a natural debriding action (which draws dead tissues, foreign bodies and dead immune cells from the wound) and also reduces wound odour. These properties account for many of the reports showing the effectiveness of honey as a wound dressing.

Honey, and in particular manuka honey, has successfully been used to treat infected and non-infected wounds, burns, surgical incisions, leg ulcers, pressure sores, traumatic injuries, meningococcal lesions, side effects from radiotherapy and gingivitis.


Read more – Use them and lose them: finding alternatives to antibiotics to preserve their usefulness


What about eating manuka honey?

Most of the manuka honey sold globally is eaten. Manuka may inhibit the bacteria that cause a sore (“strep”) throat or gingivitis, but the main components responsible for the antimicrobial activity won’t survive the digestion process.

Nonetheless, honey consumption can have other therapeutic benefits, including anti-inflammatory, anti-oxidant and prebiotic (promoting the growth of beneficial intestinal microorganisms) properties. Although, these properties are not solely linked to manuka honey and various other honeys may also work.

What doesn’t it do?

There is a commonly touted belief that eating manuka (or local) honey will help with hay fever because it contains small doses of the pollens that are causing the symptoms, and eating this in small quantities will help your immune system learn not to overreact.

But there’s no scientific evidence eating honey helps hay fever sufferers. Most of the pollen that causes hay fever comes from plants that are wind pollinated (so they don’t produce nectar and are not visited by bees).

There is some preliminary work showing honey might protect from some side effects of radiation treatment to the head and neck that warrants further investigation. But other claims honey has anti-cancer activity are yet to be substantiated.

If you’re putting honey in your hair you’re probably just making a sticky mess. from shutterstock.com

There isn’t any robust scientific evidence that manuka lowers cholesterol, treats diabetes or improves sleep. Although one interesting study did show honey was more effective than cough medicine for reducing night time coughs of children, improving their sleep (and their parents’). Manuka honey wasn’t used specifically, but it may well be as helpful.

Claims that anything helps to “detox” are innately ridiculous. Similarly “superfood” is more about marketing than much else, and the cosmetic and anti-ageing claims about manuka are scientifically unfounded.

Final verdict

If consumers are buying manuka honey for general daily use as a food or tonic, there is no need to buy the more active and therefore more expensive types. But the right kind of honey is very effective as a wound dressing. So if manuka is to be used to treat wounds or skin infections, it should be active, sterile and appropriately packaged as a medicinal product.

The best way to ensure this is to check the product has a CE mark or it’s registered with the Australian Therapeutic Goods Administration (marked with an AUST L/AUST R number).

The ConversationManuka honey isn’t a panacea or a superfood. But it is grossly underutilised as a topical treatment for wounds, ulcers and burns, particularly in the face of the looming global superbug crisis.

Nural Cokcetin, Postdoctoral Researcher, University of Technology Sydney and Shona Blair, General Manager, ithree institute UTS

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.

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The water industry needs to join the fight against superbugs

The Conversation

By Peter Fisher, RMIT University and Peter Collignon, Australian National University

The fight against antibiotic-resistant bacteria – so-called “superbugs” – is a huge challenge, one that the World Health Organization has described as a grave global problem.

When superbugs hit the headlines it’s often because of hospital outbreaks, such as the outbreak of Vancomycin Resistant Enterococcus that infected babies in Melbourne in 2013. Yet the problem isn’t confined to hospitals – the wider environment can be important in the development and spread of these bugs, and people can be infected through food and water.

The problem of antibiotic resistance is being exacerbated worldwide by the pollution of waste water with leftover drugs, providing breeding grounds for resistant bacteria and their genes. The problem can persist for years, constantly refreshed by new discharges of both drugs and of resistant bacteria themselves, shed by people and animals.

Vancomycin Resistant Enterococcus, which is impervious to one of the antibiotics used as a last resort by many doctors. Source: 
Janice Henry Carr/US Centers for Disease Control and Prevention

Warning from history

The fact that penicillin was found in soldiers’ urine in the second world war was, in hindsight, an early indication that antibiotics are present in waste water, and that drugs like this might go on to have an afterlife in streams, lakes and other waterways, clinging to sediment particles and upsetting the delicate bacterial balances in soils and aquatic ecosystems.

But no-one gave the issue much thought until chance intervened in 1992, when German scientists looking for herbicides in rivers, groundwater and lakes stumbled across a chemical they didn’t recognise – it turned out to be the cholesterol-lowering drug clofibrate, a cousin of the weedkiller 2-4-D.

