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Antibiotic resistance



What Are Treatments?

Throughout life, every person will have at least one infection and more than likely, dozens of them. Fortunately, in many cases these infections will be relatively minor and will not require special treatment. However, some infections will need treatment to prevent them from spreading further and causing complications.

When you think about treating an infection, antibiotics (an-tie-by-AH-tiks) come to mind. Antibiotics are medicines aimed at halting the growth and spread of bacteria * , and they are a relatively new development in the history of medicine. None of the antibiotics we know today existed before the twentieth century. Before that time, people had to try to fight serious bacterial infections with other, mostly ineffective, treatments.

For thousands of years, it was not known what caused infections. However, it was known that once certain infections began, they could spread, sometimes with deadly results. Early physicians noticed that how an infection was treated could affect how a person recovered. Celsus, physician to the Roman gladiators, both observed the changes that we now call inflammation * and commented that keeping wounds dry, clean, and warm had beneficial effects. Yet it would be about a thousand years before it was fully understood why. Through the centuries, wounds and infections were treated with a variety of poultices, compounds, and elixirs. These substances, which might be made of herbs, various acids or caustic liquids, and even mud, were among the treatments used to prevent infections from spreading. Some of these treatments may have had some beneficial effects, though many probably did not.

Before the development of antibiotics, one of the primary treatments for a significant bacterial infection was cutting open the infected tissue and draining any pus * before the bacteria could spread further. Opening, or lancing, boils * and abscesses * was among the most common medical procedures. Physicians at a battlefield would amputate (AM-pyoo-tayt), or remove, limbs to prevent infections in wounds from spreading further in the injured soldiers. In fact, more soldiers died of infections during the American Civil War than died of bullet wounds. Dentists would travel from town to town to yank out infected teeth, and their patients would be glad to rid themselves of the pain. To make matters worse, treatment of pain was not very advanced either.

* bacteria (bak-TEER-e-uh) are microscopic organisms, some types of which can cause disease.

* inflammation (in-flah-MAY-shun) is the body's reaction to irritation, infection, or injury that often involves swelling, pain, redness, and warmth.

* pus is a thick, creamy fluid, usually yellow or greenish in color, that forms at the site of an infection. Pus contains infection-fighting white cells and other substances.

* boils are skin abscesses, or collections of pus in the skin.

* abscesses (AB-seh-sez) are localized or walled off accumulations of pus caused by infection that can occur anywhere within the body.

* immune system is the system of the body composed of specialized cells and the substances they produce that helps protect the body against disease-causing germs.

Nevertheless, many people survived their infections. Fortunately, the human body evolved with an immune system * that is able to fight off infection much of the time. The surgeries of the past worked partly because removing the infected tissue (an infected toe, for example) gave the body enough time to mount a successful defense against the infection. Still, before antibiotics and before doctors understood the need for

The Greek physician Hippocrates (ca. 460-370 B.C.) is considered the founder of clinical medicine. His descriptions of case histories of patients and comments on the symptoms of various diseases show the emerging rational and scientific approach to the diagnosis of disease, though his treatments had limited success. Photo Researchers, Inc.
The Greek physician Hippocrates (ca. 460-370 B.C.) is considered the founder of clinical medicine. His descriptions of case histories of patients and comments on the symptoms of various diseases show the emerging rational and scientific approach to the diagnosis of disease, though his treatments had limited success.
Photo Researchers, Inc.
complete cleanliness (sterility) during surgical procedures, treating a bacterial infection was often painful and destructive. Many infections that are successfully treated today, such as bacterial infections of the throat, lungs, heart, or nervous system, once were disabling or fatal.

Even though there is little need today for amputations to treat infections, the use of surgery to help combat certain types of infections is still important. This is particularly true for infections that are deep within the body—and where pockets of pus need to be removed (or drained). Other types of infections, like those involving bone, may also need surgery to help the healing process. Surgery often is required to prevent the spread of infection when a foreign object such as a bullet enters the body and needs to be removed.

Antibiotics and Bacterial Infections

Although today's antibiotics have only been around for two or three generations, herbs and other naturally occurring substances were among the treatments used to fight bacterial infection for thousands of years. In the fifteenth century, arsenic and mercury were used to treat syphilis * . These deadly compounds did have some success in killing the tiny bacterium that caused syphilis, but they unfortunately often poisoned the patient as well.

