Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 267
Filtrar
1.
Mycopathologia ; 189(5): 87, 2024 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-39312077

RESUMEN

Candida auris is a pathogenic yeast frequently exhibiting multidrug resistance and thus warrants special attention. The prompt detection and proper identification of this organism are needed to prevent its spread in healthcare facilities. The authors of this paper had previously developed LAMPAuris, a loop-mediated isothermal amplification assay, for the specific detection of C. auris. LAMPAuris is evaluated in this report for its ability to identify C. auris from five clades and to detect it from clinical specimens. A total of 103 skin swab samples were tested in comparison with a culture-based method and C. auris-specific SYBR green qPCR. The results show that the LAMPAuris assay had specificities ranging from 97 to 100% and sensitivities ranging from 66 to 86%. The lower sensitivity could be attributed to DNA degradation caused by the prolonged storage of the samples. In conclusion, LAMPAuris proved to be a rapid and reliable method for identifying C. auris and for detecting it in clinical specimens. Fresh specimens should ensure better yield and higher sensitivities.


Asunto(s)
Candida auris , Candidiasis , Técnicas de Diagnóstico Molecular , Técnicas de Amplificación de Ácido Nucleico , Sensibilidad y Especificidad , Humanos , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificación de Ácido Nucleico/métodos , Candidiasis/diagnóstico , Candidiasis/microbiología , Candida auris/genética , Candida auris/aislamiento & purificación , Piel/microbiología , Factores de Tiempo , Candida/aislamiento & purificación , Candida/genética , Candida/clasificación
2.
J Agric Food Chem ; 72(36): 19948-19956, 2024 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-39186810

RESUMEN

The key mutations, such as the Gly-4891-Glu substitution and the Ile-4734 multiple substitutions within the ryanodine receptors (RyR), are linked to diamide resistance in fall armyworm (FAW), Spodoptera frugiperda. In this study, we found that FAW remained sensitive to cyantraniliprole and chlorantraniliprole, while its sensitivity to flubendiamide was reduced. Moreover, a low level of heterozygous mutation at I4743 was observed. To facilitate the detection procedure of these mutations, a simple and efficient loop-mediated isothermal amplification (LAMP) protocol was developed for operation. The reaction for detecting the G4891E and I4743 single or multiple mutations was carried out at 68 °C for 85 min and 68 °C for 85 min or 68 °C for 65 min, respectively. These LAMP reactions can be easily observed via visualization of the color change from pink to yellow. This assay provides a simple, convenient, and effective means of detecting mutations in the RyR of FAW for pest management purposes.


Asunto(s)
Proteínas de Insectos , Mutación , Técnicas de Amplificación de Ácido Nucleico , Canal Liberador de Calcio Receptor de Rianodina , Spodoptera , Animales , Canal Liberador de Calcio Receptor de Rianodina/genética , Canal Liberador de Calcio Receptor de Rianodina/metabolismo , Canal Liberador de Calcio Receptor de Rianodina/química , Spodoptera/genética , Spodoptera/efectos de los fármacos , Técnicas de Amplificación de Ácido Nucleico/métodos , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Proteínas de Insectos/química , Insecticidas/farmacología , ortoaminobenzoatos/farmacología , Benzamidas/farmacología , Sulfonas/farmacología , Pirazoles/farmacología , Resistencia a los Insecticidas/genética , Fluorocarburos , Ftalimidas , Técnicas de Diagnóstico Molecular
3.
Anal Biochem ; 694: 115615, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-39002745

