What causes antimicrobial (drug) resistance?
Causes of Antimicrobial (Drug) Resistance. Microbes, such as bacteria, viruses, fungi, and parasites, are living organisms that evolve over time. Their primary function is to reproduce, thrive, and spread quickly and efficiently.
Can there be too much antibiotic resistance?
Originally touted as a miracle discovery, we are seeing that there can be too much of a good thing. The use of antibiotics has saved millions of lives, but its pervasive use to treat any infection, whether serious, minor, or even viral has lead to the increase in antibiotic resistance.
Do antimicrobials in animals increase the risk of drug resistance?
They expressed concern that use of antimicrobials in animals, either for therapeutic use or to promote growth, can lead to the development of drug-resistant microbes (largely bacteria, such as salmonella and campylobacter) that subsequently are transmitted to humans, usually through food products.
How do non-resistant bacteria become resistant to drugs?
Non-resistant bacteria recieve the new DNA and become resistant to drugs. In the presence of drugs, only drug-resistant bacteria survive. The drug resistant bacteria multiply and thrive. The use of antimicrobials, even when used appropriately, creates a selective pressure for resistant organisms.
What factors can lead to drug resistance?
Microbes also may get genes from each other, including genes that make the microbe drug resistant. Bacteria multiply by the billions. Bacteria that have drug-resistant DNA may transfer a copy of these genes to other bacteria. Non-resistant bacteria receive the new DNA and become resistant to drugs.
What are the 5 mechanisms of drug resistance?
The main mechanisms of resistance are: limiting uptake of a drug, modification of a drug target, inactivation of a drug, and active efflux of a drug. These mechanisms may be native to the microorganisms, or acquired from other microorganisms.
What are the main causes of antibiotic resistance?
The main cause of antibiotic resistance is antibiotic use. When we use antibiotics, some bacteria die but resistant bacteria can survive and even multiply. The overuse of antibiotics makes resistant bacteria more common. The more we use antibiotics, the more chances bacteria have to become resistant to them.
How do you get drug resistance?
The standard method for identifying drug resistance is to take a sample from a wound, blood or urine and expose resident bacteria to various drugs. If the bacterial colony continues to divide and thrive despite the presence of a normally effective drug, it indicates the microbes are drug-resistant.
What are the 3 mechanisms of antibiotic resistance?
The three fundamental mechanisms of antimicrobial resistance are (1) enzymatic degradation of antibacterial drugs, (2) alteration of bacterial proteins that are antimicrobial targets, and (3) changes in membrane permeability to antibiotics.
What does it mean to be resistant to a drug?
(... reh-ZIH-stunts) When cancer cells or microorganisms, such as bacteria or viruses, don't respond to a drug that is usually able to kill or weaken them. Drug resistance may be present before treatment is given or may occur during or after treatment with the drug.
What are 4 ways that bacteria resist antibiotics?
Antibiotic resistance mechanismsPump the antibiotic out from the bacterial cell. Bacteria can produce pumps that sit in their membrane or cell wall. ... Decrease permeability of the membrane that surrounds the bacterial cell. ... Destroy the antibiotic. ... Modify the antibiotic.
When does antibiotic resistance occur?
Antimicrobial resistance happens when germs like bacteria and fungi develop the ability to defeat the drugs designed to kill them. That means the germs are not killed and continue to grow.
What is an example of antibiotic resistance?
Examples of bacteria that are resistant to antibiotics include methicillin-resistant Staphylococcus aureus (MRSA), penicillin-resistant Enterococcus, and multidrug-resistant Mycobacterium tuberculosis (MDR-TB), which is resistant to two tuberculosis drugs, isoniazid and rifampicin.
Who is most at risk for antibiotic resistance?
Who is at risk of antibiotic-resistant infections? Everyone is at risk of antibiotic-resistant infections, but those at the greatest risk for antibiotic-resistant infections are young children, cancer patients, and people over the age of 60.
Can overuse of antibiotics cause resistance?
The overuse of antibiotics — especially taking antibiotics when they're not the correct treatment — promotes antibiotic resistance. According to the Centers for Disease Control and Prevention, about one-third of antibiotic use in people is not needed nor appropriate.
What are two things that you can do to help with antibiotic resistance?
