Why bacterial resistance to antibiotics

However, some bacteria have become resistant to commonly used antibiotics. Antibiotic resistant bacteria are bacteria that are not controlled or killed by antibiotics. They are able to survive and even multiply in the presence of an antibiotic. Most infection-causing bacteria can become resistant to at least some antibiotics. Bacteria that are resistant to many antibiotics are known as multi-resistant organisms MRO.

Antibiotic resistance is a serious public health problem. It can be prevented by minimising unnecessary prescribing and overprescribing of antibiotics, the correct use of prescribed antibiotics, and good hygiene and infection control. Some bacteria are naturally resistant to some antibiotics.

For example, benzyl penicillin has very little effect on most organisms found in the human digestive system gut. Some bacteria have developed resistance to antibiotics that were once commonly used to treat them.

In the past, these infections were usually controlled by penicillin. The most serious concern with antibiotic resistance is that some bacteria have become resistant to almost all of the easily available antibiotics.

These bacteria are able to cause serious disease and this is a major public health problem. Important examples are:. Standard precautions in hospitals are work practices that provide a basic level of infection control for the care of all people, regardless of their diagnosis or presumed infection status.

These precautions should be followed in all hospitals and healthcare facilities and include:. Implementing standard precautions minimises the risk of transmission of infection from person to person, even in high-risk situations. Additional precautions are used when caring for people who are known or suspected to be infected or colonised with highly infectious pathogens micro-organisms that cause disease. Additional precautions are tailored to the particular pathogen and route of transmission.

Additional precautions may include:. Antibiotic resistant bacteria can also be passed from person to person within the community.

This is becoming more common. Ways to prevent transmission of organisms, including antibiotic resistant bacteria, are:. This page has been produced in consultation with and approved by:. Anthrax is a rare but potentially fatal bacterial disease that occasionally infects humans. Some help us. Some make people, crops, or animals sick. Some of those germs are resistant to antibiotics. Antibiotics kill germs that cause infections. But antibiotic-resistant germs find ways to survive.

Antibiotics also kill good bacteria that protect the body from infection. Antibiotic-resistant germs can multiply. Some resistant germs can also give their resistance directly to other germs. Once antibiotic resistance emerges, it can spread into new settings and between countries. Top of Page. Germ Defense Strategies Antibiotics fight germs bacteria and fungi. Examples of Defense Strategies for Germs Germs can use defense strategies to resist the effects of antibiotics.

Here are a few examples. Resistance Mechanisms Defense Strategies Resistance Mechanisms Defense Strategies Description Restrict access of the antibiotic Germs restrict access by changing the entryways or limiting the number of entryways.

Get rid of the antibiotic Germs get rid of antibiotics using pumps in their cell walls to remove antibiotic drugs that enter the cell. Change or destroy the antibiotic Germs change or destroy the antibiotics with enzymes, proteins that break down the drug.

Example: Some Staphylococcus aureus bacteria can bypass the drug effects of trimethoprim Change the targets for the antibiotic Many antibiotic drugs are designed to single out and destroy specific parts or targets of a bacterium. To receive email updates about this page, enter your email address: Email Address. The biggest worry is that new strains of bacteria may emerge that cannot be treated by any existing antibiotics. This video explains why antibiotics do not work on viral infections.

Page last reviewed: 23 May Next review due: 23 May Antibiotics are no longer routinely used to treat infections because: many infections are caused by viruses, so antibiotics are not effective antibiotics are often unlikely to speed up the healing process and can cause side effects the more antibiotics are used to treat trivial conditions, the more likely they are to become ineffective for treating more serious conditions Both the NHS and health organisations across the world are trying to reduce the use of antibiotics, especially for health problems that are not serious.