RESUMEN

With the rise in extreme weather due to global warming, coupled with globalization facilitating the spread of infectious diseases, there's a pressing need for portable testing platforms offering simplicity, low cost, and remote transmission, particularly beneficial in resource-limited and non-urban areas. We have developed a portable device using loop-mediated isothermal amplification (LAMP) with spectrometric detection to identify Salmonella Typhimurium DNA. The device utilizes the LinkIt 7697 microcontroller and a microspectrometer to capture and transmit spectral signals in real-time, allowing for improved monitoring and analysis of the reaction progress. We built a hand-held box containing a microspectrometer, thermoelectric cooler, ultraviolet LED, disposable reaction tube, and homemade thermal module, all powered by rechargeable batteries. Additionally, we conducted thorough experiments to ensure temperature accuracy within 1 °C under thermal control, developed a heating module with a LinkIt 7697 IoT development board to heat the DNA mixture to the reaction temperature within 3 min, and integrated foam insulation and a 3D-printed frame to enhance the device's thermal stability. We successfully demonstrated the amplification of Salmonella Typhimurium DNA with an impressive sensitivity of 2.83 × 10-4 ng/µL. A remote webpage interface allows for monitoring the temperature and fluorescence during the LAMP process, improving usability. This portable LAMP device with real-time detection offers a cost-effective solution for detecting Salmonella Typhimurium in food products. Its unique design and capabilities make it a promising tool for ensuring food safety.


Asunto(s)
ADN Bacteriano , Técnicas de Amplificación de Ácido Nucleico , Salmonella typhimurium , Técnicas de Amplificación de Ácido Nucleico/métodos , Técnicas de Amplificación de Ácido Nucleico/instrumentación , Salmonella typhimurium/aislamiento & purificación , Salmonella typhimurium/genética , ADN Bacteriano/análisis , ADN Bacteriano/genética , Microbiología de Alimentos , Técnicas de Diagnóstico Molecular
4.
Int J Biol Macromol ; 274(Pt 1): 133243, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38901507

RESUMEN

To enhance the DNA/RNA amplification efficiency and inhibitor tolerance of Bst DNA polymerase, four chimeric Bst DNA polymerase by fusing with a DNA-binding protein Sto7d and/or a highly hydrophobic protein Hp47 to Bst DNA polymerase large fragment. One of chimeric protein HpStBL exhibited highest inhibitor tolerance, which retained high active under 0.1 U/µL sodium heparin, 0.8 ng/µL humic acid, 2.5× SYBR Green I, 8 % (v/v) whole blood, 20 % (v/v) tissue, and 2.5 % (v/v) stool. Meanwhile, HpStBL showed highest sensitivity (93.75 %) to crude whole blood infected with the African swine fever virus. Moreover, HpStBL showed excellent reverse transcriptase activity in reverse transcription loop-mediated isothermal amplification, which could successfully detect 0.5 pg/µL severe acute respiratory syndrome coronavirus 2 RNA in the presence of 1 % (v/v) stools. The fusion of two domains with different functions to Bst DNA polymerase would be an effective strategy to improve Bst DNA polymerase performance in direct loop-mediated isothermal amplification and reverse transcription loop-mediated isothermal amplification detection, and HpStBL would be a promising DNA polymerase for direct African swine fever virus/severe acute respiratory syndrome coronavirus 2 detection due to simultaneously increased inhibitor tolerance and reverse transcriptase activity.


Asunto(s)
Virus de la Fiebre Porcina Africana , ADN Polimerasa Dirigida por ARN , ADN Polimerasa Dirigida por ARN/metabolismo , ADN Polimerasa Dirigida por ARN/genética , Virus de la Fiebre Porcina Africana/genética , Virus de la Fiebre Porcina Africana/enzimología , Animales , Proteínas Recombinantes de Fusión/genética , SARS-CoV-2/efectos de los fármacos , SARS-CoV-2/genética , Porcinos , Técnicas de Amplificación de Ácido Nucleico/métodos , Dominios Proteicos , ADN Polimerasa Dirigida por ADN/genética , ADN Polimerasa Dirigida por ADN/metabolismo , Inhibidores de la Transcriptasa Inversa/farmacología , COVID-19/virología , ARN Viral/genética
5.
Diagn Microbiol Infect Dis ; 110(1): 116398, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38908041