* syphilis (SIH-fih-lis) is a sexually transmitted disease that, if untreated, can lead to serious lifelong problems throughout the body, including blindness and paralysis.

The era of modern antibiotics began in the 1890s when a German physician, Paul Ehrlich, began experimenting to develop methods to fight germs. He had noted that bacteria could be stained with dyes (colored chemicals) to be better seen through a microscope. Ehrlich believed that dyes could be created that would poison only the bacteria and not people. This idea of creating chemicals that would selectively kill bacteria (and other germs) and not their human hosts is the basis for modern antibiotics.

In 1928, Alexander Fleming, a Scottish scientist, first observed that the mold Penicillium notatum interfered with the growth of Staphylococcus (stah-fih-lo-KAH-kus) bacteria on a culture plate. Fleming's student, Cecil Paine, successfully used a crude extract of the mold to treat eye infections.

The job of purifying the extract to make the medicinal use of penicillin more practical was left to two British scientists, Howard Florey and Ernst Chain. By the end of World War 11 (1939-1945), the drug penicillin was produced for general use. Penicillin, the "wonder drug," transformed medical care, wiping out serious infections ranging from strep throat to pneumonia * to syphilis and from tuberculosis * to infections from war wounds. Penicillin gave birth to the wave of antibiotics that swept into the medical field throughout the twentieth century. Today a wide variety of antibiotics work by various means to prevent the growth and kill a wide range of disease-causing bacteria.

Different antibiotics work in different ways, but in general, these medicines work by interfering with key aspects of the life cycle of bacteria and limiting their growth. Others work to kill the bacteria by damaging their structure. In the future, antibiotics will work by a number of other mechanisms, including interfering with how bacteria attach to cells.

Antibiotics not only treat infections but also may be used in certain situations to prevent some infections from starting. For example, patients who have certain types of heart defects may be at risk for bacterial endocarditis (en-do-kar-DYE-tis), an inflammation of the inner membranes of the heart. They receive preventive (or prophylactic, pro-fih-LAK-tik) antibiotics to ward off bacterial infections when they undergo procedures that could involve minor bleeding, such as dental procedures. Preventive antibiotics also are given when someone is exposed to meningococcal meningitis (meh-nin-JY-tis); meningitis causes an inflammation of the membranes (or meninges; meh-NIN-jeez) that surround the brain and spinal cord and can be fatal if not treated promptly. People who have been exposed to pertussis (per-TUH-sis), or whooping cough, receive preventive antibiotics as well; whooping cough, a disease caused by the Bordetella pertussis bacterium, is a serious infection that can be fatal, especially in infants.

People who are at increased risk for developing bacterial infections may take daily antibiotics to help prevent infections. Among those who benefit from these preventive antibiotics are people with sickle-cell disease * , those who have had their spleen * removed, some children with chronic ear infections (otitis, o-TIE-tis), and people with HIV * infection.

* pneumonia (nu-MO-nyah) is inflammation of the lung.

* tuberculosis (too-ber-kyoo-LO-sis) is a bacterial infection that primarily attacks the lungs but can spread to other parts of the body.

* sickle-cell disease is a hereditary condition in which the red blood cells, which are usually round, take on an abnormal crescent shape and have a decreased ability to carry oxygen throughout the body.

* spleen is an organ in the upper left part of the abdomen that stores and filters blood. As part of the immune system, the spleen also plays a role in fighting infection.

* HIV, or human immunodeficiency (HYOO-mun ih-myoo-no-dih-FIH-shen-see) virus, is the virus that causes AIDS (acquired immunodeficiency syndrome).

How are antibiotics given?

For antibiotics to work, they have to get to the bacteria, and that can happen in a number of ways. Topical antibiotics are placed directly on the involved area; oral medicine is swallowed as a pill or liquid; intravenous (in-tra-VEE-nus) antibiotics are injected into a vein using a liquid form; and intramuscular medication enters the body through a shot (or injection) into a muscle. Which form of medication and way it is given depends on the type of infection, where in the body the infection is, how severe the infection is, how much medication is needed, and the method that is most effective for the particular type of antibiotic. Some medications cannot be taken by mouth because the stomach acids would destroy them, for example.

