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1.
Med Mycol ; 62(2)2024 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-38327232

RESUMO

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.


Assuntos
Nanopartículas de Magnetita , Mucorales , Mucormicose , Humanos , Mucormicose/diagnóstico , Mucormicose/veterinária , Sensibilidade e Especificidade , Técnicas de Amplificação de Ácido Nucleico/métodos , Técnicas de Amplificação de Ácido Nucleico/veterinária , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/veterinária , Mucorales/genética
2.
Vet Rec ; 193(10): e3309, 2023 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-37700460

RESUMO

BACKGROUND: Bovine genital leptospirosis (BGL) causes chronic reproductive disease in cattle. This study aimed to apply a combined serological-molecular testing protocol under field conditions for diagnosing BGL in cows with gestational losses. METHODS: Three beef herds with reproductive failures were studied, and 60 cows with gestational losses (20 from each herd) were randomly selected for laboratory diagnosis of BGL. In addition, 40 cows with normal pregnancy were included as a control. Blood samples were collected from all 100 cows for microscopic agglutination testing, and cervicovaginal mucus (CVM) samples were collected from 28 cows with gestational losses and 20 control cows for lipL32-PCR. RESULTS: All herds had high Leptospira seroreactivity (>65%), mainly against serogroup Sejroe. Ten of the 28 CVM samples from cows with gestational losses were PCR-positive, while all samples from the control group were negative (p < 0.05). LIMITATIONS: Unfortunately, the positive samples did not amplify in secY-PCR for nucleotide sequencing, which would allow the identification of leptospiral strains. CONCLUSION: Serology was sufficient to indicate leptospirosis at the herd level, but the definitive diagnosis of BGL was only possible using CVM PCR. Although seroreactivity against serogroup Sejroe has been associated with gestational losses, this is the first study to conduct CVM PCR as a confirmatory test for BGL diagnosis in extensive beef herds under field conditions.


Assuntos
Doenças dos Bovinos , Leptospira , Leptospirose , Gravidez , Feminino , Bovinos , Animais , Doenças dos Bovinos/diagnóstico , Leptospirose/diagnóstico , Leptospirose/veterinária , Técnicas de Diagnóstico Molecular/veterinária , Genitália
3.
J Avian Med Surg ; 37(1): 32-40, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37358200

RESUMO

Avian chlamydiosis is a disease that occurs in birds, especially parrots, and is caused by the Gram-negative bacterium Chlamydia psittaci. Wild Animal Screening Centers in Brazil receive, maintain, treat, and place (preferably to nature) wild animals recovered from illegal trafficking. We performed molecular testing for avian chlamydiosis in parrots from the genus Amazona that were presented to these centers. Cloacal swab samples were collected from 59 parrots (Amazona species) and transported in aqueous or culture medium. The samples were subsequently submitted for DNA extraction by the boiling method, polymerase chain reaction (PCR) amplification using CPF/CPR primers, and agarose gel electrophoresis. Conjunctivitis, nasal discharge, and poor body condition were the clinical signs associated with a differential disease diagnosis of avian chlamydiosis. Transport medium did not have an effect on the test results. The prevalence of C psittaci in the samples was 37% (22/59, 95% confidence interval: 25-49). There was a significant (P = 0.009) association between the PCR test results and clinical signs. Follow-up testing was conducted on a subgroup of 14 individuals that initially tested negative on PCR; 50% (7/14) of these birds were found to be positive within 24 days of the first test. The results of this study confirm the feasibility of using the CPF/CFP primer-based PCR to detect C psittaci in Amazona species, describe a less costly method of transporting biological material for DNA extraction, and evaluate the temporal aspect for obtaining positive results through molecular testing for C psittaci in Amazona species.


Assuntos
Amazona , Doenças das Aves , Chlamydophila psittaci , Psitacose , Animais , Amazona/genética , Brasil/epidemiologia , Prevalência , Doenças das Aves/diagnóstico , Doenças das Aves/epidemiologia , Doenças das Aves/microbiologia , Psitacose/diagnóstico , Psitacose/epidemiologia , Psitacose/veterinária , Chlamydophila psittaci/genética , Animais Selvagens , Aves , Técnicas de Diagnóstico Molecular/veterinária , DNA
4.
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1451777