RESUMEN

Carbapenem-resistant significant members of Acinetobacter calcoaceticus-Acinetobacter baumannii (CR-SM-ACB) complex have emerged as an important cause of sepsis, especially in ICUs. This study demonstrates the application of loop-mediated-isothermal-amplification (LAMP) assay for detection of CR-SM-ACB-complex from patients with sepsis. Whole-blood and culture-broths(CB) collected from patients with culture-positive sepsis were subjected to LAMP and compared with PCR, and RealAmp. Vitek-2 system and conventional PCR results were used as confirmatory references. The sensitivity and specificity of LAMP(97 % & 100 %) and RealAmp(100 % & 100 %) for detection of CR-SM-ACB-complex from CB were better than PCR(87 % & 100 %). Diagnostic accuracy of LAMP, RealAmp, and PCR for detection of SM-ACB-complex from CB was 98.5 %, 100 %, and 88.5 % respectively. Turnaround time of Culture, LAMP, PCR, and RealAmp was 28-53, 6-20, 9-23, and 6-20hours, respectively. LAMP is a simple, inexpensive tool that can be applied directly to positive CB and may be customized to detect emerging pathogens and locally-prevalent resistance genes and to optimize antimicrobial use.


Asunto(s)
Infecciones por Acinetobacter , Acinetobacter baumannii , Acinetobacter calcoaceticus , Carbapenémicos , Unidades de Cuidados Intensivos , Técnicas de Diagnóstico Molecular , Técnicas de Amplificación de Ácido Nucleico , Sensibilidad y Especificidad , Sepsis , Humanos , Infecciones por Acinetobacter/diagnóstico , Infecciones por Acinetobacter/microbiología , Acinetobacter baumannii/efectos de los fármacos , Acinetobacter baumannii/genética , Acinetobacter baumannii/aislamiento & purificación , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/economía , Sepsis/diagnóstico , Sepsis/microbiología , Técnicas de Amplificación de Ácido Nucleico/métodos , Técnicas de Amplificación de Ácido Nucleico/economía , Carbapenémicos/farmacología , Acinetobacter calcoaceticus/genética , Acinetobacter calcoaceticus/efectos de los fármacos , Acinetobacter calcoaceticus/aislamiento & purificación , Antibacterianos/farmacología , Análisis Costo-Beneficio
6.
Int J Mol Sci ; 25(11)2024 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-38891961

RESUMEN

Southern stem canker (SSC) of soybean, attributable to the fungal pathogen Diaporthe aspalathi, results in considerable losses of soybean in the field and has damaged production in several of the main soybean-producing countries worldwide. Early and precise identification of the causal pathogen is imperative for effective disease management. In this study, we performed an RPA-CRISPR/Cas12a, as well as LAMP, PCR and real-time PCR assays to verify and compare their sensitivity, specificity and simplicity and the practicality of the reactions. We screened crRNAs targeting a specific single-copy gene, and optimized the reagent concentrations, incubation temperatures and times for the conventional PCR, real-time PCR, LAMP, RPA and Cas12a cleavage stages for the detection of D. aspalathi. In comparison with the PCR-based assays, two thermostatic detection technologies, LAMP and RPA-CRISPR/Cas12a, led to higher specificity and sensitivity. The sensitivity of the LAMP assay could reach 0.01 ng µL-1 genomic DNA, and was 10 times more sensitive than real-time PCR (0.1 ng µL-1) and 100 times more sensitive than conventional PCR assay (1.0 ng µL-1); the reaction was completed within 1 h. The sensitivity of the RPA-CRISPR/Cas12a assay reached 0.1 ng µL-1 genomic DNA, and was 10 times more sensitive than conventional PCR (1.0 ng µL-1), with a 30 min reaction time. Furthermore, the feasibility of the two thermostatic methods was validated using infected soybean leaf and seeding samples. The rapid, visual one-pot detection assay developed could be operated by non-expert personnel without specialized equipment. This study provides a valuable diagnostic platform for the on-site detection of SSC or for use in resource-limited areas.


