Molecular Detection Research Articles

Molecular Detection and Characterization of Haemoplasmas in Different Animal Species in Egypt

Molecular Detection and Characterization of Haemoplasmas in Different Animal Species in Egypt

Seroprevalence and molecular detection of brucellosis among Pakistani women with spontaneous abortion

BackgroundHuman brucellosis is a neglected disease transmitted to humans from animals such as cattle, goats, dogs, and swine. The causative agents are bacteria of the genus Brucella, intracellular pathogens usually confined to the reproductive organs of their animal hosts causing sterility and abortions. The objective of the study was to determine the seroprevalence of brucellosis among women with spontaneous abortions (SAW) and compare this seroprevalence with that of healthy pregnant women (HPW).MethodsThe case–control study was designed to determine the seroprevalence and molecular detection of brucellosis in women who suffered from spontaneous abortion and healthy pregnant women of the Haripur District of Pakistan. A total of 770 blood samples (n = 385 for each group) were collected from 9 public and 11 private hospitals in Haripur District from December 2021–March 2023. Data on demographic features, epidemiological variables, and risk factors were collected from each participant by structured questionnaires. Initial screening for brucellosis was performed by Rose Bengal Plate Test followed by qRT-PCR for molecular detection of the genus-specific BCSP-31 gene of Brucella.ResultsThe study showed that anti-Brucella antibodies were more found in SAW 23.63% (91/385) than in HPW 1.29% (5/385). Brucella specific DNA was amplified in 89.01% (81/91) seropositive samples of SAW. Demographic features and risk factors such as age, urbanicity, socioeconomic status, education, occupation, and animal contact were found significantly associated with brucellosis (p ≤ 0.05). Consumption of unpasteurized raw milk (OR = 18.28, 95%CI: 8.16–40.94) was found highly concomitant with seroprevalence.ConclusionThis study reports the first evidence of involvement of brucellosis in spontaneous abortions in women of Pakistan. The study can be used to develop strategies for risk management during pregnancy, to raise awareness for brucellosis, and develop control programs.

Molecular Imprinting-Based SERS Detection Strategy for the Large-Size Protein Quantitation and Curbing Non-Specific Recognition.

Molecular imprinting-based surface-enhanced Raman scattering (MI-SERS) sensors have shown remarkable potential from an academic standpoint. However, their practical applications, especially in the detection of large-size protein (≥10 nm), face challenges due to the lack of versatile sensing strategies and nonspecific fouling of matrix species. Herein, we propose a Raman reporter inspector mechanism (RRIM) implemented on a protein-imprinted polydopamine (PDA) layer coated on the SERS active substrate. In the RRIM, after large-size protein recognition, the permeability of the PDA imprinted cavities undergoes changes that are scrutinized by Raman reporter molecules. Target proteins can specifically bind and fully occupy the imprinted cavities, whereas matrix species cannot. Then, Raman reporter molecules with suitable size are introduced to serve as both inspectors of the recognition status and inducers of the SERS signal, which can only penetrate through the vacant and nonspecifically filled cavities. Consequently, changes in the SERS signal exclusively originate from the specific binding of target proteins, while the nonspecific recognition of matrix species is curbed. The RRIM enables reproducible quantitation of the large-size cyanobacteria-specific protein model (≥10 nm), phycocyanin, at the level down to 2.6 × 10-3 μg L-1. Finally, the practical applicability of the RRIM is confirmed by accurately analyzing crude urban waterway samples over 21 min without any pretreatment.

Circulating tumour DNA-Based molecular residual disease detection in resectable cancers: a systematic review and meta-analysis

