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PLoS Neglected Tropical Diseases May 2024Francisella tularensis, the bacterium that causes tularemia, has been a persistent and widespread pathogen in various regions of the world for centuries. Francisella... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Francisella tularensis, the bacterium that causes tularemia, has been a persistent and widespread pathogen in various regions of the world for centuries. Francisella tularensis can affect humans and various domestic and wild animals. The current study aimed to determine the epidemiological status of tularemia in countries of the WHO Eastern Mediterranean Region (EMRO) through a systematic review and meta-analysis.
METHODS
All included studies were identified through a systematic search of online databases, including Scopus, PubMed, Web of Science, and EMBASE, through July 26, 2022, using keywords and suitable combinations. We focused on cross-sectional studies investigating the prevalence of F. tularensis. The weighted pooled prevalence was calculated using a random-effects model.
RESULTS
A total of 206 studies were identified, of which 20 were finally included in the analysis. The human seroprevalence of tularemia in WHO-EMRO countries was 6.2% (95% CI, 4.2 9.2). In the subgroup analysis, anti-F. tularensis antibodies were found in 6.92% and 5.5% of the high-risk individuals and Iran, respectively. The pooled prevalence of F. tularensis in environmental samples (water and soil) from the WHO-EMRO countries was 5.8% (9.4% by PCR and 0.5% by culture). In addition, 2.5% (95% CI, 0.2 0.22.7) of ticks in WHO-EMRO countries were positive for F. tularensis. The pooled prevalence of F. tularensis in rodents is 2.0% (1.1% by PCR and 3.7% by serology). In addition, 0.6% of domestic ruminants (0.4% by PCR and 2.4% by serology) were positive for F. tularensis in WHO-EMRO countries.
CONCLUSION
According to the results of the present study, tularemia is an endemic but neglected disease in the WHO-EMRO region. However, most studies on tularemia are limited to a few countries in this region. Studies on tularemia in human populations, reservoirs, and vectors have been conducted in all countries in the WHO-EMRO region to obtain more detailed information about the epidemiology of tularemia in these regions.
Topics: Tularemia; Humans; Animals; Francisella tularensis; Mediterranean Region; Prevalence; Seroepidemiologic Studies; World Health Organization; Cross-Sectional Studies; Ticks
PubMed: 38728365
DOI: 10.1371/journal.pntd.0012141 -
The Veterinary Quarterly Dec 2024Duck plague (DP) is an acute, contagious and fatal disease, caused by duck enteritis virus (DEV), with worldwide distribution causing several outbreaks and posing severe...
Duck plague (DP) is an acute, contagious and fatal disease, caused by duck enteritis virus (DEV), with worldwide distribution causing several outbreaks and posing severe economic losses. The present study was carried out with a goal of development of a live attenuated cell culture based DP vaccine using an Indian strain of DEV and evaluation of its safety, efficacy along with complete genome analysis. The live attenuated DP vaccine (DPvac/IVRI-19) was developed by serial propagation of a virulent isolate of DEV (DEV/India/IVRI-2016) in the chicken embryo fibroblast (CEF) primary cell culture. Adaptation of DEV in CEF cell culture was indicated by more rapid appearance of cytopathic effects (CPE) and gradual increase of virus titre, which reached up to 10 TCID/mL after 41 passages. The safety, immunogenicity and efficacy of the vaccine were determined by immunization trials in ducklings. The DPvac/IVRI-19 was found to be avirulent and completely safe in the ducklings. Further, the vaccine induced both humoral and cell mediated immune responses and afforded 100% protection against the virulent DEV challenge. A comparison of the whole genome of DPvac/IVRI-19 (MZ911871) and DEV/India/IVRI-2016 (MZ824102) revealed significant number of mutations, which might be associated with viral attenuation. Phylogenetic tree of DEV/India/IVRI-2016 revealed its evolutionary relationship with other DEV isolates, but it formed a separate cluster with certain unique mutations. Thus, with the proven safety and 100% efficacy, the DPvac/IVRI-19 is suitable for large scale production with precisely pure form of vaccine and has potential utility at national and global levels.
Topics: Animals; Vaccines, Attenuated; Ducks; Poultry Diseases; Fibroblasts; Chick Embryo; Viral Vaccines; Mardivirus; Herpesviridae Infections; India
PubMed: 38726839
DOI: 10.1080/01652176.2024.2350668 -
MBio Jun 2024Transmission of by fleas depends on the formation of condensed bacterial aggregates embedded within a gel-like matrix that localizes to the proventricular valve in the...