Asunto(s)
Ascomicetos , Sistemas CRISPR-Cas , Glycine max , Sistemas CRISPR-Cas/genética , Glycine max/microbiología , Glycine max/genética , Ascomicetos/genética , Ascomicetos/aislamiento & purificación , Técnicas de Amplificación de Ácido Nucleico/métodos , Sensibilidad y Especificidad , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/genética , Técnicas de Diagnóstico Molecular/métodos , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Reacción en Cadena de la Polimerasa/métodos
7.
Am J Vet Res ; 85(9)2024 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-38942062

RESUMEN

OBJECTIVE: To improve the current recommendations for the diagnosis of canine heartworm (Dirofilaria immitis) disease. ANIMALS: Blood samples collected from 35 shelter dogs in the Republic of Korea. METHODS: Samples were tested for the presence of microfilaria using the modified Knott (MK) test and D immitis DNA using species-specific loop-mediated isothermal amplification (LAMP) PCR. The blood samples were additionally assessed for the presence of heartworm antigens using the Antigen Rapid Canine Heartworm AG Test Kit 2.0 (Bionote Co). The performance of the MK test and LAMP PCR was assessed through statistical analysis, with a paired McNemar test utilized for comparison. RESULTS: The heartworm antigen was detected in 28.5% of the subjects. Of the 10 positive animals, the MK test detected microfilaria in 4 of 35 (11.4%) animals, and LAMP PCR detected D immitis DNA in 6 of 35 (17.1%). The results of this study indicate that the LAMP PCR showed more positive results in samples compared to the conventional MK test. CLINICAL RELEVANCE: The D immitis-specific LAMP PCR assay has the potential to function as an alternative to current detection methods. It could complement the existing antigen detection tests in diagnosing canine heartworm infections.


Asunto(s)
Antígenos Helmínticos , Dirofilaria immitis , Dirofilariasis , Enfermedades de los Perros , Técnicas de Amplificación de Ácido Nucleico , Animales , Perros , Dirofilariasis/diagnóstico , Enfermedades de los Perros/diagnóstico , Enfermedades de los Perros/parasitología , Técnicas de Amplificación de Ácido Nucleico/veterinaria , Técnicas de Amplificación de Ácido Nucleico/métodos , República de Corea , Femenino , Masculino , Reacción en Cadena de la Polimerasa/veterinaria , Reacción en Cadena de la Polimerasa/métodos , Sensibilidad y Especificidad , Técnicas de Diagnóstico Molecular/veterinaria , Técnicas de Diagnóstico Molecular/métodos
8.
Biosensors (Basel) ; 14(5)2024 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-38785731

RESUMEN

Loop-mediated isothermal amplification (LAMP) technology is extensively utilized for the detection of infectious diseases owing to its rapid processing and high sensitivity. Nevertheless, conventional LAMP signaling methods frequently suffer from a lack of sequence specificity. This study integrates a triplex-forming oligonucleotide (TFO) probe into the LAMP process to enhance sequence specificity. This TFO-LAMP technique was applied for the detection of Group B Streptococcus (GBS). The TFO probe is designed to recognize a specific DNA sequence, termed the TFO targeting sequence (TTS), within the amplified product, facilitating detection via fluorescent instrumentation or lateral flow biosensors. A screening method was developed to identify TFO sequences with high affinity to integrate TFO into LAMP, subsequently incorporating a selected TTS into an LAMP primer. In the TFO-LAMP assay, a FAM-labeled TFO is added to target the TTS. This TFO can be captured by an anti-FAM antibody on lateral flow test strips, thus creating a nucleic acid testing biosensor. The efficacy of the TFO-LAMP assay was confirmed through experiments with specimens spiked with varying concentrations of GBS, demonstrating 85% sensitivity at 300 copies and 100% sensitivity at 30,000 copies. In conclusion, this study has successfully developed a TFO-LAMP technology that offers applicability in lateral flow biosensors and potentially other biosensor platforms.


