Difference Between Germs and Bacteria

The main difference between germs and bacteria is that the germs can be any microscopic particle that can cause illness in another living organism whereas the bacteria are unicellular prokaryotes that can be either beneficial or harmful. Furthermore, germs can be a worm, protist, fungus, bacterium or a virus

Germs and bacteria are two types of microorganisms. Both can cause diseases in other living organisms.  

Key Areas Covered 

1. What are Germs
     – Definition, Types, Diseases
2. What are Bacteria
     – Definition, Facts, Importance
3. What are the Similarities Between Germs and Bacteria
     – Outline of Common Features
4. What is the Difference Between Germs and Bacteria
     – Comparison of Key Differences

Key Terms 

Bacteria, Beneficial, Germs, Harmful, Microorganisms 

Difference Between Germs and Bacteria - Comparison Summary

What are Germs 

Germs are microscopic organisms that can cause diseases in living organisms such as plants, animals, and humans. Germs can be worms, protists, fungi, bacteria, or virus. A germ typically refers to very small seed that can germinate or multiply inside the body, forming a disease. Hence, it is a kind of infectious organism.  

  • Worms – Both roundworms and flatworms can cause diseases in animals and plants. But, flatworms are more parasitic.  
  • Protists – Protozoans are unicellular eukaryotes. Some protozoans live in the wall of the digestive system of animals. They become pathogenic under stressful conditions. Some diseases caused by protists are amoeboid, giardiasis, malaria, and toxoplasmosis. 
  • Fungi – Fungi are eukaryotes that can be either unicellular or multicellular. Generally, fungi excrete digestive enzymes on the substrate and absorb nutrients through their cell wall. Some fungal infections are candida infection, athlete’s foot, and ringworm infection.  
    Difference Between Germs and Bacteria

    Figure 1: Oral Candidiasis

  • Bacteria – It is a unicellular prokaryote. Many disease-causing bacteria produce chemicals called toxins, which can damage cells in the body. Some bacteria can invade tissues. Some examples of bacterial infections include strep throat, tuberculosis, urinary tract infections, etc. Different types of antibiotics are effective for different types of bacterial infections. 
  • Virus – Virus are non-living particles which require a host cell for their replication. Some diseases caused by viruses are AIDS, common cold, Ebola hemorrhagic fever, genital herpes, influenza, measles, chickenpox, and shingles. Antibiotics are not effective for viruses.  

The three steps that can prevent diseases caused by germs are hand-washing, vaccines, and medicine.  

What are Bacteria 

Bacteria are unicellular, microscopic organisms that can live in most habitats such as soil, water, air, clouds, acidic hot springs or radioactive waste. Since bacteria are prokaryotes, they do not contain membrane-bound organelles such as nucleus, mitochondria, chloroplasts, Golgi, and ER.  All metabolic reactions of bacteria hence occur inside the cytoplasm. The cell wall of bacteria is made up of murein. Bacteria show a high rate of multiplication, which occurs through binary fission.  

Main Difference - Germs and Bacteria

Figure 2: Bacteria

Bacteria are mainly classified as Gram-positive and Gram-negative based on the presence of a peptidoglycan layer in the cell wall. Apart from that, bacteria are also classified based on their shape as bacillus, coccus, spirillum. Some  bacteria are motile due to the presence of flagella. 

Germs and Bacteria

Figure 3: Bacterial Shapes

Some bacteria are beneficial while the other can be harmful. The metabolic products of some bacteria such as ethanol, lactic acid, antibiotics, vaccines, etc.  are useful to humans.

Similarities Between Germs and Bacteria 

  • Germs and bacteria are microscopic organisms that can be unicellular. 
  • Both can cause diseases in other living organisms under certain conditions. 

Difference Between Germs and Bacteria 


Germs refer to microorganisms, especially ones which causes disease while bacteria refer to microorganisms, usually one-celled, that can be found everywhere.

Type of Organisms 

The germs can be worms, protists, fungi, bacteria or virus while the bacteria are unicellular prokaryotes. 


Germs can be either eukaryotes or prokaryotes while bacteria are prokaryotes. 


The germs are harmful organisms while the bacteria can be either beneficial or harmful. 


Germs may require a host for reproduction while bacteria do not require a host for their reproduction. 


The germs can be either worms, protists, fungi, bacteria or virus while bacteria are unicellular prokaryotes. Also, germs are harmful microorganisms while bacteria can be either beneficial or harmful. Therefore, the main difference between germs and bacteria is the type of organisms and their behavior. 


1. “Germs: Protect against Bacteria, Viruses and Infection.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 8 Mar. 2017, Available Here
2. Vidyasagar, Aparna. “What Are Bacteria?” LiveScience, Purch, 23 July 2015, Available Here

Image Courtesy:

1. “Human tongue infected with oral candidiasis” By James Heilman, MD – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Bacteria (248 28) Airborne microbes” By Doc. RNDr. Josef Reischig, CSc. – Author’s archive (CC BY-SA 3.0) via Commons Wikimedia
3. “Bacteria morphologic forms simplified” By Mariana ruiz LadyofHats – did it myself (Public Domain) via Commons Wikimedia

About the Author: Lakna

Lakna, a graduate in Molecular Biology and Biochemistry, is a Molecular Biologist and has a broad and keen interest in the discovery of nature related things. She has a keen interest in writing articles regarding science.

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