Antibiotic resistance is a phenomenon that concerns everyone's health. To combat it, it is important to use antibiotics only when necessary.
The term "antibiotic resistance" encompasses two clinically irreconcilable realities: a power of immense therapeutic value and a mechanism that works against it. Antibiotics are pharmacological substances capable of combating bacterial infections, and their discovery has revolutionised modern medicine. It is thanks to antibiotics, in fact, that many infectious diseases have been brought under control and that it is possible today to manage more or less complex clinical situations, such as surgery and the care of oncology patients. On the other hand, resistance is an acquired defensive strategy that allows bacterial infections to evade the effects of these drugs.
The World Health Organisation (WHO) has placed antibiotic resistance among the most formidable threats to public health.
Antibiotic resistance is the ability of bacteria to complete their life cycle even in the presence of hostile pharmacological agents. It is a form of evolutionary adaptation as well as an ancient phenomenon, arising from the coexistence, within the same ecological niche, of bacteria and naturally occurring antimicrobial substances. It is no coincidence that these microorganisms possess a degree of genetic plasticity, modifying themselves and becoming less vulnerable to the agents they come into contact with, including modern synthetic antibiotics.
Bacteria that are susceptible to a given antibiotic drug can develop new resistance capabilities, reducing or eliminating that susceptibility. This can occur through two mechanisms: the development of spontaneous mutations within the bacterial genome and the acquisition of genetic material "provided" by another bacterium (the so-called "horizontal gene transfer"). In either case, a resistant bacterial subpopulation will emerge, equipped with new tools to defend itself against the antibiotic. These bacteria may, for example, create a kind of barrier to shield themselves from the drug, or learn to expel the bactericidal substance before it can damage them.
The biological mechanisms mentioned above therefore underlie the phenomenon, although they are not sufficient on their own to generate a serious large-scale impact. Let us try to shed some light on this.
Fuelled by misinformation, using antibiotics incorrectly encourages the proliferation of resistant bacterial strains, resulting in reduced efficacy of commonly used drugs. "Improper use" refers to taking these medicines without a medical prescription and, in any case, without a genuine need. Consider the futile attempt to treat a common nasal congestion caused mostly by a viral pathogen — not a bacterial one, as the name implies.
So when should they be used? Well, when the doctor — who should always be consulted — considers it genuinely necessary. This may be based on their professional judgement and experience, and/or following a targeted microbiological investigation. Equally, the doctor may rule out their usefulness, identifying the non-bacterial nature of a given condition.
It is also always the doctor who determines the dosage of antibiotics. How much to take and for how long is crucial, both for the success of treatment and in the fight against antimicrobial resistance. Ignoring the doctor's instructions — skipping doses or stopping treatment earlier than prescribed — encourages the emergence of resistant strains.
In addition to people's poor habits, there are other significant factors that have been clearly identified as causes of antibiotic resistance. In clinical practice, first and foremost, every doctor should act with the utmost awareness. Excessive prescriptions, in fact, represent a clear predisposing factor.
Insufficient attention to the problem in certain professional fields is a further aggravating factor. The heavy use of antibiotics (aimed at controlling infections) in veterinary medicine and in the agricultural and livestock sectors inevitably spills over into the human sector as well, given the deep interconnection between our wellbeing, that of other living organisms, and the environment in which we live. Last but by no means least, there is the widespread disregard for the risk of infection and the most basic hygiene standards, which exacerbates the primary cause leading to antibiotic use in the first place — namely, the onset of bacterial infections.
If we consider the efforts, in terms of research and development, required to bring new antibiotics to market, we can begin to appreciate the scale of the damage. And when the phenomenon results in poor therapeutic response, in prolonged illness and in the emergence of serious complications, placing additional strain on healthcare systems, the issue becomes tangible for everyone.
A particularly sensitive aspect concerns bacteria with multi-resistance, which are therefore capable of evading the effects of several antibiotics. Among multi-resistant bacteria we count the species Escherichia coli and Pseudomonas aeruginosa, as well as Staphylococcus aureus and Klebsiella pneumoniae. These are names that may be unfamiliar to non-specialists, but are well known among healthcare workers and in hospital settings, where vulnerable and sometimes immunocompromised patients are at high risk of contracting the serious infections associated with these pathogens.
The use of antibiotics in inadequate ways proves harmful on multiple levels. Residual portions of these drugs enter the natural environment, contaminating vegetation, soil and aquatic ecosystems. Depositing in these areas, the antibiotic substances continue to act on the bacteria that live there, driving the development of new resistance phenomena.
