Antibiotic resistance



With the term antibiotic resistance we mean the ability of a bacterium to resist the action of one or more antibiotic drugs and therefore to survive and multiply even in their presence. This type of resistance can be both natural (when the bacterium is naturally resistant to an antibiotic), and acquired (when a bacterium adapts to resist an antibiotic drug through changes in its genetic heritage).

Antibiotics are a very important resource for health since, since their discovery, they have contributed significantly to preventing the spread of bacterial infections, minimizing serious complications. Many of the infectious diseases that were not curable in a "pre-antibiotic era" are now more easily curable.

In recent years, however, antibiotics that were commonly used to treat bacterial infections (such as, for example, penicillin in pneumonia) have become less effective or no longer work due to their inappropriate use in the past. The fact that bacteria develop resistance to an antibiotic is a natural evolutionary process but this phenomenon is accelerated and aggravated by the excessive and often incorrect use of these drugs. Any bacterium that survives an antibiotic treatment can become resistant to treatment subsequent, multiply and transfer its ability to resist antibiotics to other bacteria.

It should be noted that the risk of becoming infected with antibiotic-resistant bacteria concerns not only the person who takes antibiotics improperly but also those who will subsequently be infected with those same bacteria.

A further problem is given by bacteria that become resistant to more antibiotics at the same time (multi-resistance) since in these cases finding a cure becomes very difficult. The decrease in the effectiveness of existing antibiotics, in fact, is not compensated by the discovery of new molecules and with the increase in resistance it will become increasingly difficult to cure infections.

Among the most important bacterial species that have become resistant to antibiotics are the Staphylococcus aureus, which can cause infections of the skin and the whole body (septicemia); klebsiella pneumoniae, which causes septicemia, urinary and lung infections; the campylobacter, which causes intestinal infections, and the "escherichia coli which can cause various types of infections, the most common being urinary tract infections.

Antibiotic resistance today is one of the main public health problems worldwide and in recent decades, international organizations including the World Health Organization (WHO), have produced recommendations and proposed strategies aimed at containing the phenomenon with a "One Health" approach that considers the health of humans, animals and the environment in an integrated way.

Causes of antibiotic resistance

One of the main causes of antibiotic resistance is precisely the excessive use, and often useless, of antibiotics also to treat viral infections against which antibiotics have no effect. It is absolutely useless, for example, to take antibiotics in case of colds and / or flu as these infections are due to viruses.It must also be considered that the antibiotic attacks all bacteria present in the body, even those that are part of the so-called bacterial flora or microbiome, that is, the bacteria that colonize the surfaces of the body (skin, respiratory tract, intestine, uro-genital tract) and they carry out beneficial activities for the organism.

Even taking antibiotics without following the prescriptions (for example at lower doses or for a different time than the one indicated by the doctor), can help to develop resistance.

The creation of antibiotic-resistant "super bacteria" can be encouraged when:

  • antibiotics are used without having been prescribed by the doctor
  • the time intervals between one dose and the next are not respected: antibiotics must be taken at regular intervals; if you miss a dose, take it as soon as possible. If, however, it is close to the time for your next dose, it is best to avoid taking a double dose
  • the cure is not completed (as prescribed by your doctor) and keep the leftover antibiotic for future use
  • unused antibiotics are shared with others
  • antibiotics are taken to treat viral infections (such as a cold or the flu) against which they are ineffective

Antibiotic resistance is a phenomenon that involves not only human medicine but also the zootechnical and veterinary sector. One of the factors contributing to its development, in fact, is the administration of antibiotics to farm animals to avoid the appearance of diseases in the overcrowded environments of factory farms. Since the antibiotics used to treat and prevent bacterial infections in animals intended for human consumption belong to the same classes as those used for humans, it is possible that resistant bacteria developed in animals are transmitted to humans through food.

Consequences of antibiotic resistance

Infections caused by antibiotic-resistant bacteria can be very serious and difficult to cure and are becoming a major public health problem around the world.

The spread of resistant bacteria in hospitals or healthcare facilities is a major safety concern for people as it increases the number of illnesses and deaths, as does the length of hospital stays. In Italy, about 30-60% of the bacteria that cause hospital infections are resistant to the most commonly used antibiotics (first choice).

The major concern is that bacteria resistant to all available antibiotics (pan-resistant) may develop. Cases of almost total resistance have already been reported in our country.