No end of pharmaceutical pollution has since been found in the world’s water – analgesics, antibiotics, lipid regulators, antiseptics, beta-blockers, contraceptive hormones, anticonvulsants and X-ray contrast agents. Detectable levels of clofibrate alone are now found throughout the North Sea.

We now know that partially degraded drugs and ointments can be converted back into their active form through chemical reactions once you’ve said goodbye to them in the loo or shower. Many biodegrade, but others can be very persistent in their new environmental home.

Water treatment plants are thus the last barrier to drug residues and other synthetic chemicals being set loose into soils and waterways (meanwhile, there is no barrier at all for freely administered livestock drugs such as the antibiotics sulphasalazine and oxytetracycline).

Crucial treatment

Treatment plants’ ability to strip out waste drugs varies enormously according to age, level of expertise and design standard. Even the best ones don’t remove all foreign chemicals. Advanced treatment processes are designed more for removing pathogens than for breaking down molecules, although chlorination and what’s known in the trade as “ozonation” do have some ability to change the chemistry of drug molecules (to exactly what is unclear).

As the use of recycled water increases, the quality of this water becomes more critical and good management of all sewer inputs by water companies becomes more important. Thus, pharmaceuticals are being identified as a potential risk in recycled water risk-management systems of utilities such as South East Water in Melbourne, Orange County Sanitation District in California, and Singapore’s NEWater scheme.

This is leading to an increased awareness of the waste contributions from domestic catchments and high-concentration point sources such as hospitals.

It is time for the health and water industries to strike a bargain. Health professionals need to be aware of the need for pharmaceuticals to be managed as organic and persistent pollutants. They can help the water treatment industry by being aware of what their activities are putting into the sewerage and waste disposal systems, in view of the limited extent to which these systems can deal with the large number of drugs that are stable. They should consider prescribing less toxic, less environmentally persistent, but equally effective drugs where possible, as well as trying to reduce overall drug use in the community.

Meanwhile, Australia should build on its reputation for innovation in water management by addressing this health issue. Tackling hot spots in “source control” such as hospitals and clinics could make significant inroads on the amount of waste drugs entering treatment plants. Treatment at source may be preferable to facing increased trade waste charges by utilities if they deem hospital wastewater inputs to be problematic. Water firms should discourage hospital staff from emptying half-empty syringes into wash basins (which is probably common despite being against protocols) should also be discouraged. Rubbish disposal systems that minimise medicines ending up in landfill are another must.

The water industry should to ensure that treatment plants are operating under optimal conditions and that the older ones are either replaced or upgraded. Where appropriate, the industry could also help hospitals with in-house waste treatment, and suggest ways for householders to dispose of unwanted drugs – perhaps along the lines of Orange County’s No Drugs Down the Drain” campaign.

The search for new antibiotics to beat superantibiotics goes on. The discovery of one of the very few new candidate antibiotics in the past 30 years, teixobactin, while encouraging, is no cause for complacency.

This article was co-authored by David Smith, water quality manager for South East Water, Melbourne.

The ConversationThis article was originally published on The Conversation. (Reblogged by permission). Read the original article.

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We need new antibiotics to beat superbugs, but why are they so hard to find?

The Conversation

By Matthew Cooper, The University of Queensland

We’ve heard a lot lately about superbugs – bacteria that are resistant to current antibiotics. But as the threat of superbugs continues to rise, the number of new treatments available has flatlined. This has placed us dangerously close to the edge of a return to the pre-antibiotic era, when even simple infections caused death.

We’ve developed antibiotics in the past, so why it is now so difficult to discover and develop new antibiotics? To find out, let’s look back to the “golden age” of antibiotic discovery from the 1940 to 1970s.

How we found antibiotics in the past

The majority of antibiotics we use at home or in hospitals today have their origins in natural products.

The penicillins, cephalosporins, aminoglycosides, rifamycins, tetracyclines and glycopeptide-based antibiotics all came from bacteria or fungi. They were made by nature in response to selective evolutionary pressure over eons of “chemical warfare”, in which microorganisms battled to survive by killing off their competitors with antibiotics.

In the past, the toolkit to develop new antibiotics was simple.
Matej Kastelic/Flickr

Of course, they also co-evolved resistance mechanisms to avoid being killed by their own compounds, so antibiotic resistance is equally ancient. Scientists have found antibiotic resistance genes in bacteria isolated from 30,000-year-old permafrost, long before antibiotics were discovered and used by humans.

Most antibiotics found during the “golden age” were from micro-organisms themselves, isolated from soil or plants and then cultured in the laboratory. They were easily screened on agar culture plates or liquid culture broths to see if they could kill pathogenic bugs.