Asunto(s)
Técnicas Biosensibles , Técnicas de Amplificación de Ácido Nucleico , Oligonucleótidos , Streptococcus/genética , Streptococcus/aislamiento & purificación , Humanos , ADN Bacteriano/análisis , Técnicas de Diagnóstico Molecular
9.
Diagnostics (Basel) ; 14(9)2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38732380

RESUMEN

Influenza viruses cause highly contagious respiratory diseases that cause millions of deaths worldwide. Rapid detection of influenza viruses is essential for accurate diagnosis and the initiation of appropriate treatment. We developed a loop-mediated isothermal amplification and lateral flow assay (LAMP-LFA) capable of simultaneously detecting influenza A and influenza B. Primer sets for influenza A and influenza B were designed to target conserved regions of segment 7 and the nucleoprotein gene, respectively. Optimized through various primer set ratios, the assay operated at 62 °C for 30 min. For a total of 243 (85 influenza A positive, 58 influenza B positive and 100 negative) nasopharyngeal swab samples, the performance of the influenza A/B multiplex LAMP-LFA was compared with that of the commercial AllplexTM Respiratory Panel 1 assay (Seegene, Seoul, Korea). The influenza A/B multiplex LAMP-LFA demonstrated a specificity of 98% for the non-infected clinical samples, along with sensitivities of 94.1% for the influenza A clinical samples and 96.6% for the influenza B clinical samples, respectively. The influenza A/B multiplex LAMP-LFA showed high sensitivity and specificity, indicating that it is reliable for use in a low-resource environment.

10.
Diagnostics (Basel) ; 14(10)2024 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-38786325

RESUMEN

Infections by carbapenemase-producing Enterobacterales constitute a global public health threat. The rapid and efficient diagnosis of Enterobacterales infection is critical for prompt treatment and infection control, especially in hospital settings. We developed a novel loop-mediated isothermal amplification (LAMP) method combined with DNA chromatography to identify five major groups of carbapenemase-producing genes (blaNDM, blaOXA-48-like, blaIMP, blaKPC, and blaVIM). This method uses DNA-DNA hybridization-based detection in which LAMP products can be easily visualized as colored lines. No specific technical expertise, expensive equipment, or special facilities are required for this method, allowing its broad application. Here, 73 bacteria collections including strains with carbapenemase-producing genes were tested. Compared to sequencing results, LAMP DNA chromatography for five carbapenemase-producing genes had a sensitivity and specificity of 100% and >97%, respectively. This newly developed method can be a valuable rapid diagnostic test to guide appropriate treatments and infection control measures, especially in resource-limited settings.

11.
Pest Manag Sci ; 80(8): 4069-4073, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38563512

RESUMEN

BACKGROUND: The tomato leafminer, Phthorimaea absoluta (Meyrick) (Lepidoptera: Gelechiidae), is a destructive invasive pest that originated in South America and has spread within China since 2017. A rapid method for on-site identification of P. absoluta is urgently needed for interception of this pest across China. RESULTS: We developed a loop-mediated isothermal amplification (LAMP) technique to differentiate P. absoluta from Liriomyza sativae, Chromatomyia horticola, and Phthorimaea operculella using extracted genomic DNA, which was then refined to create an on-site LAMP diagnostic method that can be performed under field conditions without the need for laboratory equipment. CONCLUSION: In the present research, we developed an on-site diagnostic method for rapid differentiation of P. absoluta from other insects with similar morphology or damage characteristics in China. © 2024 Society of Chemical Industry.


