What is the most common way that a bacterium can acquire a plasmid with genes for antibiotic resistance from another bacterium quizlet?
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What is antibiotic resistance? Show
Why do bacteria become resistant to antibiotics? Some resistance occurs without human action, as bacteria can produce and use antibiotics against other bacteria, leading to a low-level of natural selection for resistance to antibiotics. However, the current higher-levels of antibiotic-resistant bacteria are attributed to the overuse and abuse of antibiotics. In some countries and over the Internet, antibiotics can be purchased without a doctor's prescription. Patients sometimes take antibiotics unnecessarily, to treat viral illnesses like the common cold. How do bacteria become resistant? Mutations, rare spontaneous changes of the bacteria's genetic material, are thought to occur in about one in one million to one in ten million cells. Different genetic mutations yield different types of resistance. Some mutations enable the bacteria to produce potent chemicals (enzymes) that inactivate antibiotics, while other mutations eliminate the cell target that the antibiotic attacks. Still others close up the entry ports that allow antibiotics into the cell, and others manufacture pumping mechanisms that export the antibiotic back outside so it never reaches its target. Bacteria can acquire antibiotic resistance genes from other bacteria in several ways. By undergoing a simple mating process called "conjugation," bacteria can transfer genetic material, including genes encoding resistance to antibiotics (found on plasmids and transposons) from one bacterium to another. Viruses are another mechanism for passing resistance traits between bacteria. The resistance traits from one bacterium are packaged into the head portion of the virus. The virus then injects the resistance traits into any new bacteria it attacks. Bacteria also have the ability to acquire naked, "free" DNA from their environment. Any bacteria that acquire resistance genes, whether by spontaneous mutation or genetic exchange with other bacteria, have the ability to resist one or more antibiotics. Because bacteria can collect multiple resistance traits over time, they can become resistant to many different families of antibiotics. How does antibiotic resistance spread? Can bacteria lose their antibiotic resistance? Intrinsic ResistanceIn some cases, a type of bacteria will survive antibiotic treatment and multiply because it is intrinsically resistant. For example, although many types of bacteria have cell walls, some don’t. An antibiotic like penicillin that prevents cell-wall building can’t harm a bacterium that doesn’t build a cell wall in the first place. Acquired ResistanceBacteria can also acquire resistance. This happens when a type of bacteria changes in a way that protects it from the antibiotic. Bacteria can acquire resistance in two ways: either through a new genetic change that helps the bacterium survive, or by getting DNA from a bacterium that is already resistant. Genetic ChangeSo how can a simple DNA change protect bacteria from antibiotics? Remember, DNA provides instructions to make proteins, so a change in DNA can cause a change in a protein. Sometimes this DNA change will affect the protein’s shape. If this happens at the place on the protein where an antibiotic acts, the antibiotic may no longer be able to recognize where it needs to do its job. Changes like this can prevent an antibiotic from getting into the cell, or prevent the antibiotic from working once it’s inside. Once a change occurs, it can spread in a population of bacteria through processes like reproduction or DNA transfer. DNA TransferBacteria are very good at sharing genes, including genes for antibiotic resistance. They can share resistance genes that have been in the population, as well as new genetic changes that occur. If you explored Agent Antibiotic, you saw a bacterium with an antibiotic resistance gene give a copy of that gene to another bacterium. This process is called lateral gene transfer. There are other ways bacteria can transfer DNA. Did you know bacteria can get infected with a type of virus called a bacteriophage? As part of its life cycle, the bacteriophage packages DNA. When the bacterium dies, these packages of DNA (which sometimes include antibiotic resistance genes) are released and can be taken up and used by other bacteria. What is the most common way that a bacterium can acquire a plasmid with genes for antibiotic resistance from another bacterium?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.
How do bacteria acquire plasmids?Bacteria can pick up new plasmids from other bacterial cells (during conjugation) or from the environment. They can also readily lose them – for instance, when a bacterium divides in two, one of the daughter cells might miss out on getting a plasmid.
How do bacteria cells acquire antibiotic resistance quizlet?Bacteria can acquire antibiotic-resistance genes by becoming infected with a virus that contains an antibiotic-resistance gene. Bacteria can acquire antibiotic resistance by a variety of methods, including random mutation and genetic transfer by transformation, transduction, or conjugation.
How Do bacteria acquire genes from other bacteria?Genetic exchanges among bacteria occur by several mechanisms. In transformation, the recipient bacterium takes up extracellular donor DNA. In transduction, donor DNA packaged in a bacteriophage infects the recipient bacterium. In conjugation, the donor bacterium transfers DNA to the recipient by mating.
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