The Difference Between Antimicrobial & Antibacterial – Who’s Best

The world is full of rigorous contentions – football vs. soccer, tea vs. coffee, Messi vs. Ronaldo, Trump vs, the world and so on. One such rivalry in the pharmaceutical world is between the performance and efficacy of antibacterials vs. antimicrobials.

In layman terms, the words “antibacterial” and “antimicrobial” are used synonymously, but by now it must be clear that the case is quite the opposite. While both our contenders are have shown excellent results in their own field, the main question is: Who does it the best?

Now let’s come to the textbook definition of each of them. Antibacterials include chemicals which can kill bacterias or inhibit their growth, thus they act only upon bacteria. On the other hand, antimicrobials destroy or stall the growth of microorganisms. Therefore, antimicrobials cover a lot of microorganisms which include fungi, protozoa, helminths like Cestodes, nematodes, and bacteria as well.

While antibacterial soaps and detergents restrict and prevent the growth of bacteria, antimicrobials like alcohol-based hand sanitizers provide a broad range of protection from parasites, fungi, bacteria, worms, and even some viruses. All in all, antimicrobials serve the function of both, antibacterials and antiparasitic.

So we can safely say that every antimicrobial is an antibacterial agent, but every antibacterial is not an antimicrobial.

The use of antimicrobials has been prevalent since ancient times. Egyptians in 2000BC used some molds and their extracts as antimicrobials. Louis Pasteur, in the 19th century, was the first to notice adverse reactions when two microorganisms interacted and proposed its use in medicine. However, the first antibiotic, Penicillin, was discovered by Alexander Flemming in 1942, from antimicrobial fungi and it was used to treat a Streptococcal infection successfully.
Since then, a lot of progress has been made in the field of antimicrobials. A diversification occurred and antimicrobials with specific actions developed. Some of them are listed below.


Antibacterials specifically used for treating bacterial infections internally are known as antibiotics. Their levels of drug toxicity is much less than that of other antibacterials. Prolonged use of antibiotics can, however, affect the gut flora, which has a negative impact on health. Deaths due to bacterial infections have reduced dramatically after the emergence of antibiotics. However, in recent years, a spectacular rise in antibiotic resistance has been noted. This is due to their injudicious and indiscriminate use. This demands renewed efforts for the discovery of newer antibiotics by studying the bioactive compounds released by these antibiotic-resistant pathogens.

Antibacterials can either be bacteriostatic or bactericidal. While bacteriostatic agents inhibit and stall the growth of bacteria, the bactericidal ones are potent enough to kill live bacteria.

Antiseptics: These are topical antibacterial agents used for treating bacterial skin infections.

Disinfectants: Like antiseptics, they are used externally for killing or inhibiting bacterial growth on nonliving subjects. Care should be taken not to apply it on the skin, as they are highly corrosive.


Antifungals: Antifungals are used to prevent or stall the growth of fungi. Fungal diseases like ringworm, thrush, candidiasis are treated with such medications. These drugs act by exploiting the difference between human and fungal cells. However, unlike bacteria, both mammalian and fungal cells are eukaryotic, therefore, these drugs have a hard time trying to differentiate between the host cell and fungal cell. Hence, they have a lot of side effects, and some of them can be life-threatening if the drug is not used properly.

Other than pharmaceutical agents, a lot of antifungals are used for preventing mold and mildew formation on walls and damp places. Fumigation with sodium bicarbonate (baking soda) is done in damp places to prevent fungus formation. Hydrogen peroxide, added in antifungal paints are used to coat walls of places prone to moisture like bathrooms and kitchens. It forms a thin surface coating which encapsulates spores and prevents their release.


Antivirals: They are a group of drugs used to treat viral infections. These drugs can kill or inhibit viruses specifically. Unlike, antifungals, they are relatively harmless to humans or other mammalian hosts and can be used to treat viral infections.

Different types of antivirals are available for different types of viral infections. Neuraminidase inhibitors like Oseltamivir have been recently incorporated as an Influenza medication. HIV and other retroviral infections are controlled using antiretroviral drugs like protease inhibitors. Herpes virus, responsible for cold sores and genital herpes is generally treated with Acyclovir, a nucleoside analog.
Antivirals must not be confused with virucides, which are used for killing viruses from nonliving external surfaces.

Antiparasitic: They are medical agents used to kill parasites like cestodes, trematodes and nematodes, infectious amoeba which cause intestinal infections and infectious protozoa which cause malaria, leishmaniasis, etc. They must be able to kill these parasites without significantly harming the hosts.

There are a lot of nonpharmaceutical agents which are used as antimicrobials.

·Organic acids like acetic acid (vinegar), citric acid and their salts are used as a preservative. They are sprayed on beef and other meats to prevent the growth of E. coli and other bacteria.

·Copper alloys have an intrinsic antimicrobial property and are used to kill organisms like E. coli and Methicillin-resistant strains of Staphylococci.

·Silver is a potent antimicrobial and has been used for ages. It binds with the thiol group of enzymes present in infectious organisms, thus inhibiting their action and killing the microorganism.

·Ozone is a gaseous agent and is used widely as a disinfectant in places which are hard to reach.

·Heating and radiations are also effective for killing microorganisms and are used to sterilize lab equipment and other instruments used in medical operations like surgery.

Will you say that a boat and a yacht are the same things? Many will say yes and many others will say no. Both of them have similar functions, that is, they both float in water and can carry people over water, but somehow they are a lot different.

It’s the same with antibacterial and antimicrobial agents. While they may appear to be similar in the first glance, the major differences manifest later on.

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