If in the future antibiotics should become ineffective and what is defined should occur it was post-antibiotic, even common infections and light wounds that have been easily healed for decades could become a health threat again. Furthermore, it would become risky to carry out surgery or perform transplants, implant prostheses or chemotherapy treatments.

Prevent antibiotic resistance

To prevent the development of antibiotic resistance it is essential to limit the use of antibiotics to cases where they are really needed and to follow a few simple rules:

  • do not ask your GP for antibiotics if this / a has not prescribed them
  • take antibiotics following the doctor's instructions only
  • complete the entire course of care even if it feels better
  • ask your doctor how to behave if you forget to take a dose
  • do not take advanced antibiotics on your own from previous treatment
  • never take antibiotics prescribed for another person
  • never take antibiotics if you have a cold and / or flu

Taking antibiotics against mild bacterial infections, such as some types of sore throats, bronchitis or ear infections, is often superfluous because, in most cases, the action of the body's defense system is sufficient to heal these diseases (immune system). In these cases, if necessary and on the advice of the doctor, drugs can be taken to relieve the present discomfort (for example, anti-inflammatory). it is advisable to contact your doctor who, in the case of a bacterial infection, will prescribe antibiotics.

However, there are cases in which it is necessary to consult a doctor immediately, especially when the person:

  • is over 65 years old
  • suffer from asthma or diabetes
  • have chronic lung disease (for example chronic bronchitis or emphysema)
  • have heart problems
  • you are taking drugs that inhibit the immune system (for example cortisone or chemotherapy drugs)

Not all antibiotics are effective against all bacteria; therefore, it is necessary that a doctor indicate which is the most suitable type for the treatment of the infection in progress. To do this, in many cases it is necessary to carry out a culture test with an antibiogram. This analysis consists in taking a small amount of material (sample) from the area where the infection is present, sow it in specific culture media, check after a few days if bacterial strains develop and which type they belong to (culture test), then treat them with different types of antibiotics to check which is the most effective (antibiogram).

To avoid becoming infected with antibiotic-resistant bacteria, it is good practice to pay attention to hygiene: wash your hands regularly with soap and water, especially after using the bathroom, before eating, before preparing food and after handling raw meat. .Food products of animal origin are often contaminated with bacteria and therefore can also constitute a transmission route for antibiotic-resistant bacteria. Fruits and vegetables can also be a way of transmission if they come into contact with animal waste or contaminated water, so it is important to wash them well and keep kitchen work surfaces clean at all times.

Antibiotic resistance in Italy

According to a recent European study, Italy is in first place in Europe for the number of antibiotic-resistant infections (more than 200,000) and deaths due to antibiotic-resistance (about 10,000); most antibiotic-resistant infections are due to hospital infections caused by multidrug-resistant bacteria.

Following the recommendations of international institutions, in Italy, in 2017 the "National Antimicrobial-Resistance Plan (PNCAR) 2017-2020" was approved, containing the strategies useful for combating the phenomenon at local, regional and national level in agreement with the objectives of the WHO and EU action plans.

The national surveillance of antibiotic resistance, called AR-ISS, is coordinated by the Istituto Superiore di Sanità (ISS). This surveillance is based on a network of hospital microbiology laboratories distributed throughout the country which, annually, provide the ISS with antibiotic resistance data relating to a selected group of microorganisms isolated from clinically important infections (bacteremia or meningitis). For each microorganism, the focus is mainly on certain antibiotics or classes of antibiotics that are particularly significant in therapy. The surveillance makes it possible to monitor the trend of antibiotic resistance in Italy from year to year by analyzing the data from hospital laboratories present in all Italian regions.

The European Antibiotics Day, which is celebrated every year on November 18th, was established to make the population aware of the problem of antibiotic resistance and to encourage the correct use of antibiotics, to maintain the effectiveness of these important drugs.

In-depth link

Ministry of Health. Prevent infections with proper hand washing; 2020

Ministry of Health. National plan to combat antimicrobial resistance (PNCAR); 2017-20

Ministry of Health. Correct use of antibiotics in companion animals

EpiCentro (ISS). Antibiotic resistance

e-Bug. Fun games and teaching resources about microbes and antibiotics (English)

European Center for Disease Control and Prevention (ECDC). European antibiotic awareness day

Cassini A et al. Attributable deaths and disability-adjusted life-years caused by infections with antibiotic-resistant bacteria in the EU and the European Economic Area in 2015: a population-level modeling analysis. Lancet Infectious Diseases 2019; 19:56–66

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