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Sometimes, when a bacterium is multiplying, a random mistake in the bacterium’s DNA will create a gene that gives it resistance to antibiotics. Every time a multiplication event happens, there is a chance a mutation can occur.
This mutation gave the bacteria an ability to fend off the vancomycin molecule. Some bacteria acquire resistance when they are “given” a gene by another bacterium through a process called horizontal gene transfer (HGT). There are three ways that HGT can occur. Transduction – This occurs when a virus attacks a bacterium and steals some of its DNA.
Some bacteria are naturally equipped with defenses against antibiotics. One defense that some bacteria have is a chemical that destroys the antibiotic molecule. When the antibiotic is near the bacteria, they release their chemical defense, which causes the antibiotic to stop working.
For instance, many antibiotics try to latch onto a bacteria’s receptors, molecules that sit on the outside of bacteria and receive signals. Some of these bacteria can change the shape of their receptors, so that the antibiotic can’t bind to it. If it can’t bind, it can’t kill it.
There are two main ways that bacterial cells can acquire antibiotic resistance. One is through mutations that occur in the DNA of the cell during replication. The other way that bacteria acquire resistance is through horizontal gene transfer.
Antibiotic resistance mechanismsPump the antibiotic out from the bacterial cell. Bacteria can produce pumps that sit in their membrane or cell wall. ... Decrease permeability of the membrane that surrounds the bacterial cell. ... Destroy the antibiotic. ... Modify the antibiotic.
Some bacteria acquire resistance when they are “given” a gene by another bacterium through a process called horizontal gene transfer (HGT). There are three ways that HGT can occur. Transduction – This occurs when a virus attacks a bacterium and steals some of its DNA.
Some bacteria are naturally equipped with defenses against antibiotics. One defense that some bacteria have is a chemical that destroys the antibiotic molecule. When the antibiotic is near the bacteria, they release their chemical defense, which causes the antibiotic to stop working. Another way they defend themselves is by changing some ...
There is a very common antibiotic-resistant bacteria species called Clostridium difficile that causes people to have bad diarrhea. C. diff uses both chemical and shape-changing defenses, and tends to thrive in people who are taking antibiotics for other bacteria.
One bacteria species in which this happened is Vancomycin-resistant Enterococci (VRE), a strain of bacteria that is resistant to an antibiotic called vancomycin. VRE have been around for over thirty years, and they are very well studied. In fact, scientists have been able to group different strains of VRE according to how they defend themselves ...
For two types, called VanA and VanB, the bacteria gained resistance when a mutation occurred in their DNA. This mutation gave the bacteria an ability to fend off the vancomycin molecule.
A dangerous, but also very widespread, bacteria called Carbapenem-resistant Enterobacteriaceae (CRE) is known for its ability to spread ‘resistance’ genes through HGT. CRE can cause infections in our bloodstream, wounds, and urinary tract, and are one of the hardest bacteria to kill, because they can survive almost all antibiotics.
The bacterium can absorb these genes and add them to their own DNA. Conjugation – Two bacteria can trade genes by briefly fusing to one another, and sending genes to one another through the connection.
In America, at least 23,000 people die every year from infections caused by antibiotic-resistant bacteria, according to the Centers for Disease Control and Prevention. Another 2 million become sick from resistant bacteria.
Resistance is a natural byproduct of evolution. When you prescribe an antibiotic, it may kill most of the bacteria causing the trouble. But bacteria that survive, perhaps through a genetic mutation protecting them from the antibiotic, will multiply and pass on their protective mutations. Overtime, the protected bacteria outnumber the vulnerable bacteria and it is resistant to that particular antibiotic.
Antibiotics are used to treat infections caused by bacteria. Examples for young children include a documented case of strep throat or an ear infection , especially if the infection is on one side, the child is quite ill and you’ve tried ibuprofen but the child is getting worse. In older children, a bacterial pneumonia or a urinary tract infection could be candidates for antibiotics.
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In Week 2 you looked at how antibiotics target bacteria, either killing them or preventing their growth. But bacteria are constantly fighting back against this threat to their survival.
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