Circulating tumour DNA (ctDNA)-based molecular residual disease (MRD) detection technology has been widely used for recurrence evaluation, but there is no agreement on the efficacy of assessing recurrence and overall survival (OS) prognosis, as well as the sensitivity and specificity of landmark detection and longitudinal detection. We systematically searched Pubmed, Embase, Cochrane, and Scopus for prospective studies or randomized controlled trials that collected blood samples prospectively. The search period was from Jan 1, 2013, to Sept 10, 2023. We excluded retrospective studies. The primary endpoint was to assess the hazard ratio (HR) between circulating tumour DNA positive (ctDNA+) and negative (ctDNA-) for recurrence-free survival incidence (RFS), disease-free survival (DFS), progression-free survival (PFS), event-free survival (EFS), time to recurrence (TTR), distant metastasis-free survival (DMFS) or OS in patients with resectable cancers. We calculated the pooled HR of recurrence and OS and 95% confidence interval (CI) in patients with resected cancers using a random-effects model. Pooled sensitivity and specificity were estimated using the bivariate random effects model. This systematic review and meta-analysis returned 7578 records, yielding 80 included studies after exclusion. We found that the HR of recurrence across all included cancers between patients with ctDNA+ and ctDNA- was 7.48 (95% CI 6.39-8.77), and the OS was 5.58 (95% CI 4.17-7.48). We also found that the sensitivity, area under the summary receiver operating characteristic curve (AUSROC) and diagnostic odds ratio (DOR) of longitudinal tests were higher than that of landmark tests between patients with ctDNA+ and ctDNA- (0.74, 95% CI 0.68-0.80 vs 0.50, 95% CI 0.46-0.55; 0.88 vs. 0.80; 25.70, 95% CI 13.20-45.40 vs. 9.90, 95% CI 7.77-12.40). Postoperative ctDNA testing was a significant prognosis factor for recurrence and OS in patients with resectable cancers. However, the overall sensitivity of ctDNA-MRD detection could be better. Longitudinal monitoring can improve the sensitivity, AUSROC, and DOR. Special fund project for clinical research of Qingyuan People's Hospital (QYRYCRC2023006), plan on enhancing scientific research in GMU (GZMU-SH-301).

Molecular Detection of Some Most Important Pathogenic Bacteria by Multiplex PCR for Diagnosis of Subclinical Mastitis in Bovine

Background: The dairy sector faces formidable obstacles in the early detection of the bacteria causing subclinical mastitis and in the proactive treatment of those cases. The objective of the study was to access multiplex PCR assays (MPCR) and conventional methods for the concurrent identification of significant bacteria that cause sub-clinical mastitis and to compare these methods. 200 samples of pooled milk from cows and buffaloes in Rajasthan were gathered between 2020 and 2021. Methods: The primary bacterial pathogens in milk samples were identified using conventional methods such multiplex PCR, biochemical testing and culture. Result: From 200 combined samples of cow and buffalo milk, the traditional approach was able to extract 97 different strains. Staphylococcus aureus 54 (27%), Streptococcus spp. 30 (15%) and E. coli 13 (6.5%) were shown to be prevalent as single or mixed infections, respectively. Staphylococcus was the main pathogen that was discovered. concurrently, S. aureus, Streptococcus and E. coli. Direct detection of Staphylococcus 65 (32.5%), Streptococcus 37 (18.5%), E. coli and 16 (8%) by multiplex PCR was found in milk samples. The analysis revealed that because multiplex PCR assays have higher specificity and sensitivity than conventional procedures, they are more reliable. The multiplex PCR method employed in the current study was a simple and quick technique to identify the major pathogens and it has the potential to be a very helpful tool for determining the pathogens that cause environmental mastitis and evaluating the health of the herd.

Enhancing Candida auris Surveillance in High-Risk Settings by Implementing a High-Throughput Molecular Assay on the Hologic Fusion Open Access Platform

Candida auris, a resilient pathogenic yeast with frequent multidrug resistance, presents a persistent challenge in healthcare settings. The timely identification of C. auris is crucial for infection control and prevention, especially in facilities facing unique hurdles, such as our institution, which serves four major hospitals and approximately 80% of the Texas inmate population. Understaffing, communal living, and financial constraints exacerbate infection control issues. To address common staff shortages, streamline testing services, and enhance testing efficiency, there was a pressing need for rapid and high-throughput detection of C. auris. This study presents the validation and utility of an assay implemented on the Hologic Fusion Open Access platform using samples collected from high-risk patients’ axilla and groin areas, as well as environmental swab samples from patient rooms. Our assay complemented efforts to control C. auris outbreaks within our healthcare system, providing valuable insights into its presence within surveillance samples. This assay demonstrated the value of high-throughput molecular detection platforms in challenging healthcare environments by aiding infection preventionists in containing the spread of C. auris and preventing nosocomial infections. Our research contributes essential data on the suitability and performance of the Hologic Fusion Open Access platform for C. auris detection. These findings hold significant implications for enhancing surveillance and control measures in high-risk settings, making a significant impact on the field of infection control and prevention.

