Effectiveness of hand washing

Did you wash your hands today?  For example, after using the toilet or before eating?  I’m sure you did, yeah?  Now, do you actually know why you washed your hands?  Why is it important to have clean hands?  Sometimes we do certain actions, which are second nature to us, without necessary thinking why – we know it is important, or so the “experts” say, but we may not know why.  Well, in this case, we wash our hands to eliminate any pathogenic (disease-causing) microorganisms that may be present, which is a high probability after using the toilet and to reduce the possibility of foodborne disease, we wash again before eating.  The humble act of hand-washing to ensure clean hands is still one of the most effective acts of personal hygiene, as it was when Joseph Lister suggested the importance of clean hands during surgery, in his ground-breaking work carried out in a Glasgow hospital in the 1860s. While clean hands and the importance of personal hygiene is commonplace today and generally understood, it of course wasn’t always like this.  For much of history, the world held to the Miasma theory of disease (Figure 1).  This arose around 250 and was the only school of thought for the transmission of infectious disease for much of history.  The Miasma theory of disease is based on the idea that bad air, foul smells, stenches and the like, cause disease, especially at night.  Therefore, hospital wards used to be aired in the middle of the day and in some places, people would be wary of venturing out at night and would stay indoors with all windows closed.   In the mid-1500s, the first suggestion that particular entities, what we now know as microorganisms, may cause disease was postulated.  However, the first compelling evidence for this germ theory of disease came over three centuries later, with the above-mentioned work in Glasgow of Joseph Lister (Figure 2).  Lister read of the pioneering work of French microbiologist and chemist, Louis Pasteur (inventor of pasteurisation – one of the most common heat processing methods for all kinds of foods), and decided to try some of the ideas Pasteur put forward.  One was the use of a chemical antiseptic, in this case phenol, in the surgical wards and on the hands of surgeons and other staff to ensure clean (disinfected) hands.  The results were astounding – there was a dramatic decrease in the incidence of infections and death in the hospital wards where the tests were carried out.  This work was a turning point in hygiene and the use of antiseptics and was published in a series of papers in the reputable medical journal – The Lancet.  The year was 1869.  This convincing evidence for the benefits of clean hands spread first to France and Germany and then throughout Europe.  Thus, in the 1870s, Europe had accepted this germ theory of disease as the means for the spread of infection and therefore, accepted also, the idea that disinfecting hands could stop infectious disease transmission. However, across the Atlantic, it was a different story – the Americans were steadfast in their belief for the Miasma theory, that bad air caused disease.  This was all to change in the 1880s however.  In early July of 1881, James Garfield (Figure 3), 20th President of the United States was about to set off on his summer holiday, by train, from Washington, D.C..  He was to travel to the New England region, and was set to deliver a talk at his alma mater, Williams College in Williamstown, MA.  All went horribly wrong when he arrived at the station – as he was walking through the station waiting room, he was gunned down from behind.  As bad as this was, the events that unfolded immediately after the shooting and until his death were worse.  The President collapsed to the floor, and the first medical staff on hand had only one objective – to find the bullet.  Thus, they set to work on trying to locate it, but the main problem was, they were ignorant to the germ theory of disease and had no regard for personal hygiene.  Therefore, they probed the President’s wound with their bare, non-disinfected fingers and non-sterile instruments – one physician even put his whole hand into the President’s wound, right up to his wrist!  Over the next two and a half months or so of the President’s apparent convalescence, around 12-15 doctors poked and prodded and probed the President’s wounds, each and every time with non-sterile instruments and/or unclean hands.  This, no doubt, introduced untold numbers of microorganisms into the wound and slowly, infection after infection took hold.  Eventually, in the third week of September, the President’s ultimate demise took place, when he died at a seaside hamlet.  Thus, there is no doubt that the would-be assassin did shoot President Garfield, however, the shooting did not kill him.  The actions of the medical team and their ignorance of the germ theory of disease and therefore their inability to wash their hands were the actions that killed the President.  The death of James Garfield in 1881, the 20th President of the United States, is one of the biggest medical blunders of all time and remains one of the most significant incidents of medical malpractice in history. Hand-washing, which gives clean hands, can prevent the spread of infectious microorganisms and thus can eliminate the spread of infectious disease.  It is a simple, quick action (Figure 4) that has significant benefits.  Please wash your hands after using the toilet, before eating and be particularly strict with hand-washing during food preparation.  Your life and the life of your loved ones could depend on it.