The toolkit required was pretty simple: some dirt, a culture flask to grow the antibiotic-producing bacteria or fungi, a column to separate and isolate the potential new antibiotic, and a culture plate and incubator to test if the compound could kill a disease-causing pathogenic bacteria.

Chemists were then able to “tweak” these new structures to extend their activity against different bacteria and improve their ability to treat infection in the clinic. Most of the antibiotics we have are derived from just one soil-dwelling bacterial order – the Actinomycetales.

Most antibiotics we use were derived from soil-dwelling bacteria.
whitaker/Shutterstock

The problem is that by using this tried and trusted method over and over again, we have found all of the low-hanging fruit antibiotics. So scientists have been forced to look further afield, turning to coral reefs, deep oceans and cave-dwelling bacteria to search for new promising molecules.

Key challenges

Philosopher Sun Tzu said “the supreme art of war is to subdue the enemy without fighting”. We are now in a protracted war against superbugs, as we have overplayed a key weapon against disease. Our unfortunate misuse and abuse of antibiotics means that bacteria have developed new ways to inactivate the drugs, to stop them getting to their targets within the bacteria cells, and to pump them back out of the cell when they do get in.

The cost and time required to bring new drugs to market are staggering. Estimates for the time to bring a new antibiotic through the preclinical, clinical and regulatory approval process are in the order of 13 to 15 years and around US$1.2 billion. If the costs of failures are factored in, it is closer to US$2.5 billion.

Because we expect to pay $20 or at most $200 for a course of antibiotics (compared to more than $20,000 for many cancer treatments), and because we only take antibiotics for a week or two, almost all of the companies that were active in antibiotic discovery have left the field over the last 20 years.

What are scientists doing?

It’s not all doom and gloom. Scientists have developed many innovative approaches to the search for new antibiotics, such as one recently reported in Nature, in which bacteria from soil are sealed into 10,000 separate miniature culture cells in a chip device, then buried in the soil they came from again to grow in their natural environment. The chip device is then dug up, and each cell screened for compounds that can kill pathogenic bacteria.

Developing new antibiotics is a long and expensive process.
Jenni Konrad/Flickr, CC BY-NC

This type of approach led to the discovery of one of the very few new candidate antibiotics in the last 30 years, teixobactin.

This type of innovation illustrates an important maxim: with good people, the right motivation, perseverance, and sufficient funding we can start to fix some of problems we face in this area.

What are governments doing?

Fortunately, governments around the world have started to respond.

British Prime Minister David Cameron and Chief Medical Officer Dame Sally Davis have been consistent vocal supporters of a cross-government strategy and action plan against superbugs. In fact, Dame Davies recognised that the threat from infections resistant to frontline antibiotics was so serious that she called for the issue to be added to the UK government’s national risk register of civil emergencies, alongside pandemic influenza and terrorism.

The European Union has stepped up with the Innovative Medicines Initiative (IMI), Europe’s largest public-private initiative aiming to speed up the development of better and safer medicines for patients. They have pledged more than €680 million (A$985 million) to fund drug-discovery platforms for antibiotics; new treatments for cystic fibrosis; hospital-acquired pneumonia and urinary tract infections; understanding how drugs get into, and then stay inside bacteria; and new ways of designing and implementing efficient clinical trials for novel antibiotics.

Scientists have been forced to look to coral reefs, deep oceans and cave-dwelling bacteria to search for promising new molecules.
©UCAR/Flickr, CC BY-NC

In the United States, the National Institutes of Health (NIH) invest more than US$5 billion (17% of total funds) into infectious diseases research, making it second only to cancer research at US$5.4 billion (18%). In a further show of support, US President Barack Obama also announced an Executive Order commanding a dozen government agencies to action a comprehensive action plan against superbugs.

So how are we doing in Australia? Infectious disease research for new antibiotics and diagnostic methods to identify superbugs is not yet an Australian national health priority area. In 2014, the Australian government, through the National Health and Medical Research Council, invested A$13.4 million into antibiotic development and resistance research, less than half of which was directed to discovery of new compounds. This equates to around 2% of the 2014 research budget.

We need better stewardship of existing antibiotics, better diagnostic methods and new antibiotics that we can take better care of this time around.

Unfortunately, we are dragging our feet in dealing with the superbug threat. This year, after more than 20 years of reviews and white papers, the Australian ministers for health and agriculture will be presented with comprehensive recommendations from leading clinicians, health-care workers, scientists, and policymakers about how we can work together to finally overcome the challenges of combating bacterial infections.

Yes, we’ve heard a lot lately about superbugs.

Now it’s time to act.

This article was originally published on The Conversation. (Reblogged with permission). Read the original article.

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