RESUMO

Several agents can cause hemoparasitic diseases in dogs, and blood-sucking arthropods transmit these diseases. These agents can cause several clinical manifestations and, in some cases, can kill the host. Because these agents are essential in animal health, this study aims to detect the frequency of Ehrlichia canis, Rickettsia rickettsii, Anaplasma platys, and Rangelia vitalii by real-time PCR and Babesia vogeli in dogs in the southern region of the city of São Paulo, São Paulo. Of the 98 dog samples, 18 (18.4%) tested positive with real-time polymerase chain reaction for at least one studied agent. Of these 18 samples, 17 tested positive for a single agent (11.2% for B. canis vogeli, 1.02% for R. vitalii, and 5.1% for E. canis), and one showed co-infection with B. canis vogeli and R. vitalii. The results demonstrate the presence of hemoparasites in the studied animals, which can influence the quality and life expectancy of these animals. The Rangeliadetection warns small animal clinicians to include it as a differential diagnosis for hemoparasitosis.(AU)


As hemoparasitoses em cães podem ser causadas por diversos agentes, sendo essas doenças transmitidas por artrópodes hematófagos. Esses agentes podem causar diversas manifestações clínicas e, em alguns casos, podem matar o hospedeiro. Este estudo teve como objetivo detectar por PCR em tempo real a frequência de Ehrlichia canis, Rickettsia rickettsii, Anaplasma platys, Rangelia vitalii e Babesia canis vogeli em amostras de cães da zona sul da cidade de São Paulo, Brasil. Das 98 amostras de cães, 18 (18,4%) testaram positivo com reação em cadeia da polimerase em tempo real para pelo menos um agente estudado. Destas 18 amostras, 17 testaram positivo para um único agente (11,2% para B. canis vogeli, 1,02% para R. vitalii e 5,1% para E. canis), e uma apresentou coinfecção com B. canis vogeli e R. vitalii. Os resultados demonstram a presença de hemoparasitas nos animais estudados, o que pode influenciar a qualidade e a expectativa de vida desses animais. Além disso, é o primeiro relato da detecção de R. vitalli na zona sul de São Paulo e serve de alerta para os clínicos de pequenos animais incluírem esse agente como diagnóstico diferencial para as hemoparasitoses.(AU)


Assuntos
Animais , Infecções por Protozoários/diagnóstico , Babesiose/diagnóstico , Ehrlichiose/diagnóstico , Cães/microbiologia , Brasil , Reação em Cadeia da Polimerase/veterinária , Piroplasmida , Técnicas de Diagnóstico Molecular/veterinária , Ehrlichia canis
5.
Vet Ital ; 58(2)2022 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-36586114

RESUMO

The orf virus (ORFV) is an epitheliotropic virus causing a highly contagious skin disease mainly in sheep and goats. Several diagnostics including molecular tools like Loop mediated isothermal amplification (LAMP) assay are available to detect ORFV in affected species. However, the carry-over contamination associated with LAMP as open tube format prevents the assay applicability as point of care test in field diagnostic settings. In this study, the B2L gene based LAMP assay was optimized in a closed tube format using hydroxynaphthol blue (HNB) and calcein as pre-addition dyes and it has shown a clear positive and negative signal at 60 °C using 4 and 5 mM concentrations of MgSO4 respectively for these dyes. Optimitimzed assay that could reveal the result within one hour is highly specific and senstive with a limit of detection at 12.5 femtogram of viral genomic DNA or ~85 virus genome equivalent. This improved method prevented the cross-contamination of future LAMP reactions in the laboratory without compromising diagnostic sensitivity (100%) and specificity (100%) when compared to open tube system. This closed tube LAMP method has potential to act as a simple visual detection assay for the rapid and specific diagnosis of ORFV in sheep and goats.


Assuntos
Vírus do Orf , Animais , Ovinos , Vírus do Orf/genética , Cabras , Sensibilidade e Especificidade , Técnicas de Amplificação de Ácido Nucleico/veterinária , Técnicas de Amplificação de Ácido Nucleico/métodos , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/veterinária , Corantes
6.
Vet Med Sci ; 8(4): 1400-1408, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35339118