Be safe with food

This post was originally published on 26 October 2016 on a previous blog of mine, Agrifood Research Central. Here we have a slight revision and a republishing. We all have the right to access food that is safe to eat – but is that all there is to the story? How proactive are we in ensuring the safety of food that we handle ourselves? Once upon a time, the food manufacturing industry was rife with unsafe practices, resulting in substances, today known as toxic, added intentionally to food to serve various purposes. This was 19th century England where various copper, lead and mercury compounds, for example, would be added. Today, in many countries, strict regulations govern food production and manufacturing in addition to food service, and thus the likelihood of acquiring a foodborne disease outside of the home is remote. Food manufacturing operations apply a quality assurance type of approach, through the Hazard Analysis Critical Control Points (HACCP) concept (Figure 1) which maintains very strict conditions of safe manufacture according to local and international standards. From a purely business perspective, it can be devastating indeed to a food manufacturing business to have recalled products due to a safety issue or worse, have consumer morbidity or mortality. Such a situation could collapse a business and be so severe that it cannot rise from such a crippling effect of consumer mistrust. Therefore, food companies are extremely strict in how they conduct their manufacturing operations and in their adherence to the Food Standards Code, or international equivalent. Increasingly, the largest danger with regard to food safety, is right in our own kitchen, where many dangers lurk.  These pathogenic (disease-causing) microorganisms are waiting to inflict illness on us and our families if you do not exercise the appropriate food safety precautions. For example, the temperature danger zone (Figure 2) and cross contamination (Figure 3) are critical concepts that domestic food handlers must be mindful of, so as to ensure foodborne disease risks are kept at an absolute minimum. People generally know that meat poses the highest foodborne disease risks, but how many people know that rice poses a similar risk?  It is not uncommon for people to pack rice meals for lunch and keep them at room temperature from the time they leave home in the morning until lunchtime – that is taking a huge risk, as even small numbers of pathogenic microorganisms could reach extreme numbers by the middle of the day, if the food is kept in the temperature ‘danger zone’. How about the ‘five second rule”? Another food safety myth – microorganisms are everywhere and going to attach to food in an instant, they have no concept of time and waiting for five seconds before they ‘latch’ on to a piece of fallen food!  Check out my video below to understand more:  Another area of food safety where there is much discussion and debate is food additives. Are they bad? Are they ok? Can we trust the government in our own country to regulate their use? Why are some banned in some countries but not in others? One aspect is certain – food manufacturers only put into food what we want in our food. Then you might say, “Hey, I don’t want this additive and that additive with all those E numbers and long names I can’t pronounce!” Sure, you might not want a particular additive in your food, but do you know what that additive does? Are you prepared to make a sacrifice for giving up that additive? You might be thinking, “Come on, these food companies are just piling in the additives to cover something up or to somehow increase their profits”. Well consider this – the reason you can buy a jam with consistent texture each time is the pectin that is added. If you are a home jam maker, you’ll appreciate the benefit of using pectin to ensure a consistently gelling product each time, after all, who wants runny jam (Figure 4) that is going to flow right off your toast as soon as you pick it up! Maybe you’re not concerned about pectin, a plant-based gelling agent found in the skins of fruits, but say, red food colouring. Well, ok, eliminate the red food dye – then, would you or your children really drink strawberry flavoured milk that is white? This is just one example, but it shows the various characteristics of food and drink we have come to expect. Food additives are used in everything from shelf-life extension to giving food the colour we expect, the flavour we expect and appropriate textures too – in short, we can’t do without them with our current range of foods. However, if we are willing to change our expectations on quality, lower our expectations on consistency and in fact change our perception of what is “normal” for a given food product, then we could eliminate food additives. As stated earlier, food companies give us what we want because they need to make money by selling us something that we are going to buy. If we don’t like something in a product, then buy an alternative. If no alternative exists, then make your own and maybe, they could be a market out there to up-scale your home innovation to industrial scale. If enough people stop buying a product, then the food company will have no choice but to drop that line, it is that simple. They cannot continue producing an item that is not popular, and therefore profitable.   There are many facets to food safety, however, one thing is clear – by and large, we are in control of the safety of the foods we consume.  The domestic kitchen tends to be less safe than commercial kitchens, so please be mindful during food preparation and cleaning at home.  Manufactured food products may legally contain some ingredients that we are not too keen on.  However, from a safety point of view all additives are fine for the general population and it is really

A natural way to get your dose of good bacteria.

