from the world's big
Antibiotic resistance: Researchers have directly proven that bacteria can change shape inside humans to avoid antibiotics
Antibiotic resistance poses one of the biggest threats to global public health.
Widespread antibiotic use is largely to blame for the emergence of antibiotic resistant bacteria, which is currently one of the biggest threats to global health.
Not only does antibiotic resistance already cause an estimated 700,000 deaths a year, it's also made numerous infections, including pneumonia, tuberculosis, and gonorrhoea, harder to treat. Without knowing how to stop bacteria from developing antibiotic resistance, it's predicted that preventable diseases could cause 10m deaths a year by 2050.
Some of the ways that bacteria become resistant to antibiotics is through changes in the bacteria's genome. For example, bacteria can pump the antibiotics out, or they can break the antibiotics down. They can also stop growing and divide, which makes them difficult to spot for the immune system.
However, our research has focused on another little known method that bacteria use to become antibiotic resistant. We have directly shown that bacteria can “change shape" in the human body to avoid being targeted by antibiotics – a process that requires no genetic changes for the bacteria to continue growing.
Virtually all bacteria are surrounded by a structure called the cell wall. The wall is like a thick jacket which protects against environmental stresses and prevents the cell from bursting. It gives bacteria a regular shape (for example, a rod or a sphere), and helps them divide efficiently.
Human cells don't possess a cell wall (or “jacket"). Because of this, it's easy for the human immune system to recognise bacteria as an enemy because its cell wall is noticeably different. And, because the cell wall exists in bacteria but not in humans, it's an excellent target for some of our best and most commonly used antibiotics, such as penicillin. In other words, antibiotics targeting the wall can kill bacteria without harming us.
However, bacteria can occasionally survive without their cell wall. If the surrounding conditions are able to protect the bacteria from bursting, they can turn into so-called “L-forms", which are bacteria that don't have a cell wall. These bacteria were discovered in 1935 by Emmy Klieneberger-Nobel, who named them after the Lister Institute where she was working at the time.
In a lab, we often use sugar to create a suitably protective environment. In the human body, this change in form is typically triggered by antibiotics that target the bacteria's cell wall, or certain immune molecules – such as lysozyme, a molecule that's present in our tears which helps protect us from bacterial infections.
Bacteria without a cell wall often become fragile and lose their regular shape. However, they also become partially invisible to our immune system, and completely resistant to all types of antibiotics that specifically target the cell wall.
Scientists long suspected that L-form switching might contribute to recurrent infections by helping bacteria hide from the immune system and resist the antibiotics. However, it was difficult to find evidence for this theory due to the elusive nature of L-forms and lack of appropriate methods to detect them.
Watching bacteria change shape
Our study, published in Nature Communications, looked specifically at bacterial species associated with recurrent urinary tracts infections (UTIs). It found that many different bacterial species – including E. coli and Enterococcus – can indeed survive as L-forms in the human body. This is something that has never been directly proven before. We were able to detect these sneaky bacteria using fluorescent probes that recognise bacterial DNA.
We tested urine samples from elderly patients with recurrent UTIs by growing them in a petri dish high in sugars. Not only did this environment help protect bacteria from bursting, it also isolated the L-form bacteria that were present in these samples. In a separate experiment, we were able to see the whole process take place in living zebrafish embryos in the presence of antibiotics.
After the antibiotic was removed, the bacteria transformed back from L-forms to their regular form with cell walls. (Credit to Newcastle University, UK)
Importantly, our study shows that antibiotics need to be tested in conditions more reflective of the human body. The ones that are currently used in the medical laboratory don't provide enough protection for delicate L-forms to survive.
Before we can fully understand how important L-form switching is compared to other forms of antibiotic resistance, further research using more patients will be needed. It will also be important to investigate what role L-forms may play in other recurrent infections, such as sepsis or pulmonary infections.
Until now, research into L-forms has been a controversial field, but our hope is that these findings will motivate more research into L-forms in disease situations. Our hope is that these findings will help find a way to clear these sneaky bacteria from our body. Combining cell wall active antibiotics with ones that would kill L-forms might be one solution of fighting antibiotic resistant infections.