What can I do to prevent antibiotic resistance?Don't take an antibiotic for a virus.Don't save an antibiotic for the next time you get sick.Take antibiotics exactly as prescribed. Don't skip doses. ... Never take an antibiotic prescribed for someone else.
What are the types of drug resistance?
Types of drug-resistant TB It includes any resistance to rifampicin, in the form of mono-resistance, poly-resistance, MDR or XDR.
What is an example of drug resistance?
Some bacteria have developed resistance to antibiotics that were once commonly used to treat them. For example, Staphylococcus aureus ('golden staph' or MRSA) and Neisseria gonorrhoeae (the cause of gonorrhoea) are now almost always resistant to benzyl penicillin.
What is drug resistance write its type and mechanism of drug resistance?
Mechanisms of Acquired Drug ResistanceMechanismAntimicrobial AgentDestroy drugAminoglycoside Beta-lactam antibiotics (penicillin and cephalosporin) ChloramphenicolAlters drug targetAminoglycosides Beta-lactam antibiotics (penicillin and cephalosporin) Erythromycin Quinolones Rifampin Trimethoprim1 more row
What is drug resistance in microbiology?
Antimicrobial resistance happens when germs like bacteria and fungi develop the ability to defeat the drugs designed to kill them. That means the germs are not killed and continue to grow.
What factors cause drug resistance?
Misuse and overuse of antimicrobials are the main drivers in the development of drug-resistant pathogens. Lack of clean water and sanitation and inadequate infection prevention and control promotes the spread of microbes, some of which can be resistant to antimicrobial treatment.
How does resistance to drugs develop?
The evolution of drug resistance is facilitated by a number of factors, including increasing use of antibiotics and antimalarials; insufficient controls on drug prescribing; inadequate compliance with treatment regimens; poor dosing; lack of infection control; increasing frequency and speed of travel, which lead to the …
What are the main causes of antibiotic resistance?
Antibiotic resistance is accelerated by the misuse and overuse of antibiotics, as well as poor infection prevention and control. Steps can be taken at all levels of society to reduce the impact and limit the spread of resistance.
What are the mechanisms of drug resistance?
The main mechanisms of resistance are: limiting uptake of a drug, modification of a drug target, inactivation of a drug, and active efflux of a drug. These mechanisms may be native to the microorganisms, or acquired from other microorganisms.
How is antibiotic resistance prevented?
It can be prevented by minimising unnecessary prescribing and overprescribing of antibiotics, the correct use of prescribed antibiotics, and good hygiene and infection control.
Who is at risk for antibiotic resistance?
Who is at risk of antibiotic-resistant infections? Everyone is at risk of antibiotic-resistant infections, but those at the greatest risk for antibiotic-resistant infections are young children, cancer patients, and people over the age of 60.
Can you reverse antibiotic resistance?
Yes, antibiotic resistance traits can be lost, but this reverse process occurs more slowly. If the selective pressure that is applied by the presence of an antibiotic is removed, the bacterial population can potentially revert to a population of bacteria that responds to antibiotics.
Economic Burden
Although few estimates have been made of the economic impact of drug resistance in developing countries, there is some indication that this burden is substantial.
Interventions
In this section, we discuss interventions to address the challenge of drug resistance ( table 55.3 ). Many interventions to address the problem of resistance are the same as those that reduce the burden of disease (these are discussed in detail in the relevant disease-specific chapters in this volume).
Agenda for Action
Although the evolution of resistance is a biological phenomenon, it is influenced strongly by the behavior of physicians, patients, and hospital administrators.
Conclusion
Modern medicine rests on the bedrock of effective anti-infective drugs. Unfortunately, the use of drugs creates selective pressure for resistance to arise, and thus, the growth of resistance may be an unavoidable consequence of our actions in treating disease.
Footnotes
The fitness cost of resistance is an evolutionary disadvantage placed on resistant pathogens. However, some argue that although most resistance-determining mutations engender some fitness cost, these costs are likely to be ameliorated by subsequent compensatory mutations.
What are the causes of antibiotic resistance?
In summary, the 6 main causes of antibiotic resistance have been linked to: 1 Over-prescription of antibiotics 2 Patients not finishing the entire antibiotic course 3 Overuse of antibiotics in livestock and fish farming 4 Poor infection control in health care settings 5 Poor hygiene and sanitation 6 Absence of new antibiotics being discovered
Why are antibiotics not taken for the entire prescribed course?
