INTRODUCTION
Antibiotic is considered as one of the most important discoveries in the history of medicine since they made possible the effective treatment of infectious diseases saving millions of human lives in about seven decades. However, the inappropriate use of commercial antibiotics in humans and agriculture, along with the evolution and spread of mobile genetic resistance elements, has triggered the increase of multidrug resistance (MDR) and extremely drug resistance in the last decades (Banin et al., 2017). In February 2017, the World Health Organization (WHO) published the global priority list of antibiotic-resistant bacteria aiming to guide the research and development efforts of new and effective antibiotic treatments in the next years (World Health Organization, 2017). The report classified 12 bacteria and bacterial families in three categories of priority: (i) critical, (ii) high, and (iii) medium. The classification of those bacterial groups and their specific resistance are presented in Table 1 (World Health Organization, 2017).
The pathogenicity level of those priority bacteria and their resistance to most of the recent antibiotic treatments suggest that an effective scientific collaboration between different disciplines in several fields is necessary to face this resistance phenomenon. In this regard, bibliometric analysis constitutes a holistic framework for monitoring the research efforts on a particular field and to identify the characteristics of those studies. Despite the extensive research on the disease and antibiotic area (Liao et al., 2018; Ramirez-Malule, 2018; Soosaraei et al., 2018; Sweileh et al., 2016), a lack of bibliometric studies regarding multidrug and antibiotics resistance was identified. This contribution presents a bibliometric analysis of the most recent scientific contributions in the multidrug and antibiotics resistance fields in the period between 2017 and 2018.
 | Table 1. Global priority list of antibiotic-resistant bacteria reported by the World Health Organization [adapted from World Health Organization (2017)]. [Click here to view] |
 | Table 2. Top-10 leading authors of multidrug- and antibiotics-resistance studies between 2017 and 2018. [Click here to view] |
METHODS
For this study, data search and collection were performed from Scopus database. The systematic search strategy included the terms in the title of the article, abstract, and keywords. Additionally, the “document type” was limited only to articles. Thus, the resulting search was as follows:
- [TITLE-ABS-KEY (“multidrug resistance”) AND TITLE-ABS-KEY (“antibiotics resistance”)] AND [LIMIT-TO (PUBYEAR, 2018) OR LIMIT-TO (PUBYEAR, 2017)] AND [LIMIT-TO (DOCTYPE, “ar”)].
- Timespan: 2017–2018.
The information retrieved from the Scopus database included: (i) citation information, (ii) bibliographical information, (iii) abstract and keywords, and (iv) other information. The software VOS viewer 1.6.10 was used for visualization and data analysis (van Eck and Waltman, 2010).
RESULTS AND DISCUSSION
A total of 2,362 documents were found in the Scopus database as published in the years 2017 and 2018. Table 2 shows the most relevant authors, their affiliation, and number of publications that contributed substantially to research on the multidrug and antibiotics resistance fields. The obtained information provides insights about the main researchers and leading institutions in the area, which could be also useful for the identification of collaboration opportunities and funding.
Figure 1 shows the areas of knowledge related to multidrug- and antibiotics-resistance studies. In this case, medicine contributed 38.8% of the indexed documents, followed by immunology and microbiology and, pharmacology, toxicology and pharmaceutics with 20.5% and 11.9%, respectively. As expected, medicine was ranked as first on this list since multidrug and antibiotics resistance is directly linked to negative consequences on human health and the increase of morbidity rates (Magira et al., 2018). On the other hand, veterinary also appeared in the top-10 fields since some of those resistant bacteria affect animal health as well (e.g., dogs, cats, horses, camels, among others) (Saputra et al. 2017; Sharma et al. 2017; Videla et al. 2018).
The leading countries in studies related to multidrug and antibiotics resistance were United States and China, which contributed with 474 and 332, respectively. The top-10 leading countries based on the number of publications related to multidrug and antibiotics resistance are shown in Table 3. Nevertheless, when the ratio between the number of citations and publications was considered as an indicator of the impact of the research, a redistribution of the top-10 leading countries was observed. In this regard, the United States was the country with the highest impact in the field, followed by Germany and the United Kingdom. This information is coincident with the most productive authors and the countries where their institutes are located (Tables 2 and 3). When productivity was stratified by gross domestic product (GDP), Iran ranked first followed by Spain and India (Table 3) leaving the United States, China, and Germany in the last places. From a different standpoint, if productivity is stratified by calculating the average of the number of citations by GDP, the leading countries were Iran, Spain, and Australia. Interestingly, Iran was the leading country in number of publications—and also number of citations—based on the GDP but had the last place when the ratio of the number of citations and the number of publications was used as an indicator of the productivity. These results evidence an efficient use of the resources dedicated to research and development of this field in those countries with lower income when compared with the middle-high income countries.