UNLABELLED
Transmission of by fleas depends on the formation of condensed bacterial aggregates embedded within a gel-like matrix that localizes to the proventricular valve in the flea foregut and interferes with normal blood feeding. This is essentially a bacterial biofilm phenomenon, which at its end stage requires the production of a exopolysaccharide that bridges the bacteria together in a cohesive, dense biofilm that completely blocks the proventriculus. However, bacterial aggregates are evident within an hour after a flea ingests , and the bacterial exopolysaccharide is not required for this process. In this study, we characterized the biochemical composition of the initial aggregates and demonstrated that the yersinia murine toxin (Ymt), a phospholipase D, greatly enhances rapid aggregation following infected mouse blood meals. The matrix of the bacterial aggregates is complex, containing large amounts of protein and lipid (particularly cholesterol) derived from the flea's blood meal. A similar incidence of proventricular aggregation occurred after fleas ingested whole blood or serum containing , and intact, viable bacteria were not required. The initial aggregation of in the flea gut is likely due to a spontaneous physical process termed depletion aggregation that occurs commonly in environments with high concentrations of polymers or other macromolecules and particles such as bacteria. The initial aggregation sets up subsequent binding aggregation mediated by the bacterially produced exopolysaccharide and mature biofilm that results in proventricular blockage and efficient flea-borne transmission.
IMPORTANCE
, the bacterial agent of plague, is maintained in nature in mammal-flea-mammal transmission cycles. After a flea feeds on a mammal with septicemic plague, the bacteria rapidly coalesce in the flea's digestive tract to form dense aggregates enveloped in a viscous matrix that often localizes to the foregut. This represents the initial stage of biofilm development that potentiates transmission of when the flea later bites a new host. The rapid aggregation likely occurs via a depletion-aggregation mechanism, a non-canonical first step of bacterial biofilm development. We found that the biofilm matrix is largely composed of host blood proteins and lipids, particularly cholesterol, and that the enzymatic activity of a phospholipase D (Ymt) enhances the initial aggregation. transmitted by flea bite is likely associated with this host-derived matrix, which may initially shield the bacteria from recognition by the host's intradermal innate immune response.
Topics: Yersinia pestis; Phospholipase D; Siphonaptera; Biofilms; Plague; Extracellular Polymeric Substance Matrix; Polysaccharides; Microscopy, Electron, Transmission; Proteome; Animals; Mice; Lipids
PubMed: 38722159
DOI: 10.1128/mbio.00124-24 -
Philosophical Transactions of the Royal... Jun 2024Concerns about perceived widespread declines in insect numbers have led to recognition of a requirement for long-term monitoring of insect biodiversity. Here we examine...
Concerns about perceived widespread declines in insect numbers have led to recognition of a requirement for long-term monitoring of insect biodiversity. Here we examine whether an existing, radar-based, insect monitoring system developed for research on insect migration could be adapted to this role. The radar detects individual larger (greater than 10 mg) insects flying at heights of 150-2550 m and estimates their size and mass. It operates automatically and almost continuously through both day and night. Accumulation of data over a 'half-month' (approx. 15 days) averages out weather effects and broadens the source area of the wind-borne observation sample. Insect counts are scaled or interpolated to compensate for missed observations; adjustment for variation of detectability with range and insect size is also possible. Size distributions for individual days and nights exhibit distinct peaks, representing different insect types, and Simpson and Shannon-Wiener indices of biodiversity are calculated from these. Half-month count, biomass and index statistics exhibit variations associated with the annual cycle and year to year changes that can be attributed to drought and periods of high rainfall. While species-based biodiversity measures cannot be provided, the radar's capacity to estimate insect biomass over a wide area indicates utility for tracking insect population sizes. This article is part of the theme issue 'Towards a toolkit for global insect biodiversity monitoring'.
Topics: Animals; Insecta; Biodiversity; Radar; Population Density; Entomology; Biomass
PubMed: 38705193
DOI: 10.1098/rstb.2023.0117 -
Mayo Clinic Proceedings May 2024The rapidly evolving coaching profession has permeated the health care industry and is gaining ground as a viable solution for addressing physician burnout, turnover,...