[Clinical characteristics and prognosis analysis of pulmonary sarcomatoid carcinoma].

Objective: To summarize the clinical characteristics, treatment, and outcomes of patients with pulmonary sarcomatoid carcinoma (PSC) in order to improve clinicians' understanding of this disease. Methods: The clinical data of patients diagnosed with PSC in our hospital from January 1, 2015 to November 30, 2023 were retrospectively analyzed. According to whether radical resection was performed, the patients were divided into resectable group and unresectable group. The characteristics and treatments of PSC in different groups were compared. The survival curves were drawn by Kaplan-Meier method to compare the prognosis of different groups of patients. Results: A total of 43 PSC patients were included, including 32 males, with an average age of (62.79±9.59) years, and 31 smokers. Peripheral-type tumors were more common, with imaging showing predominantly solid soft tissue masses, and the maximum diameter of the tumor was more than 5 cm in 14 patients. Among the 23 patients who underwent NGS gene testing, the KRAS mutation rate was 43.5%, the TP53 mutation rate was 30.4%, and the MET mutation rate was 8.7%, all of which were MET-14 exon skipping mutations. PD-L1 expression was detected in 13 patients, 10 of whom showed high expression. The median overall survival (mOS) of the 43 patients with PSC was 24.6 months (13.0-52.7 months). Among them, 22 patients underwent radical lobectomy plus mediastinal lymph node dissection, 13 patients had postoperative recurrence, and 7 patients died during follow-up. The median disease-free survival (mDFS) was 12.3 months, the mOS was not achieved and the 1-year OS rate was 77.3 %. Twenty-one patients had unresectable locally advanced or advanced stage, and 15 patients died. The mDFS was 2.5 months, the mOS was 6.2 months, and the 1-year OS rate was 42.9 %. Seventeen patients received immunotherapy, and 1 patient received targeted therapy with the MET inhibitor glumetinib. Conclusions: PSC has a higher incidence in the elderly, smokers, and males, is highly malignant and has a poor prognosis. Based on its molecular biological characteristics, PD-L1 expression and tumor molecular detection can be performed to guide treatment options.

Prevalence, Molecular Detection, and Antimicrobial Resistance of Salmonella Isolates from Poultry Farms across Central Ethiopia: A Cross-Sectional Study in Urban and Peri-Urban Areas

A cross-sectional study was conducted to assess the prevalence, molecular detection, and antimicrobial resistance of Salmonella isolates within 162 poultry farms in selected urban and peri-urban areas of central Ethiopia. A total of 1515 samples, including cloacal swabs (n = 763), fresh fecal droppings (n = 188), litter (n = 188), feed (n = 188), and water (n = 188), were bacteriologically tested. The molecular detection of some culture-positive isolates was performed via polymerase chain reaction (PCR) by targeting spy and sdfl genes for Salmonella Typhimurium and Salmonella Enteritidis, respectively. Risk factors for the occurrence of the bacterial isolates were assessed. Antimicrobial susceptibility testing of PCR-confirmed Salmonella isolates was conducted using 12 antibiotics. In this study, it was observed that 50.6% of the farms were positive for Salmonella. The overall sample-level prevalence of Salmonella was 14.4%. Among the analyzed risk factors, the type of production, breed, and sample type demonstrated a statistically significant association (p < 0.05) with the bacteriological prevalence of Salmonella. The PCR test disclosed that 45.5% (15/33) and 23.3% (10/43) of the isolates were positive for genes of Salmonella Typhimurium and Salmonella Enteritidis, respectively. The antimicrobial susceptibility test disclosed multi-drug resistance to ten of the tested antibiotics that belong to different classes. Substantial isolation of Salmonella Typhimurium and Salmonella Enteritidis in poultry and on poultry farms, along with the existence of multi-drug resistant isolates, poses an alarming risk of zoonotic and food safety issues. Hence, routine flock testing, farm surveillance, biosecurity intervention, stringent antimicrobial use regulations, and policy support for the sector are highly needed.