Our battle with bacteria is ongoing. As we come up with new strategies to fight them, they come up with ways to fight back. Our study highlights yet another way that bacteria adapt that we'll need to take into account in our continuing battle with infectious disease.
- Antibiotic Resistance. Be Afraid. REALLY! Be VERY Afraid! - Big Think ›
- Antibiotic Resistance is a Growing Problem. Have We Just Figured ... ›
Andy Samberg and Cristin Milioti get stuck in an infinite wedding time loop.
- Two wedding guests discover they're trapped in an infinite time loop, waking up in Palm Springs over and over and over.
- As the reality of their situation sets in, Nyles and Sarah decide to enjoy the repetitive awakenings.
- The film is perfectly timed for a world sheltering at home during a pandemic.
In more than a dozen countries as far apart as Portugal and Russia, 'Smith' is the most popular occupational surname
- 'Smith' is not just the most common surname in many English-speaking countries
- In local translations, it's also the most common occupational surname in a large part of Europe
- Ironically, Smiths are so ubiquitous today because smiths were so special a few centuries ago
Meet the Smiths, Millers, Priests and Imams - the most popular occupational surnames across Europe.
Image: Marcin Ciura<p>Although very few people are smiths by profession these days, there are millions of Smiths by surname the world over. It's the most popular surname in Britain, Australia, New Zealand and the United States, as well as the second most popular surname in Canada and the fifth most popular one in Ireland. And they're a thriving bunch, at least in the U.S.: the 2010 Census (1) counted 2,442,977 Americans called Smith, 2.8% more than in 2000.</p><p>Curiously, 'Smith' also is one of the most popular surnames across most of Europe –translated in the various local vernaculars, of course. This map shows the most common occupational surnames in each country. By colour-coding the professions, this map shows a remarkable pro-smith consistency across Europe – as well as some curious regional exceptions.</p>
‘Smith’ popular throughout Europe<p>'Smith', in all its variations, is the most popular occupational surname throughout Europe. Not just in the UK, but also in:</p> <ul><li>Belgium (<em>Desmet</em>) and Luxembourg, (<em>Schmitt</em>);</li> <li>France (<em>Lefebvre</em>), Italy (<em>Ferrari</em>) and Portugal (<em>Ferreira</em>);</li> <li>Slovenia (<em>Kovačič</em>), Croatia (<em>Kovačevič</em>), Hungary (<em>Kovács</em>), Slovakia (<em>Kováč</em>), Poland (<em>Kowalski</em>), Lithuania (<em>Kavaliauskas</em>), Latvia (<em>Kalējs</em>) and Belarus (<em>Kavalyov</em>);</li> <li>Estonia (<em>Sepp</em>); and</li> <li>Russia (<em>Kuznetsov</em>).</li></ul>
‘Miller’ on top in many Germanic-language countries<p>'Miller' is the most popular occupational surname in many Germanic-language countries, but also in Spain and Ukraine (perhaps because the grain in both countries is mainly in the plain):</p> <ul><li>There's <em>Müller</em> (in Germany and Switzerland), <em>M</em><em>ø</em><em>ller</em> (in Denmark and Norway) and <em>Möller</em> (Sweden);</li> <li><em>Molina</em> (in Spain – the map also shows the most popular surname in Catalonia/Catalan: <em>Ferrer</em>, i.e. 'Smith'); and</li> <li><em>Melnik</em> (in Ukraine).</li></ul>
Clergy surnames rule in the Balkans<p>Catholic clergy must remain celibate, so 'Priest' as a surname is rare to non-existent throughout Europe. Except in the Balkans, where Catholicism is largely absent. Here, the Orthodox and Islamic clergies have passed on the title from father to son, eventually as a surname, to popular effect. Orthodox clergy are addressed as <em>papa</em> or <em>pope</em> (which means 'father' – so the surname rather redundantly translates to 'father's son'). Islamic teachers or imams are known by the Turkish/Persian term <em>hodzha</em>. An overview:</p> <ul><li><em>Popov</em> (in Bulgaria), <em>Popovic</em> (in both Serbia and Montenegro), <em>Popovski</em> (in Macedonia);</li> <li><em>Popa</em> (in Romania); </li> <li><em>Papadopoulos</em> (in Greece); and</li> <li><em>Hodžić</em> (in Bosnia-Herzegovina), <em>Hoxha</em> (in both Kosovo and Albania).</li></ul>
