Bacteria are tiny organisms found on our skin, in our digestive system, in the air, in soil, and on almost all the things we touch every day. There are many different kinds. Most are harmless and do not cause disease. Some bacteria are even helpful, such as those that aid digestion. A few types of bacteria cause disease in humans, animals and plants. They are called pathogenic bacteria or pathogens.
A virus is a strand of genetic material in a protein coat. Viruses must infect a living cell to grow and reproduce. They cause many types of illness, including the common cold, influenza, chickenpox, and AIDS (HIV). Viral infections are usually more contagious than bacterial infections.
Antibiotics are chemical compounds that prevent bacteria from growing (bacteriostatic) or kill it (bacteriocidal). They do this without seriously harming the host (an infected human or animal). A bacteriostatic drug gives the person’s immune (defence) system time to destroy the non-growing bacterial infection. Bacteriocidal drugs actually kill the bacteria. These drugs are used when a person’s immune system is not able to destroy the bacteria on its own.
Many types of antibiotics are available. Each works a little differently and affects a different kind of bacteria. You must have a prescription to buy antibiotics. Your doctor decides which antibiotic will work best for your type of infection. The right drug must be used to stop the bacteria. Antibiotics cannot help your body fight a virus.
Antibiotics are used in both humans and animals to treat illness caused by bacteria. Sometimes antibiotics are used to prevent bacterial infection, as in before surgery or some dental procedures. They are also used to increase growth in certain animals raised as food and in pesticides to control bacterial infections in food crops. There are hundreds of antibiotics, most of which belong to eight major family groups. The drugs are classified according to their basic chemical structure. For instance, one of the most common families is penicillin.
Not all antibiotics have the same effect on different strains of bacteria. Some antibiotics only work against specific types of bacteria. Others effectively fight a wide range of bacteria.
Antibiotics can be misused. An incorrect diagnosis might mean antibiotics are prescribed to treat a viral infection. In other cases, the antibiotic does not work against the type of bacteria causing the infection. The Center for Disease Control estimates that half of all antibiotic prescriptions written by doctors are not necessary.
Antibiotics are also misused if they are not taken for the full period of time prescribed to kill all of the bacteria. Doctors and pharmacists insist that you take the full course of your antibiotic even if you no longer feel the symptoms.
The delicate balance of microorganisms in the environment has been upset by the presence of antibiotics. Bacteria that was susceptible to antibiotics for decades have become resistant not only to older antibiotics, but to new ones as well. Some bacteria are naturally resistant to certain types of antibiotics. They also become resistant through a genetic change or by acquiring resistance from other bacteria.
Bacterial resistance was first discovered in the 1940s after the introduction of penicillin. Since then more types of bacteria have shown resistance to newer and more powerful antibiotics at an increasingly faster rate. If an antibiotic is overused or misused, bacteria can become resistant to it. This antibiotic will not be able to kill bacteria or keep it from growing anymore. Some bacteria causing common infections are now resistant to many different antibiotics. For instance, Clostridium difficle, a type of bacteria that causes lung infections, is no longer easily treated with antibiotics such as penicillin.
If large numbers of bacteria are resistant to antibiotics, it becomes harder and more expensive to treat bacterial infections. More time must be spent on visits to the doctor, on sick days and in hospital. More expensive antibiotics are needed to replace older, ineffective ones. In the most extreme case, antibiotics may no longer work at all on very resistant bacteria. If antibiotics fail to work, sometimes death can be the result.
Both you and your health care providers can play an active role in helping reduce the serious and growing problem of antibiotic resistance. Patients can follow some simple guidelines. Take antibiotics exactly as directed. For instance, some medications are to be taken with food and sometimes without food. Do not ask for antibiotics against your doctor’s advice. Take all medication prescribed, even if symptoms disappear. If treatment stops too soon, some bacteria may survive and re-infect. Finally, avoid requesting specific antibiotics from your doctor. The chosen medication must target the bacteria that are causing the infection.
Scientists are fighting antibiotic resistance in several ways. Existing antibiotics can be changed so the bacterial enzymes causing resistance cannot attack them. ‘Decoy’ molecules may also be used along with the antibiotic. This way, bacterial resistance enzymes attack the decoy instead of the antibiotic. Decoy molecules such as clavulanic acid are already used to block enzymes that destroy the penicillin family of drugs. Finally, new antibiotics are being developed. This process is long and expensive. It takes about ten years and $300 million dollars to bring a new antibiotic to market.
Use good hygiene! One of the most effective ways to prevent infections caused by bacteria is hand washing. By washing your hands thoroughly and often with soap and water, you help prevent disease. In fact, hands spread 80 per cent of the most common infections. As well, cooking meat thoroughly and hygienic food handling can help prevent food-borne illnesses.
Antibiotics must only be taken when prescribed by a doctor for an illness caused by bacteria. Antibiotics do not work against viruses. The common cold and the flu are examples of infections caused by viruses. Your doctor will decide if an antibiotic is appropriate and then select the antibiotic that will work best for your infection. When used as prescribed, antibiotics can be powerful medical tools for fighting bacterial diseases.
Doctors examine patients and consider their symptoms to decide if an antibiotic is necessary and, if so, which one. Doctors can also take a culture to see if bacteria are causing a particular illness. For instance, a throat culture can confirm the presence of Strep throat. An antimicrobial susceptibility report may also be used. This report tells which families of antibiotic drugs are useful for the particular bacteria causing the infection. Your doctor can then select the best antibiotic. Your doctor and pharmacist work together to ensure you take the right antibiotic for the time necessary to treat the bacteria causing your infection.
Always follow these simple rules when your doctor prescribes an antibiotic for you.
When antibiotics aren’t used properly, weak bacteria are killed but stronger, more resistant ones can survive and multiply. These resistant bacteria, sometimes called ‘super bugs,’ can cause infections that are very difficult to treat. This means that antibiotics might not work as well when someone really needs them.
It may seem like a good idea to hoard or stockpile medication. However, using the wrong medication can contribute to bacterial resistance. Only use antibiotics prescribed by a doctor to treat a specific bacterial infection.
What should I ask my pharmacist about antibiotics?
Talk to the pharmacist about any allergies to avoid having a reaction to the antibiotic.
Contact your doctor’s office if:
The Center for Disease Control and Prevention (CDC), a branch of the Government of the United States, is the lead U.S. federal agency for protecting public health and safety. The Canadian equivalent is Health Canada’s Population and Public Health Branch. Both agencies work in the areas of disease prevention and control, environmental health, health promotion and education activities. Since there are many similarities between the populations of Canada and the United States, these agencies frequently collaborate.
Used properly, antibiotics are valuable tools in the treatment of bacterial infections. Work with your health care provider to take an active role in the correct use of antibiotics.