When antibiotics are not taken for the entire prescribed course, pathogenic bacteria can adapt to the presence of low dose antibiotics, and eventually form a population that is completely resistant to the antibiotic regardless of the dosage.
Why are antibiotics used?
The use of antibiotics has saved millions of lives, but its pervasive use to treat any infection, whether serious, minor, or even viral has lead to the increase in antibiotic resistance. Antibiotics strictly target bacteria, but it is sometimes difficult to differentiate between viral and bacterial infections without costly tests. It is often less time-consuming and more cost effective to proactively prescribe antibiotics, rather than take precautions and prescribe only the correct treatment.
Can a hospital curb the spread of a pathogen?
Hospitals and clinics are seeing more and more patients with infections, and it is not always possible to curb the spread of a pathogen in a population. Identification, isolation or treatment of all infectious diseases are not often feasible, resulting in the addition of more pathogens to the local community.
Is antibiotic resistance a global threat?
Antibiotic resistance has become a global threat, and with Antibiotic Awareness Week, it is important to understand the series of events that have led the world to this predicament.
Is there a vaccine for TB?
The Bacille Calmette-Guérin (BCG) vaccine is used in some countries to help prevent serious TB infections in children. However, the BCG vaccine isn’t used in the United States due to a general lack of efficacy overall.
Is drug-resistant TB spread the same way as regular TB?
Yes. Drug-resistant TB is also airborne and spreads through air droplets from a person with an active TB infection. What makes drug-resistant TB different is that the bacteria that cause the infection are resistant to medications normally used to treat it.
When did drug-resistant TB start?
While the exact timeline isn’t known, scientists first identified antibiotic resistance in the 1940s. Since then, more antibiotic-resistant infections have developed, with the Centers for Disease Control and Prevention (CDC) declaring antibiotic resistance one of the “most urgent public health problems” worldwide.
Is drug-resistant TB fatal?
Most cases of TB are curable. However, drug-resistant TB is more difficult to cure because the medications normally used to treat the infection don’t work. This type of bacterial resistance could increase the risk of death from TB, making early diagnosis critical.
How does antibiotic resistance happen?
How Antibiotic Resistance Happens. Antibiotics save lives but any time antibiotics are used, they can cause side effects and lead to antibiotic resistance. Since the 1940s, antibiotics have greatly reduced illness and death from infectious diseases. However, as we use the drugs, germs develop defense strategies against them.
What bacteria break down antibiotics?
Germs change or destroy the antibiotics with enzymes, proteins that break down the drug. Example: Klebsiella pneumoniae bacteria produce enzymes called carbapenemases, which break down carbapenem drugs and most other beta-lactam drugs. Bypass the effects of the antibiotic.
How do antibiotics fight germs?
Antibiotics fight germs (bacteria and fungi). But germs fight back and find new ways to survive. Their defense strategies are called resistance mechanisms . Bacteria develop resistance mechanisms by using instructions provided by their DNA. Often, resistance genes are found within plasmids, small pieces of DNA that carry genetic instructions from one germ to another. This means that some bacteria can share their DNA and make other germs become resistant.
Can germs resist antibiotics?
Germs can use defense strategies to resist the effects of antibiotics. Here are a few examples.
How do antimicrobial resistances develop?
An antimicrobial resistant organism may be acquired by emergence of resistance in endogenous flora, or by acquisition from other patients and the environment. Emergence from endogenous flora has been frequently reported among gram-negative organisms with inducible beta-lactamases and in Pseudomonas aeruginosa. A recent important example is the emergence of glycopeptide intermediate MRSA (GISA). These strains have usually developed in patients with persistent or relapsing MRSA infection associated with foreign bodies such as hemodialysis catheters which have not been removed, and after prolonged vancomycin therapy.
What are the highest risk patients for antimicrobial resistance?
These include patients at extremes of age with biologically impaired immune systems, such as premature neonates and the very old. Other patients have acquired immunodeficiency, which is often therapeutically induced. These include the increasing numbers of solid organ and bone marrow transplant patients and profoundly neutropenic patients, as well as patients with severe trauma or extensive burns. These highest risk patients are primarily cared for in large, tertiary care, teaching hospitals. Hospitalized patients experience repeated interventions for monitoring or therapy which further impair normal host defenses and increase the risk of infection. Indwelling urethral catheters, central vascular lines, endotracheal tubes, and surgical wounds permit access of microorganisms to normally sterile body sites. Recent evolution in health care delivery with shortened hospital stay and increased patient acuity means patients now hospitalized are at even greater risk for infection.