Although antibiotics have saved and improved the lives of millions, like all medications they still have risks as well as benefits. Some antibiotics can react negatively with other medications or treatments a person is taking. Sometimes antibiotics can cause side effects that may be unpleasant, such as an upset stomach or a rash. Less commonly, the use of antibiotics can lead to damage to the body, dangerous allergic reactions, and other undesirable effects. Physicians, pharmacists, and other medical providers are trained to make choices regarding which antibiotics to use and when to use them.

Bacterial resistance

In recent years, many bacteria have become resistant to antibiotics. That means bacteria that once would have been easily killed by certain antibiotics now require greater and greater doses of antibiotics before they are destroyed. Some bacteria now even survive the antibiotic completely. Why have certain bacteria become resistant? A number of factors are involved, including overuse and misuse of antibiotics for non-bacterial infections such as colds, influenza * , and other viral infections; widespread use of antibiotics with animals; and the ability of many bacteria to pass resistance on to new generations of bacteria. Together they have contributed to drug-resistant forms of bacteria.

Antibiotic resistance tends to increase as strains * of hardy bacteria reproduce and pass from one person (or other host) to the next. Those that are killed or sensitive to the antibiotic are wiped out, leaving the resistant ones to reproduce. Because bacteria multiply rapidly, there is concern among researchers that these drug-resistant forms of the organism may become increasingly responsible for human disease and be ever more difficult to treat. Tuberculosis, malaria * , and even ear infections are just a few diseases that have become more difficult to treat because of drug-resistant germs.

* influenza (in-floo-EN-zuh), also known as the flu, is a contagious viral infection that attacks the respiratory tract, including the nose, throat, and lungs.

* strains are various subtypes of organisms, such as viruses or bacteria.

* malaria (mah-LAIR-e-uh) is a disease spread to humans by the bite of an infected mosquito.

* viruses (VY-rus-sez) are tiny infectious agents that can cause infectious diseases. A virus can only reproduce within the cells it infects.

Drug-resistant infections prove particularly problematic in hospitals, where there are high numbers of microbes and wide use of antibiotics and other drugs. Strains of Staphylococcus aureus (stah-fih-lo-KAH-kus ARE-ree-us) in U.S. hospitals have recently proved increasingly resistant to vancomycin, a powerful antibiotic that was believed to be able to kill off any Staphylococcus bacteria. Viruses * may also become resistant to medications used to combat them. For example, recent studies have shown an apparent drug resistance developing in the HIV virus.

To fight drug resistance, the National Center for Infectious Diseases recommends that people:

  • not take antibiotics to treat anything but a bacterial infection
  • not save antibiotics that were prescribed for one illness to use for a future illness
  • not share another person's medication
  • take all prescriptions precisely according to a doctor's instructions.

The problem of drug resistance has made doctors and others in the health care field increasingly careful about prescribing, and over-prescribing, medications. To deal with drug-resistant bacteria, new types of antibiotics are being developed, and new knowledge from scientists throughout the world points to ways that disease-causing microscopic organisms can be dealt with.

Treating Infections Caused by Viruses
and Other Organisms

Not all infections are caused by bacteria; in fact, most infections are not. Viruses cause many infections, such as the common cold, influenza, various types of pneumonia, and most types of encephalitis (en-seh-fuh-LYE-tis, inflammation of the brain). With only a few exceptions, there are no specific medications that kill or slow the growth of most viruses. Take the common cold, for example, which is caused by any one of a number of respiratory viruses. When people get colds, there is little they can do to make them go away faster. Resting, drinking plenty of fluids (maybe even chicken soup), and taking medications to lower fever can help people feel better, but it will usually still take 5 to 10 days for the cold to run its course. It was that way a thousand years ago, and it is that way today.

A few viruses do respond to medications developed to fight them. One example is the herpes (HER-peez) virus, which can cause a number of infections, including cold sores and infections of the newborn central nervous system. The antiviral medication used against the herpes virus does not kill it, but it can slow the virus growth and shorten the length of an outbreak. Human immunodeficiency virus (HIV) can be suppressed with antiviral medications that interfere with an enzyme * critical for the functioning of the HIV virus. These special anti-HIV medications have helped people with HIV/AIDS live longer, more symptom-free lives.

Soup for the Soul?

Mom was right. Chicken soup is good for a cold or the flu. While a steaming mug will not drive the virus away, the warm fluid can ease symptoms of illness such as dehydration * , a stuffy nose, or a sore throat. Chicken soup is also easy on the stomach, which can be appealing if a person is not feeling very hungry.