Exploring the roles and potential therapeutic strategies of inflammation and metabolism in the pathogenesis of vitiligo: a mendelian randomization and bioinformatics-based investigation

Introduction:Vitiligo, a common autoimmune acquired pigmentary skin disorder, poses challenges due to its unclear pathogenesis. Evidence suggests inflammation and metabolism’s pivotal roles in its onset and progression. This study aims to elucidate the causal relationships between vitiligo and inflammatory proteins, immune cells, and metabolites, exploring bidirectional associations and potential drug targets.Methods:Mendelian Randomization (MR) analysis encompassed 4,907 plasma proteins, 91 inflammatory proteins, 731 immune cell features, and 1400 metabolites. Bioinformatics analysis included Protein-Protein Interaction (PPI) network construction, Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Subnetwork discovery and hub protein identification utilized the Molecular Complex Detection (MCODE) plugin. Colocalization analysis and drug target exploration, including molecular docking validation, were performed.Results:MR analysis identified 49 proteins, 39 immune cell features, and 59 metabolites causally related to vitiligo. Bioinformatics analysis revealed significant involvement in PPI, GO enrichment, and KEGG pathways. Subnetwork analysis identified six central proteins, with Interferon Regulatory Factor 3 (IRF3) exhibiting strong colocalization evidence. Molecular docking validated Piceatannol’s binding to IRF3, indicating a stable interaction.Conclusion:This study comprehensively elucidates inflammation, immune response, and metabolism’s intricate involvement in vitiligo pathogenesis. Identified proteins and pathways offer potential therapeutic targets, with IRF3 emerging as a promising candidate. These findings deepen our understanding of vitiligo’s etiology, informing future research and drug development endeavors.

A Catalogue of 13CO Clumps from the MWISP in l = 10°--20°

Abstract In this study, we comprehensively validate the effectiveness of a molecular clump detection workflow using 13CO data from the Milky Way Image Scroll Painting (MWISP) project, covering the inner Milky Way within the longitude range 10° ≤ l ≤ 20° and a latitude strip of |b| ≤ 5:25°. The workflow, namely Facet-SS-3D-Clump, initially employs FacetClumps to identify molecular clumps. Subsequently, high-confidence clumps are obtained by cross-matching with the clumps detected by other algorithms, such as Dendrogram. Then, these high-confidence clumps are used as prior knowledge to train a semi-supervised deep clustering approach, SS-3D-Clump, which is applied to verify candidate clumps detected by FacetClumps, providing confidence levels for the molecular clumps. Finally, a catalogue comprising 18,757 molecular clumps extracted from 13CO (J = 1 - 0) emission data was obtained using the workflow. By matching with Herschel infrared dust clumps, we found that 82.3% of the dust clumps correspond to 13CO clumps, which confirmed the accuracy of the workflow. The catalogue is 90% complete above 37 K km s-1. We observe a significant deviation of the mean Galactic latitude for clumps within|b| ≤ 2° from the midplane, with b = -0.110°. In the future, Facet-SS-3D-Clump will be applied to detect 13CO clumps in the entire MWISP data.

In this study, we present a catalogue of molecular clumps extracted from 13CO (J = 1 - 0) emission data of the Milky Way Image Scroll Painting (MWISP) project. The data covers the inner MilkyWay within the longitude range 10° ≤ l ≤ 20° and the latitude strip of |b| ≤ 5:25°. The clumps extraction of workflow, namely Facet-SS-3D-Clump, consists of two parts: the identification of clumps candidates and their verification. First, Facet-SS-3D-Clump employs FacetClumps to identify clumps candidates. Subsequently, high-confidence clumps are obtained by cross-matching with the clumps detected by other algorithms, such as Dendrogram. Second, these high-confidence clumps are used as prior knowledge to train a semi-supervised deep clustering approach, SS-3D-Clump, which is applied to verify clumps candidates detected by FacetClumps, providing confidence levels for the molecular clumps. Finally, the catalogue comprising 18,757 molecular clumps was obtained using Facet-SS-3D-Clump, and the catalogue is 90% complete above 37 K km s-1. We observe a significant deviation of the mean Galactic latitude for clumps within |b| ≤ 2° from the midplane, with b = -0.110°. We found that 82.3% of the dust clumps correspond to 13CO clumps by matching with Herschel infrared dust clumps. In the future, Facet-SS-3D-Clump will be applied to detect 13CO clumps in the entire MWISP data.