RESUMO

BACKGROUND: Canine histiocytic sarcoma (HS) is an aggressive cancer with morphologically variable features; therefore, obtaining a definitive diagnosis can be challenging. Two proteins, IBA-1, ionised calcium-binding adapter molecule 1, and CD204, a macrophage scavenger receptor, have been shown to be specific immunohistochemical markers helpful in distinguishing HS from other tumour types with similar morphological features. OBJECTIVES: This study was performed to demonstrate the use of RNA in situ hybridisation (ISH) technology allowing single-molecule RNA visualisation in formalin-fixed paraffin-embedded (FFPE) tissues as a molecular tool for the diagnosis of canine HS. METHODS: Reverse transcription polymerase chain reaction (RT-PCR) and western blot analysis for IBA-1 and CD204 were performed to correlate gene expression and protein expression of these two markers in the histiocytic sarcoma DH82 cell line. RNA-ISH for IBA-1 and CD204 was performed on the DH82 cell line to validate the RNA-ISH probes. RNA-ISH and immunohistochemistry (IHC) were performed in clinical HS FFPE samples to demonstrate mRNA and protein expression of IBA-1 and CD204. FFPE archived samples of canine round cell tumours, melanoma and anaplastic sarcoma were used as negative controls. RESULTS: RNA-ISH and IHC showed moderate to strong expression for IBA-1 and CD204 in the neoplastic cells in both the canine DH82 cell line and the archived canine HS samples. RNA-ISH and IHC showed scattered positive staining in the control tumours samples, consistent with macrophagic infiltration. CONCLUSION: RNA-ISH for CD204 and IBA-1 appeared to have a high specificity and sensitivity in our samples and may be an additional valuable diagnostic technique in identifying HS.


Assuntos
Doenças do Cão , Sarcoma Histiocítico , Neoplasias , Animais , Biomarcadores , Doenças do Cão/diagnóstico , Doenças do Cão/patologia , Cães , Sarcoma Histiocítico/diagnóstico , Sarcoma Histiocítico/patologia , Sarcoma Histiocítico/veterinária , Imuno-Histoquímica , Técnicas de Diagnóstico Molecular/veterinária , Neoplasias/veterinária , RNA
7.
J Parasitol ; 107(6): 846-852, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34731237

RESUMO

The Asian fish tapeworm (Schyzocotyle acheilognathi syn. Bothriocephalus acheilognathi) (AFT) is an invasive parasite that can infect many species of fish, although most hosts are primarily members of Cyprinidae. Pathogenicity has most often been reported in aquaculture settings in fry and fingerling stages of carp (Cyprinus spp.). More recently, it has been shown to cause growth retardation in the endangered bonytail chub (Gila elegans) and found to be widespread in populations of endangered humpback chub (Gila cypha) in the Colorado River, Grand Canyon, Arizona. AFT spreads most often through the transport of infected fish, particularly baitfish. Despite its harmful potential, there is no efficient or accurate ante mortem test to detect AFT in water or fish samples before transport. Herein, we report on the development of a sensitive and specific loop-mediated isothermal amplification (LAMP) assay to detect the parasite in under 30 min from laboratory prepared samples. Six LAMP primers were designed to amplify a variable region of the 18S ribosomal RNA gene in AFT with the detection and quantification of DNA on a real-time fluorometer. The limit of detection was 1 × 101 copies/µl of DNA extracted from as few as 2 AFT eggs. Future application of our assay would be a low-cost test to rapidly and accurately detect AFT DNA from environmental samples on-site so that preventive actions can be taken to halt the spread of the AFT through the movement of infected fish.


Assuntos
Carpas/parasitologia , Cestoides/isolamento & purificação , Infecções por Cestoides/veterinária , Doenças dos Peixes/parasitologia , Técnicas de Diagnóstico Molecular/veterinária , Técnicas de Amplificação de Ácido Nucleico/veterinária , Animais , Cestoides/genética , Infecções por Cestoides/parasitologia , RNA Ribossômico 18S/genética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
8.
Vet Res ; 52(1): 126, 2021 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-34600578

RESUMO

This work modifies a loop-mediated isothermal amplification (LAMP) assay to detect the bovine respiratory disease (BRD) bacterial pathogens Pasteurella multocida, Mannheimia haemolytica, and Histophilus somni in a colorimetric format on a farm. BRD causes a significant health and economic burden worldwide that partially stems from the challenges involved in determining the pathogens causing the disease. Methods such as polymerase chain reaction (PCR) have the potential to identify the causative pathogens but require lab equipment and extensive sample processing making the process lengthy and expensive. To combat this limitation, LAMP allows accurate pathogen detection in unprocessed samples by the naked eye allowing for potentially faster and more precise diagnostics on the farm. The assay developed here offers 66.7-100% analytical sensitivity, and 100% analytical specificity (using contrived samples) while providing 60-100% concordance with PCR results when tested on five steers in a feedlot. The use of a consumer-grade water bath enabled on-farm execution by collecting a nasal swab from cattle and provided a colorimetric result within 60 min. Such an assay holds the potential to provide rapid pen-side diagnostics to cattle producers and veterinarians.


