#1: Cell membrane disruption
The first pathway involves the disruption of the bacterial cell membrane. Bacterial cell membranes consist of a phospholipid bilayer, which acts as a selective barrier to allow the passage of small molecules while excluding large ones. Antibiotics such as penicillin and cephalosporins work by inhibiting the synthesis of a critical component of the bacterial cell wall, called peptidoglycan. Without a functional peptidoglycan layer, the bacterial cell membrane is unable to maintain its structural integrity and eventually ruptures, leading to cell death.
#2: Inhibition of protein synthesis
Some antibiotics target bacterial protein synthesis. Antibiotics such as tetracyclines and aminoglycosides prevent the bacterial ribosome from attaching to the mRNA and preventing protein synthesis. Ribosomes are the protein manufacturing machinery found in bacteria and are essential for their survival. The lack of protein synthesis ultimately leads to bacterial cell death.
#3: DNA and RNA inhibition
Antibiotics such as rifampicin, fluoroquinolones, and macrolides act by interfering with bacterial DNA and RNA synthesis. These antibiotics prevent the transcription and translation of essential bacterial genes, inhibiting DNA replication and leading to cell death. Bacteria are more reliant on their DNA and RNA synthesis to carry out essential cellular processes, making them more vulnerable to these antibiotics.
#4: Bacterial enzyme inhibition
Some antibiotics work by inhibiting bacterial enzymes that are essential for cellular metabolism. The inhibition of these enzymes leads to a disruption of essential cellular processes, causing bacterial cell death. Examples of these antibiotics include β-lactams, aminoglycosides, and clavamates, which all inhibit bacterial cell wall synthesis enzymes.
#5: Interference with bacterial cell division
Certain antibiotics act by disrupting bacterial cell division. Cell division is a critical process for bacterial survival, allowing for the growth and proliferation of bacterial populations. Examples of antibiotics that target bacterial cell division include daptomycin and the macrolides. These antibiotics prevent cell division by interfering with the bacterial cell wall and cytoskeleton, respectively.
In conclusion, antibiotics work on bacteria through five primary pathways: disruption of the bacterial cell membrane, inhibition of protein synthesis, inhibition of DNA and RNA synthesis, inhibition of bacterial enzymes, and interference with bacterial cell division.
