Bacteria vs. Viruses - Scientist Next Door

Bacteria Vs. Viruses (or simply Germs?)

“Germs” (Latin germen, meaning ‘seed’ or ‘sprout’) is a common term that includes bacteria, viruses, and other microscopic particles (fungi, and protozoa) that cause illness in humans. This term is however not widely used in formal science these days.

Bacteria (bak·teeuh·ree·uh) and viruses (vai·ruh·suhz) are found almost everywhere and anywhere. You can find them in soil, water, air, your clothes, house and inside your body too. They are present in the depths of the oceans as well as on the top of the mountains. You can find them in the extreme of the extreme conditions on the planet where you would expect no life to exist (check ‘what are extremophiles?’). They can infect plants, animals, and people, but don’t necessarily make us sick every time.

Feature/Character	Bacteria	Virus
How do they look? You’ll need a microscope though since they are microscopic
How many cells do they have? (humans have on an average ~37 trillion cells)	Single-celled	No cell
Size (Human: 175 cm)	0.3 - 2 μ (0.00003 - 0.0002 cm)	0.02 - 0.3 μ (0.000002 - 0.00003 cm) The largest virus is still smaller than the smallest bacterium
Cell type (humans are eukaryotic)	Prokaryotic	Acellular (no cellular organelles, cannot grow or divide or carry out independent metabolism)
Made of?	Organelles and genetic material within a cell wall	Genetic material within protein capsule (some have an envelope too)
Genetic material	DNA and RNA	DNA or RNA
Living attributes	Living	Between living and non-living things
Need for host	Can replicate without host too	Need a living cell to replicate
Where do they survive	Anywhere and everywhere (Outside/inside body)	Host needed (only reproduce by attaching themselves to cells)
Cellular machinery (ribosome, etc)	Present	Absent
Type of organism	Mostly intercellular (live between cells); some intracellular	Intracellular (live inside the cell)
Harmful?	Most are harmless. Some are beneficial while some are disease-causing (pathogenic)	Most are harmful
Infections	Food poisoning, gastritis, ulcers, pneumonia, etc	Common cold, influenza, chickenpox, AIDS etc
Treatment	Antibiotics	Antiviral drugs
Benefits	Some bacteria are beneficial (as normal flora, probiotics, fermenters, etc.)	Viruses are not beneficial. (can be useful in genetic engineering)
Examples	Escherichia coli, Salmonella, Mycobacteria, Staphylococcus species	Coronavirus, Ebola virus, SARS, HIV, Hepatitis A virus