From the moment we wake up, we are surrounded by them—microscopic organisms that are a fundamental part of our world. We often associate germs with sickness, but what are they really? These tiny entities, also known as pathogens, are not all bad, but the ones that can cause harm are truly fascinating. Prepare to be amazed by a world you can’t see, a world of incredible survival, astonishing reproduction, and surprising homes. Dive in to discover some of the most intriguing facts about germs you never knew.
Four Types of Germs
Germs, also known as pathogens, are categorized into four primary types: bacteria, protozoa, viruses, and fungi. Each of these groups has distinct characteristics and ways they can cause disease. Bacteria are single-celled organisms that can reproduce quickly and are responsible for infections like strep throat and food poisoning. Viruses are even smaller than bacteria and require a host cell to reproduce, leading to illnesses like the common cold, flu, and COVID-19. Protozoa are single-celled organisms that are larger and more complex than bacteria, often causing infections like giardiasis. Lastly, fungi are multi-celled organisms that can cause a variety of skin infections, such as athlete’s foot, and other more serious systemic illnesses.
E. coli and the Period
The bacterium E. coli, a common inhabitant of the intestines, is remarkably small. To put its size into perspective, an estimated 31,800 E. coli could fit on the surface of the period at the end of a sentence. This fact highlights the microscopic scale at which many germs exist, making them invisible to the naked eye and easily spread from person to person or surface to surface.
Pathogen’s Greek Origin
The word “pathogen,” another term for germ, has a meaningful origin rooted in the Greek language. It is derived from the Greek word “pathos,” which translates to “suffering” or “passion.” This etymology directly reflects the nature of pathogens, as they are agents that cause suffering or disease in a host. The term accurately describes the function of these microbes in relation to living organisms.
The World’s Largest Bacterium
Contrary to the general perception of bacteria as being microscopic, the largest known bacterium, Thiomargarita magnifica, shatters this notion. It is about the size of an eyelash and can be picked up with tweezers, making it visible without a microscope. This bacterium is over 5,000 times bigger than the average microbe, demonstrating the vast size diversity within the microbial world.
The Germiest Item in a House
The kitchen sponge is, surprisingly, the germiest item in most people’s homes. It provides a warm, moist, and food-rich environment, making it an ideal breeding ground for bacteria. These sponges can harbor hundreds of millions of bacteria, and over 75% of home dish sponges and rags are contaminated with coliform bacteria, a group that includes E. coli, which indicates fecal contamination.
Belly Button Bacteria
The average human belly button is a thriving ecosystem for microbes, hosting over 300 different types of bacteria. These bacteria can cause various health issues, including infections, rashes, and even belly button discharge. This fact underscores how even seemingly clean parts of our bodies are home to a diverse and large microbial community.
Coronavirus’s Lifespan on Surfaces
The coronavirus can survive on various surfaces for different durations, which is a key factor in its transmission. It can remain viable on plastic and stainless steel for up to 72 hours, on cardboard for up to 24 hours, and on copper for up to 4 hours. These timeframes emphasize the importance of regular cleaning and sanitizing of high-touch surfaces to prevent the spread of the virus.
The Germy Phone
A person’s phone is a breeding ground for bacteria, largely because it is a constantly handled item that is often brought into the bathroom. Three out of four people admit to taking their phones into the bathroom, which exposes the device to a multitude of germs. As a result, phones can carry over 10 times more bacteria than a toilet seat, making them a significant vector for germ transmission.
Salmonella and E. coli’s Longevity
Bacteria like salmonella and E. coli can survive on hard, non-porous surfaces for extended periods, facilitating their spread. They can live for up to 4 hours on these surfaces. This longevity means that if someone with contaminated hands touches a doorknob, countertop, or other hard surface, the bacteria can persist long enough to be transferred to another person who later touches the same surface.
Antonie van Leeuwenhoek’s Discovery
In 1676, the Dutch scientist Antonie van Leeuwenhoek became the first person to discover germs (bacteria) with his powerful microscope. He was astounded by the tiny, moving organisms he observed in water and other samples, and he referred to them as “animalcules,” or “little animals.” His discovery was a foundational moment in microbiology, revealing an entire world of life previously unknown to science.