 | Figure 1. Contributions in multidrug and antibiotics resistance per area of knowledge between 2017 and 2018. Other areas contributed 5.3%. [Click here to view] |
Figure 2 shows the research-topic network of publications regarding multidrug and antibiotics resistance in 2017 and 2018. Notice that five and six clusters were observed for the years 2017 and 2018, respectively. Additionally, the ranking of keywords and their occurrences are presented in Table 4. Interestingly, the top-10 keywords in 2017 and 2018 were the same but in different order.
Antibiotic resistance, MDR, and antimicrobial resistance were the biggest nodes in the network, as expected. Furthermore, a significative number of studies were focused on four pathogenic bacteria: Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae, which are included in the critical priority level according to the WHO (Table 1). This information suggests that important scientific efforts have been dedicated, in the last 2 years, to the study of multidrug and antibiotics resistance in those bacteria (Bassetti et al., 2018; Biswas et al., 2018; Costa et al., 2018; Nazari Alam et al., 2018). Although most of the bacteria considered in the critical priority level (Table 1) has received attention, considerably less importance has been given to those of high and medium priority level. Therefore, it is necessary to intensify the research focused on those bacterial groups that also represent a high risk for human and animal health.
Institutions have an important role not only in the research but also in the formulation of disease control policies and strategies. As shown in Figure 3, the leading institutions included universities, research centers, and government entities.
In total, 4,421 institutions were involved in 1,309 publications in the year 2017 and 3,846 participated in 1,053 contributions in 2018. These numbers lead to a ratio of 3.4 and 3.6 institutions per article during the years 2017 and 2018, respectively. In this regard, and for the case of the year 2017, only 41 institutions reached the threshold of three published articles but only four of these institutions were interconnected. When the threshold was augmented to five articles, only three institutions appeared and all of them were disconnected. A similar behavior was observed for the year 2018. Therefore, it is clear that stronger collaboration efforts are required to deal with this global health problem.
 | Table 3. Top-10 leading countries of multidrug- and antibiotics-resistance studies between 2017 and 2018. [Click here to view] |
 | Figure 2. Research-topic network visualization of publications related to multidrug and antibiotics resistance. (a) Year 2017. (b) Year 2018. Note: the minimum number of occurrences of a keyword is 15. [Click here to view] |
 | Table 4. Top-10 keywords of multidrug- and antibiotics-resistance studies in the period of 2017–2018. [Click here to view] |
 | Figure 3. Top-10 leading institutions in research on multidrug and antibiotics resistance in the period between 2017 and 2018. [Click here to view] |
FUTURE PERSPECTIVES
Multidrug and antibiotics resistance are global concern issues (World Health Organization, 2017). New drug combinations, novel antimicrobial compounds, in addition to better understanding of the biological causes of resistance and mechanisms of dispersion, undoubtedly will help to deal with the antibiotics-resistance problem (Frieri et al., 2017; Piddock, 2017). The creation of further collaboration networks, including different countries, universities, research centers, and government entities is needed to confront and overcome the challenges of the multidrug and antibiotics resistance.
CONCLUSION
A total of 2,362 articles were published between 2017 and 2018 in the field of multidrug and antibiotics resistance. The research efforts were mainly focused on the critical bacteria according to the WHO priority list, in contrast with the low research activity dealing with high and medium priority bacteria. In terms of the areas: (i) Medicine, (ii) immunology and microbiology, and (iii) pharmacology, toxicology, and pharmaceutics concentrated the majority of multidrug- and antibiotics-resistance studies. The United States, China, and India were the top-leading countries according to the number of publications. Nevertheless, the United States, Germany, and the United Kingdom had the highest impact of their publications based on the ratio of number of citations and number of publications. Iran was the leading country related to number of publications—and also to number of citations—based on the GDP. Finally, a strengthening of scientific collaboration is required for dealing with this global health problem and ensures successful implementation of new antibacterial treatments.
FUNDING
This research was funded by Universidad del Valle (grant number CI 131).
CONFLICT OF INTEREST
Authors declare that there are no conflict of interest.
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