Bibliometric and visualized analysis of global research on fungal keratitis from 1959 to 2019

Global research on keratomycosis: New insights from latent Dirichlet allocation and HJ-Biplot-driven knowledge mapping study

BACKGROUND

Keratomycosis is a form of infectious keratitis, an infection of the cornea, which is caused by fungi. This disease is a leading cause of ocular morbidity globally with at least 60 % of the affected individuals becoming monocularly blind.

OBJECTIVE

This bibliometric analysis aimed to comprehensively assess the existing body of literature, providing insights of the evolution of keratomycosis research by identifying key themes and research gaps.

METHODS

This work used the modeling method Latent Dirichlet Allocation (LDA) to identify and interpret scientific information on topics concerning existing categories in a set of documents. The HJ-Biplot method was also used to determine the relationship between the analyzed topics, taking into consideration the years under study.

RESULTS

This bibliometric analysis was performed on a total of 2,599 scientific articles published between 1992 and 2022. The five leading countries with more scientific production and citations on keratomycosis were The United States of America, followed by India, China, United Kingdom and Australia. The top five topics studied were Case Reports and Corneal Infections, which exhibited a decreasing trend; followed by Penetrating Keratoplasty and Corneal Surgery, Ocular Effects of Antifungal Drugs, Gene Expression and Inflammatory Response in the Cornea and Patient Data which have been increasing throughout the years. However Filamentous Fungi and Specific Pathogens, and Antifungal Therapies research has been decreasing in trend.

CONCLUSION

Additional investigation into innovative antifungal drug therapies is crucial for proactively tackling the potential future resistance to antifungal agents in scientific writing.

Bibliometric analysis and thematic review of Candida pathogenesis: Fundamental omics to applications as potential antifungal drugs and vaccines

Invasive candidiasis caused by the pathogenic Candida yeast species has resulted in elevating global mortality. The pathogenicity of Candida spp. is not only originated from its primary invasive yeast-to-hyphal transition; virulence factors (transcription factors, adhesins, invasins, and enzymes), biofilm, antifungal drug resistance, stress tolerance, and metabolic adaptation have also contributed to a greater clinical burden. However, the current research theme in fungal pathogenicity could hardly be delineated with the increasing research output. Therefore, our study analysed the research trends in Candida pathogenesis over the past 37 years via a bibliometric approach against the Scopus and Web of Science databases. Based on the 3993 unique documents retrieved, significant international collaborations among researchers were observed, especially between Germany (Bernhard Hube) and the UK (Julian Naglik), whose focuses are on Candida proteinases, adhesins, and candidalysin. The prominent researchers (Neils Gow, Alistair Brown, and Frank Odds) at the University of Exeter and the University of Aberdeen (second top performing affiliation) UK contribute significantly to the mechanisms of Candida adaptation, tolerance, and stress response. However, the science mapping of co-citation analysis performed herein could not identify a hub representative of subsequent work since the clusters were semi-redundant. The co-word analysis that was otherwise adopted, revealed three research clusters; the cluster-based thematic analyses indicated the severeness of Candida biofilm and antifungal resistance as well as the elevating trend on molecular mechanism elucidation for drug screening and repurposing. Importantly, the in vivo pathogen adaptation and interactions with hosts are crucial for potential vaccine development.

The preparation and therapeutic effects of β-glucan-specific nanobodies and nanobody-natamycin conjugates in fungal keratitis