Development of a novel sequence based real-time PCR assay for specific and sensitive detection of Burkholderia pseudomallei in clinical and environmental matrices

BackgroundMelioidosis, caused by the category B biothreat agent Burkholderia pseudomallei, is a disease with a high mortality rate and requires an immediate culture-independent diagnosis for effective disease management. In this study, we developed a highly sensitive qPCR assay for specific detection of Burkholderia pseudomallei and melioidosis disease diagnosis based on a novel target sequence.MethodsAn extensive in-silico analysis was done to identify a novel and highly conserved sequence for developing a qPCR assay. The specificity of the developed assay was analyzed with 65 different bacterial cultures, and the analytical sensitivity of the assay was determined with the purified genomic DNA of B. pseudomallei. The applicability of the assay for B. pseudomallei detection in clinical and environmental matrices was evaluated by spiking B. pseudomallei cells in the blood, urine, soil, and water along with suitable internal controls.ResultsA novel 85-nucleotide-long sequence was identified using in-silico tools and employed for the development of the highly sensitive and specific quantitative real-time PCR assay S664. The assay S664 was found to be highly specific when evaluated with 65 different bacterial cultures related and non-related to B. pseudomallei. The assay was found to be highly sensitive, with a detection limit of 3 B. pseudomallei genome equivalent copies per qPCR reaction. The detection limit in clinical matrices was found to be 5 × 102 CFU/mL for both human blood and urine. In environmental matrices, the detection limit was found to be 5 × 101 CFU/mL of river water and 2 × 103 CFU/gm of paddy field soil.ConclusionsThe findings of the present study suggest that the developed assay S664 along with suitable internal controls has a huge diagnostic potential and can be successfully employed for specific, sensitive, and rapid molecular detection of B. pseudomallei in various clinical and environmental matrices.

The discovery of human Plasmodium among domestic animals in West Sumba and Fakfak, Indonesia

Background In Indonesia, malaria incidence is at a high rate despite maximum preventive efforts. Therefore, this study aims to determine the possibility of a Plasmodium reservoir among domestic animals in malaria-endemic areas. Methods Animal blood was collected using EDTA tubes, then smeared and stained with Giemsa for Plasmodium microscopic identification. About 10 μl of blood was dropped on to a filter paper to capture Plasmodium DNA. Nested PCR was used for parasite molecular detection, while Plasmodium species were identified using the sequenced DNA. Results A total of 208 and 62 animal blood samples were collected from Gaura village, West Sumba and Fakfak village, West Papua, Indonesia respectively. In total, 32 samples from Gaura contained P. falciparum or P. vivax, while the Plasmodium percentage in buffalo, horse, goat, and dogs were 20.7%, 14.3%, 5.8%, 16.7%, respectively. P. knowlesi was not found in any of the samples, and no other species were detected in 18 pig blood samples. Conclusion Human Plasmodium existence among domestic animals in Indonesia partly explains the high prevalence and persistence of malaria in some endemic areas due to a reservoir host presence. Therefore, future studies need to ascertain the cause.

A comparison of DNA extraction methods used in the direct molecular detection of Burkholderia pseudomallei from blood.

Melioidosis is caused by Burkholderia pseudomallei. Direct molecular detection from unamplified blood remains insensitive. Three different extraction methods-QIAamp UCP Pathogen Mini Kit, High Pure PCR template and MagNA Pure Pathogen Universal-were trialled using spiked human ethylenediaminetetraacetic acid blood. A type III secretion system 1 (TTSS-1) polymerase chain reaction was used for detection. The QIAamp UCP Pathogen Mini Kit performed best, with a limit of detection of 1.5×102cfu/ml. It is planned to use the QIAamp UCP Pathogen Mini Kit to do a larger study on blood collected from patients with melioidosis.