Germ Morphology
Most germs, specifically bacteria, have one of three primary shapes. They can be spherical, resembling tiny balls; rod-shaped, which are like tiny rods; or spiral-shaped, which look like miniature spirals. This limited range of shapes makes it easier for scientists to classify and identify different types of bacteria.
Hand Sanitizer’s Effectiveness
Hand sanitizer can be a highly effective tool for killing germs, but its efficacy depends on specific criteria. The sanitizer must contain at least 70% isopropyl alcohol to be strong enough to destroy the microbes. Furthermore, to be most effective, it must be allowed to stand on the hands for at least 30 seconds before being wiped off or dried, which allows the alcohol sufficient time to penetrate and kill the germs.
Paper Towels vs. Hand Dryers
When it comes to drying hands, a simple paper towel is significantly more effective at removing bacteria than a hand dryer. A study found that using a hand dryer can actually increase the number of germs on hands by up to 225% because the warm, moist environment within the dryer is a perfect breeding ground for bacteria, which are then blown onto the hands. This makes hand dryers a potential vector for spreading rather than reducing germs.
“Conan the Bacterium”
Deinococcus radiodurans, nicknamed “Conan the Bacterium,” is an extraordinary microbe known as an extremophile. It has a remarkable ability to survive in extreme conditions that would be lethal to most other life forms, including high levels of radiation, acid, and extreme cold. Its resilience has earned it the moniker “Conan,” a nod to its incredible toughness.
The Sneeze’s Path
A sneeze is a powerful biological event that can project germs over a large area. Germs from a single sneeze can travel at speeds of up to 100 mph and reach distances of up to 26 feet. Furthermore, the aerosolized droplets containing these germs can remain suspended in the air for up to 10 minutes, making a sneeze a potent “biological germ explosion” that can easily spread illness.
The Germiest Bathroom Item
The toothbrush holder is the germiest item in most bathrooms. This is due to a combination of factors, including its location near the toilet and the constant moisture from toothbrushes and the surrounding environment. This combination of moisture and proximity to the toilet’s “plume” creates a perfect environment for bacterial growth.
Public Restroom Hand Dryers
High-speed jet air dryers in public restrooms are a double-edged sword when it comes to hygiene. While they dry hands quickly, they can also blow fecal material from the toilet plume back onto the hands and throughout the air. This makes paper towels a safer and often faster alternative for drying hands and reducing the spread of germs.
Foodborne Illnesses
Foodborne illnesses are a significant global health issue, affecting over 600 million people worldwide each year, including 48 million Americans. These illnesses are caused by consuming food contaminated with bacteria, viruses, parasites, or toxins. The staggering number of cases underscores the importance of food safety practices to prevent widespread disease.
Bacterial Reproduction
A single bacterium has an incredible ability to reproduce at an exponential rate. In a mere 24 hours, a single bacterium can multiply and produce over 8 million offspring. This rapid reproduction rate is a key reason why bacterial infections can spread so quickly and overwhelm the body’s defenses.
The Food “Danger Zone”
Food is most susceptible to bacterial growth when it is left in the “danger zone” of temperatures, which is between 40°F and 140°F (4°C and 60°C). In this temperature range, bacteria can double their population in as little as 20 minutes and continue to grow exponentially. This is why it is crucial to refrigerate food promptly to prevent the proliferation of harmful bacteria.
The Human Gut Microbiome
A single gram of human feces contains an astounding number of microbes—approximately 1 trillion. This fact highlights the vast and complex microbial ecosystem that resides within the human gut. While many of these microbes are harmless or even beneficial, a large concentration of pathogens can be a sign of illness.
The Toilet Plume
When a toilet is flushed, it releases a cloud of aerosolized pathogens into the air, a phenomenon known as a “toilet plume.” This spray can linger in the air for hours, contaminating nearby surfaces like sinks, countertops, and even toothbrushes. This is why it’s recommended to close the toilet lid before flushing to contain the germs.
Frequently Asked Questions About Germs
What is a germ?
