Microbes From Smallest to Largest

Hey there! Your body consists of innumerable cells, but not all of them are you, exactly. In fact, more than half of what is you are microorganisms that hitch a ride on and inside your body. The average human is home to about 40 trillion microbes, against 30 trillion of their own cells. And outside of your body, there are trillions of times more. Feels pretty crowded now, huh? Let's take a look at what they are, starting from the smallest. The tiniest single-cell organism doesn't even have a name yet. It's 9 nanometers long. 150,000 of these critters fit on the tip of a hair. Viruses are the smallest creatures ever, and PCV is the smallest among them at 17 nanometers. And only pigs should be afraid of this one. Despite being just 20 nanometers long, Parvovirus is no laughing matter. If you have a pooch, better protect it from this one. Bromovirus, 26 nanometers, is carried naturally by bugs, and plants have to suffer the consequences. Oh dear… CPMV, 28 nanometers, only affects cowpea plants and causes their leaves to look like a mosaic. HAV is 30 nanometers long and is the smallest of the hepatitis viruses that affect humans, which doesn't make it less nasty. HBV, 42 nanometers, seems to be one of the most ancient human viruses, found in our distant ancestors. Hepatitis C, 50 nanometers, is more diverse, and can be found not only in humans, but in horses and dogs too. Zika virus, 55 nanometers, is why you should avoid mosquitoes if you travel across Africa. Just trust me. Lambda phage, 58 nanometers, is actually the first virus on this list that's good for you. It feeds on harmful bacteria. HPV, 60 nanometers, is kinda harmful, but in most cases, it goes away without causing discomfort and never comes back. Adenovirus, 65 nanometers, is one of the culprits you should blame when you get a runny nose and coughs. Now you know. Just 5 nanometers bigger, alpha virus is much more dangerous. Carried by ticks, it causes encephalitis. Orthobornavirus, 75 nanometers, is usually to be blamed if not you, but your cow gets a runny nose and coughs. Rotavirus, 80 nanometers, might be the reason why my little nephew occupied the bathroom for so long the other day. Yeah, I know adenovirus has already been mentioned, but these ones are larger at 90 nanometers and can affect most animals, including humans. Influenza is 100 nanometers long and causes the disease we all know as flu. It's tougher and more dangerous than a common cold. If ricksetia virus is round-shaped, then it's 100 nanometers in diameter and causes the spotted fever in animals. SARS virus, 120 nanometers, hits probably the hardest of all viruses, causing troubles with the respiratory tract and lungs. Measles, 150 nanometers, is something you'll forget about if you just use a vaccine against it. Simple as that. Chlorobium, 170 nanometers, is the second bacterium on this list. It lives in hot springs and just loves sulfur. Rabies, 180 nanometers, is a virus that doesn't like fooling around. It causes inflammation of the brain, and medical help is necessary. Herpes virus, 200 nanometers, has lots of types, but only 9 of them are hazardous for humans and common among them too. Thermoplasma, 250 nanometers, are bacteria that also adore high temperatures. They can be found in hot springs too. Chlamydia, 300 nanometers, are the first bacteria on our list that can be pretty nasty if they get inside your body. Variola, 360 nanometers, is a virus that is all but extinct in humans thanks to vaccines. It's also known as smallpox. Ferroplasma, 400 nanometers, feed on sulfide minerals. That is, they eat sulfur. Wow. At 500 nanometers, Mimivirus was thought to be the largest virus until a few other types were found just several years ago. Neisseria, 600 nanometers, has 11 species, 9 of which are completely harmless for humans. The other two, though, can be quite annoying. Apicomplex, 650 nanometers, is a microbe family that's almost completely made up of parasites. They can be rather nasty too. Megavirus, 700 nanometers, is the first giant virus discovered after the Mimivirus. Yet it's still not the largest. Badnavirus, 750 nanometers, is a giant peculiar for its name. It's an abbreviation of Bacilliform DNA virus. And yes, it's bad for you. Aeroprium, 800 nanometers, is yet another bacteria type that likes it hot. You can often find it chilling with other heat-loving microbes. Such as Halicoccus, 850 nanometers long. These guys form huge sheets in water body sediments, painting them in bright colors. Cephalobus, 900 nanometers, is a bacterium that not only loves heat but also feeds on sulfur just like the guys I mentioned earlier. Ebola virus, 950 nanometers, is a thin but very long virus native to Africa. You've probably heard about it too. Pandoravirus, 1 micrometer, is the second largest virus in the world. Luckily, it only affects amoeba. Morazella, 1 micrometer, is as common a bacterium as it gets. It's of normal size and shape. It's normally present in humans. Quite boring if you ask me. B. saphensis, 1.2 micrometers, was first found on a spacecraft returning from Mars. It might just stay alive on the Red Planet too. Pneumococcus, 1.3 micrometers, is a pathogen that often creates serious problems with lungs. So beware. Brucella, 1.4 micrometers, is a type of bacteria that affects mostly humans and their dog friends. If you get ill, you get ill together. Pithovirus is the largest virus ever found at 1.5 micrometers. No, it has nothing to do with pizza, unfortunately. Acidilibus, 1.7 micrometers, feels pretty comfy when the temperature of water it sits in is about 185 degrees Fahrenheit. Enterococcus, 2 micrometers, can be