Acquired resistance occurs when a bacterium that was originally sensitive to an antibiotic develops resistance. For example resistance genes can be transferred from one plasmid to another plasmid or chromosome, or resistance can occur due to a random spontaneous chromosomal mutation. Microbes that cause disease are called pathogens. Find out which microbe is responsible for malaria! An infection can be seen as a battle between the invading pathogens and host.
How does the immune system work? Homepage Why Microbiology Matters What is microbiology? 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. Here are other circumstances in which prophylactic preventive antibacterial drugs may be prescribed for children. 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.
If you find blood or mucus in your stool, or experience severe abdominal pain or cramping, you should follow up with your physician immediately to assess if there may be a secondary infection, such as C.
See page When one antibiotic fails to eradicate an infection, your physician may have to move on to less conventional drugs, which might be more expensive or associated with more serious side-effects. Physicians reserve these antibiotics for use in specific situations and circumstances only, to avoid the development of antibiotic resistance.
Antibiotics alter the course of life-threatening infections, decreasing mortality and loss of organs or limbs. Still other antibiotics fight infections by stopping bacteria from producing folic acid — an essential vitamin — or disputing the structure of a bacterium's cell membrane, which controls how substances move in and out of the cell.
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