A germ is a tiny microorganism that can cause disease. The term is not a scientific classification but is a common name for any disease-causing microorganism. These microorganisms, also known as pathogens, are broadly classified into four main types: bacteria, viruses, fungi, and protozoa. Each type of germ is distinct in its structure, method of reproduction, and how it causes illness.
How do germs spread?
Germs spread in several ways. One of the most common is through direct contact, such as shaking hands with an infected person. They can also spread via indirect contact by touching a contaminated surface (like a doorknob or phone) and then touching your face. Airborne transmission occurs when germs are released into the air through sneezes or coughs and are then inhaled by others. Food and water contamination is another significant route, as germs can proliferate in improperly handled food or unclean water. Finally, germs can be transmitted through animal or insect bites, as is the case with illnesses like malaria (from mosquitos) or Lyme disease (from ticks).
What are the four main types of germs?
The four main types of germs are:
- Bacteria: These are single-celled organisms that can live in almost any environment. While many are harmless and even beneficial, some cause diseases like strep throat, tuberculosis, and food poisoning.
- Viruses: Much smaller than bacteria, viruses are not considered living organisms because they cannot reproduce on their own. Instead, they invade a host cell and use its machinery to create copies of themselves. Viruses cause a wide range of diseases, including the flu, chickenpox, and HIV.
- Fungi: This group includes yeasts, molds, and mushrooms. Fungi can be both single-celled and multi-celled. They cause conditions like athlete’s foot, ringworm, and some types of pneumonia.
- Protozoa: These are single-celled organisms that often thrive in moist environments. They can be transmitted through contaminated water or food and are responsible for illnesses such as giardiasis and malaria.
Where are germs most commonly found?
Germs are found everywhere—in the air, water, on surfaces, and inside our bodies. However, some places are more hospitable to their growth than others. The kitchen sponge is a prime example, as it provides a warm, moist, and food-rich environment. Other common germ hotspots include:
- Public places: Doorknobs, elevator buttons, ATMs, and public restroom surfaces.
- Personal items: Mobile phones, which can carry over 10 times more bacteria than a toilet seat, and remote controls.
- Bathrooms: The toothbrush holder, due to its proximity to the toilet and moisture, is often the germiest item in the bathroom. The toilet plume can contaminate surfaces up to 26 feet away.
What’s the difference between a germ and a microbe?
The terms “germ” and “microbe” are often used interchangeably, but there’s a key distinction. A microbe (short for microorganism) is a broad scientific term for any living organism too small to be seen with the naked eye. This includes bacteria, viruses, fungi, and protozoa, but also other microscopic organisms like algae. A germ, on the other hand, is a more colloquial term specifically for a microbe that causes disease. Therefore, all germs are microbes, but not all microbes are germs. For example, the beneficial bacteria in your gut are microbes, but they are not considered germs.
Does hand sanitizer really work?
Yes, hand sanitizer can be highly effective, but it has to meet certain criteria. To be effective, the sanitizer must contain at least 70% isopropyl alcohol. This high concentration is necessary to break down the outer membrane of many germs, killing them. Hand sanitizers are most effective against bacteria and some viruses but may not work well against certain germs like norovirus or C. diff. For best results, it’s recommended to rub the sanitizer on your hands for at least 30 seconds.
How long can germs survive on surfaces?
The survival time of germs on surfaces varies widely depending on the type of germ and the surface material. For example, bacteria like E. coli can survive on hard, non-porous surfaces for up to 4 hours. The coronavirus has been shown to live on plastic and stainless steel for up to 72 hours, on cardboard for up to 24 hours, and on copper for up to 4 hours.
Why is it better to dry hands with a paper towel than a hand dryer?
Drying hands with a paper towel is more effective at removing germs than using a hand dryer. High-speed air dryers can actually increase the number of germs on hands by up to 225% because they can aerosolize and blow out bacteria living inside the machine. Additionally, these jet dryers can blow microscopic fecal material from the “toilet plume” back onto your hands. Paper towels physically rub away germs and provide a cleaner, more hygienic way to dry your hands.