Asunto(s)
Especies Introducidas , Mariposas Nocturnas , Técnicas de Amplificación de Ácido Nucleico , Animales , Mariposas Nocturnas/genética , Técnicas de Amplificación de Ácido Nucleico/métodos , Larva , Técnicas de Diagnóstico Molecular/métodos , China
12.
Biol Methods Protoc ; 9(1): bpae012, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38566776

RESUMEN

While the detection of single-nucleotide variants (SNVs) is important for evaluating human health and disease, most genotyping methods require a nucleic acid extraction step and lengthy analytical times. Here, we present a protocol which utilizes the integration of locked nucleic acids (LNAs) into self-annealing loop primers for the allelic discrimination of five isocitrate dehydrogenase 1 R132 (IDH1-R132) variants using loop-mediated isothermal amplification (LAMP). This genotyping panel was initially evaluated using purified synthetic DNA to show proof of specific SNV discrimination. Additional evaluation using glioma tumor lysates with known IDH1-R132 mutational status demonstrated specificity in approximately 35 min without the need for a nucleic acid extraction purification step. This LNA-LAMP-based genotyping assay can detect single base differences in purified nucleic acids or tissue homogenates, including instances where the variant of interest is present in an excess of background wild-type DNA. The pH-based colorimetric indicator of LNA-LAMP facilitates convenient visual interpretation of reactions, and we demonstrate successful translation to an end-point format using absorbance ratio, allowing for an alternative and objective approach for differentiating between positive and negative reactions. Importantly, the LNA-LAMP genotyping panel is highly reproducible, with no false-positive or false-negative results observed.

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.
Diagn Microbiol Infect Dis ; 109(3): 116297, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38604076

RESUMEN

The LAMPdirect Genelyzer KIT allows for the detection of SARS-CoV-2 RNA in saliva samples with a loop-mediated isothermal amplification (LAMP) method and generates results within 20 min. It has been approved by the Pharmaceuticals and Medical Devices Agency in Japan. In this study, the performance of the LAMPdirect Genelyzer KIT was compared with that of the RT-qPCR reference method using 50 nasopharyngeal swabs and 100 saliva samples. In addition, we evaluated the applicability of an alternative reverse transcriptase and the effects of an inactivation buffer. The total agreement rates were 80.0 % and 82.0 % for nasopharyngeal and saliva samples, respectively. When considering samples at the detection limit (50 copies/reaction) that increases the chance of transmission between humans, the total agreement rates were 100% and 94.1% for nasopharyngeal and saliva samples, respectively. The LAMP method is simple, fast, and inexpensive, making it useful for small medical institutions or rural areas.


Asunto(s)
COVID-19 , Técnicas de Diagnóstico Molecular , Nasofaringe , Técnicas de Amplificación de Ácido Nucleico , ARN Viral , SARS-CoV-2 , Saliva , Humanos , Saliva/virología , SARS-CoV-2/genética , SARS-CoV-2/aislamiento & purificación , Nasofaringe/virología , Técnicas de Amplificación de Ácido Nucleico/métodos , ARN Viral/genética , ARN Viral/aislamiento & purificación , COVID-19/diagnóstico , COVID-19/virología , Técnicas de Diagnóstico Molecular/métodos , Sensibilidad y Especificidad , Juego de Reactivos para Diagnóstico/normas , Prueba de Ácido Nucleico para COVID-19/métodos , Prueba de Ácido Nucleico para COVID-19/instrumentación , Manejo de Especímenes/métodos
15.
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
16.
Small ; 20(24): e2311764, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38506607

RESUMEN

The development of novel method for drug-resistant bacteria detection is imperative. A simultaneous dual-gene Test of methicillin-resistant Staphylococcus aureus (MRSA) is developed using an Argonaute-centered portable biosensor (STAR). This is the first report concerning Argonaute-based pathogenic bacteria detection. Simply, the species-specific mecA and nuc gene are isothermally amplified using loop-mediated isothermal amplification (LAMP) technique, followed by Argonaute-based detection enabled by its programmable, guided, sequence-specific recognition and cleavage. With the strategy, the targeted nucleic acid signals gene are dexterously converted into fluorescent signals. STAR is capable of detecting the nuc gene and mecA gene simultaneously in a single reaction. The limit of detection is 10 CFU/mL with a dynamic range from 10 to 107 CFU/mL. The sample-to-result time is <65 min. This method is successfully adapted to detect clinical samples, contaminated foods, and MRSA-infected animals. This work broadens the reach of Argonaute-based biosensing and presents a novel bacterial point-of-need (PON) detection platform.