Fungal keratitis (FK) is a severe infectious corneal disease. Since traditional eye drops exhibit poor dissolution and high corneal toxicity, the efficacy of current treatments for FK remains limited. It is needed to develop new approaches to control the cornea damage from FK. In this study, a nanobody (Nb) specific to β-glucan in the fungal cell wall was prepared. The conjugate of the Nb with natamycin (NAT), a traditional antifungal drug, was synthesized. Firstly, we found the Nb specific to β-glucan inhibited fungal growth by disrupting cell wall and biofilm formation.. In addition, the content of β-glucan in the fungal cell wall decreased after Nb treatment. The Nb also reduced the adhesion ability of fungal conidia to human corneal epithelial cells (HCECs). Further, we examined the difference between NAT and Nb-NAT in antifungal growth. Nb-NAT showed better antifungal effects than NAT which was caused by the interaction between Nb and β-glucan. Moreover, Nb concentration below 0.5 mg/mL did not affect the viability of HCECs. Nb-NAT had less cytotoxicity and ocular surface irritation than NAT. Nb specific to β-glucan attenuated Aspergillus fumigatus (A. fumigatus) virulence and relieved inflammatory responses in FK. Nb-NAT treatment of the cornea improved therapeutic effects compared with NAT. It decreased clinical scores and expression level of inflammatory factors. To our knowledge, this study is the first to report a Nb specific to β-glucan and Nb-NAT for the treatment of FK. These unique functions of the Nb specific to β-glucan and Nb-NAT would render it as an alternative molecule to control fungal infections including FK. STATEMENT OF SIGNIFICANCE: Fungal keratitis is a corneal disease with a high rate of blindness. Due to the poor dissolution and high corneal toxicity exhibited by traditional eye drops, the efficacy of current therapeutic treatments for fungal keratitis (FK) remains limited. To enhance the therapeutic effect of natamycin in treating fungal keratitis, this study developed an innovative approach by preparing a β-glucan-specific nanobody and loading it with the antifungal drug natamycin. The β-glucan-specific nanobody has the ability to control both fungal pathogen invasion and inflammation, which can cause damage to the cornea in FK. The conjugation with the β-glucan-specific nanobody significantly increased the antifungal capacity of natamycin and reduced its toxicity. The further application of natamycin conjugated with the β-glucan-specific nanobody could be expanded to other diseases caused by fungal pathogen infections.

Species Diversity in the Fusarium solani (Neocosmospora) Complex and Their Pathogenicity for Plants and Humans

The Fusarium solani species complex is a large group of soil saprotrophs with a broad adaptive potential, which allows the fungi to exist under various conditions and to parasitize on different hosts. The review analyzes the modern data concerning the genetic peculiarities of species from this complex by the example of F. solani f. sp. pisi and generalizes the data on the most widespread species pathogenic for both plants and humans. The enhanced resistance of the F. solani species complex to the most of modern antifungal agents and the need for novel therapeutic agents against fusariosis has been considered.

The global research trend on microbially induced carbonate precipitation during 2001-2021: a bibliometric review

Microbially induced carbonate precipitation (MICP) is a remarkable method that creates sustainable cementitious binding material for use in geotechnical/structural engineering and environmental engineering. This is due to the increasing demand for alternative environmentally friendly technologies and materials that result in minimal or zero carbon footprint. In contrast to the previously published literature, through bibliometric analysis, this review paper focuses on the current prospects and future research trends of MICP technology via the Scopus database and VOSviewer analysis. The objective of the study was to determine the annual publications and citations trend, most contributing countries, the leading journals, prolific authors, productive institutions, funding sponsors, trending author keywords, and research directions of MICP. There were a total of 1058 articles published from 2001 to 2021 on MICP. The result demonstrated that the volume of publications is increasing. China, Construction and Building Materials, Satoru Kawasaki, Nanyang Technological University, and the National Natural Science Foundation of China are the leading country, journal, author, institution, and funding sponsor in terms of total publications. Through the co-occurrence analysis of the author keywords, MICP was revealed to be the most frequently used author keyword with 121 occurrences, a total link strength of 213, and 152 links to other author keywords. Furthermore, co-occurrence analysis of text data revealed that researchers are concentrating on four important research areas: precipitation, MICP, compressive strength, and biomineralization. This review can provide information to researchers that can lead to novel ideas and research collaboration or engagement on MICP technology.