Phenotypic and Molecular Detection of Methicilin Resistant Staphylococcus aureus Isolated from Clinical Samples in some Selected Hospitals in Dutsin-Ma and Kurfi LGAS, Katsina State, Nigeria

Phenotypic and Molecular Detection of Methicilin Resistant Staphylococcus aureus Isolated from Clinical Samples in some Selected Hospitals in Dutsin-Ma and Kurfi LGAS, Katsina State, Nigeria

Functional Investigation and Two-sample Mendelian Randomization Study of Inguinal Hernia Hub Genes Obtained by Bioinformatics Analysis.

Inguinal hernia in adults is a common and frequent disease in surgery, prone to occur in the elderly or in those with a weak abdominal wall. Despite its prevalence, Molecular mechanisms underlying inguinal hernia formation are unclear. This study aims to identify potential gene markers for inguinal hernia and available drugs. Pubmed2Ensembl text mining was used to identify genes related to "inguinal hernia" keywords. The GeneCodis system was used to specify GO biological process terms and KEGG pathways defined in the Kyoto Encyclopedia of Genes and Genomes (KEGG). The STRING tool was used to construct protein-protein interaction networks, which were then visualized using Cytoscape.CytoHubba and Molecular Complex Detection were utilized to analyze the module (MCODE). A GO and KEGG analysis of gene modules was conducted using the DAVID platform database. Hub genes are those that are concentrated in prominent modules. The druggene interaction database was also used to identify potential drugs for inguinal hernia patients based on their interactions between the hub genes. Finally, a Mendelian randomization study was conducted based on genome-wide association studies to determine whether hub genes cause inguinal hernias. The identification of 96 genes associated with inguinal hernia was carried out using text mining techniques. It was constructed using PPI networks with 80 nodes and 476 edges, and the sequence of the genes was performed using CytoHubba. MCODE analysis identified three gene modules. Three modules contain 37 genes clustered as hub candidate genes associated with inguinal hernia patients. The PI3K-Akt, MAPK, AGE-RAGE, and HIF-1 pathways were found to be enriched in signaling pathways. Sixteen of the 37 genes were found to be targetable by 30 existing drugs. The relationship between hub genes and inguinal hernia was examined using Mendelian randomization. The research revealed nine genes that may be connected with inguinal hernia, such as POMC, CD40LG, TFRC, VWF, LOX, IGF2, BRCA1, TNF, and HGF in the plasma. By inverse variance weighting, ALB was associated with an increased risk of inguinal hernia with an OR of 1.203 (OR [95%] = 1,04 [1.012 to 1.089], p = 0.008). We identified potential hub genes for inguinal hernia, predicted potential drugs for inguinal hernia, and reverse-validated potential genes by Mendelian randomization. This may provide further insights into asymptomatic pre-diagnostic methods and contribute to studies to understand the molecular mechanisms of risk genes associated with inguinal hernia.

Identifying key inflammatory genes in psoriasis via weighted gene co-expression network analysis: Potential targets for therapy

Psoriasis is a globally prevalent chronic inflammatory skin disease. This study aimed to scrutinize the hub genes related to inflammation and potential molecular mechanisms in psoriasis. Utilizing mRNA expression profiles from public datasets GSE13355, GSE78097, and GSE14905, we set up a comprehensive analysis. Initially, we selected differentially expressed genes (DEGs) from psoriasis and control samples in GSE13355, followed by calculating inflammatory indices using genomic set variation analysis (GSVA). Weighted gene co-expression network analysis (WGCNA) was then applied to link significant modules with the inflammatory index. This process helped us identify differentially expressed inflammation-related genes (DE-IRGs). A protein-protein interaction (PPI) network was established, with the molecular complex detection (MCODE) plug-in pinpointing six chemokine genes (CCR7, CCL2, CCL19, CXCL8, CXCL1, and CXCL2) as central hub genes. These genes demonstrated pronounced immunohistochemical staining in psoriatic tissues compared to normal skin. Notably, the CCR7 gene exhibited the highest potential for m6A modification sites. Furthermore, we constructed transcription factor-microRNA-mRNA networks, identifying 139 microRNAs and 52 transcription factors associated with the hub genes. For the LASSO logistic regression model, the area under the curve (AUC) in the training set was 1, and in the two validation cohorts GSE78097 and GSE14905 were 1 and 0.872, respectively. In conclusion, our study highlights six chemokine genes (CCR7, CCL2, CCL19, CXCL8, CXCL1, and CXCL2) as potential biomarkers in psoriasis, providing insights into the immune and inflammatory responses as pivotal instances in disease pathogenesis. These findings pave the way for exploring new therapeutic targets, particularly focusing on chemokine-associated pathways in psoriasis treatment.

