Скачать с ютуб Remarkable Botulism – the Putin of food pathogens (Clostridium botulinum) в хорошем качестве

Remarkable Botulism – the Putin of food pathogens (Clostridium botulinum)

“I had a wonderful time writing this story, I hope you enjoy it” - Karen Constable of The Rotten Apple, a weekly newsletter for food professionals. In this video, the narrator indulges her ghoulish fascination with one of the super-stars of food pathogens: Clostridium botulinum. Find the full article and links to sources here: https://therottenapple.substack.com/p... Transcript: Botulism – a deadly foodborne illness – made an unexpected appearance in plant-based milk last month. And it sent a chill through the food safety community. Botulism is deadly Botulism is possibly the scariest food-borne illness there is. And I for one would NOT want to get it. Here’s what happens to you if you are unlucky enough to eat food that contains the toxin that causes botulism, botulinum toxin. A few hours to a few days after eating heavily contaminated food you start experiencing neurological symptoms that include blurred vision, difficulty speaking and swallowing, then paralysis. If you don’t get medical help quickly the toxin paralyses your heart and lungs and you experience respiratory failure and then death (source). The friend of a victim described the final two months of his life before he succumbed to the disease as follows: “He could not move, he couldn’t talk, he couldn’t breathe, but he was conscious and aware and could understand and somewhat able to communicate,” (source) The good news is that there are antitoxins and in the United States, the fatality rate is around five percent (source). The bad news is that the antitoxins do not reverse paralysis but just stop it from progressing. Recovery depends on your body regenerating new nerve connections and patients may need to be on ventilators for weeks or months. Survivors can experience fatigue and shortness of breath for years (source). You only need a tiny amount of toxin to cause life-threatening symptoms. In fact, one teaspoon of the toxin contains enough to kill more than 70 million people. (This is based on a lethal dose of 70 nanograms for a 70 kg adult). Botulism is an ever-present risk Botulism is rare, but it’s surprisingly easy to create an outbreak by disregarding food safety practices. Botulism, the disease, is caused by botulinum toxin getting into people. Usually, it gets in when someone eats food that contains the toxin. Less commonly, the toxin forms inside people. The toxin is produced when Clostridium botulinum bacteria grow and reproduce in food or inside people’s intestines, which occurs with infant botulism or inside deep wounds. The C. botulinum bacterium is everywhere. Or, more correctly, its spores are everywhere (microbiologists call them ‘ubiquitous’). I have fond memories of a laboratory assignment from my second year of university. My lab partner and I were given the task of finding C. botulinum, isolating it and identifying it using traditional micro/chemical tests. We ducked outside the microbiology lab and grabbed a handful of dirt from the garden under the window to culture. We found C. botulinum on our first attempt. (I also remember a class-mate swabbing his crotch to obtain Streptococcus 😊) Botulinum toxin is a covert operator Botulinum toxin is not just super super toxic. It is also colourless and tasteless in food – at least in the concentrations that occur naturally. So you won’t know if it is in the food you are eating until it is much too late. The botulism pathogen is tough The spores of C. botulinum can survive heat, cold and dehydration and remain viable for decades. When they are exposed to the correct conditions they germinate and grow into colonies of live bacteria, producing toxin in the process. To protect food from botulinum toxin contamination, then, we must prevent the bacteria from reproducing in food. Because C. botulinum is ‘ubiquitous’, food safety controls are based on the assumption that all raw food could carry its spores. Only one spore is needed for the pathogen to grow and form toxin. So, to prevent such growth we have two types of ‘weapons’: (1) Treat the food with extreme heat to deactivate C. botulinum spores so they cannot grow and produce toxin. (2) Ensure the food is too acidic or too cold or too dry or too salty or too well-oxygenated to support the growth of the bacterium, even though its spores are present. Fighting the pathogen Commercial food canning processes and the sterilisation of medical equipment work by deactivating C. botulinum spores with heat. The process requires exposure to at least 121 degrees C for more than three minutes. Because most food contains a lot of water and because water cannot reach temperatures greater than 100 degrees at normal air pressure, achieving temperatures of 121 degrees can be a challenge. One way to reach 121 degrees is to use high pressure conditions, by heating the food inside a sealed can, jar, pouch, pressure cooker, autoclave machine or retort. Other food protection methods rely on...