Assuntos
Doenças dos Bovinos/diagnóstico , Colorimetria/veterinária , Testes Diagnósticos de Rotina/veterinária , Técnicas de Diagnóstico Molecular/veterinária , Técnicas de Amplificação de Ácido Nucleico/veterinária , Infecções por Pasteurellaceae/veterinária , Pasteurellaceae/isolamento & purificação , Animais , Bovinos , Doenças dos Bovinos/microbiologia , Colorimetria/instrumentação , Testes Diagnósticos de Rotina/instrumentação , Mannheimia haemolytica/isolamento & purificação , Técnicas de Diagnóstico Molecular/instrumentação , Nariz/microbiologia , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Infecções por Pasteurella/diagnóstico , Infecções por Pasteurella/microbiologia , Infecções por Pasteurella/veterinária , Pasteurella multocida/isolamento & purificação , Infecções por Pasteurellaceae/diagnóstico , Infecções por Pasteurellaceae/microbiologia
9.
Vet Res ; 52(1): 124, 2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34593042

RESUMO

The parasitic gastrointestinal nematode Haemonchus contortus causes serious economic losses to agriculture due to infection and disease in small ruminant livestock. The development of new therapies requires appropriate viability testing, with methods nowadays relying on larval motility or development using procedures that involve microscopy. None of the existing biochemical methods, however, are performed in adults, the target stage of the anthelmintic compounds. Here we present a new test for the viability of H. contortus adults and exsheathed third-stage larvae which is based on a bioluminescent assay of ATP content normalized to total protein concentration measured using bicinchoninic acid. All the procedure steps were optimized to achieve maximal sensitivity and robustness. This novel method can be used as a complementary assay for the phenotypic screening of new compounds with potential antinematode activity in exsheathed third-stage larvae and in adult males. Additionally, it might be used for the detection of drug-resistant isolates.


Assuntos
Trifosfato de Adenosina/uso terapêutico , Hemoncose/veterinária , Haemonchus/isolamento & purificação , Medições Luminescentes/veterinária , Técnicas de Diagnóstico Molecular/veterinária , Doenças dos Ovinos/diagnóstico , Animais , Feminino , Hemoncose/diagnóstico , Hemoncose/parasitologia , Haemonchus/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Medições Luminescentes/instrumentação , Masculino , Técnicas de Diagnóstico Molecular/instrumentação , Ovinos , Doenças dos Ovinos/parasitologia , Carneiro Doméstico
10.
BMC Vet Res ; 17(1): 279, 2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34412635

RESUMO

BACKGROUND: C. psittaci has recently emerged as an equine abortigenic pathogen causing significant losses to the Australian Thoroughbred industry, while Equine herpesvirus-1 (EHV-1) is a well-recognized abortigenic agent. Diagnosis of these agents is based on molecular assays in diagnostic laboratories. In this study, we validated C. psittaci and newly developed EHV-1 Loop Mediated Isothermal Amplification (LAMP) assays performed in a real-time fluorometer (rtLAMP) against the reference diagnostic assays. We also evaluated isothermal amplification using commercially available colorimetric mix (cLAMP), and SYBR Green DNA binding dye (sgLAMP) for "naked eye" end-point detection when testing 'real-world' clinical samples. Finally, we applied the C. psittaci LAMP assays in two pilot Point-of-Care (POC) studies in an equine hospital. RESULTS: The analytical sensitivity of C. psittaci and EHV-1 rt-, and colorimetric LAMPs was determined as one and 10 genome equivalents per reaction, respectively. Compared to reference diagnostic qPCR assays, the C. psittaci rtLAMP showed sensitivity of 100%, specificity of 97.5, and 98.86% agreement, while EHV-1 rtLAMP showed 86.96% sensitivity, 100% specificity, and 91.43% agreement. When testing rapidly processed clinical samples, all three C. psittaci rt-, c-, sg-LAMP assays were highly congruent with each other, with Kappa values of 0. 906 for sgLAMP and 0. 821 for cLAMP when compared to rtLAMP. EHV-1 testing also revealed high congruence between the assays, with Kappa values of 0.784 for cLAMP and 0.638 for sgLAMP when compared to rtLAMP. The congruence between LAMP assays and the C. psittaci or EHV-1 qPCR assays was high, with agreements ranging from 94.12 to 100% for C. psittaci, and 88.24 to 94.12% for EHV-1, respectively. At the POC, the C. psittaci rt- and c-LAMP assays using rapidly processed swabs were performed by technicians with no prior molecular experience, and the overall congruence between the POC C. psittaci LAMPs and the qPCR assays ranged between 90.91-100%. CONCLUSIONS: This study describes reliable POC options for the detection of the equine pathogens: C. psittaci and EHV-1. Testing 'real-world' samples in equine clinical setting, represents a proof-of-concept that POC isothermal diagnostics can be applied to rapid disease screening in the equine industry.