Abstract LB106: Ultra-short ctDNA: A new paradigm for ctDNA liquid biopsy

Abstract Mononucleosomal ctDNA (mnctDNA, 157-bp, double-stranded) spearheads liquid biopsy (LB) for cancer detection, treatment and clinical care. The bottleneck of mnctDNA LB are low copy number of ctDNA and limit of detection of platform technologies. Recent discovery of ultra-short ctDNA (usctDNA, 52-54 nt, single-stranded) that harbors somatic mutations prompted us to explore the quantification and stoichiometry of usctDNA to mnctDNA in plasma and saliva of NSCLC patients. Paired plasma and saliva from 20 advanced NSCLC patients with tissue genotyped positive for L858R were processed for cfDNA extraction and quantification with Qubit and Tape Station. Digital PCR assays targeting L858R somatic mutation to generate amplicons of 57-bp (usctDNA) and 100-bp (mnctDNA) were performed by UCLA and independently by NIST. Results in Table 1 revealed that three findings of usctDNA that will have potential to impact ctDNA liquid biopsy. First, the somatic mutation (L858R) is present in usctDNA. Second, The stoichiometric ratio of usctDNA to mnctDNA is similar in plasma and saliva at 1.6X. For the wild-type counterpart, the ratio is 1.1X for plasma and 0.6X for saliva. Third, the copy number of usctDNA and mnctDNA in saliva to plasma is 7.8X and 7.7X. Conclusion: Detection of tumor-associated/specific EGFR L858R somatic mutations in uscfDNA is translationally impactful, adding 1.6X of the ctDNA targets for molecular detection, effectively cumulating 2.6X of total ctDNA targets, permitting earlier cancer detection, treatment monitoring and therapy prognostication. The finding that saliva harbors 7X of the us- and mnctDNA further raises the prospect of advancing saliva ctDNA liquid biopsy for NSCLC detection as it may effectively allow 15.5X (7.8X+7.7X) ability to detect malignancy-associated ctDNA. Table 1. Quantification of usctDNA and mnctDNA in Plasma and Saliva Mut usctDNA (L858R) WT cfDNA usctDNA mnctDNA U/M uscfDNA mncfDNA U/M Plasma 1555 ± 326 964 ± 209 1.6X 15201 ± 1509 13261 ± 1424 Saliva 12158 ± 1731 7442 ± 1020 1.6X 340896 ± 27170 601733 ± 71573 1.1X Saliva/Plasma (fold X) 7.8 7.7 1.6X 22.4 45.3 0.6X Citation Format: Feng Li, Fang Wei, Hua-Jun He, Chien-Chung Lin, Szu-Chun Yang, Allen Wei-Lun Huang, Cheuk Ying Tang, Yong Kim, David T. Wong. Ultra-short ctDNA: A new paradigm for ctDNA liquid biopsy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB106.

Molecular characterization of hypermucoviscous carbapenemase-encoding Klebsiella pneumoniae isolates from an Egyptian hospital.

This study aimed to screen antibiotic resistance and virulence genes in carbapenem-resistant hypermucoviscous Klebsiella pneumoniae isolates from an Egyptian hospital. Among 38 previously confirmed carbapenem-nonsusceptible K. pneumoniae isolates, a string test identified three isolates as positive for hypermucoviscosity. Phenotypic characterization and molecular detection of carbapenemase- and virulence-encoding genes were performed. PCR-based multilocus sequence typing and phylogenetics were used to determine the clonality and global epidemiology of the strains. The coexistence of virulence and resistance genes in the isolates was analyzed statistically using a chi-square test. Three isolates showed the presence of carbapenemase-encoding genes (blaNDM, blaVIM, and blaIMP), adhesion genes (fim-H-1 and mrkD), and siderophore genes (entB); the isolates belonged to sequence types (STs) 101, 1310, and 1626. The relatedness between these sequence types and the sequence types of globally detected hypermucoviscous K. pneumoniae that also harbor carbapenemases was determined. Our analysis showed that the resistance and virulence profiles were not homogenous. Phylogenetically, different clones clustered together. There was no significant association between the presence of resistance and virulence genes in the isolates. There is a need for periodic surveillance of the healthcare settings in Egypt and globally to understand the true epidemiology of carbapenem-resistant, hypermucoviscous K. pneumoniae.

Seroprevalence and molecular detection of foot and mouth disease virus in cattle in selected districts of Wolaita Zone, Southern Ethiopia

Foot and mouth disease (FMD) is a highly contagious, endemic, and acute viral cattle ailment that causes major economic damage in Ethiopia. Although several serotypes of the FMD virus have been detected in Ethiopia, there is no documented information about the disease's current serostatus and serotypes circulating in the Wolaita zone. Thus, from March to December 2022, a cross-sectional study was conducted to evaluate FMDV seroprevalence, molecular detection, and serotype identification in three Wolaita Zone sites. A multistage sample procedure was used to choose three peasant associations from each study region, namely Wolaita Sodo, Offa district, and Boloso sore district. A systematic random sampling technique was employed to pick 384 cattle from the population for the seroprevalence research, and 10 epithelial tissue samples were purposefully taken from outbreak individuals for molecular detection of FMDV. The sera were examined using 3ABC FMD NSP Competition ELISA to find antibodies against FMDV non-structural proteins, whereas epithelial tissue samples were analyzed for molecular detection using real-time RT-PCR, and sandwich ELISA was used to determine the circulating serotypes. A multivariable logistic regression model was used to evaluate the associated risk variables. The total seroprevalence of FMD in cattle was 46.88% (95% CI 41.86–51.88), with Wolaita Sodo Town having the highest seroprevalence (63.28%). As a consequence, multivariable logistic regression analysis revealed that animal age, herd size, and interaction with wildlife were all substantially related to FMD seroprevalence (p < 0.05). During molecular detection, only SAT-2 serotypes were found in 10 tissue samples. Thus, investigating FMD outbreaks and identifying serotypes and risk factors for seropositivity are critical steps in developing effective control and prevention strategies based on the kind of circulating serotype. Moreover, further research for animal species other than cattle was encouraged.

Development of SCAR Markers for Genetic Authentication of Metarhizium acridum

In this study, molecular typing using Randomly Amplified Polymorphic DNA (RAPD-PCR) was conducted on 16 original isolates of Metarhizium acridum obtained from locusts (Schistocerca piceifrons ssp. piceifrons.) in Mexico (MX). The analysis included reference strains of the genus Metarhizium sourced from various geographical regions. The isolates were identified by phenotypic (macro and micromorphology) and genotypic methods (RAPD-PCR and Amplified Fragment Length Polymorphisms (AFLP), through a multidimensional analysis of principal coordinates (PCoA) and a minimum spanning network (MST). Subsequently, Sequences-Characterized Amplified Region (SCAR) markers were developed for the molecular detection of M. acridum, these markers were chosen from polymorphic patterns obtained with 14 primers via RAPD-PCR. Phenotypic and genotypic characterization identified the MX isolates as M. acridum. Of all the polymorphic patterns obtained, only OPA04 and OPA05 were chosen, which presented species-specific bands for M. acridum, and further utilized to create SCAR markers through cloning and sequencing of the specific bands. The specificity of these two markers was confirmed via Southern hybridization. The SCAR markers (Ma-160OPA-05 and Ma-151OPA-04) exhibit remarkable sensitivity, detecting down to less than 0.1 ng, as well as high specificity, as evidenced by their inability to cross-amplify or generate amplification with DNAs from other strains of Metarhizium (as Metarhizium anisopliae) or different genera of entomopathogenic fungi (Cordyceps fumosorosea and Akanthomyces lecanii). These SCAR markers yield readily detectable results, showcasing high reproducibility. They serve as a valuable tool, especially in field applications.