The Wilbur D. May Museum at Rancho San Rafael has a wide range of historic artifacts
The Wilbur D. May Museum at Rancho San Rafael has a wide range of historic artifacts

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County Home => Health => Epidemiology Home => Antimicrobial Resistance => Frequently Asked Questions About Antimicrobial Resistance

Bacteria (singular: bacterium) are one-celled organisms visible only through a microscope. There are many types of bacteria, only some of which cause disease. Most are harmless and even some are helpful (“good” bacteria), by aiding digestion or breaking down rotting material. Bacteria are found almost everywhere.
An antibiotic is a powerful medication designed to kill bacteria or stop them from growing, such as an illness caused by strep throat. They cannot cure illnesses caused by viruses, such as a cold or the flu. Different antibiotics may be used for different types of bacterial infections. Your health care provider will determine what infection you have and if an antibiotic is appropriate to treat it.
Antibiotics either inhibit the growth of bacteria (bacteriostatic) or actually kill the bacteria (bacteriocidal). By stopping the growth of bacteria, it gives the body time to mount an immune response and allows the body to eliminate the bacteria. Drugs that kill the bacteria are the preferred choice when someone has a weakened immune system and whose body cannot destroy the bacteria on its own. Antibiotics are not effective against viruses.
Unnecessary antibiotics can be harmful. Antibiotics only fight bacterial infections. They do nothing to help viral illnesses like colds or influenza (flu). If you take an antibiotic when it is not necessary, such as for a cold, you increase the risk of developing an infection caused by antibiotic-resistant bacteria. Antibiotics also destroy “good” bacteria in your body.
Antibiotic resistance occurs when an antibiotic has lost its ability to effectively control or kill bacterial growth. These bacteria are considered to be “resistant” to an antibiotic. Overuse and misuse of antibiotics are the main reason for antibiotic resistance.
Some bacteria are naturally resistant to certain types of antibiotics. Bacteria can also become resistant by a genetic mutation or by acquiring resistance from another bacterium. Because bacteria can collect multiple resistance traits over time, they can become resistant to many different families of antibiotics, which allows the resistant bacteria to continue to live/and multiply even in the presence of antibiotic treatment.
No, this is a common misconception. People may exhibit allergic reactions to antibiotics, but they are not resistant to them. It is the bacteria, not the person, which become resistant.
There are three ways in which you can get an antibiotic-resistant infection:

* You can develop antibiotic-resistant infections when you take an antibiotic. The bacteria could figure out how to outsmart the antibiotic and stay alive. In that case, you can transmit these resistant bacteria to others and they too may become ill * You can catch antibiotic resistant-infections from people or objects around you that are infected with resistant bacteria. Not properly washing hands can increase your risk of catching all kinds of infections. * You can develop an antibiotic-resistant infection when the bacteria inside your body change; it mutates or acquires genes that allow them to resist antibiotic treatment.

Antibiotic-resistant bacteria can also develop in pigs, chickens, cattle and other farm animals, which are exposed to low doses of antibiotics in their daily feed. These resistant bacteria can then spread to humans, causing antibiotic-resistant infections. Guidelines are being developed to address this concern.
No. The common cold and the “flu” (influenza) are caused by viruses, not by bacteria.. Antibiotics do not work against viruses. Normal cold symptoms include sore throat, fever, cough, and/or a runny nose. A runny nose often starts out with clear drainage and then turns to a green or yellow color. This is a good sign that the body is fighting the virus. If your runny nose is not getting better after 10-14 days, please talk to your healthcare provider.
No. Viruses cause most bronchitis.
No. Viruses cause most sore throats. Only strep throat needs an antibiotic; it is caused by strep A bacteria.
Sometimes. Viruses and bacteria can cause ear infections. Your doctor may wait to see if the ear infection improves by itself before deciding to give antibiotics.
Sometimes. Bacteria or viruses cause sinus infections. Antibiotics are needed for bacterial sinus infections. A bacterial sinus infection may be present if cold symptoms do not improve after 10-14 days.
It is very important to have your body help itself. Get plenty of sleep, drink lots of fluids and eat healthy foods. Help decrease the symptoms by using a vaporizer or use over-the-counter medicines like saline nose drops, gargles or throat lozenges. Viral infections simply take time to get better.
For household use, antibacterial products are no better than ordinary soap for preventing infections. Hand washing for 15 seconds with ordinary soap and water will reduce the risk of most common infections and does not add to antibiotic resistance.
Yes. It is becoming a major public health concern. Each time you take an antibiotic unnecessarily or improperly, you increase your chance of developing drug-resistant bacteria. We could run out of ways to kill disease-causing bacteria.

You don't know who is carrying anti-biotic resistant bacteria and they may pass that resistant bacteria on to you and make you ill. This could mean stronger, more expensive antibiotics, hospitalization and, sometimes, death.
Reduce the need for antibiotics.
  • Wash your hands! Wash your hands! And, wash your hands! By washing your hands often and thoroughly with plain soap and water, you are helping to prevent disease and, therefore, the need for antibiotics.
  • Prevent food borne illnesses by properly refrigerating perishable foods, thoroughly cooking all food from animal sources, and avoiding cross-contamination of other foods.
  • Consider pets, even if not ill, as potential sources of infection.
  • Dispose of feces, urine, diapers and contaminated articles properly.

Also, you should take antibiotics only when necessary. Don't insist on an antibiotic when your doctor says, "no". Never take an antibiotic for a viral infection such as cold, cough, or flu. Take an antibiotic exactly as the doctor prescribes. And take the antibiotic until it is gone, even if you are feeling better. Never save the medication to treat yourself or others later.

Common Antibiotics (PDF)

Viruses versus bacteria (PDF)