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1.
Sci Rep ; 14(1): 10612, 2024 05 09.
Artículo en Inglés | MEDLINE | ID: mdl-38719936

RESUMEN

Molecular diagnostics involving nucleic acids (DNA and RNA) are regarded as extremely functional tools. During the 2020 global health crisis, efforts intensified to optimize the production and delivery of molecular diagnostic kits for detecting SARS-CoV-2. During this period, RT-LAMP emerged as a significant focus. However, the thermolability of the reagents used in this technique necessitates special low-temperature infrastructure for transport, storage, and conservation. These requirements limit distribution capacity and necessitate cost-increasing adaptations. Consequently, this report details the development of a lyophilization protocol for reagents in a colorimetric RT-LAMP diagnostic kit to detect SARS-CoV-2, facilitating room-temperature transport and storage. We conducted tests to identify the ideal excipients that maintain the molecular integrity of the reagents and ensure their stability during room-temperature storage and transport. The optimal condition identified involved adding 5% PEG 8000 and 75 mM trehalose to the RT-LAMP reaction, which enabled stability at room temperature for up to 28 days and yielded an analytical and diagnostic sensitivity and specificity of 83.33% and 90%, respectively, for detecting SARS-CoV-2. This study presents the results of a lyophilized colorimetric RT-LAMP COVID-19 detection assay with diagnostic sensitivity and specificity comparable to RT-qPCR, particularly in samples with high viral load.


Asunto(s)
COVID-19 , Colorimetría , Liofilización , Técnicas de Diagnóstico Molecular , Técnicas de Amplificación de Ácido Nucleico , ARN Viral , SARS-CoV-2 , Humanos , COVID-19/diagnóstico , COVID-19/virología , SARS-CoV-2/aislamiento & purificación , SARS-CoV-2/genética , Colorimetría/métodos , Técnicas de Amplificación de Ácido Nucleico/métodos , Técnicas de Diagnóstico Molecular/métodos , ARN Viral/análisis , ARN Viral/genética , Sensibilidad y Especificidad , Juego de Reactivos para Diagnóstico/normas , Prueba de Ácido Nucleico para COVID-19/métodos
2.
PLoS Negl Trop Dis ; 18(5): e0011637, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38713648

RESUMEN

BACKGROUND: Diagnosis of visceral leishmaniasis (VL) in resource-limited endemic regions is currently based on serological testing with rK39 immunochromatographic tests (ICTs). However, rK39 ICT frequently has suboptimal diagnostic accuracy. Furthermore, treatment monitoring and detection of VL relapses is reliant on insensitive and highly invasive tissue aspirate microscopy. Miniature direct-on-blood PCR nucleic acid lateral flow immunoassay (mini-dbPCR-NALFIA) is an innovative and user-friendly molecular tool which does not require DNA extraction and uses a lateral flow strip for result read-out. This assay could be an interesting candidate for more reliable VL diagnosis and safer test of cure at the point of care. METHODOLOGY/PRINCIPLE FINDINGS: The performance of mini-dbPCR-NALFIA for diagnosis of VL in blood was assessed in a laboratory evaluation and compared with the accuracy of rK39 ICTs Kalazar Detect in Spain and IT LEISH in East Africa. Limit of detection of mini-dbPCR-NALFIA was 650 and 500 parasites per mL of blood for Leishmania donovani and Leishmania infantum, respectively. In 146 blood samples from VL-suspected patients from Spain, mini-dbPCR-NALFIA had a sensitivity of 95.8% and specificity 97.2%, while Kalazar Detect had a sensitivity of 71.2% and specificity of 94.5%, compared to a nested PCR reference. For a sample set from 58 VL patients, 10 malaria patients and 68 healthy controls from Ethiopia and Kenya, mini-dbPCR-NALFIA had a pooled sensitivity of 87.9% and pooled specificity of 100% using quantitative PCR as reference standard. IT LEISH sensitivity and specificity in the East African samples were 87.9% and 97.4%, respectively. CONCLUSIONS/SIGNIFICANCE: Mini-dbPCR-NALFIA is a promising tool for simplified molecular diagnosis of VL and follow-up of treated patients in blood samples. Future studies should evaluate its use in endemic, resource-limited settings, where mini-dbPCR-NALFIA may provide an accurate and versatile alternative to rK39 ICTs and aspirate microscopy.


Asunto(s)
Leishmania donovani , Leishmaniasis Visceral , Sensibilidad y Especificidad , Leishmaniasis Visceral/diagnóstico , Leishmaniasis Visceral/parasitología , Humanos , Leishmania donovani/genética , Leishmania donovani/aislamiento & purificación , Inmunoensayo/métodos , Leishmania infantum/genética , Leishmania infantum/aislamiento & purificación , Reacción en Cadena de la Polimerasa/métodos , España , Técnicas de Diagnóstico Molecular/métodos , Femenino , Masculino , Adulto , Adolescente , Niño , Adulto Joven , Persona de Mediana Edad , África Oriental , ADN Protozoario/genética , ADN Protozoario/sangre , Preescolar
3.
Anal Chim Acta ; 1307: 342560, 2024 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-38719398

RESUMEN

BACKGROUND: Point-of-care (POC) nucleic acid amplification tests (NAAT) can significantly expand testing coverage, which is critical for infectious disease diagnostics and monitoring. The development of various isothermal amplification techniques greatly simplifies NAATs, but the cumbersome nucleic acid extraction step remains a bottleneck for the POC. Alternatively, extraction-free amplification, where crude samples are directly added into the assay, substantially simplifies the workflow. However, sample dilution is often needed in extraction-free amplification to reduce assay inhibition from sample matrices. Since NAATs are typically run at small volumes around 20 µL, the input sample quantity is therefore limited, resulting in an inevitable sensitivity loss. RESULTS: Here we explore the potential to perform isothermal amplification in larger reaction volumes to accommodate larger sample quantities, thereby improving sensitivity in extraction-free amplification. We demonstrated the approach by developing large-volume reverse transcription loop-mediated isothermal amplification (RT-LAMP) for HIV RNA detection from fingerstick plasma. We found that LAMP at reaction volumes up to 1 mL maintained the same performance. We then identified plasma dilution conditions needed to maintain the limit of detection in RT-LAMP. Subsequently, using inactivated HIV virus, we showed the successful detection of 24 HIV RNA copies in a 500 µL RT-LAMP reaction in the presence of 20 µL plasma (fingerstick volumes), translating to a viral load of 1200 copies per mL. To reduce the increased reagent cost with expanded reaction volumes, we further identified lower-cost reagents with maintained assay performance. Moreover, we showed that large-volume LAMP, compared to 20 µL reactions, could tolerate higher concentrations of various inhibitors in the sample, such as albumin and GuSCN. SIGNIFICANCE AND NOVELTY: NAATs are conventionally conducted at small reaction volumes. Here we demonstrated that LAMP can be run at large reaction volumes (over 100 µL) with maintained assay performance, allowing sample inhibition to be mitigated while accommodating larger sample quantities. The same strategy of expanding reaction volumes could be applied to other isothermal amplification methods and various POC applications, to streamline test workflows and/or improve assay sensitivity.


Asunto(s)
Técnicas de Amplificación de Ácido Nucleico , ARN Viral , Técnicas de Amplificación de Ácido Nucleico/métodos , Humanos , ARN Viral/sangre , Infecciones por VIH/sangre , Infecciones por VIH/diagnóstico , Infecciones por VIH/virología , VIH-1/genética , VIH-1/aislamiento & purificación , Límite de Detección , Técnicas de Diagnóstico Molecular
4.
Mycopathologia ; 189(3): 38, 2024 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-38704795

RESUMEN

OBJECTIVES: To describe the epidemiology of Pneumocystis jirovecii pneumonia and colonization diagnosed by next-generation sequencing (NGS) and explore the usefulness of the number of P. jirovecii sequence reads for the diagnosis of P. jirovecii pneumonia. METHODS: We examined the NGS results for P. jirovecii in respiratory samples collected from patients and analysed their clinical, radiological and microbiological characteristics. RESULTS: Among 285 respiratory samples collected over a 12-month period (January to December 2022), P. jirovecii sequences were detected in 56 samples from 53 patients. Fifty (94.3%) of the 53 patients were HIV-negative. Following our case definitions, 37 (69.8%) and 16 (30.2%) of the 53 patients had P. jirovecii infection and colonization respectively. P. jirovecii infection was associated with presence of underlying disease with immunosuppression (94.6% vs 18.8%, P < 0.05), positive serum 1,3-ß-D-glucan (41.2% vs 0%, P < 0.01) and higher number of P. jirovecii sequence reads (P < 0.005). In contrast, P. jirovecii colonization was associated with the male sex (93.8% vs 54.1%, P < 0.01), another definitive infectious disease diagnosis of the respiratory tract (43.8% vs 2.7%, P < 0.001) and higher survival (100% vs 67.6%, P < 0.01). Although P. jirovecii pneumonia was associated with higher number of P. jirovecii reads in respiratory samples, only a sensitivity of 82.14% and a specificity of 68.75% could be achieved. CONCLUSION: Detection of P. jirovecii sequences in respiratory samples has to be interpreted discreetly. A combination of clinical, radiological and laboratory findings is still the most crucial in determining whether a particular case is genuine P. jirovecii pneumonia.


Asunto(s)
Secuenciación de Nucleótidos de Alto Rendimiento , Pneumocystis carinii , Neumonía por Pneumocystis , Humanos , Neumonía por Pneumocystis/diagnóstico , Neumonía por Pneumocystis/microbiología , Masculino , Pneumocystis carinii/genética , Pneumocystis carinii/aislamiento & purificación , Femenino , Persona de Mediana Edad , Anciano , Adulto , Anciano de 80 o más Años , Sistema Respiratorio/microbiología , Adulto Joven , Técnicas de Diagnóstico Molecular/métodos
5.
Surg Pathol Clin ; 17(2): 307-320, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38692813

RESUMEN

Adoption of molecular testing in lung cancer is increasing. Molecular testing for staging and prediction of response for targeted therapy remain the main indications, and although utilization of blood-based testing for tumor is growing, the use of the diagnostic cytology and tissue specimens is equally important. The pathologist needs to optimize reflex testing, incorporate stage-based algorithms, and understand types of tests for timely and complete assessment in the majority of cases. When tissue is limited, testing should capture the most frequent alterations to maximize the yield of what are largely mutually exclusive alterations, avoiding the need for repeat biopsy.


Asunto(s)
Biomarcadores de Tumor , Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/diagnóstico , Biomarcadores de Tumor/genética , Técnicas de Diagnóstico Molecular , Estadificación de Neoplasias , Guías de Práctica Clínica como Asunto , Mutación , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico
6.
Viral Immunol ; 37(4): 177-185, 2024 05.
Artículo en Inglés | MEDLINE | ID: mdl-38625025

RESUMEN

Viral infections are major causes of mortality in solid-organ and hematopoietic stem cell transplant recipients. Epstein-Barr virus (EBV) and Parvovirus B19 (B19V) are among the common viral infections after transplantation and were recommended for increased screening in relevant guidelines. Therefore, the development of rapid, specific, and cost-effective diagnostic methods for EBV and B19V is of paramount importance. We applied Fluorescence of Loop Primer Upon Self-Dequenching Loop-mediated Isothermal Amplification (FLOS-LAMP) for the first time to develop a novel multiplex assay for the detection of EBV and B19V; the fluorophore attached to the probe are self-quenched in unbound state. After binding to the dumbbell-shaped DNA target, the fluorophore is dequenched, resulting in fluorescence development. The novel multiplex FLOS-LAMP assay was optimized by testing various ratios of primer sets. This novel assay, with great specificity, did not cross-react with the common virus. For the detection of EBV and B19V, the limits of detection could reach 969 and 798 copies/µL, respectively, and the assay could be completed within 25 min. Applying this novel assay to detect 200 clinical transplant individuals indicated that the novel assay had high specificity and good sensitivity. We developed multiplex FLOS-LAMP assay for the detection of EBV and B19V, which has the potential to become an important tool for clinical transplant patient screening.


Asunto(s)
Infecciones por Virus de Epstein-Barr , Herpesvirus Humano 4 , Técnicas de Diagnóstico Molecular , Técnicas de Amplificación de Ácido Nucleico , Parvovirus B19 Humano , Sensibilidad y Especificidad , Humanos , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/aislamiento & purificación , Técnicas de Amplificación de Ácido Nucleico/métodos , Parvovirus B19 Humano/genética , Parvovirus B19 Humano/aislamiento & purificación , Infecciones por Virus de Epstein-Barr/diagnóstico , Infecciones por Virus de Epstein-Barr/virología , Técnicas de Diagnóstico Molecular/métodos , Fluorescencia , Cartilla de ADN/genética , Receptores de Trasplantes , Infecciones por Parvoviridae/diagnóstico , Infecciones por Parvoviridae/virología , ADN Viral/genética , Trasplante de Órganos
7.
Viruses ; 16(4)2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38675848

RESUMEN

Rapid and early detection of infectious diseases in pigs is important, especially for the implementation of control measures in suspected cases of African swine fever (ASF), as an effective and safe vaccine is not yet available in most of the affected countries. Additionally, analysis for swine influenza is of significance due to its high morbidity rate (up to 100%) despite a lower mortality rate compared to ASF. The wide distribution of swine influenza A virus (SwIAV) across various countries, the emergence of constantly new recombinant strains, and the danger of human infection underscore the need for rapid and accurate diagnosis. Several diagnostic approaches and commercial methods should be applied depending on the scenario, type of sample and the objective of the studies being implemented. At the early diagnosis of an outbreak, virus genome detection using a variety of PCR assays proves to be the most sensitive and specific technique. As the disease evolves, serology gains diagnostic value, as specific antibodies appear later in the course of the disease (after 7-10 days post-infection (DPI) for ASF and between 10-21 DPI for SwIAV). The ongoing development of commercial kits with enhanced sensitivity and specificity is evident. This review aims to analyse recent advances and current commercial kits utilised for the diagnosis of ASF and SwIAV.


Asunto(s)
Fiebre Porcina Africana , Virus de la Influenza A , Infecciones por Orthomyxoviridae , Juego de Reactivos para Diagnóstico , Sensibilidad y Especificidad , Animales , Fiebre Porcina Africana/diagnóstico , Fiebre Porcina Africana/virología , Fiebre Porcina Africana/epidemiología , Porcinos , Infecciones por Orthomyxoviridae/diagnóstico , Infecciones por Orthomyxoviridae/veterinaria , Infecciones por Orthomyxoviridae/virología , Virus de la Influenza A/genética , Virus de la Influenza A/aislamiento & purificación , Virus de la Fiebre Porcina Africana/genética , Virus de la Fiebre Porcina Africana/aislamiento & purificación , Técnicas de Laboratorio Clínico/métodos , Enfermedades de los Porcinos/diagnóstico , Enfermedades de los Porcinos/virología , Técnicas de Diagnóstico Molecular/métodos
8.
Rev Esp Quimioter ; 37(3): 252-256, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38606841

RESUMEN

The increased knowledge on virology and the increased potential of their diagnostic has risen several relevant question about the role of an early viral diagnosis and potential early treatment on the management of respiratory tract infections (RTI). In order to further understand the role of viral diagnostic tests in the management of RTI, a panel of experts was convened to discuss about their potential role, beyond what had been agreed in Influenza. The objective of this panel was to define the plausible role of aetiologic viral diagnostic into clinical management; make recommendations on the potential expanded use of such tests in the future and define some gaps in the management of RTI. Molecular Infection Viral Diagnostic (mIVD) tests should be used in all adult patients admitted to Hospital with RTI, and in paediatric patients requiring admission or who would be referred to another hospital for more specialised care. The increased use of mIVD will not only reduce the inappropriate use of antibiotics so reducing the antibiotic microbe resistance, but also will improve the outcome of the patient if an aetiologic viral therapy can be warranted, saving resource requirements and improving patient flows. Implementing IVD testing in RTI has various organizational benefits as well, but expanding its use into clinical settings would need a cost-effectiveness strategy and budget impact assessment.


Asunto(s)
Infecciones del Sistema Respiratorio , Humanos , Infecciones del Sistema Respiratorio/diagnóstico , Infecciones del Sistema Respiratorio/tratamiento farmacológico , Infecciones del Sistema Respiratorio/virología , Virosis/diagnóstico , Técnicas de Diagnóstico Molecular , Niño
9.
J Hazard Mater ; 471: 134323, 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38640680

RESUMEN

Sensitive detection and point-of-care test of bacterial pathogens is of great significance in safeguarding the public health worldwide. Inspired by the characteristics of horseradish peroxidase (HRP), we synthesized a hybrid nanoflower with peroxidase-like activity via a three-component self-assembled strategy. Interestingly, the prepared nanozyme not only could act as an alternative to HRP for colorimetric biosensing, but also function as a unique signal probe that could be recognized by a pregnancy test strip. By combining the bifunctional properties of hybrid nanoflower, isothermal amplification of LAMP, and the specific recognition and non-specific cleavage properties of CRISPR/Cas12a system, the dual-readout CRISPR/Cas12a biosensor was developed for sensitive and rapid detection of Salmonella enterica. Moreover, this platform in the detection of Salmonella enterica had limits of detection of 1 cfu/mL (colorimetric assay) in the linear range of 101-108 cfu/mL and 102 cfu/mL (lateral flow assay) in the linear range of 102-108 cfu/mL, respectively. Furthermore, the developed biosensor exhibited good recoveries in the spiked samples (lake water and milk) with varying concentrations of Salmonella enterica. This work provides new insights for the design of multifunctional nanozyme and the development of innovative dual-readout CRISPR/Cas system-based biosensing platform for the detection of pathogens.


Asunto(s)
Técnicas Biosensibles , Sistemas CRISPR-Cas , Salmonella enterica , Salmonella enterica/genética , Salmonella enterica/aislamiento & purificación , Técnicas Biosensibles/métodos , Leche/microbiología , Técnicas de Amplificación de Ácido Nucleico/métodos , Nanoestructuras/química , Colorimetría/métodos , Animales , Límite de Detección , Técnicas de Diagnóstico Molecular
10.
Health Secur ; 22(2): 93-107, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38608237

RESUMEN

To better identify emerging or reemerging pathogens in patients with difficult-to-diagnose infections, it is important to improve access to advanced molecular testing methods. This is particularly relevant for cases where conventional microbiologic testing has been unable to detect the pathogen and the patient's specimens test negative. To assess the availability and utility of such testing for human clinical specimens, a literature review of published biomedical literature was conducted. From a corpus of more than 4,000 articles, a set of 34 reports was reviewed in detail for data on where the testing was being performed, types of clinical specimens tested, pathogen agnostic techniques and methods used, and results in terms of potential pathogens identified. This review assessed the frequency of advanced molecular testing, such as metagenomic next generation sequencing that has been applied to clinical specimens for supporting clinicians in caring for difficult-to-diagnose patients. Specimen types tested were from cerebrospinal fluid, respiratory secretions, and other body tissues and fluids. Publications included case reports and series, and there were several that involved clinical trials, surveillance studies, research programs, or outbreak situations. Testing identified both known human pathogens (sometimes in new sites) and previously unknown human pathogens. During this review, there were no apparent coordinated efforts identified to develop regional or national reports on emerging or reemerging pathogens. Therefore, development of a coordinated sentinel surveillance system that applies advanced molecular methods to clinical specimens which are negative by conventional microbiological diagnostic testing would provide a foundation for systematic characterization of emerging and underdiagnosed pathogens and contribute to national biodefense strategy goals.


Asunto(s)
Técnicas de Diagnóstico Molecular , Salud Pública , Humanos , Brotes de Enfermedades/prevención & control , Metagenómica/métodos , Secuenciación de Nucleótidos de Alto Rendimiento
11.
Mol Biol Rep ; 51(1): 551, 2024 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-38642170

RESUMEN

Fish health management is critical to aquaculture and fisheries as it directly affects sustainability and productivity. Fish disease diagnosis has taken a massive stride because of advances in immunological and molecular diagnostic tools which provide a sensitive, quick, and accurate means of identifying diseases. This review presents an overview of the main molecular and immunological diagnostic methods for determining the health of fish. The immunological techniques help to diagnose different fish diseases by detecting specific antigens and antibodies. The application of immunological techniques to vaccine development is also examined in this review. The genetic identification of pathogens is made possible by molecular diagnostic techniques that enable the precise identification of bacterial, viral, and parasitic organisms in addition to evaluating host reactions and genetic variation associated with resistance to disease. The combination of molecular and immunological methods has resulted in the creation of novel techniques for thorough evaluation of fish health. These developments improve treatment measures, pathogen identification and provide new information about the variables affecting fish health, such as genetic predispositions and environmental stresses. In the framework of sustainable fish farming and fisheries management, this paper focuses on the importance of these diagnostic techniques that play a crucial role in protecting fish populations and the aquatic habitats. This review also examines the present and potential future directions in immunological and molecular diagnostic techniques in fish health.


Asunto(s)
Acuicultura , Enfermedades de los Peces , Animales , Explotaciones Pesqueras , Anticuerpos , Técnicas de Diagnóstico Molecular , Enfermedades de los Peces/diagnóstico , Enfermedades de los Peces/genética , Peces/genética
12.
Biosensors (Basel) ; 14(4)2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38667150

RESUMEN

Since its first appearance in 1981, HIV-1 has remained a global concern. Current methods for diagnosing HIV-1, while effective, are mostly specific to a given subtype of HIV-1 and often require expensive equipment and highly trained individuals to collect and process the sample. It is necessary to develop a sensitive diagnostic method that can be administered with minimal equipment to provide better care in low-resource settings. Loop-mediated isothermal amplification is a rapid and sensitive method for detecting the presence of specific nucleic acid sequences. Herein we report the development and comparison of two different HIV LAMP assays, integrase and VPR, as well as the comparison between TRIZol and magnetic beads RNA extraction methods for each assay. Our analysis shows that the integrase assay was able to detect the virus from multiple subtypes in under 30 min with a variable limit of detection (LOD) that was dependent on the HIV-1 subtype.


Asunto(s)
Infecciones por VIH , VIH-1 , Técnicas de Amplificación de Ácido Nucleico , VIH-1/aislamiento & purificación , VIH-1/genética , Técnicas de Amplificación de Ácido Nucleico/métodos , Humanos , Infecciones por VIH/diagnóstico , Infecciones por VIH/virología , Técnicas de Diagnóstico Molecular/métodos , Límite de Detección , ARN Viral/análisis
13.
Biosens Bioelectron ; 257: 116292, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-38653014

RESUMEN

We report the development and initial validation of a paper-based nucleic acid testing platform that integrates Loop-mediated isothermal amplification (LAMP) with clustered regularly interspaced short palindromic repeats (CRISPR) technology, referred to as PLACID (Paper-based LAMP-CRISPR Integrated Diagnostics). LAMP eliminates the need for thermal cycling, resulting in simplified instrumentation, and the CRISPR-associated protein (Cas 12a) system eliminates false positive signals from LAMP products, resulting in highly selective and sensitive assays. We optimized the assay to perform both amplification and detection entirely on paper, eliminating the need for complex fluid handling steps and lateral flow assay transfers. Additionally, we engineered a smartphone-operated system that includes a low-powered, non-contact IR heating chamber to actuate paper-based LAMP and CRISPR reactions and enable the detection of fluorescent signals from the paper. The platform demonstrates high specificity and sensitivity in detecting nucleic acid targets with a limit of detection of 50 copies/µL. We integrate an equipment-free sample preparation separation technology designed to streamline the preparation of crude samples prior to nucleic acid testing. The practical utility of our platform is demonstrated by the successful detection of spiked SARS-CoV-2 RNA fragments in saliva, E. Coli in soil, and pathogenic E. Coli in clinically fecal samples of infected patients. Furthermore, we demonstrate that the paper-based LAMP CRISPR chips employed in our assays possess a shelf life of several weeks, establishing them as viable candidates for on-site diagnostics.


Asunto(s)
Técnicas Biosensibles , COVID-19 , Sistemas CRISPR-Cas , Técnicas de Diagnóstico Molecular , Técnicas de Amplificación de Ácido Nucleico , Papel , SARS-CoV-2 , Técnicas de Amplificación de Ácido Nucleico/métodos , Técnicas de Amplificación de Ácido Nucleico/instrumentación , Humanos , Técnicas Biosensibles/métodos , SARS-CoV-2/genética , SARS-CoV-2/aislamiento & purificación , COVID-19/diagnóstico , COVID-19/virología , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/instrumentación , Sistemas CRISPR-Cas/genética , Límite de Detección , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas/genética , Diseño de Equipo , Prueba de Ácido Nucleico para COVID-19/métodos , Prueba de Ácido Nucleico para COVID-19/instrumentación , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Proteínas Asociadas a CRISPR/genética , Teléfono Inteligente
14.
J Clin Microbiol ; 62(5): e0174923, 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38624235

RESUMEN

The timely identification of microbial pathogens is essential to guide targeted antimicrobial therapy and ultimately, successful treatment of an infection. However, the yield of standard microbiology testing (SMT) is directly related to the duration of antecedent antimicrobial therapy as SMT culture methods are dependent on the recovery of viable organisms, the fastidious nature of certain pathogens, and other pre-analytic factors. In the last decade, metagenomic next-generation sequencing (mNGS) has been successfully utilized as a diagnostic tool for various applications within the clinical laboratory. However, mNGS is resource, time, and labor-intensive-requiring extensive laborious preliminary benchwork, followed by complex bioinformatic analysis. We aimed to address these shortcomings by developing a largely Automated targeted Metagenomic next-generation sequencing (tmNGS) PipeLine for rapId inFectIous disEase Diagnosis (AMPLIFIED) to detect bacteria and fungi directly from clinical specimens. Therefore, AMPLIFIED may serve as an adjunctive approach to complement SMT. This tmNGS pipeline requires less than 1 hour of hands-on time before sequencing and less than 2 hours of total processing time, including bioinformatic analysis. We performed tmNGS on 50 clinical specimens with concomitant cultures to assess feasibility and performance in the hospital laboratory. Of the 50 specimens, 34 (68%) were from true clinical infections. Specimens from cases of true infection were more often tmNGS positive compared to those from the non-infected group (82.4% vs 43.8%, respectively, P = 0.0087). Overall, the clinical sensitivity of AMPLIFIED was 54.6% with 85.7% specificity, equating to 70.6% and 75% negative and positive predictive values, respectively. AMPLIFIED represents a rapid supplementary approach to SMT; the typical time from specimen receipt to identification of potential pathogens by AMPLIFIED is roughly 24 hours which is markedly faster than the days, weeks, and months required to recover bacterial, fungal, and mycobacterial pathogens by culture, respectively. IMPORTANCE: To our knowledge, this represents the first application of an automated sequencing and bioinformatics pipeline in an exclusively pediatric population. Next-generation sequencing is time-consuming, labor-intensive, and requires experienced personnel; perhaps contributing to hesitancy among clinical laboratories to adopt such a test. Here, we report a strong case for use by removing these barriers through near-total automation of our sequencing pipeline.


Asunto(s)
Bacterias , Infecciones Bacterianas , Hongos , Secuenciación de Nucleótidos de Alto Rendimiento , Metagenómica , Micosis , Humanos , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Hongos/genética , Hongos/aislamiento & purificación , Hongos/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Bacterias/clasificación , Infecciones Bacterianas/diagnóstico , Infecciones Bacterianas/microbiología , Metagenómica/métodos , Micosis/diagnóstico , Micosis/microbiología , Automatización de Laboratorios/métodos , Sensibilidad y Especificidad , Técnicas de Diagnóstico Molecular/métodos , Factores de Tiempo , Biología Computacional/métodos , Masculino , Femenino , Niño , Adolescente , Adulto , Preescolar
16.
Int J Mol Sci ; 25(7)2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38612622

RESUMEN

Aspergillus species create major postharvest problems due to the food losses caused by their mere presence and the hazardous mycotoxins they produce, such as aflatoxin B1 (AFB1) and ochratoxin A (OTA). These mycotoxins are mainly produced by A. flavus and A. carbonarius, respectively. In this study, we developed a rapid detection method for the two aforementioned species based on loop-mediated isothermal amplification (LAMP). The primers were designed to target genes belonging to the mycotoxin clusters pks and aflT for A. carbonarius and A. flavus, respectively. Result visualization was carried out in real time via the detection of fluorescent signals. The method developed showed high sensitivity and specificity, with detection limits of 0.3 and 0.03 pg/reaction of purified DNA of A. carbonarius and A. flavus, respectively. The assays were further implemented on inoculated nuts, including pistachios and almonds, after one-step crude DNA extraction. These tests revealed a detection level of 0.5 spore/g that shows the effectiveness of LAMP as a rapid method for detecting potentially toxigenic Aspergillus spp. directly in food. The validation of the assays included tests on a larger scale that further confirmed their sensitivity and specificity, as well as enabling the production of ready-to-use LAMP prototype kits. These kits are easy to use and aim to simplify the screening of food samples in order to monitor the presence of specific Aspergillus contaminations.


Asunto(s)
Aspergillus flavus , Técnicas de Diagnóstico Molecular , Micotoxinas , Técnicas de Amplificación de Ácido Nucleico , Aspergillus flavus/genética , Nueces , ADN
18.
Ann Clin Microbiol Antimicrob ; 23(1): 37, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38664821

RESUMEN

PURPOSE: Group B Streptococcus (GBS) is the leading cause of invasive infections in newborns. The prevention of GBS neonatal disease relies on the administration of an intrapartum antibiotic prophylaxis to GBS-colonized women. In recent years, rapid intrapartum detection of GBS vaginal colonization using real-time nucleic acid amplification tests (NAATs) emerged as an alternative to antenatal culture screening methods. METHODS: We compared the performances of two loop-mediated isothermal amplification (LAMP) tests, the Ampliflash® GBS and the PlusLife® GBS tests, to standard culture for GBS detection in vaginal specimens from pregnant women. The study was conducted from April to July 2023 in a French hospital of the Paris area. RESULTS: A total of 303 samples were analyzed, including 85 culture-positive samples (28.1%). The Ampliflash® GBS test and the PlusLife® GBS tests gave a result for 100% and 96.3% tests, respectively. The performances of the tests were as follows: sensitivity 87.1% (95% confidence interval (CI) 78.3-92.6) and 98.7% (95% CI 93.0-99.8), specificity 99.1% (95% CI 96.7-99.8), and 91.9% (95% CI 87.3-95.0), respectively. False negative results of the Ampliflash® GBS test correlated with low-density GBS cultures. Time-to-results correlated with GBS culture density only for the PlusLife® GBS test (p < 0.001). CONCLUSION: Both techniques provide excellent analytical performances with high sensitivity and specificity together with a short turnaround time and results available in 10 to 35 min. Their potential to further reduce the burden of GBS neonatal disease compared with antenatal culture screening needs to be assessed in future clinical studies.


Asunto(s)
Técnicas de Diagnóstico Molecular , Técnicas de Amplificación de Ácido Nucleico , Complicaciones Infecciosas del Embarazo , Sensibilidad y Especificidad , Infecciones Estreptocócicas , Streptococcus agalactiae , Vagina , Humanos , Femenino , Técnicas de Amplificación de Ácido Nucleico/métodos , Streptococcus agalactiae/genética , Streptococcus agalactiae/aislamiento & purificación , Embarazo , Infecciones Estreptocócicas/diagnóstico , Infecciones Estreptocócicas/microbiología , Vagina/microbiología , Complicaciones Infecciosas del Embarazo/diagnóstico , Complicaciones Infecciosas del Embarazo/microbiología , Técnicas de Diagnóstico Molecular/métodos , Recién Nacido , Adulto
19.
Gan To Kagaku Ryoho ; 51(4): 383-387, 2024 Apr.
Artículo en Japonés | MEDLINE | ID: mdl-38644301

RESUMEN

As genomic medicine advances, opportunities for molecular pathology diagnosis by pathologists to be used as companion diagnostics is increasing. Pathological specimens must be useful not only for pathological diagnosis, but also for genetic testing panel and molecular pathology diagnosis. Companion diagnostics performed by pathologists uses immunohistochemical staining and fluorescence in situ hybridization to determine patient eligibility for molecular target drugs and immune checkpoint inhibitors. By accurately observing a wide variety of diagnostic criteria and performing with high precision, pathological diagnosis will become closer to therapeutic pathology.


Asunto(s)
Neoplasias , Humanos , Neoplasias/diagnóstico , Neoplasias/genética , Neoplasias/patología , Patología Molecular , Terapia Molecular Dirigida , Técnicas de Diagnóstico Molecular , Biomarcadores de Tumor/genética , Medicina de Precisión
20.
J Infect Dev Ctries ; 18(3): 435-440, 2024 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-38635619

RESUMEN

INTRODUCTION: Tubercular meningitis (TBM) is a serious public health problem in developing countries as it leads to significant mortality and residual neurological sequelae. The estimated mortality due to TBM in India is 1.5 per 100,000 population. In resource-limited settings, only the Ziehl-Neelsen (ZN) stain, which has very little sensitivity, is available. The World Health Organization recommended the Loop Mediated Isothermal Amplification (TB LAMP) assay for pulmonary tuberculosis only. We evaluated this test for tubercular meningitis as well. METHODOLOGY: In a cross-sectional study of 2-year duration, we have taken 239 cerebrospinal fluid samples from suspected cases of tubercular meningitis patients. ZN staining along with Mycobacteria Growth Indicator Tube (MGIT) TB culture, Xpert MTB/RIF Ultra assay, and commercial TB LAMP assay were performed for each sample. RESULTS: Out of 239 samples, 40 samples (16.73%) were found TB LAMP assay positive, 48 samples (20.08%) were found Xpert ultra-assay positive, 12 samples (5.02%) were MGIT TB culture positive and acid-fast bacillus smear positive in ten samples (4.18 %). Out of 12 MGIT-positive samples, all samples (100%) were TB LAMP and Xpert ultra positive and one sample (8.33%) was ZN smear positive. In 199 negative samples from the TB LAMP assay, eight samples were positive by Xpert, none by MGIT TB culture and AFB smear. Sensitivity and specificity were found as 100% and 87.66%, respectively, for the TB LAMP assay. CONCLUSION: TB LAMP assay is a rapid, cost-effective, sensitive, and specific test for tubercular meningitis infection in resource-limited settings.


Asunto(s)
Técnicas de Diagnóstico Molecular , Mycobacterium tuberculosis , Técnicas de Amplificación de Ácido Nucleico , Tuberculosis Meníngea , Humanos , Tuberculosis Meníngea/diagnóstico , Mycobacterium tuberculosis/genética , Configuración de Recursos Limitados , Estudios Transversales , Sensibilidad y Especificidad , Esputo/microbiología
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