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Bacteria defense strategies against antibiotics


Bacteria Defense Strategies 

Antibiotics fight bacteria, But bacteria also fight back and find new ways to survive. Their defense strategies are called resistance mechanisms. Bacteria develop resistance mechanisms by using instructions provided by their DNA. Often, resistance genes are found within plasmids, small pieces of DNA that carry genetic instructions from one germ to another. This means that some bacteria can share their DNA and make other bacteria become resistant.
Examples of Defense Strategies for bacteria
Bacteria can use defense strategies to resist the effects of antibiotics. Here are a few examples.

Resistance Mechanisms (Defense Strategies)
Resistance Mechanisms
(Defense Strategies)
Restrict access of the antibiotic Bacteria restrict access by changing the entryways or limiting the number of entryways.
Example: Gram-negative bacteria have an outer layer (membrane) that protects them from their environment. These bacteria can use this membrane to selectively keep antibiotic drugs from entering.
Get rid of the antibioticBacteria get rid of antibiotics using pumps in their cell walls to remove antibiotic drugs that enter the cell.
Example: Some Pseudomonas aeruginosa bacteria can produce pumps to get rid of several different important antibiotic drugs, including fluoroquinolones, beta-lactams, chloramphenicol, and trimethoprim.
Change or destroy the antibioticBacteria change or destroy the antibiotics with enzymes, proteins that break down the drug.
Example: Klebsiella pneumoniae bacteria produce enzymes called carbapenemases, which break down carbapenem drugs and most other beta-lactam drugs
Bypass the effects of the antibioticBacteria develop new cell processes that avoid using the antibiotic’s target. 
Example: Some Staphylococcus aureus bacteria can bypass the drug effects of trimethoprim
Change the targets for the antibioticMany antibiotic drugs are designed to single out and destroy specific parts (or targets) of a bacterium. Germs change the antibiotic’s target so the drug can no longer fit and do its job.
Example: Escherichia coli bacteria with the mcr-1 gene can add a compound to the outside of the cell wall so that the drug colistin cannot latch onto it

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