The rapidly evolving coaching profession has permeated the health care industry and is gaining ground as a viable solution for addressing physician burnout, turnover, and leadership crises that plague the industry. Although various coach credentialing bodies are established, the profession has no standardized competencies for physician coaching as a specialty practice area, creating a market of aspiring coaches with varying degrees of expertise. To address this gap, we employed a modified Delphi approach to arrive at expert consensus on competencies necessary for coaching physicians and physician leaders. Informed by the National Board of Medical Examiners' practice of rapid blueprinting, a group of 11 expert physician coaches generated an initial list of key thematic areas and specific competencies within them. The competency document was then distributed for agreement rating and comment to over 100 stakeholders involved in physician coaching. Our consensus threshold was defined at 70% agreement, and actual responses ranged from 80.5% to 95.6% agreement. Comments were discussed and addressed by 3 members of the original group, resulting in a final model of 129 specific competencies in the following areas: (1) physician-specific coaching, (2) understanding physician and health care context, culture, and career span, (3) coaching theory and science, (4) diversity, equity, inclusion, and other social dynamics, (5) well-being and burnout, and (6) physician leadership. This consensus on physician coaching competencies represents a critical step toward establishing standards that inform coach education, training, and certification programs, as well as guide the selection of coaches and evaluation of coaching in health care settings.
Topics: Humans; Clinical Competence; Consensus; Delphi Technique; Leadership; Mentoring; Physicians; Professional Competence
PubMed: 38702127
DOI: 10.1016/j.mayocp.2024.01.002 -
PLoS Neglected Tropical Diseases May 2024Plague, caused by the bacterium Yersinia pestis, is a zoonotic disease that poses considerable threats to human health. Nucleic acid tests are crucial for plague...
BACKGROUND
Plague, caused by the bacterium Yersinia pestis, is a zoonotic disease that poses considerable threats to human health. Nucleic acid tests are crucial for plague surveillance and the rapid detection of Y. pestis. However, inhibitors in complex samples such as soil and animal tissues often hamper nucleic acid detection, leading to a reduced rate of identifying low concentrations of Y. pestis. To address this challenge, we developed a sensitive and specific droplet digital polymerase chain reaction (ddPCR) assay for detecting Y. pestis DNA from soil and animal tissue samples.
METHODS
Three genes (ypo2088, caf1, and pla) from Y. pestis were used to develop a multi-target ddPCR assay. The limits of detection (LoD), reproducibility, and specificity were assessed for bacterial genomic DNA samples. The ability of the assay to detect low concentrations of Y. pestis DNA from simulated soil and mouse liver tissue samples was respectively evaluated and compared with that of quantitative real-time PCR (qPCR).
RESULTS
The results showed that the ddPCR LoDs ranged from 6.2 to 15.4 copies/reaction for the target genes, with good reproducibility and high specificity for Y. pestis. By testing 130 soil and mouse liver tissue samples spiked with Y. pestis, the ddPCR assay exhibited a better sensitivity than that of the qPCR assay used in the study, with LoDs of 102 colony forming units (CFU)/100 mg soil and 103 CFU/20 mg liver. Moreover, the assay presented good quantitative linearity (R2 = 0.99) for Y. pestis at 103-106 CFU/sample for soil and liver samples.
CONCLUSION
The ddPCR assay presented good performance for detecting Y. pestis DNA from soil and mouse tissue samples, showing great potential for improving the detection rate of low concentrations of Y. pestis in plague surveillance and facilitating the early diagnosis of plague cases.
Topics: Yersinia pestis; Animals; Plague; Mice; Sensitivity and Specificity; Soil Microbiology; Polymerase Chain Reaction; DNA, Bacterial; Reproducibility of Results; Bacterial Proteins; Liver; Limit of Detection; Humans
PubMed: 38701065
DOI: 10.1371/journal.pntd.0012167 -
Cell Apr 2024Plant diseases cause famines, drive human migration, and present challenges to agricultural sustainability as pathogen ranges shift under climate change. Plant breeders... (Review)
Review
Plant diseases cause famines, drive human migration, and present challenges to agricultural sustainability as pathogen ranges shift under climate change. Plant breeders discovered Mendelian genetic loci conferring disease resistance to specific pathogen isolates over 100 years ago. Subsequent breeding for disease resistance underpins modern agriculture and, along with the emergence and focus on model plants for genetics and genomics research, has provided rich resources for molecular biological exploration over the last 50 years. These studies led to the identification of extracellular and intracellular receptors that convert recognition of extracellular microbe-encoded molecular patterns or intracellular pathogen-delivered virulence effectors into defense activation. These receptor systems, and downstream responses, define plant immune systems that have evolved since the migration of plants to land ∼500 million years ago. Our current understanding of plant immune systems provides the platform for development of rational resistance enhancement to control the many diseases that continue to plague crop production.
Topics: Plant Diseases; Plant Immunity; Plants; Disease Resistance; Humans
PubMed: 38670067
DOI: 10.1016/j.cell.2024.03.045 -
Scientific Reports Apr 2024While deep learning has become the go-to method for image denoising due to its impressive noise removal capabilities, excessive network depth often plagues existing...
