In digestion, for example, there are bacteria that feed on foods that we cannot digest with our human cells alone. The waste products of these bacteria are nutrients for our human systems.
Probiotics refer to live microorganisms thought to have beneficial effects, and popular knowledge of this has led to a surge in probiotic use; however, other bacteria have harmful effects, especially when they overpopulate specific areas of our bodies. Infection with pathogenic bacteria can happen following an injury, when common external bacteria enter the human body through the bloodstream, or by contamination with unfriendly microorganisms that produce toxic by-products, as in many cases of food poisoning.
Antibiotics do not usually affect human cells, which is why we can ingest them safely for use as a medicine. However, like all medicines, some people may react or have side-effects from antibiotics as well. Some antibiotics attack a wide range of bacteria broad-spectrum antibiotics , while researchers develop others to only attack specific pathogenic strains narrow-spectrum antibiotics. There are antibiotics that work only against bacteria that need oxygen aerobic and others that work against bacteria that live in the absence of oxygen anaerobic.
When you swallow an antibiotic pill or liquid, it enters your digestive tract and is absorbed into the blood stream just as nutrients are from food. From there, it circulates throughout the body, soon reaching its target area, where pathogenic bacteria are causing an infection.
In some situations, such as when an infection is especially severe, physicians might administer antibiotics via injection intravenously, directly into the bloodstream. With certain skin infections, the most effective way to get the antibiotic to the pathogenic organisms quickly is to apply it directly to the infection as a topical cream or ointment.
Your physician chooses a particular antibiotic and its route of administration based on a number of factors, such as the exact type and extent of infection. It is sometimes necessary to have a specimen analyzed at the laboratory to determine the exact species and strain of bacteria causing the infection. Your physician might also prescribe antibiotics before bowel surgery or another medical procedure that comes with a high risk of bacterial infection, which is a preventative prophylactic use of antibiotics.
One of the common side-effects from taking antibiotics is loose bowel movements diarrhea , as the antibiotic disrupts the normal, healthy bacteria in your gut that are keeping you regular. Your physician might recommend the use of probiotics following antibiotic treatment to help your body re-populate healthy strains of bacteria.
But the vitamin cannot enter bacterial cells and thus bacteria must make their own. The sulfa drugs such as sulfonamides inhibit a critical enzyme--dihydropteroate synthase--in this process. Once the process is stopped, the bacteria can no longer grow. Another kind of antibiotic--tetracycline--also inhibits bacterial growth by stopping protein synthesis.
Both bacteria and humans carry out protein synthesis on structures called ribosomes. Tetracycline can cross the membranes of bacteria and accumulate in high concentrations in the cytoplasm. Tetracycline then binds to a single site on the ribosome--the 30S smaller ribosomal subunit--and blocks a key RNA interaction, which shuts off the lengthening protein chain.
In human cells, however, tetracycline does not accumulate in sufficient concentrations to stop protein synthesis. Similarly, DNA replication must occur in both bacteria and human cells. The process is sufficiently different in each that antibiotics such as ciprofloxacin--a fluoroquinolone notable for its activity against the anthrax bacillus--can specifically target an enzyme called DNA gyrase in bacteria.
There are drugs called antivirals that have been developed to fight viruses. For children, antibiotics are available in a number of forms, including tablets, capsules, liquids, and chewables. Some antibiotics come as ointments and others come as drops eg, for ear infections. When your pediatrician prescribes an antibiotic, your pediatrician will choose the best one for the specific germ that is making your child sick.
Antibacterials fight infectious bacteria in the body. They attack the disease process by destroying the structure of the bacteria or their ability to divide or reproduce.
Scientists often categorize antibacterials in the following way:. Some antibacterials eg, penicillin, cephalosporin kill bacteria outright and are called bactericidal.
They may directly attack the bacterial cell wall, which injures the cell. The bacteria can no longer attack the body, preventing these cells from doing any further damage within the body. Often called bacteriostatic antibiotics, they prevent nutrients from reaching the bacteria, which stops them from dividing and multiplying. Some antibacterials are called broad spectrum and can fight many types of germs in the body, while others are more specific.
As powerful and useful as antibiotics can be, they may produce side effects in some people. In children, they can cause stomach discomfort, loose stools, or nausea. Some youngsters have an allergic reaction to penicillin and other antibiotics, producing symptoms such as skin rashes or breathing difficulties.
If these allergic symptoms become severe, causing labored breathing, difficulty swallowing because of a tight throat, or wheezing, call your pediatrician and go to the emergency department right away. While antimicrobial drugs are mostly used to treat infections that your infant or child may develop, they are sometimes prescribed to prevent an illness from ever occurring. Medicines can kill the bacteria before they have a chance to cause an infection.
Antibiotics are sometimes used in a limited numbers of patients before surgery to ensure that patients do not contract any infections from bacteria entering open cuts. Without this precaution, the risk of blood poisoning would become much higher, and many of the more complex surgeries doctors now perform may not be possible.
What are antibiotics and how do they work? This makes antibiotics subtly different from the other main kinds of antimicrobials widely used today: Antiseptics are used to sterilise surfaces of living tissue when the risk of infection is high, such as during surgery.
Disinfectants are non-selective antimicrobials, killing a wide range of micro-organisms including bacteria. They are used on non-living surfaces, for example in hospitals. However, some microbes only produce antibiotics in the laboratory How do antibiotics work?
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