Multidrug-resistant bacteria (MDR) are a major threat to public health. These bacteria, such as methicillin-resistant *Staphylococcus aureus* (MRSA), *Klebsiella pneumoniae*, and *Escherichia coli*, are capable of resisting multiple treatments, making the infections they cause sometimes fatal.

In France, the figures are alarming: nearly 104,000 cases of resistant bacterial infections are recorded each year, with approximately 4,500 associated deaths. These data highlight the urgency of finding solutions to limit their spread and protect the population.

To counter this threat, it is important to understand the risks and challenges associated with their management, as well as the actions of health authorities and professionals. This article explores these essential issues and the measures implemented to combat these bacteria.

Understanding the threat of multi-resistant bacteria

What is a multi-resistant bacteria?

Bacteria are considered multi-resistant to antibiotics (MDR) when, due to the accumulation of acquired resistance, they are only susceptible to a very limited number of therapeutically-useable antibiotics. This means that these bacteria have developed defense mechanisms that make them resistant to several families of antibiotics, often more than three.

This multi-resistance results from genetic mutations or the acquisition of resistance genes, which makes them particularly difficult to treat. Multidrug-resistant bacteria are among the organisms with multidrug resistance, a situation that can lead to a worrying therapeutic dead end.

The dynamics of antibiotic resistance in the hospital environment

In a hospital setting, the dynamics of antibiotic resistance are particularly complex. Hospitals provide a favorable environment for the selection and spread of multi-resistant bacteria due to the intensive use of antibiotics and invasive care that increases the risk of transmission.

Hospitalized patients, often immunocompromised or with comorbidities, are more vulnerable to nosocomial infections caused by these bacteria.

The spread of multi-resistant bacteria in hospitals is amplified by a lack of rigor in hygiene precautions, the reuse of non-sterilized equipment, and the transfer of patients between departments or hospitals. This situation requires constant vigilance and strict prevention measures to limit their spread.

Main multi-resistant bacteria present in hospitals

Among the most commonly detected multi-resistant bacteria in hospitals are methicillin-resistant Staphylococcus aureus (MRSA), extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae, and vancomycin-resistant Enterococci (VRE).

MRSA is particularly concerning because it is responsible for serious infections that are difficult to treat, such as skin infections, pneumonia, and blood infections. ESBLs, including species such as Klebsiella pneumoniae and Escherichia coli, are also of concern because of their ability to produce enzymes that destroy a wide range of beta-lactam antibiotics.

Risks associated with multi-resistant bacteria in hospitals

Impact on patient safety

Multidrug-resistant bacteria represent a major threat to the safety of hospitalized patients. One of the main concerns is the delay in initiating effective treatment, as antibiotic sensitivity tests often require a waiting period.

This delay can lead to serious complications, or even increased mortality, particularly in cases of severe infections such as pyelonephritis or bacteremia.

In addition, patients colonized or infected with multi-resistant bacteria generally require longer and more complex treatments, thus increasing the risk of complications and sequelae. The use of last-line antibiotics, which are often more toxic and less well-tolerated, adds an additional level of risk to patient health.

Consequences on healthcare and economic burdens

Infections related to multidrug-resistant bacteria have a significant impact on healthcare and associated costs. Patients often require prolonged hospital stays, leading to increased costs and greater resource consumption.

Moreover, the complex treatments and intensive care required to manage these infections lead to an increase in economic burdens for healthcare systems. The prevention and control of these bacteria require significant investments, including the implementation of strict hygiene protocols, the use of protective equipment, and staff training. Although these measures are essential, they represent an additional burden for hospitals.

Risks for hospital staff

Hospital staff are also exposed to significant risks when treating patients with multidrug-resistant bacteria. Cross-transmission can occur if hygiene precautions are not scrupulously observed, exposing caregivers to a risk of colonization or infection.

This situation requires constant vigilance and strict adherence to prevention protocols to limit these risks. Furthermore, the stress and pressure associated with managing these patients can have psychological and emotional repercussions on healthcare staff, affecting their well-being and work performance.

Challenges in managing multi-resistant bacteria

Detection and monitoring

Detection and surveillance of multi-resistant bacteria represent a major challenge in healthcare facilities. Implementing effective surveillance systems is essential to identify and monitor the emergence and spread of these bacteria.

However, this task remains complex due to the need to collect and analyze data systematically and continuously. Key indicators, such as the incidence density per 1,000 hospitalization days (HD) and the attack rate per 100 hospitalized patients, must be calculated with rigorous precision to ensure reliable results.

In addition, healthcare facilities must adopt standardized protocols to identify patients carrying multi-resistant bacteria upon admission. This requires close coordination between laboratory services, care teams, and infection prevention and control units (IPCU).

Limitations of available therapeutic options

One of the main difficulties in managing multi-resistant bacteria lies in the limited therapeutic options available. These bacteria, such as MRSA and EBLSE, are often resistant to most commonly used antibiotics, forcing clinicians to resort to last-line treatments.

These treatments, although sometimes effective, are often more toxic, less well tolerated, and can lead to serious side effects, further complicating patient management.

In addition, the shortage of new antibiotics in development and the increasing ineffectiveness of current treatments exacerbate the situation. The research and development of new antimicrobial agents are essential, but this process remains slow and costly, leaving a critical therapeutic void in the immediate term.

Current solutions to counter the spread of multi-resistant bacteria

Infection prevention and control

Prevention and control of infections play a key role in combating the spread of multi-resistant bacteria. Among the most effective measures, hand hygiene is recognized as essential to interrupt the transmission of microorganisms.

According to data from theWorld Health Organization (WHO), improving hand hygiene could reduce healthcare-associated infections by 50%.

Cleaning and disinfecting surfaces and equipment is also essential. Multiresistant bacteria can survive and multiply on inanimate surfaces for weeks or even months. This highlights the importance of regular and preventive cleaning and disinfection.

Advanced techniques, such as vaporized hydrogen peroxide, can be used for additional terminal disinfection. However, these methods should not replace standard cleaning.

Screening patients upon admission, particularly for bacteria such as MRSA, VRE or GNBPC, is an important measure. This screening identifies carrier or at-risk patients and implements additional precautions to prevent transmission.

These precautions include isolating patients and using appropriate personal protective equipment.

Innovative prevention and treatment strategies

To strengthen the prevention and treatment of infections caused by multi-resistant bacteria, innovative strategies are being deployed. Programs promoting the rational use of antibiotics are essential to reduce the incidence of resistant bacteria.

These programs aim to optimize the use of antibiotics, limit unnecessary prescriptions, and encourage the use of alternative treatments when possible.

Advances in diagnostic microbiology also play a crucial role. The adoption of the latest standard criteria for susceptibility testing, such as those of EUCAST, allows for more accurate and rapid detection of resistance mechanisms. Furthermore, the mastery of standardized methods for detecting resistance genes by infectious disease specialists and clinical epidemiologists facilitates more effective management of cases of multidrug-resistant bacteria.

Finally, the research and development of new antimicrobial agents, as well as the exploration of alternative therapies such as phagotherapies or immunotherapies, offer promising prospects. These approaches could provide safer, more effective therapeutic solutions for patients infected by these bacteria.

The actions of the Network for Alert, Investigation and Surveillance of Nosocomial Infections (RAISIN) and their impact

The role of RAISIN in monitoring multi-resistant bacteria

The Network for Alert, Investigation and Surveillance of Nosocomial Infections (RAISIN) plays an essential role in the prevention and surveillance of nosocomial infections, particularly those caused by multi-resistant bacteria. Created to coordinate efforts at the national level, RAISIN is under the aegis of the Public Health Institute. It relies on five regional coordination structures and two national advisory committees of the Ministry of Health, as well as public health agencies.

The network is responsible for implementing national surveillance systems, such as prevalence surveys conducted every five years, as well as specific networks to analyze trends and characterize priority nosocomial infections. RAISIN also manages the mandatory reporting of nosocomial infections that meet specific criteria for alerts. In addition, it defines the technical specifications of surveillance systems, coordinates their implementation, and supports responses to alerts, emergencies, or outbreaks of nosocomial infections.

Examples of successes and challenges to be met

RAISIN initiatives have achieved remarkable results in the fight against nosocomial infections in France. For example, its data revealed an overall decrease in the risk of nosocomial infections in acute care. Between 2001 and 2006, a 38% reduction in infections related to methicillin-resistant Staphylococcus aureus (MRSA) was observed.

Furthermore, the REA-Raisin network, integrated into RAISIN, has been effectively monitoring nosocomial infections in adult intensive care since 2004. It has developed a common methodology for assessing risks in intensive care and has helped identify the main risk factors as well as the characteristics of patients in intensive care.

However, despite these successes, RAISIN still faces significant challenges. Constant vigilance in the face of the emergence of new multi-resistant bacteria and the strengthening of surveillance and prevention capacities in all hospitals remain priorities.

In addition, the integration of surveillance data into daily clinical practices and the continuous awareness of care staff regarding prevention protocols are key elements to ensure the lasting effectiveness of HAIs prevention efforts.

Conclusion

The threat of multi-resistant bacteria to antibiotics represents a major challenge for public health. It impacts not only patients, but also hospital staff and healthcare systems as a whole. Understanding the nature of these bacteria, their mechanisms of resistance, as well as the risks they pose in hospital and community settings is essential.

To limit their spread, it is essential to implement prevention and control efforts, such as strict adherence to hygiene rules, systematic monitoring, and rational use of antibiotics. These actions are essential pillars to curb this threat.

The role of surveillance networks, such as RAISIN, is fundamental to coordinating these initiatives and ensuring an effective response. There is an urgent need to strengthen surveillance capacities, develop new antimicrobial therapies, and raise awareness of this issue among both the public and healthcare professionals. Together, we have the power to act to prevent the spread of multi-resistant bacteria and protect everyone's health.

FAQ

What are the main factors favouring the presence of multi-resistant bacteria in a hospital environment?

The main factors that promote the presence of multi-resistant bacteria in the hospital environment include:

• Recent hospitalization, which exposes the patient to an environment where these bacteria are present.
• Recent exposure to outpatient care.
• Recent antibiotic treatment, particularly with fluoroquinolones or beta-lactams.

How are multi-resistant bacteria transmitted, and what are the most common modes of transmission?

Multi-resistant bacteria are mainly transmitted by:

• Via direct contact, notably through the hands of healthcare staff, which are a major source of spread in the hospital environment.
• Via indirect contact, involving contaminated food, water, or objects.

Moreover, inanimate surfaces, even after cleaning and disinfection, can harbor these bacteria and contribute to their transmission.

How do you know if you are a carrier of multi-resistant bacteria, and what types of samples are necessary to determine this?

The detection of multi-resistant bacteria relies on several types of tests and samples:

• Phenotypic, biochemical, and molecular tests.
• Sampling from different anatomical sites, such as blood, urine, or respiratory secretions, to improve detection sensitivity.

Methods include:

• The antibiogram.
• MALDI-TOF tests.
• Immunochromatographic tests.
• Molecular tests, such as the RAPID system, which detects resistance genes.

Should multi-resistant bacteria be treated in case of colonization, or only in case of active infection?

In the event of colonization by multi-resistant bacteria, antibiotic treatment is generally not necessary, as colonization does not correspond to an active infection.

However, it is important to note that colonization increases the risk of infection. Antibiotic treatment is reserved only for cases where an active infection is present.