While deep learning has become the go-to method for image denoising due to its impressive noise removal capabilities, excessive network depth often plagues existing approaches, leading to significant computational burdens. To address this critical bottleneck, we propose a novel lightweight progressive residual and attention mechanism fusion network that effectively alleviates these limitations. This architecture tackles both Gaussian and real-world image noise with exceptional efficacy. Initiated through dense blocks (DB) tasked with discerning the noise distribution, this approach substantially reduces network parameters while comprehensively extracting local image features. The network then adopts a progressive strategy, whereby shallow convolutional features are incrementally integrated with deeper features, establishing a residual fusion framework adept at extracting encompassing global features relevant to noise characteristics. The process concludes by integrating the output feature maps from each DB and the robust edge features from the convolutional attention feature fusion module (CAFFM). These combined elements are then directed to the reconstruction layer, ultimately producing the final denoised image. Empirical analyses conducted in environments characterized by Gaussian white noise and natural noise, spanning noise levels 15-50, indicate a marked enhancement in performance. This assertion is quantitatively corroborated by increased average values in metrics such as Peak Signal-to-Noise Ratio (PSNR), Structural Similarity Index (SSIM), and Feature Similarity Index for Color images (FSIMc), outperforming the outcomes of more than 20 existing methods across six varied datasets. Collectively, the network delineated in this research exhibits exceptional adeptness in image denoising. Simultaneously, it adeptly preserves essential image features such as edges and textures, thereby signifying a notable progression in the domain of image processing. The proposed model finds applicability in a range of image-centric domains, encompassing image processing, computer vision, video analysis, and pattern recognition.
PubMed: 38664440
DOI: 10.1038/s41598-024-60139-x -
Microbiology Spectrum Jun 2024Enteric yersiniosis, the third most common food-borne zoonosis in Europe, is mainly caused by the pathogen . In France the yersiniosis microbiological surveillance is...
UNLABELLED
Enteric yersiniosis, the third most common food-borne zoonosis in Europe, is mainly caused by the pathogen . In France the yersiniosis microbiological surveillance is conducted at the National Reference Laboratory (YNRL). Since 2017, isolates have been characterized by whole genome sequencing (WGS) followed by a 500-gene -cgMLST. We report here the data of the WGS-based surveillance on isolates for the 2017-2021 period. The YNRL characterized 7,642 strains distributed in 2,497 non-pathogenic isolates from lineages 1Aa and 1Ab, and 5,145 specimens belonging to 8 pathogenic lineages. Among pathogenic isolates, lineage 4 was the most common (87.2%) followed by lineages 2/3-9b (10.6%), 2/3-5a (1.2%), 2/3-9a (0.6%), 3-3b, 3-3c, 1B, and 3-3d (0.1% per each). Importantly, we developed a routine surveillance system based on a new typing method consisting of a 1,727-genes core genome Multilocus Sequence Typing (cgMLST) specific to the species followed by isolate clustering. Thresholds of allelic distances (AD) were determined and fixed for the clustering of isolates: AD ≤ 5 for lineages 4, 2/3-5a, and 2/3-9a, and AD ≤ 3 for lineage 2/3-9b. Clustering programs were implemented in 2019 in routine surveillance to detect genomic clusters of pathogenic isolates. In total, 419 clusters with at least 2 isolates were identified, representing 2,504 of the 3,503 isolates characterized between 2019 and 2021. Most clusters ( = 325) comprised 2 to 5 isolates. The new typing method proved to be useful for the molecular investigation of unusual grouping of cases as well as for the detection of genomic clusters in routine surveillance.
IMPORTANCE
We describe here the new typing method used for molecular surveillance of infections in France based on a novel core genome Multilocus Sequence Typing (cgMLST) specific to species. This method can reliably identify the pathogenic subspecies and compare the isolates with a high discriminatory power. Between 2017 and 2021, 5,145 pathogenic isolates belonging to 8 lineages were characterized and lineage 4 was by far the most common followed by lineage 2/3-9b. A clustering program was implemented, and detection thresholds were cross-validated by the molecular and epidemiological investigation of three unusual groups of infections. The routine molecular surveillance system has been able to detect genomic clusters, leading to epidemiological investigations.
Topics: Yersinia enterocolitica; Yersinia Infections; Humans; France; Multilocus Sequence Typing; Disease Outbreaks; Whole Genome Sequencing; Phylogeny; Genome, Bacterial; Genomics; Epidemiological Monitoring
PubMed: 38651883
DOI: 10.1128/spectrum.00504-24