The facilitating effect of blue light on the antifungal agent susceptibilities of passaged conidia from the ocular-derived Fusarium solani species complex

The eye is a light-receiving organ and has anatomical advantages to accept phototherapy. Fungi colonizing on the eyes, which cause ocular mycoses, are affected by daily blue light and could easily accept additional light irritation. Ocular mycoses are recalcitrant and blindness-causing eye diseases, and antifungal agent treatments are insufficient. Our team previously found that blue light could inhibit Fusarium solani hyphal growth but promote conidiation. Here, we investigated the antifungal susceptibilities and biological characteristics of the passaged conidia. Twelve Fusarium solani strains (11 ocular-derived strains and 1 standard laboratory strain) were inoculated under blue light (0.5 mW/cm2) and darkness conditions, respectively, to obtain the passaged conidia of blue light group (n = 12) and darkness group (n = 12). Two groups were tested to determine the growth abilities and in vitro antifungal susceptibilities to five antifungal drugs (voriconazole (VRC), amphotericin B (AMB), terbinafine (TRB), caspofungin (CAS), and 5-flucytosine (5FC)), which were examined by microscopy for morphological observation and spectrophotometry for turbidity analysis. The results showed that blue light group passaged conidia were more sensitive to antifungal drugs (AMB, VRC, TRB, and CAS) compared to darkness group. The MIC50 of VRC significantly decreased after blue light treatment (P < 0.05). The fungal inhibition rate significantly increased for VRC, AMB, and TRB in the low concentration range (P < 0.05 or P < 0.01). Blue light did not affect germination or hyphal extension of passaged conidia. These results suggested that blue light could facilitate fungal inhibition effect of AMB, VRC, TRB, and CAS and may improve the therapeutic efficiency in VRC and AMB clinical applications. Blue light phototherapy may provide a new adjuvant approach for the treatment of ocular mycosis.

Systematic mapping of DNAzymes research from 1995 to 2019

DNAzymes (catalytic DNA) have gained significant diagnostic and therapeutic applications with increasing research output over the years. Functional oligonucleotides are used as molecular recognition elements within biosensors for detection of analytes and viral infections such as SARS-CoV-2. DNAzymes are also applied for silencing and regulating cancer specific genes. However, there has not been any report on systematic analysis to track research status, reveal hotspots, and map knowledge in this field. Therefore, in the present study, research articles on DNAzymes from 1995 to 2019 were extracted from Web of Science (SCI-Expanded) after which, 1037 articles were imported into Rstudio (version 3.6.2) and analysed accordingly. The highest number of articles was published in 2019 (n = 138), while the least was in 1995 (n = 1). The articles were published across 216 journals by 2344 authors with 2337 multi-author and 7 single authors. The most prolific authors were Li Y (n = 47), Liu J (n = 46), Wang L (n = 33), Willner I (n = 33) and Zhang L (n = 33). The top three most productive countries were China (n = 2018), USA (n = 447) and Canada (n = 251). The most productive institutions were Hunan University, China (n = 141), University of Illinois, USA (n = 139) and Fuzhou University, China (n = 101). Despite the increasing interest in this field, international collaborations between institutions were very low which requires immediate attention to mitigate challenges such as limited funding, access to facilities, and existing knowledge gap.

Trends in research on corneal cross linking from 2001 to 2020: a bibliometric analysis

CLINICAL RELEVANCE

The research status and hotspots in the field of corneal cross linking (CXL) can benefit clinicians, researchers and the general public.

BACKGROUND

The purpose of this study was to map the publishing trend on CXL research and explore the research hotspots.

METHODS

A bibliometric analysis was performed using the Web of Science Core Collection to investigate the publishing trend on CXL research. VOSviewer was used to build the knowledge map to visualise the number of annual publications, distribution of countries and institutions, international cooperation, author productivity, source journals and research hotspots in the field of CXL.

RESULTS

A total of 2061 peer-reviewed articles on CXL research were collected from 2001 to 2020, and the annual research production increased over time. The United States was the country with the largest number of published articles, and the University of Zurich was the most active institution. Hafezi F published the largest number of articles on CXL, while Cornea was the journal with the largest number of studies on CXL. The most frequently cited references mainly focus on CXL in the treatment of keratoconus. The keywords were divided in 5 categories: 1) CXL mechanism, 2) ectasia diseases and refractive surgery, 3) corneal biomechanics, 4) efficacy evaluation, 5) treatment of infectious keratitis.

CONCLUSION

The quantity and quality of articles on CXL were evaluated using bibliometric techniques by extracting the data from the Web of Science Core Collection. The research hotspots could provide insights on CXL research, providing valuable information for clinicians to perform research in this field and find potential partners.

