Wednesday, June 24, 2020

The most common antimicrobial resistance in bacteria

I am not a native English speaker. You may find mistakes in my writings.

Microorganisms, in general, can show resistance apparatus due to interspecific interactions that occur between microorganisms of different species. These defense mechanisms against antimicrobials are evolutionary achievements of these microorganisms and occur naturally and favor the evolution of bacteria and fungi and other microorganisms—as an example: Bacteria species (A) needs to grow in an environment where bacteria species (B) are also multiplying. (A) bacteria can use their metabolism to synthesize antimicrobial substances in an attempt to inhibit the growth of bacterium (B). What was just described is very common and normal. The problem with this mechanism is when these microorganisms are pathogenic and affect the health of both animals and humans. When they are pathogenic, their skills of resistance leads to diseases and deaths because they start to overpopulate their host organisms; the bacteria toxic secondary metabolites can lead to the death of their host.



The most common mechanisms of resistance to antimicrobials by bacteria are by the destruction or enzymatic inactivation of the drug when it manages to enter the bacterial cell. The enzymatic lyzes of the antibiotics affect drugs such as penicillins and cephalosporins. These drugs have a beta-lactam ring that is readily denatured by bacteria through beta-lactamase enzymes. The second most common form of resistance of bacteria against antibiotics is by offering physical resistance to the entrance of the drugs into the bacterial cell. This mechanism is primarily known in gram-negative bacteria. Gram-negative bacteria have protein channels in their cell membranes that allow water and solute to cross the plasma membrane, these pores are call porins. Gram-negative bacteria can change the diameter or hide their porins, not allowing antibiotics to cross the plasmatic membrane. Another common mechanism of resistance is shifting the drug's target site. This mechanism works by changing the molecular shape of the proteins, inactivating the active site, so the antibiotics no longer bind to the bacteria target site. A fourth most common mechanism of resistance is the presence of transmembrane proteins that act as efflux pumps, pumping antibiotics out of the bacteria cell, decreasing its concentration.

I suggest reading the article below if you need a more detailed overview of the antimicrobial resistance mechanisms of bacteria.

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