Landowners and other professions<p>Austria and the Czech Republic have different national languages but are neighbours and share a lot of history. Could that explain why they have a similar most popular occupational surname, for 'landowner'?</p> <ul><li><em>Huber</em> (in Austria) and</li> <li><em>Dvořák</em> (in the Czech Republic).</li></ul> <p>Just four professions, that wraps up all but five countries on this map. Those five each have their very own most popular occupational surname:</p> <ul><li><em>Bakker</em> (in the Netherlands): 'Baker'</li> <li><em>Kinnunen</em> (in Finland): 'Skinner'</li> <li><em>Ceban</em> (in Moldova): 'Shepherd'</li> <li><em>Avci</em> (in Turkey): 'Hunter'</li> <li><em>Murphy</em> (in Ireland): 'Sea Warrior' </li></ul>
Even more Smiths<p>Judging from the popularity of these surnames, your generic European village of a few centuries ago really couldn't do without a smithy. It was a much more essential craft even than that of the miller (or the baker, who put the miller's flour to good use) – except in the Balkans, where spiritual sustenance apparently sated a greater need. On the outskirts of <em>Anytown, Europe</em> live the shepherd and the hunter, the skinner and the pirate.<br></p><p>A bit too simplistic? Perhaps not simplistic enough. This map could have been dominated by even more Smiths. As the original poster explains, he always picked the most frequent version of an occupational surname, even if multiple variants point to a more popular alternative. </p><p>In the Netherlands, for instance, people with the surnames <em>Smit, Smits, Smid, de Smit, Smet </em>and <em>Smith</em> collectively outnumber those with the surnames <em>Bakker, Bekker, de Bakker</em> and <em>Backer</em>. So, the Netherlands could be considered another win for 'Smith' – except that the variant <em>Bakker</em> is more frequent than any other single variant.</p><p>Same story in Germany: added up, there are more people named <em>Schmidt, Schmitt, Schmitz </em>and <em>Schmid</em> than <em>Müller</em>. Ditto for Spain: <em>Herrero, Herrera </em>and <em>Ferrer</em> together outnumber <em>Molina</em>. Also in Finland, where <em>Seppä</em>, <em>Seppälä</em> and <em>Seppänen</em> together have a higher count than <em>Kinnunen</em>. </p>
Smiths in other cultures<p>'Smith' was a crucial occupation in other cultures too, judging from the familiar ring it has in these languages:<br></p><ul><li><em></em><em>Demirci</em> (Turkish)</li><li><em>Hadad</em> (Syriac, Aramaic, Arabic)</li><li><em>Nalbani</em> (Albanian)</li><li><em>McGowan</em> (Gaelic)</li><li><em>Faber</em> (Latin)<span></span></li></ul>
Other most popular surnames<p>Take note, though: 'Smith' may be the most popular surname in in the Anglosphere, this map does not mean to show that its variants in French, Russian and other languages also are the most popular surnames in the countries marked grey. They are merely the most popular <em>occupational</em> surnames.<br></p><p>As this sample of most common ones for each country shows, surnames can refer to a host of other things. Personal qualities or physical attributes, for example:</p> <ul><li>Russia: <em>Smirnov</em> ('the quiet one')</li> <li>Turkey: <em>Yilmaz</em> ('unflinching')</li> <li>Hungary: <em>Nagy</em> ('big')</li> <li>Italy: <em>Rossi/Russo</em> ('red', in northern and southern Italy, respectively)</li></ul> <p>Another option: the origin of the name-bearer (be it a place or a person):</p> <ul><li>Sweden: <em>Andersson</em> ('son of Anders')</li> <li>Slovakia: <em>Horvath</em> ('Croat')</li> <li>Kosovo: <em>Krasniqi</em> (refers to the Krasniq tribe and their mountainous home region)</li> <li>Portugal: <em>Silva</em> ('woodland')</li> <li>Latvia: <em>Bērziņš</em> ('little birch tree')</li> <li>Estonia: <em>Tamm</em> ('oak')</li></ul> <p>But sometimes, even for the most popular ones, the exact origin of the surname is lost in time:</p> <ul><li>Spain: <em>Garcia</em> (originally Basque, possibly meaning 'young', 'bear' or 'young bear')</li> <li>Finland: <em>Korhonen</em> ('hard of hearing' or 'dim-witted'; 'village elder'; 'proud'; 'upright'). </li></ul>