* dehydration (dee-hi-DRAY-shun) is a condition in which the body is depleted of water, usually caused by excessive and unreplaced loss of body fluids, such as through sweating, vomiting, or diarrhea.

* enzyme (EN-zime) is a protein that helps speed up a chemical reaction in the body.

* fungi (FUNG-eye) are microorganisms that can grow in or on the body, causing infections of internal organs or of the skin, hair, and nails.

* parasites (PAIR-uh-sites) are organisms such as protozoa (one-celled animals), worms, or insects that must live on or inside a human or other organism to survive. An animal or plant harboring a parasite is called its host. Parasites live at the expense of the host and may cause illness.

As described elsewhere in this volume, a number of fungi * also cause significant human disease worldwide. Parasites * , too, are widespread, particularly in polluted rivers, ponds, and drinking water, as well as in contaminated meat, such as bears or pigs infested with a parasitic worm known as Trichinella spiralis. A large number of medications are available to combat fungi and parasite infections.

Many infections require treatment to prevent them from spreading. In fact, in the case of some infections, such as HIV, giving treatment to an infected mother can prevent infection of her baby before it is born. If treatment is given to both the mother and the child, the risk of transmission declines from 25 percent to less than 10 percent.
Many infections require treatment to prevent them from spreading. In fact, in the case of some infections, such as HIV, giving treatment to an infected mother can prevent infection of her baby before it is born. If treatment is given to both the mother and the child, the risk of transmission declines from 25 percent to less than 10 percent.


The best disease fighter is, of course, the human body, with its complex array of defenses. As scientists study the human immune system, they learn about substances naturally made by the body that have powerful protective effects. One such substance is interferon (in-ter-FEER-on). Inteferon is a type of immunostimulant, a substance the body's cells produce naturally to increase the immune system's effectiveness in fighting infections and certain types of cancer. Synthetic, or man-made, versions of the drug can be used for a number of diseases, including hepatitis * .

* hepatitis (heh-puh-TIE-tis) is an inflammation of the liver. Hepatitis can be caused by viruses, bacteria, and a number of other noninfectious medical conditions.

The Future of Treatment

Will humans ever be free of all infections? Perhaps someday, although not in the near future. The answer, of course, is not to wipe out all bacteria. Humans and other complex life forms need bacteria to survive. Our health depends on our better understanding of how bacteria, viruses, fungi, and other organisms almost too small to see can affect human health. It is also vital to increase our understanding of why some people get infections and others do not, how infections move through populations, and how getting (or resisting) infections is affected by such factors as age, gender, nutrition, genetics * , and even emotions. The development of new types of vaccinations * , antibiotics, immunostimulants, and other methods of fighting infections no doubt will play an increasing role in limiting the spread of certain diseases.

Let It Bleed

Before germ theory was understood, physicians and other nonmedical practitioners struggled to drain "toxic" substances from the body to cure disease. The preferred treatment was phlebotomy, or bloodletting, in which a lancet or other sharp device was pushed into a vein and used to drain blood. This practice, which dates back to the ancient Egyptians (and perhaps even before), peaked during the eighteenth and nineteenth centuries, when barber-surgeons in Europe and physicians in America enthusiastically pursued bloodletting. In fact, George Washington, the first U.S. president, died after having about 80 ounces of his blood drained within 24 hours for a throat infection. By the end of the nineteenth century, bloodletting had been abandoned. Other treatments once used to cleanse the body of infections included blistering, in which the fluid in induced blisters was believed to drain foul liquids; and purging, in which laxatives were used to empty the bowels.

* genetics (juh-NEH-tiks) is the branch of science that deals with heredity and the ways in which genes control the development and maintenance of organisms.

* vaccinations (vak-sih-NAYshunz), also called immunizations, are the giving of doses of vaccines, which are preparations of killed or weakened germs, or a part of a germ or product it produces, to prevent or lessen the severity of a disease.

See also
Laboratory Tests
Signs and Symptoms
The Nature of Germs and Infection



U.S. Centers for Disease Control and Prevention (CDC), 1600 Clifton Road, Atlanta, GA 30333. The CDC is the United States government authority for information about infectious and other diseases. The CDC offers information on specific infectious diseases and recommended treatments at its website.
Telephone 800-311-3435

Website . KidsHealth is a website created by the medical experts of the Nemours Foundation and is devoted to issues of children's health. It contains articles on a variety of health topics, including different types of treatments for infections.

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