Returning to the concept touched on earlier regarding the interconnection that exists in nature, it is to be hoped that a "One Health" approach can succeed in involving various sectors, starting with agriculture and the environmental sphere, but also the veterinary and livestock industries. The containment of antibiotic resistance — which represents the ultimate goal — involves all these realities equally and demands the same level of commitment from each of them.
Having established the scale of the problem, the World Health Organisation launched, in 2015, a Global Antimicrobial Resistance Surveillance System (Glass), highlighting the need to monitor resistance to antimicrobials (often referred to by the acronym "AMR" in dedicated documents) and promoting the systematic collection of data at national level.
In 2017, the European Commission introduced an action plan against antimicrobial resistance (A European one health action plan against antimicrobial resistance), pushing for thorough monitoring across all member states and aiming at the uniform management of trends. The European Centre for Disease Prevention and Control (Ecdc), for its part, has introduced various surveillance systems, such as the European Antimicrobial Resistance Surveillance Network (Ears-Net).
Both in terms of the spread of resistant bacteria and the uncontrolled use of antibiotics, our country tops the list of "critical" territories, alongside neighbouring Greece.
The recent report produced by the National Observatory on the Use of Medicines and published by the Italian Medicines Agency (Aifa), however, shows a slight improving trend. For the year 2021, a reduction in consumption of –3.3 per cent compared with the previous year is highlighted. The best trends are recorded in the North, with a reduction in antibiotic consumption of –6.1 per cent. The South is less virtuous, with recorded reductions of –2.2 per cent. Out of every ten citizens, three received a medical prescription for an antibiotic in the year under review, with a prevalence that increases with age, reaching fifty per cent in the over-eighties age group. With regard to the paediatric population, the highest consumption is recorded among children aged two to five, with at least one medical prescription for four out of every ten children.
Measures are already under way. For the period from 2022 to 2025 (following on from the one covering the years 2017–2021), a new National Plan to Combat Antibiotic Resistance (Pncar) has been drawn up, structured across multiple areas of intervention and incorporating a thorough surveillance, prevention and control system for the phenomenon. The Pncar was published on 2 February 2023 by the Ministry of Health.
Also significant for national monitoring is the Ar-Iss Antibiotic Resistance Surveillance System, managed by the Department of Infectious Diseases of the Istituto superiore di sanità (Iss).
A worrying figure, in any case, concerns the reckless use of broad-spectrum antibiotics, so called because they are capable of acting on multiple bacterial agents. It is precisely these drugs, in fact, that weigh most heavily on the phenomenon of resistance. The overall picture, in short, remains alarming, with consumption levels that exceed the European average.
Based on a systematic analysis published in the scientific journal The Lancet, the number of deaths recorded worldwide in 2019 and associated with antibiotic resistance stands at 4.95 million. Of these, 1.27 million show a direct correlation with infections caused by resistant bacteria. Among the microorganisms in question are also the species highlighted earlier. Regarding the classes of antibiotics most closely associated with resistance, these include fluoroquinolones and third-generation cephalosporins.
As for trends across different regions of the globe, western sub-Saharan Africa recorded the highest mortality rate, while the most moderate rate is reported for the area encompassing Asia and Australia. It is intuitive, ultimately, how the problem proves more burdensome for contexts with limited resources.
Understanding the dangers is the essential prerequisite for avoiding them. The same principle applies to antibiotic resistance, of which many people are unaware of the causes or, worse still, the very existence. Where a profound lack of awareness persists, it is necessary to inform, highlighting errors and dispelling doubts: hence the considerable importance of the medical profession. The general practitioner, by making themselves reachable and available, should always educate individual patients on the correct use of antibiotics, but should also encourage them to read the package inserts and caution them against self-medication. On the other side, the patient should ask questions about the medicine they intend to take, ascertain its actual effectiveness, as well as the counterproductive consequences of inappropriate use. It is worth recalling, in this regard, that antibiotics are formulated to combat bacterial infections, making them entirely ineffective in treating viral infections (e.g. flu and the common cold). They are therefore useless, as well as contributing to the problem of resistance.
Maintaining one's state of health, avoiding infectious diseases and ruling out in advance the need for certain medicines, is a fundamental aspect. There is therefore every reason to adopt some preventive measures against infections caused by bacteria, such as the mindful consumption of wholesome food (e.g. well-cooked meat and fish, well-washed raw vegetables, fresh milk kept refrigerated) and frequent handwashing.
Regulation in certain professional fields — namely sectors that deal with farmed animals, plants and the environment (e.g. agriculture, veterinary medicine and animal husban