Smith popularity theory<p>So why exactly is Smith – and not Miller, for example – the most popular surname in many English-speaking countries? The theory propounded by historian C.M. Matthews in <em>History Today</em> (July 1967) probably also holds for the other-language variants so popular throughout Europe:<br></p><blockquote>"The reason for (the) multiplicity (of the surname 'Smith') is not so much that metal-workers were numerous as that they were important and widespread. On the skill of the smith, both rich and poor depended for the most essential things of life, the tools of husbandry and the weapons of hunting and war. Every community in the land must have one, every castle, every manor; and so distinctive was his trade that he would seldom need another name".<em></em></blockquote><p>That does not mean all people with the surname have a forefather who forged iron into weapons and farm tools. Especially in North America, 'Smith' was adopted by many people precisely because it was already common – as a secret identity or to blend in, for example by natives, slaves and immigrants.</p>
A recent analysis of a 76-million-year-old Centrosaurus apertus fibula confirmed that dinosaurs suffered from cancer, too.
- The fibula was originally discovered in 1989, though at the time scientists believed the damaged bone had been fractured.
- After reanalyzing the bone, and comparing it with fibulas from a human and another dinosaur, a team of scientists confirmed that the dinosaur suffered from the bone cancer osteosarcoma.
- The study shows how modern techniques can help scientists learn about the ancient origins of diseases.
Centrosaurus apertus fibula
Royal Ontario Museum<p>In the recent study, the team used a combination of techniques to analyze the fibula, including taking CT scans, casting the bone and studying thin slices of it under a microscope. The analysis suggested that the dinosaur likely suffered from osteosarcoma, a type of bone cancer that affects modern humans, typically young adults.</p><p>For further evidence, the team compared the damaged fibula to a healthy fibula from a dinosaur of the same species, and also to a fibula that belonged to a 19-year-old human who suffered from osteosarcoma. Both comparisons supported the osteosarcoma diagnosis.</p>
Evans et al.<p style="margin-left: 20px;">"The shin bone shows aggressive cancer at an advanced stage," Evans said in a <a href="https://www.rom.on.ca/en/about-us/newsroom/press-releases/rare-malignant-cancer-diagnosed-in-a-dinosaur" target="_blank">press release</a>. "The cancer would have had crippling effects on the individual and made it very vulnerable to the formidable tyrannosaur predators of the time."</p><p style="margin-left: 20px;">"The fact that this plant-eating dinosaur lived in a large, protective herd may have allowed it to survive longer than it normally would have with such a devastating disease."</p><p>The fossilized fibula was originally unearthed in a bonebed alongside the remains of dozens of other <em>Centrosaurus </em><em>apertus</em>, suggesting the dinosaur didn't die from cancer, but from a flood that swept it away with its herd.</p>
Dinosaur fibula; the tumor mass is depicted in yellow.
Royal Ontario Museum/McMaster University<p>The new study highlights how modern techniques can help scientists learn more about the evolutionary origins of modern diseases, like cancer. It also shows that dinosaurs suffered through some of the same terrestrial afflictions humans face today.</p><p style="margin-left: 20px;">"Dinosaurs can seem like mythical creatures, but they were living, breathing animals that suffered through horrible injuries and diseases," Evans said, "and this discovery certainly makes them more real and helps bring them to life in that respect."</p>
Join the lauded author of Range in conversation with best-selling author and poker pro Maria Konnikova!
UPDATE: Unfortunately, Malcolm Gladwell was not able to make the live stream due to scheduling issues. Fortunately, David Epstein was able to jump in at a moment's notice. We hope you enjoy this great yet unexpected episode of Big Think Live. Our thanks to David and Maria for helping us deliver a show, it is much appreciated.