found almost anywhere in the world, including your stomach. Say hi! Helophorax, 2.3 micrometers, is another type of bacteria that can potentially survive Martian conditions. If there's gonna be life on Mars, it's gotta be them. P. larvae, 2.5 micrometers, is a nasty bug that's known all too well to beekeepers. It infects bees, making them sick. Azotobacter, 3 micrometers, is a useful type of bacteria that we use in the production of both fertilizers and food additives. Burkholderia, 3.2 micrometers, is very good for the environment, but at the same time very bad for humans. Go figure. Aloquandra, 3.5 micrometers, is the only microorganism that is perfectly square in shape. Others are either round or elongated. B. subtilis, 4 micrometers, is something you'll find in 100% of cases if you just dig up a soil in your backyard. Very common. Penicillium, 4.5 micrometers, is most famous for helping to discover what? Yes, penicillin in the 20th century. A powerful antibacterial medicine. Babesia, 5 micrometers, is another bug carried in the saliva of ticks. It mostly affects dogs and cattle, as well as horses. Malassezia, 5.5 micrometers, is the only fungus you'll find thriving right on top of your skin. Yes, it's there this very second. Aquafax, 6 micrometers, is a bacterium that can easily survive boiling water. It's just a bit too hot for them, though. Bifidobacterium, 7 micrometers, is good for you. Trillions of it can be found in fermented milk products, such as yogurt or cottage cheese. Rhodotorula, 7.5 micrometers, is another fungus that lives inside you. Not on your skin, though, thankfully. I won't tell you where, you can find it yourself. Labyrinthula, 8 micrometers, is a weird thing that includes parasitic species as well as symbiotic ones. Can't tell you which is which, though, sorry. Lactobacillus, 9 micrometers, is another good stuff found in fermented milk. It makes your insides go all cozy and content. Plasmosium, 10 micrometers, is a parasite that lives in mosquito saliva. Thankfully, it's quite rare to get this bug. Cladosporium, 11 micrometers, is what you see when your cheese or bread goes bad. And the same thing lives inside your mouth. Candida. No, not Canada the country, Candida the bug, at 12 micrometers, is a yeast that sleeps quietly in your body, but if something's wrong, it awakens and goes all nasty. Giardia, 14 micrometers, was thought to be different for every new animal it was found in, and so was given a new name each time until they found it was the same thing. Sartoria, 15 micrometers, is a bug that commonly lives in water, but sometimes decides to chill on the skin of aquatic animals, such as seals. Treponema, 17 micrometers, is just like Candida, goes about its business in your mouth without doing harm, but isn't to be messed around with. Clostridium, 18 micrometers, is one of the nastiest bacteria. It causes severe health issues, and worst of all, it's most abundant in hospitals. Borrelia, 20 micrometers, is not easy to get, but if you do, run to the doctor. It's one of the causes of highly dangerous Lyme disease. Alexandrium, 25 micrometers, is one unfriendly bug. Most of its representatives are toxic, but even those that aren't can be harmful. Cyanobacteria, 30 micrometers, is also known as blue-green algae, lives in ponds and other still water, as well as inside your stomach. Ah well… Didinium, 50 micrometers, is among the most amiable microbes out there, at least for humans, because they only feed on a specific type of bacteria. Alternaria, 60 micrometers, is bad for plants and humans alike, causing asthma and other respiratory issues. Euglyphidid, 75 micrometers, is an amoeba that is really important for the environment. It takes part in the decomposition process, kinda like what Mozart is doing now. You know, decomposing? Yes, it's an old joke. Flexobacter, 100 micrometers, only affects fish, causing various health issues in them. Vorticella, 150 micrometers, is a bacterium that's really picky when it comes to living conditions. If they don't like their current place, they change it. Ceratium, 190 micrometers, is covered in a sort of armor and has two long and peculiar arms, otherwise called horns. Foraminifera, 200 micrometers, is the largest group of microbes that have cell wall shells. These shells are called tests, by the way. Spirochaeta, 250 micrometers, is a big peaceful bug that lives in water, both fresh and saltwater. Paramecium, 300 micrometers, is quite huge for a bacterium and is often used in studies and to show to microbiology students. If you add two of them, then you'd have a pair of paramecium. Boy, I'm starting to get punchy here. Gallionella, 400 micrometers, has been known for a century and a half. It oxidizes iron. In other words, it makes it rust. Amoeboproteus, 0.5 millimeters, is one of the largest microbes. It's so big, it can be seen without a microscope. Theomargarita is not an adult beverage for Cinco de Mayo. At 0.75 millimeters, it's an even bigger bug. Put it next to a fruit fly, and you'll see it's half the insect's size. Stentor, 2 millimeters, is probably the largest microbe that is not micro any longer. A tenth of an inch in size is no joke. Gromiosphaerica, 1.7 inches in diameter, is also an amoeba, and you can clearly see it on the bottom of the ocean. Yep, it's a single cell still. Bubble algae, 1.9 inches in size, are single-celled water plants that often infest fish tanks. They look like small green bubbles. And finally, Caulerpa, the largest single-cell organism in the world. It's also a seaweed, and it can reach almost 10 feet in length. So, there you have it, a whole bunch of bugs. Boy, do I feel like I need a shower now.