Asunto(s)
Técnicas Biosensibles , Staphylococcus aureus Resistente a Meticilina , Técnicas de Amplificación de Ácido Nucleico , Staphylococcus aureus Resistente a Meticilina/genética , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Técnicas Biosensibles/métodos , Técnicas de Amplificación de Ácido Nucleico/métodos , Proteínas Argonautas/metabolismo , Proteínas Argonautas/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Proteínas de Unión a las Penicilinas/genética , Animales , Nucleasa Microcócica/metabolismo , Nucleasa Microcócica/genética
17.
Expert Rev Mol Diagn ; 24(3): 193-200, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38414348

RESUMEN

INTRODUCTION: Molecular diagnostic systems for point-of-care (POC) testing are nowadays routinely used and are part of many labs. Although often intended for bedside use outside of the microbiology lab, there is still room for expansion. AREAS COVERED: This review discusses the two techniques that are currently the most widespread, real-time polymerase-chain reaction (RT-PCR) and loop-mediated isothermal amplification (LAMP). An overview is provided of the various manufacturers and products as well as the evidence and current use in clinical practice. The article further sheds light on some newer techniques, such as CRISPR-based diagnostics and lab-on-a-chip, which are still in development. EXPERT OPINION: With many new platforms and techniques still in the pipeline and their potential currently not yet fully exploited, we expect the use of molecular POC testing to increase in the years to come. However, even when used in hospital - in lab, the main advantages of the tests being fast and easy to perform already provide significant benefits in terms of patient outcome.


Asunto(s)
Enfermedad Crítica , Pruebas en el Punto de Atención , Humanos , Técnicas de Amplificación de Ácido Nucleico/métodos , Técnicas de Diagnóstico Molecular/métodos , Reacción en Cadena en Tiempo Real de la Polimerasa , Sistemas de Atención de Punto , Sensibilidad y Especificidad
18.
Med Mycol ; 62(2)2024 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-38327232

RESUMEN

Mucormycosis is a rare disease with scarce diagnostic methods for early intervention. Available strategies employing direct microscopy using calcofluor white-KOH, culture, radiologic, and histopathologic testing often are time-intensive and demand intricate protocols. Nucleic Acid Amplification Test holds promise due to its high sensitivity combined with rapid detection. Loop-mediated isothermal amplification (LAMP) based detection offers an ultrasensitive technique that does not require complicated thermocyclers like in polymerase chain reaction, offering a straightforward means for improving diagnoses as a near-point-of-care test. The study introduces a novel magnetic nanoparticle-based LAMP assay for carryover contaminant capture to reduce false positives. Solving the main drawback of LAMP-based diagnosis techniques. The assay targets the cotH gene, which is invariably specific to Mucorales. The assay was tested with various species of Mucorales, and the limit of detections for Rhizopus microsporus, Lichtheimia corymbifera, Rhizopus arrhizus, Rhizopus homothallicus, and Cunninghamella bertholletiae were 1 fg, 1 fg, 0.1 pg, 0.1 pg, and 0.01 ng, respectively. This was followed by a clinical blindfolded study using whole blood and urine samples from 30 patients diagnosed with Mucormycosis. The assay has a high degree of repeatability and had an overall sensitivity of > 83%. Early Mucormycosis detection is crucial, as current lab tests from blood and urine lack sensitivity and take days for confirmation despite rapid progression and severe complications. Our developed technique enables the confirmation of Mucormycosis infection in < 45 min, focusing specifically on the RT-LAMP process. Consequently, this research offers a viable technique for quickly identifying Mucormycosis from isolated DNA of blood and urine samples instead of invasive tissue samples.


