Antibiotic resistant bacteria
Antibiotics are the most effective agents available to treat infectious diseases by inhibiting the growth of bacterial cells. They are employed not just for human patients and livestock who suffer from infections but also to maintain the health of livestock and aid in proactive disease outbreak prevention. Antibiotic resistance (AR) is the capability of bacteria to resist and overcome exposure to antibiotics. This ability is facilitated by the acquisition of antibiotic resistance genes (ARGs) (Davison et al., 2000).
The use of antibiotics has led to the emergence and spread of AR, posing significant public health challenges globally. Although antibiotic resistance may naturally occur at low levels in most ecosystems, the high occurrences of ARBs and ARGs are mainly due to human activities (Uluseker et al., 2021). Antibiotics are categorized into five primary groups based on their mode of action: bacterial cell wall, cell membrane, protein synthesis, DNA and RNA synthesis, and folic acid (vitamin B9) metabolism. Meanwhile, bacteria have developed four primary types of resistance mechanisms against antibiotics: target modification, efflux, immunity and bypass, and enzyme-catalyzed destruction (Wright, 2010). Resistance to antibiotics arises as an evolutionary response to the strong selective pressure that is caused by the exposure to these substances. The current use of antimicrobials in clinical practice and in agriculture (animal husbandry) may be responsible for the horizontal spread of resistance genes in bacteria species and genera with no intrinsic resistance, and for the maintenance of vertical resistance mutations in populations (Wright, 2010).
Dimension of the problem
Antibiotics have earned the title of miracle drugs. However, their excessive usage and abuse over six decades have led to a surge in bacterial resistance to most antibiotics. The bacterial adaptive evolution has been so effective that particular bacterial infections have become almost impossible to treat using antibiotics (Andersson, 2003). It is paradoxical that research into new antibiotics and mechanisms of action is decreasing while antibiotic resistance and associated morbidity and mortality are increasing. The main reasons for this trend are believed to be the expensive development costs and the low potential return on investment. At present, only a handful of new antibiotics are undergoing clinical trials (Exner et al., 2017).
Morbidity and mortality are significant outcomes of antimicrobial resistance (AMR) in patients (Founou et al., 2017). Resistant bacteria double the likelihood of developing a severe health issue and triple the likelihood of death compared to non-resistant strains (Cecchini et al., 2015). It is extremely important to address AMR in a comprehensive manner to mitigate the impact on public health. These adverse effects are exacerbated by the severity of resistant infections and the susceptibility of the host (Friedman et al., 2016). Currently, approximately 700,000 individuals worldwide die annually due to drug-resistant infections (O’Neill, 2016). Recent research conducted by the World Bank indicates that AMR will accelerate poverty rates, particularly in low-income countries, when compared to the global average. As expected, the AMR crisis would widen the gap between these countries and their developed counterparts, thereby increasing income inequality (Jonas et al., 2017).
One health concept from WHO
It is challenging to imagine a topic that better represents the principles of One Health than AMR (Robinson et al., 2016). The One Health approach, characterized as a collaborative effort of various disciplines at local, national, and global tiers to achieve optimal health for people, animals, and the environment, acknowledges the interconnectedness of human health with animal health and the environment (American Veterinary Medical Association, 2008). One Health considers the impact of interconnected and nearby ecosystems on the emergence and spread of AMR, hence addressing AMR by implementing integrated AMR interventions at the city or regional level. The transmission of antibiotic resistance crosses boundaries between different ecosystems such as farms, hospitals, wastewater treatment plants, and natural environments. The well-being of a particular ecosystem can affect the health of other ecosystems, including humans (Hernando-Amado et al., 2019).
Antibiotic resistance monitoring in hospitals
Surveillance is crucial to managing healthcare-associated infections and antibiotic resistance. It provides the information needed to develop and monitor therapy guidelines, infection control policies, and public health interventions (Tacconelli et al., 2018). Active monitoring of antibiotic resistance is crucial for the successful management of antibiotics, which facilitates appropriate antibiotic utilization that optimizes clinical outcomes for patients while minimizing unintended antibiotic effects (Barlam et al., 2016).
The Governmental Institute of Public Health of Lower Saxony established the sentinel system ARMIN (Antimicrobial Resistance Monitoring in Lower Saxony) to recognize the regional trends of antimicrobial resistance in both inpatient and outpatient care. Many laboratories, acting as sentinel sites, presently contribute single case data of their microbiological results. The data are available for interactive queries on the internet from 2006 (Scharlach et al., 2011).
Antibiotic resistance monitoring in the environment
Global and national action plans have generally adopted a One Health framework to address AMR (Hernando-Amado et al., 2019). However, there is growing recognition that more emphasis should be placed on environmental dimensions. Although there is evidence suggesting that water environments play a role, there is a lack of studies quantifying this role and associated risks (Liguori et al., 2022). The occurrence and fate of antibiotics in the environment are determined by several factors, including their excretion (metabolism) by humans or animals, their interaction with solid environmental matrices (sorption), and their persistence in different environmental matrices (transformation) (Schmitt et al., 2017). A significant challenge of monitoring environmental antimicrobial resistance is that without a clearly defined objective, the mission can become an unrealistic task of monitoring everything, everywhere (Bengtsson-Palme et al., 2023).
There were two environmental monitoring studies conducted in Lower Saxony. In 2018, the Governmental Institute of Public Health of Lower Saxony (NLGA) carried out a measurement program to gain insights into the occurrence and spread of antibiotic-resistant bacteria in the state's bathing waters (NLGA, 2019). In addition, the Lower Saxony State Agency for Water Management, Coastal Protection and Nature Conservation (NLWKN) implemented a special monitoring program in the aquatic environment. The primary objective of this program was to obtain an overview of the possible contamination of water bodies in Lower Saxony with antibiotic-resistant bacteria and antibiotic residues (NLWKN, 2019).