Mechanisms of antibiotic resistance have been a productive research topic in academia
[68]. Bibliometric methods, as an adjunct to the systematic literature review, can be used to measure the importance of AMR as a research topic, provide an overview of the knowledge base, the scientific progress of AMR, and help identify its specific characteristics based on certain indicators. Bibliometrics, as defined by the OECD Glossary of Statistical Terms, is the statistical analysis of books, articles, or other publications to measure the “output” of individuals/research teams, institutions, and countries, to identify national and international networks, and to map the development of new (multi-disciplinary) fields of science and technology”
[69]. As data, bibliometrics typically measures publication and citation counts, patents, royalty, and recently “altmetrics” or social media mentions. Bibliometric methods include various descriptive analyses of bibliometric data, as well as analytical methods such as statistical regressions, social network analysis (based on relationships such as co-authorships or shared citation patterns), and text mining.
Review of Bibliometrics and AMR Research
Bibliometric analysis was conducted on AMR research to validate recent bibliometric findings and support the definition and characteristics of the next generation AMR network as described here. Bibliometric data was sourced from Elsevier’s Scopus, the world’s largest abstract and citation database of peer-reviewed literature and collected in March 2021. The search phrases included “AMR”, “anti-microbial resistance”, “antimicrobial resistance”, and “antibiotic”. Searches were conducted on all indexed documents and publication types from 2011 to 2020.
The query resulted in 2536 publications by more than 14,000 authors affiliated with more than 9200 institutions in 151 countries. The retrieved AMR publications belonged to the following subject areas: medicine (
n = 1423; 31%); immunology and microbiology (
n = 702; 15.3%); biochemistry, genetics, and molecular biology (
n = 539; 11.7%); agricultural and biological sciences (
n = 407; 8.9%); and pharmacology, toxicology, and pharmaceutics (
n = 336; 7.3%). Similar to the findings of recent studies
[70][71][72], growth in AMR-related scientific publications was observed over the past 10 years (
Figure 1).
Figure 1. Annual growth of publications on antimicrobial resistance. The dashed line represents the trend line showing a positive trend in AMR-related research.
The growth in publication count and other bibliometric indicators (particularly the number of institutions engaged in AMR research) was obvious when the dataset was divided into two groups (2011–2015) and (2016–2020) (Table 1). A steady increase per year in the number of AMR-related publications (CAGR = 75%) and the number of contributing authors and institutions (CAGR = 81% and 86%, respectively) was noted after the release of 2015 WHO’s Global Plan of Action on AMR. The number of countries represented increased threefold, while the number of author networks increased sixfold, with a CAGR of 33% and 59% per year, respectively. Multidisciplinary research increased fivefold with a CAGR of 56%.
Table 1. Bibliometric indicators analyzed for AMR-related publications, 2011–2020.
Figure 2 shows the geographic regions that contributed to the AMR research. Europe produced more than 40% of the publications, followed by Asia and North America. These regions also stand out in terms of research influence (citations) and global collaboration.
Figure 2. Percentage (%) of publications by geographic region (2011–2020). The inner circle represents the number of AMR-related publications, middle circle represents the citations received for these publications and the outer circle represents the total link strength of these regions.
The co-occurrence of article keywords was analyzed and visualized to showcase the topical clustering and their development trajectories (Figure 3). As demonstrated in Figure 3, four major clusters were formed, with one major cluster overlapped with the others. The clusters presented in green represent the research on antibiotic consumption and stewardship programs about AMR and overlapped with the others. The clusters in yellow represent the AMR management in health, agriculture, and environment sectors while the clusters in blue represent AMR surveillance, infection control, and risk assessment from a medical perspective. Finally, the clusters in purple represent AMR causes and testing, and first line of treatment. Figure 3 reveals that in recent years, research topics have developed from AMR causes, testing and initial treatment, to AMR surveillance, infection control, and risk assessment, to antibiotic consumption and stewardship programs, and to most recently, the push for a One Health approach including management of AMR in animal and environmental sectors.
Figure 3. Co-occurrence network of keywords. The node size indicates the number of occurrences of a keyword. Edges between nodes indicate co-occurrences between keywords. The thicker an edge is, the more a keyword co-occurs with the other keyword. The node color indicates the category of a node and is scaled to the averaged publication year.
Interestingly, keywords indicating environmental research were predominantly clustered with keywords relating to agriculture and food production suggesting the need for an integrative perspective uniting agriculture, food, and the environment, hence, a one health approach. However, despite this grouping, keywords relating to One Health research in the current dataset were relatively isolated as they demonstrated less dense connections with other keywords or clusters. This implies that the One Health approach remains at the periphery of the AMR research but its location in the network is expected to improve with greater focus on this approach to better understand drivers of the global emergence, dissemination and curb the effects of AMR.
Mapping the top 100 most frequently used terms in the retrieved AMR-related publications resulted in four major clusters around different research themes (Figure 4). The first research theme (red cluster, n = 41 terms) represents research on new drugs and antibiotics to treat infections and control AMR. The second theme (green cluster, n = 24 terms) represents research on antibiotic resistance in bacteria from humans and farm animals. The third research theme (blue cluster, n = 23 terms) represents antibiotic stewardship and measures for optimizing the prescription of anti-infective agents. The fourth research theme (yellow cluster, n = 10 items) relates to knowledge, practices, and attitude toward antibiotics use. These clusters along with other research themes are complementary to the research areas that the next generation of AMR network provides in this entry.
Figure 4. Network visualization map of top 100 most frequently used terms in the retrieved AMR-related publications (2011–2020).
The growth trends of the last decade are expected to continue as scientific research on AMR increases in urgency. To foster this growth, it is critical to build research networks and capacity for transdisciplinary and multidisciplinary research on AMR. The next section defines the next generation of AMR networks, including proposed hallmarks, phase-gate milestones, and strategies to fill AMR implementation gaps.