Mucormycosis is a challenging disease to diagnose early. This study introduces a sensitive and rapid diagnostic approach using Loop-mediated isothermal amplification technology. Testing blood and urine samples from 30 patients revealed promising sensitivity and repeatability, indicating its potential for non-invasive diagnosis.


Asunto(s)
Nanopartículas de Magnetita , Mucorales , Mucormicosis , Humanos , Mucormicosis/diagnóstico , Mucormicosis/veterinaria , Sensibilidad y Especificidad , Técnicas de Amplificación de Ácido Nucleico/métodos , Técnicas de Amplificación de Ácido Nucleico/veterinaria , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/veterinaria , Mucorales/genética
19.
Biosensors (Basel) ; 14(2)2024 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-38392016

RESUMEN

Ribonucleic acid (RNA) viruses are one of the major classes of pathogens that cause human diseases. The conventional method to detect RNA viruses is real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR), but it has some limitations. It is expensive and time-consuming, with infrastructure and trained personnel requirements. Its high throughput requires sophisticated automation and large-scale infrastructure. Isothermal amplification methods have been explored as an alternative to address these challenges. These methods are rapid, user-friendly, low-cost, can be performed in less specialized settings, and are highly accurate for detecting RNA viruses. Microfluidic technology provides an ideal platform for performing virus diagnostic tests, including sample preparation, immunoassays, and nucleic acid-based assays. Among these techniques, nucleic acid isothermal amplification methods have been widely integrated with microfluidic platforms for RNA virus detection owing to their simplicity, sensitivity, selectivity, and short analysis time. This review summarizes some common isothermal amplification methods for RNA viruses. It also describes commercialized devices and kits that use isothermal amplification techniques for SARS-CoV-2 detection. Furthermore, the most recent applications of isothermal amplification-based microfluidic platforms for RNA virus detection are discussed in this article.


Asunto(s)
Ácidos Nucleicos , Virus , Humanos , Virus/genética , Técnicas de Amplificación de Ácido Nucleico/métodos , Transcripción Reversa , SARS-CoV-2/genética , Sensibilidad y Especificidad , Técnicas de Diagnóstico Molecular/métodos
20.
Anal Biochem ; 684: 115376, 2024 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-37924966

RESUMEN

Nucleic acids amplification is a widely used technique utilized for different manipulations with DNA and RNA. Although, polymerase chain reaction (PCR) remains the most popular amplification method, isothermal approaches are gained more attention last decades. Among these, loop-mediated isothermal amplification (LAMP) became an excellent alternative to PCR. LAMP requires an increased number of primers and, therefore, is considered a highly specific amplification reaction compared to PCR. LAMP primers design is still a non-trivial task, and all niceties should be taken into account during their selection. Here, we report on a new program called LAMPrimers iQ destined for high-quality LAMP primers design. LAMPrimers iQ is based on an original algorithm considering rigorous criteria for primers selection. Unlike alternative programs, LAMPrimers iQ can process long DNA or RNA sequences, and completely avoid primers that can form homo- and heterodimers. The quality of the primers designed was checked using SARS-CoV-2 coronavirus RNA as a model target. It was shown that primers selected with LAMPrimers iQ provide higher specificity and reliable detection of viral RNA compared to those obtained by alternative programs. The program is available at https://github.com/Restily/LAMPrimers-iQ.


Asunto(s)
ADN , Técnicas de Amplificación de Ácido Nucleico , Sensibilidad y Especificidad , Técnicas de Amplificación de Ácido Nucleico/métodos , Programas Informáticos , ARN
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA