Chemical Classes

There are different chemical classes of compounds that comprise the antibacterials and these include
  1. Beta Lactams
  2. Aminoglycosides
  3. Quinolones and Fluoroquinolones
  4. Streptogramins
  5. Sulfonamides
  6. Tetracyclines
  7. Nitroimidazoles
The list is by no means comprehensive or complete. Suffice to say the list keeps expanding as more and more classes are being introduced\cite{version}.  

Cellular functions as targets

Antibacterial agent-mediated cell death is a complex process that begins with the physical interaction between a drug molecule and its bacterial-specific target and involves alterations to the affected bacterium at the biochemical, molecular, and ultrastructural levels\cite{Kohanski2010}. Hence, antibacterial agents can also be classified based on the targets of action in the bacterial cells or other cells among other microbes. Since microbes vary from being prokaryotes (simple unicellular organisms without a dedicated nucleus) to advanced eukaryotes (mostly unicellular microbes with advanced cellular architecture), the targets of action vary. The more advanced they are the more they resemble the cellular machinery of the humans, thereby making it difficult to achieve exclusive antimicrobial properties. Some of these include
  1. Cell wall synthesis inhibitors
  2. Membrane function inhibitors
  3. Protein Synthesis inhibitors
  4. Nucleic acid synthesis inhibitors

Antimicrobials

Antimicrobial is a broad term encompassing all agents that act against all types of microorganisms. The term antimicrobial is derived by combining three Greek words, 'anti,' which means 'against, 'mikros' which means 'little,' and 'bios,' which means 'life'.
Herein the agents are more than just antibiotics. They also include agents for use on external surfaces of objects of daily use. Coatings form an important category here\cite{coatings}. The classes of antimicrobials include
          ●          Antibacterial against bacteria
          ●          Antifungal against fungi
          ●          Antiviral against virus
          ●          Antiparasitic against parasites
          ●          Antiprotozoal against protozoa
          ●          Broad-spectrum therapeutic deal with a wide range of microbes
          ●          Non-pharmaceutical antimicrobials are natural, and some non-medicinal chemical compounds to kill microbes include essential oils, organic acids, antimicrobial pesticides, antimicrobial metals, and alloys.
          ●          Antimicrobial scrubs that do not allow the growth of stains and odours on scrubs used for cleaning
          ●          Ozone destroys microbes in water, air, and process equipment.
          ●          Physical processes like Heat sterilization and Radiation are also used to create an antimicrobial effect.