bacteria shapes

Carlos and I spent Valentine’s Day the way we always do. He made me breakfast in bed, brought me fresh flowers, and cultivated a petri dish of bacteria in the shape of a heart. I reminded him that I found his insistence on celebrating this terrifying day of carnage to be disturbing, but as usual he won me over when the bacteria began spelling out cute phrases like “I love you” and “be mine” and “we will destroy humanity”.

Types of Pathogenic Microorganisms

The average human body contains about 10 trillion cells. Imagine how much that is! If our population was 1400 times greater in the entire world, then we still would not be more than the number of cells in the entire body. Amazing isn’t it? 

But what if I tell you the gut alone, contains 100 trillion microorganisms living within it this very minute? And hence the picture above, our world is really a microorganism’s world, we are simply the ones large enough to be seen. 

And thus we see the importance of microbiology, how exactly are these microorganisms affecting our lives? 

Most of these microorganisms are actually beneficial to our body, for example, by aiding in the process of digestion, however, there are microorganisms that are damaging to their host, either by the production of toxic products, or direct infection, and these microorganisms are termed pathogenic. 

To have an idea of this, let us talk about the types of microorganisms, and the pathogenic ones in each type, that is, the one that can give us a disease. 

Microbes that Cause Diseases

Microbes that cause diseases can be divided into 5 groups of organisms:

  1. Bacteria
  2. Fungi
  3. Protozoa
  4. Helminths and Rotifiers
  5. Viruses

There is also a recently discovered type of microbe that can cause a disease, known as a prion. 

Of these microbes, we can classify them in several different ways. 

Classification of Microbes:

Firstly, it is important to consider the status of prions and viruses. Technically, these “microbes” are not living. Prions are simply misfolded proteins, and viruses are only “alive” when they infect an organism. Thus, both prions and viruses have their own classifications. 

As for the other organisms, we can classify them in several ways:

  • Eukaryote vs Prokaryote
    • In this classification scheme, all bacteria are prokaryotes, and fungi, protozoa, helminths and rotifers are eukaryotes. 
      • The prokaryotes are further subdivided into eubacteria and archaebacteria. Eubacteria are the medically important bacteria, while archaebacteria are a group of evolutionarily distinct bacteria. 

Differences between Eukaryotes and Prokaryotes:

  • General Size
    • Eukaryotes are much larger than Prokaryotes, being about 10-100mm in diameter. 
    • Prokaryotes are much smaller, being about only 0.2-2mm in diameter. 
  • Nucleus vs Nucleoid: 
    • Eukaryotic cells contain a true nucleus, with multiple chromosomes, linear DNA, and a nuclear membrane, using mitotic apparatus to ensure chromosomes are equally distributed to the daughter cells. 
    • Prokaryotic cells contain a nucleoid, which is an area of loosely organized, circular supercondensed DNA, lacking nuclear membrane and mitotic apparatus.

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Clostridium botulinum

Clostridium botulinum are rod-shaped bacteria. They are anaerobic, meaning they live and grow in low oxygen conditions. The bacteria form protective spores when conditions for survival are poor. The spore has a hard protective coating that encases the key parts of the bacterium and has layers of protective membranes. Within these membranes and the hard coating, the dormant bacterium is able to survive for years. C. botulinum is responsible for a disease called botulism.

Botulism is a life-threatening disease caused by the ingestion of a potent neurotoxin (called BTX or BoNT) produced during growth of the C. botulinum bacteria. This neurotoxin is among the most toxic substances known; even microscopic amounts can cause illness or death. There are two main commercial types: botulinum toxin type A and botulinum toxin type B.

These toxins are used in medicine for, among others, upper motor neuron syndrome, focal hyperhidrosis, blepharospasm, strabismus, chronic migraine and bruxism. It is also widely used in cosmetic treatments.

The injection of botulinum toxin, commonly known as Botox, has become very popular for reducing wrinkles and rejuvenating the aging face. The effects are only temporary, but the injections can be done quickly, require no recovery time, and are not as complicated as many other cosmetic procedures for the face.

Key characteristics: Gram(+), beta-hemolysis, motility(+), indole(-), catalase(v-), spores(+).


Some pictures taken in micro today. The two slides on the microscope are of Bacillus. The red rod-shaped bacteria are the actual bacilli, and those green dots you see are called endospores.

Endospores are formed when essential nutrients or other environmental standards are not being met. They’re extremely heat and chemical resistant. They are formed within the cell by the bacteria replicating it’s DNA. Those spores you see are very tough protective structures that house that replicated DNA after the mother cell ceases to exist.

Also, I made a chicken out of Serratia.



This is a sad post for me because it involved my own animal. My female G. marginata was dead in her enclosure the other morning. Since getting her from the reptile expo she never did seem right and this should have been a signal to me. She never was a good eater, she would lay out in the open often, and she had a bad shed.

I did a necropsy and she looked very empty. No body fat anywhere, empty stomach, and she had white nodules throughout her liver. The cytology photos are from impressions I made of the liver. You can see scattered RBC’s, hepatocytes, and some rod shaped bacteria. I sent out tissue samples for histopathology so hopefully I will get an answer back soon. The male seems completely fine and has been eating and behaving normally from day 1 but I will be watching him closely.

This just goes to show that even veterinarians make mistakes. The moment I noticed something was amiss I should have acted but I incorrectly assumed she was just very stressed and would eventually settle in.

The microbes living on and in your skin enjoy shelter, moisture and the chemical building blocks they need for growth. Their turf is valuable, and they will fight to defend it.

Like most microbes typically found on skin, these bacteria don’t harm us, and they may protect us from treacherous intruders. Here, rod-shaped bacteria called Bacillus subtilis (purple) are locked in battle with a fungus that causes athlete’s foot (green). Like many kinds of bacteria, Bacillus subtilis cells can collect in orderly chains to form biofilms—cooperative communities that may improve self-defense. These rod-shaped cells have formed a blockade and are spewing toxic chemicals—a bold attack on an advancing colony of fungus.

The bacteria shown in this exhibition model, Bacillus subtilis, produce chemicals that kill other bacteria, as well as fungus. One strain releases an antibacterial blend called bacitracin—an ingredient in many over-the-counter antibiotic ointments. Under the right conditions, the population of Bacillus subtilis cells can double in about two hours!

Learn more amazing tales of your microbiome in the exhibition, The Secret World Inside You, open through August 2016. 

It Only Took Seven Minutes

Ashton Irwin One-Shot

Recent Writing | Masterlist

Requested? Yes
Notes: the request really wasn’t for anything specific so i took my own direction with it. hope you enjoy! 
Word Count: 1,788

Your friends had told you he wouldn’t be at the party and that was the main reason you had decided to go in the first place.

Two weeks.

You and Ashton were only going on two weeks apart, and breaking up in high school was like starting a world war. Friends departed, trenches were dug, and hearts were speared and shot straight through the center. Sometimes people would get pulled by both sides by being caught in the middle, however, in this case, that wasn’t what was happening.

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A behind-the-scenes Microbiome Monday! 

In the Museum’s exhibition studio, the finishing touches are put on a highly magnified model of human skin cells, upon which rod-shaped bacteria called Bacillus subtilis (shown in purple) are locked in battle with a fungus (green filaments) that causes athlete’s foot. Like most microbes typically found on skin, these Bacillus bacteria don’t harm us, and they may protect us from treacherous intruders.

See the finished model in the new exhibition, The Secret World Inside You, now open!