Mapping 25 Years of Molecular Diagnostics Against WHO Priority Superbugs

Antimicrobial resistance remains one of the most formidable threats to global public health, responsible for an estimated 4.95 million deaths associated with resistant bacterial infections in 2019, including 1.27 million deaths directly attributable to resistance. A new bibliometric study published in MicrobiologyOpen has now mapped a quarter-century of research into the molecular diagnostic tools designed to fight this threat, offering the most comprehensive structural picture yet of how the field has grown, where it has concentrated, and which technologies are poised to define its next phase.

The analysis, covering publications from 2000 to 2025, drew on the Scopus database and followed a PRISMA-adapted screening workflow to construct a final analytical corpus of 1,746 articles and reviews spanning 432 journals and involving 11,277 unique authors. The field has expanded at a compound annual growth rate of 17.10%, accumulating 42,075 citations with an average of 24.10 citations per document. Growth accelerated sharply after 2018: annual output rose from 84 publications in 2018 to 259 in 2025, a trajectory the study attributes to increasing prioritization of antimicrobial resistance on the global research agenda and a post-pandemic surge in translational diagnostic research.

To frame the analysis, the study anchored itself in the World Health Organization’s bacterial priority pathogen lists. The WHO’s 2017 framework classified resistant bacteria into critical, high, and medium priority categories, and its 2024 update expanded the list to 24 pathogens across 15 bacterial families using multicriteria decision analysis that weighed mortality, incidence, resistance trends, transmissibility, preventability, treatability, and the state of the drug development pipeline. The critical tier now includes carbapenem-resistant Acinetobacter baumannii, carbapenem-resistant and third-generation cephalosporin-resistant Enterobacterales, and rifampicin-resistant Mycobacterium tuberculosis, while carbapenem-resistant Pseudomonas aeruginosa was moved from critical to high priority based on regional resistance trends and comparatively lower transmission capacity.

Against this backdrop, the bibliometric results reveal a field organized around distinct pathogen axes. Staphylococcus aureus dominated the corpus with 730 publications and 21,945 total citations, followed by Mycobacterium tuberculosis with 439 publications, Enterobacterales with 389, Pseudomonas aeruginosa with 309, Acinetobacter baumannii with 279, and Enterococcus faecium with 250. Growth over the past five years was strongest for Streptococcus pneumoniae at 27.79%, Pseudomonas aeruginosa at 26.35%, and Enterobacterales at 22.81%, signaling a decisive shift in research attention toward Gram-negative carbapenem resistance as the most urgent clinical frontier.

At the platform level, conventional PCR and nucleic acid amplification testing appeared in 61.51% of publications, while whole-genome sequencing featured in 55.44%, making these two technologies the twin pillars of the literature. Because platform categories were not mutually exclusive, many publications combined both approaches. Multiplex PCR stood out for impact, averaging 42.57 citations per article, reflecting the foundational role of early target-specific resistance detection. Emerging technologies, including nanopore sequencing, metagenomic sequencing, and CRISPR-based diagnostics, appeared at low frequencies but formed distinct and growing clusters, suggesting they represent innovation fronts that have not yet reached routine clinical integration.

Resistance marker analysis identified mecA/mecC, rpoB, blaNDM, katG, and vanA/vanB as the most frequently studied molecular targets. Methicillin resistance in staphylococci, epitomized by the mecA gene and its newer variant mecC, anchored the Gram-positive research tradition, while the tuberculosis markers rpoB, katG, and inhA defined a mature and specialized diagnostic axis. Carbapenemase genes, including blaKPC, blaNDM, and blaOXA-48, together with the mobile colistin resistance gene mcr and the fluoroquinolone targets gyrA and parC, showed the strongest recent growth, with gyrA and parC expanding at compound annual rates of 44.28% and 49.53% respectively over the last five years.

Thematic mapping of keyword co-occurrence networks revealed that the literature is structured around six interpretable clusters. Two emerged as mature core themes: PCR-based rapid antimicrobial resistance detection, organized around MRSA, multiplex PCR, and the mecA/mecC and vanA/vanB markers, and a whole-genome sequencing and genomic epidemiology theme spanning multiple pathogen groups. The tuberculosis resistance marker axis formed a strong but specialized mature theme, while the carbapenemase and Gram-negative resistance gene cluster, the metagenomic and nanopore clinical diagnostics cluster, and a general cross-pathogen antimicrobial resistance cluster were identified as emerging or niche research fronts.

Thematic evolution analysis across three time windows documented a clear conceptual restructuring. The early period from 2000 to 2010 centered on target-specific markers such as mecA, vancomycin resistance, and real-time PCR, reflecting an era of single-gene rapid tests. The middle period from 2011 to 2020 brought whole-genome sequencing, tuberculosis, multiplex PCR, and the Enterobacterales-carbapenemase axis to prominence. The recent period from 2021 to 2025 represents a more integrated antimicrobial resistance framework in which WGS, Staphylococcus aureus, and antibiotic resistance concepts dominate, demonstrating the field’s transition from individual marker detection to genomically integrated, translationally oriented diagnostics.

The study’s methodological rigor included a validation exercise in which 150 randomly selected records were blindly reassessed to test the rule-based text-matching system used to classify pathogens, platforms, markers, and clinical contexts. Concordance rates reached 100% for platform and resistance-marker labels, 91.3% for pathogen labels, and 86.7% for clinical-context labels, yielding an overall average agreement of 94.5%. The analysis also mapped the geography of the field: China led production with 263 publications, followed by the United States with 252, the United Kingdom with 130, and Germany with 127, though the United Kingdom and France showed higher rates of international collaboration and network centrality, revealing a divide between volume-based productivity and collaboration-intensive influence.

The findings carry important implications for clinical practice. Prior evidence shows that rapid diagnostic tests, when deployed alongside antimicrobial stewardship programs, reduce mortality in bloodstream infections compared with blood culture alone. The bibliometric structure documented here confirms that molecular diagnostics has evolved beyond answering whether a pathogen is present, into a multilayered data-generating enterprise that supports resistance prediction, monitoring of clonal spread, and clinical and public health decision-making. At the same time, the study acknowledges limitations: PCR panels and WGS report genetic content rather than physiological state, meaning phenomena such as bacterial persistence and tolerance fall largely outside the field’s marker-centered vocabulary, and future work integrating phenotypic, genomic, and virulence-layer data will be essential to close the gap between resistance prediction and treatment outcome.

Subject of Research: Bibliometric mapping of molecular diagnostic platforms and resistance markers for WHO priority bacterial pathogens

Article Title: Molecular Diagnostics for WHO Priority Bacterial Pathogens: A Bibliometric Mapping of Diagnostic Platforms, Resistance Markers, and Antimicrobial Resistance Research Trends

Article References: Ünlü, S. (2026). Molecular Diagnostics for WHO Priority Bacterial Pathogens: A Bibliometric Mapping of Diagnostic Platforms, Resistance Markers, and Antimicrobial Resistance Research Trends. MicrobiologyOpen, 15(5), Article e70394. https://doi.org/10.1002/mbo3.70394

Image Credits: AI Generated

DOI: 10.1002/mbo3.70394

Keywords: antimicrobial resistance, molecular diagnostics, WHO priority pathogens, whole-genome sequencing, PCR, bibliometric analysis, MRSA, carbapenemase genes, Mycobacterium tuberculosis, Enterobacterales, CRISPR diagnostics, genomic epidemiology