Why is selection pressure so high?
However, a significant reason for high selection pressure in the face of modest antimicrobial expenditure is inappropriate antibiotic use.
Why are antimicrobials used in food?
Antimicrobial agents are used in food animal production to prevent disease in high-risk animals and to control or treat disease; or to improve the ability of the animal to convert feed to muscle. Unlike the situation in human medicine where individual patients can be treated, food animal medicine is often practiced on a population basis for reasons of animal welfare, logistics, and efficiency since it is impractical to individually treat each animal in a group that consists of hundreds to tens of thousands. Herd health medicine also relies heavily on preventive medicine strategies to control or prevent disease in high risk populations. Addition of antimicrobial agents to feedstuffs, or by water, or parenteral administration to groups of animals by injection to prevent or control disease progression is done strategically when certain criteria are met. These criteria include prior experience of a disease outbreak associated with animal movement or weather extremes, or a noticeable increase in clinical signs of disease in a few animals in the group. This early therapeutic administration to the entire group is warranted, since many animals will have been exposed to the index cases and are now “incubating” the pathogens. Left untreated, as time elapses, more animals will “break” with clinical signs. Strategic application of an antimicrobial agent at the right time can minimize the pathogen load within a sufficient number of animals in the group (by allowing the host immune defenses to control the infection) and ultimately restore the group to an acceptable health status. Thus, preventive medicine, as a part of a herd health program, is in some cases the best way to maintain healthy animals. It is not appropriate to allow the majority of animals to suffer or die unnecessarily before beginning treatment (which is likely to fail at that late stage of the disease course). Many critics of this well-established practice incorrectly refer to the administration of “subtherapeutic” doses of antimicrobial agents in this instance, when in fact, the doses were developed to be therapeutic for those animals exhibiting signs of disease and are sufficient to benefit those animals that are incubating the pathogen and would soon break with disease. Routine administration of antimicrobials to healthy animals, with the intention of doing so as “insurance” or to “cover” poor management or hygiene is not a practice used by the leading production companies because it would be expensive, unsuccessful, and an unsustainable method of animal production. The administration of antimicrobials to enhance performance or growth of the animals may reflect the intention of the producer, but frequently the antimicrobial agents are in reality controlling an unrecognized subclinical disease exposure in the animals.
What are the two major interventions for antimicrobial resistance?
The two major interventions are infection control to prevent transmission, and limitation of antimicrobial use. A recent consensus statement notes that all previous efforts have failed, and views this as a failure of leadership by both administration and medical staff who have not taken ownership of the problem ( Goldman et al., 1996 ).
What is the need for rapid, reliable diagnosis?
Another need is development of rapid, reliable diagnosis to identify the presence of infection, the specific infecting organism, and antimicrobial susceptibilities. Diagnostic precision is the key to effectively modifying the current approach of widespread empiric antimicrobial use in ill patients with suspected infections. Without this improved diagnostic capability, it is not realistic to expect to modify current antimicrobial practices. A further need is development of materials resistant to colonization by organisms to limit infection and colonization with antimicrobial resistant organisms on medical devices. Given the prominent role of these devices in nosocomial infection, technological development of medical devices resistant to colonization by microorganisms is a priority.
Is endogenous resistance transmitted to other patients?
There is overlap between these two types of acquisition. Once a patient develops endogenous resistance, the strain may be transmissible to other patients, leading to an outbreak or endemic colonization or infection with the resistant organism. Organisms which may initially cause outbreaks, such as MRSA and VRE, may subsequently become endemic in the facility.
How many people die from antibacterial resistance each year?
What is more, 23,000 people die each year when these drugs fail to work.
Why are bacteria prone to mutations?
Bacteria are prone to DNA mutations. This is part of their natural evolution and allows them to constantly adapt their genetic makeup. When one bug naturally becomes resistant to a drug, it survives when all others are killed. Now it’s a race against the clock.
What family fights off antibiotics?
A study recently published in Nature Communications sheds new light on how Echerichia coli and other members of the Enterobacteria family fight off commonly used antibiotics.