On Sunday 20 October 2019, I had the opportunity to present this talk twice, at the 2nd annual VegoFest in Melbourne, a celebration of all things ‘vego’, organised by the Vegetarian and Cultural Association Incorporated. What follows are the slides I used and (almost) a transcript of what I said. Slide 1 – G’day everyone, I’m Philip, an independent food microbiologist at my own start-up institute, Food Microbiology Academy.  Today I want to take you through what is one of the hottest topics in food microbiology at the moment, probiotics and gut health with this presentation titled “A natural way to get your dose of good bacteria”. Slide 2 – Before we actually get into the presentation proper, I want to give you a definition of “natural”, which will be relevant later on in the presentation, since the title of this talk refers to “natural”.  So in the food context, natural refers to a food “having had a minimum of processing or preservative treatment” – just keep this definition in the back of your mind as we progress through the talk. Slide 3 – Now, to start off with, I want to let you know, or remind you that microorganisms are indeed everywhere.  They have colonised every conceivable habitat and environmental niche on the planet – from really hot, to really cold, dark and high pressure environments.  Microorganisms are ubiquitous to the extent that if we can’t find them, then our current technology is probably not good enough to detect them! Slide 4 – Not only are they everywhere in an environmental context, but everywhere includes being on and in us too.  This image is to give you an indication that yes, microorganisms are living, growing and indeed thriving on and in our bodies, even in the harshest environments like the dry and salty skin and the highly acidic and low pH environment of the stomach. Slide 5 – This slide is to give you an indication of some of the so-called good guys and bad guys of the bacterial world, some of which you may have heard about.  Good bacteria include various species of Lactobacillus, Streptococcus thermophilus and Bifidobacterium longum.  Some of the Bacteria which always spell trouble are Salmonella typhi, most species of Streptococcus apart from Streptococcus thermophilus and Helicobacter pylori. Slide 6 – What we have here are some of the general benefits afforded by good gut Bacteria.  Starting at the top right – i) they produce various compounds which assist in digesting food, ii) some of them produce vitamins which are essential in human nutrition, iii) due to the location they reside and their numbers, they exert a protective effect on the epithelial lining of the gut, iv) modulation of the immune system is another important role they play in host non-specific defences and v) they employ various strategies to ward off pathogenic Bacteria, which we’ll cover off in the next slide. Slide 7 – Here we have various means employed by your resident gut Bacteria to resist colonisation by invading pathogenic Bacteria.  Firstly number one, on the left hand side is “Adhesion exclusion” – which means that the pathogens need to adhere to the cells lining the host’s gut in order to exert their disease potential.  However, due to competition for space and adhesion sites which the resident microbiome, the pathogens invariably miss out, and hence are excluded from gaining a ‘foothold’.  Numbers two and three refers to the fact that the pathogenic Bacteria, like all Bacteria and indeed all living organisms refer adequate nutrition.  Limitation on carbon sources, which are used for energy and micronutrients, by the good Bacteria essentially starve the invading Bacteria of the nutrients they need to thrive, grow and even survive.  If this isn’t enough, your resident good Bacteria produce antimicrobial substances and toxins which directly attack ad destroy the ‘bad guys’.  While your gut microbiota is employing all these strategies to ward off the invaders and prevent disease, the pathogens have a host of virulence factors they are expressing to combat everything ‘being thrown at them’.  Basically, there’s a ‘war’ going on in your gut, the good Bacteria of your gut versus the invading pathogenic Bacteria.  If the ‘good guys’ win, you stay healthy, but if the ‘bad guys’ win, then you get sick – it’s as simple as that! Slide 8 – So, we know probiotic Bacteria are good and we need to look after and replenish our gut microbiome, but how?  Well, there’s basically two ways – probiotic supplements, so tablets or pills containing probiotics or the alternative, the more natural way, is to consume fermented foods containing probiotics, such as these yum fermented vegetables.  Something to remember – not all fermented foods contain probiotics and not all fermented foods that are meant to contain probiotics, actually do.  For example, if sauerkraut has been heat treated after fermentation, then the probiotic Bacteria are going to be all but killed off.  Thus, the best option is actually to make your own fermented foods. Slide 9 – Here we have a range of fermented foods displayed, but like we said in the previous slide, not all of them are actually probiotic foods.  Tempeh, kombucha and soy sauce are fermented foods, but do not contain probiotics – even chocolate manufacture includes a fermentation step, but is not considered a probiotic food. Sauerkraut, kimchi and natto are fantastic vegan probiotic fermented foods while kefir is an excellent probiotic dairy drink. Slide 10 – In this slide I want to concentrate on two fermented cabbage products, Korean kimchi and German sauerkraut.  Both are amongst the healthiest fermented probiotic foods to include in your diet.  They can certainly be considered a physiologically functional food due to all these added benefits they offer – both promote immune system function while interestingly, probiotic lactobacilli starter cultures from kimchi have demonstrated anti-obesity effects when used as a dietary supplement. Slide 11 – So, to sum up – if you take antibiotics, lead a stressful lifestyle,

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