Analysis of international publication trends in artificial intelligence in ophthalmology

PURPOSE

Artificial intelligence (AI) has entered the field of medicine, and ophthalmology is no exception. The objective of this study was to report on scientific production and publication trends, to identify journals, countries, international collaborations, and major MeSH terms involved in AI in ophthalmology research.

METHODS

Scientometric methods were used to evaluate global scientific production and development trends in AI in ophthalmology using PubMed and the Web of Science Core Collection.

RESULTS

A total of 1356 articles were retrieved over the period 1966-2019. The yearly growth of AI in ophthalmology publications has been 18.89% over the last ten years, indicating that AI in ophthalmology is a very attractive topic in science. Analysis of the most productive journals showed that most were specialized in computer and medical systems. No journal was found to specialize in AI in ophthalmology. The USA, China, and the UK were the three most productive countries. The study of international collaboration showed that, besides the USA, researchers tended to collaborate with peers from neighboring countries. Among the twenty most frequent MeSH terms retrieved, there were only four related to clinical topics, revealing the retina and glaucoma as the most frequently encountered subjects of interest in AI in ophthalmology. Analysis of the top ten Journal Citation Reports categories of journals and MeSH terms for articles confirmed that AI in ophthalmology research is mainly focused on engineering and computing and is mainly technical research related to computer methods.

CONCLUSIONS

This study provides a broad view of the current status and trends in AI in ophthalmology research and shows that AI in ophthalmology research is an attractive topic focusing on retinal diseases and glaucoma. This study may be useful for researchers in AI in ophthalmology such as clinicians, but also for scientists to better understand this research topic, know the main actors in this field (including journals and countries), and have a general overview of this research theme.

Fungal Keratitis: Diagnostic Characteristics of the Potassium Hydroxide Preparation With Calcofluor White in Northern California

PURPOSE

The incidence of fungal keratitis demonstrates significant geographic and climatic variation. We report on the characteristics of the potassium hydroxide/calcofluor white (KOH-CFW) preparation observed at a tertiary center in Northern California, a region with a low incidence of fungal keratitis.

METHODS

Culture-proven cases of microbial keratitis during a 5-year period were retrospectively reviewed. The sensitivity, specificity, and posttest probabilities were determined for the KOH-CFW assay. These results were compared with documented clinical impression and values reported in the literature.

RESULTS

Three hundred three of 368 episodes of microbial keratitis during the study period documented the results of a fungal culture, KOH-CFW assay, and a clinical impression. Twenty-one (6.9%) of these cultures were positive for fungal organisms. The sensitivity and specificity of the KOH-CFW test were 29% and 93%, respectively. Clinicians' initial clinical impression based solely on patients' history and examination, without the aid of any histopathologic or biochemical test results, demonstrated a sensitivity and specificity of 33% and 89%, respectively.

CONCLUSIONS

The observed sensitivity and specificity of the KOH-CFW preparation are significantly lower than many previously reported values. In regions with low incidence of fungal keratitis, the KOH-CFW preparation may have diagnostic performance similar to that of the clinical impression formed only on the basis of history and physical examination.

Open Innovation in Medical and Pharmaceutical Research: A Literature Landscape Analysis

Open innovation in medical and pharmaceutical research has grown steadily over the last decade. However, the performance of the published literature in terms of the scientific impact and gaining social media attention remains largely unexplored. The scientific literature of open innovation was examined by means of bibliometric analyses to identify the most prolific authors, organizations, countries, journals, research areas, and recurring terms. By accessing the Web of Science Core Collection and Altmetric electronic databases, citation-related and Altmetric data were evaluated. Public-private partnerships and a selection of newly introduced potential novel drugs in the analyzed publications were identified. North America and Europe were the major literature contributors. Research outputs were mainly published in journals focused on business and economics, pharmacology and pharmacy, and engineering. Many pharmaceutical and biotechnological companies contributed to the analyzed publications, with higher mean citation counts and social media attention (Altmetric score) than nonindustry articles. Public-private partnerships fostered financial support, sharing of expertise and intellectual property, and research collaborations. In summary, open innovation might serve as a powerful strategy to both benefit the involved industry entities and accelerate the development of solutions and products for the betterment of human health.