Assuntos
Infecções por Herpesviridae/veterinária , Doenças dos Cavalos/diagnóstico , Psitacose/veterinária , Animais , Chlamydophila psittaci/isolamento & purificação , Feminino , Fluorometria/métodos , Fluorometria/veterinária , Infecções por Herpesviridae/diagnóstico , Herpesvirus Equídeo 1/isolamento & purificação , Cavalos , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/veterinária , Técnicas de Amplificação de Ácido Nucleico/métodos , Técnicas de Amplificação de Ácido Nucleico/veterinária , Sistemas Automatizados de Assistência Junto ao Leito , Psitacose/diagnóstico , Sensibilidade e Especificidade
11.
J Fish Dis ; 44(12): 1993-2001, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34411329

RESUMO

To make crucial prevention, reduce fish losses and minimize the economic damage of diseases on the fish farm owners, a rapid detection of fish pathogens is mandatory. In this study, a loop-mediated isothermal amplification assay combined with hydroxynaphthol blue dye (LAMP-HNB) was developed and used for the rapid detection of Aeromonas salmonicida that caused significant economic losses in fish farming. Firstly, a pair of outer and inner primers specific for conserved fragment of vapA gene in A. salmonicida were designed and synthesized. Secondly, by optimizing the reaction conditions including reaction temperature, time, Mg2+ concentration, dNTP concentration and primer ratio, a LAMP-HNB assay was successfully established for the detection of A. salmoncida. Thirdly, the assay showed good specificity with no false-positive and false-negative results, and good sensitivity with the detection limit of 3.077 × 10-6  ng/µl, which was 102 times more sensitive than the conventional PCR. Finally, the LAMP-HNB assay was validated by the fish samples inoculated with different concentrations of A. salmoncida. This is the first development of rapid visual detection of A. salmonicida based on LAMP-HNB assay, which has great application prospect and market for diagnostic testing, health certification and active surveillance programmers.


Assuntos
Aeromonas salmonicida/isolamento & purificação , Infecções por Bactérias Gram-Negativas/veterinária , Técnicas de Diagnóstico Molecular/veterinária , Técnicas de Amplificação de Ácido Nucleico/veterinária , Aeromonas salmonicida/genética , Animais , Aquicultura , Doenças dos Peixes/microbiologia , Linguados , Infecções por Bactérias Gram-Negativas/microbiologia , Técnicas de Diagnóstico Molecular/métodos , Naftalenossulfonatos/química , Técnicas de Amplificação de Ácido Nucleico/métodos , Sensibilidade e Especificidade , Coloração e Rotulagem
12.
Rev Sci Tech ; 40(1): 145-157, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34140734

RESUMO

This paper focuses on several new diagnostic technologies, which are set to dominate the testing landscape in the near future and have applications in animal health diagnostics, namely: next-generation sequencing, assays to detect biomarkers, and point-of-care tests. An example of real-time loop-mediated isothermal amplification validation is also provided. Validating these new technologies presents several challenges, which are addressed in this paper.


Les auteurs s'intéressent à plusieurs nouvelles technologies de diagnostic appelées à occuper, dans un futur proche, une place de choix dans le paysage du dépistage et dont il existe déjà des applications en santé animale, à savoir : le séquençage de nouvelle génération, la détection de biomarqueurs et les tests utilisables sur le lieu des soins. Ils décrivent par ailleurs l'exemple de la validation d'une amplification isotherme à médiation par boucle en temps réel. La validation de ces nouvelles technologies présente un certain nombre de difficultés, que les auteurs examinent en détail.


Los autores se centran en varias tecnologías de nuevo cuño que están llamadas a dominar el panorama de las pruebas de diagnóstico en un futuro próximo y que tienen aplicaciones de diagnóstico en sanidad animal, a saber: la secuenciación de próxima generación, los ensayos de detección de marcadores biológicos y las pruebas practicadas en el lugar de consulta. También ofrecen un ejemplo de validación de una técnica de amplificación isotérmica mediada por bucles en tiempo real. La validación de estas nuevas tecnologías presenta varias dificultades, que los autores examinan en estas líneas.


Assuntos
Técnicas de Diagnóstico Molecular , Técnicas de Amplificação de Ácido Nucleico , Animais , Sequenciamento de Nucleotídeos em Larga Escala/veterinária , Técnicas de Diagnóstico Molecular/veterinária , Técnicas de Amplificação de Ácido Nucleico/veterinária , Testes Imediatos
13.
J Vet Med Sci ; 83(8): 1321-1329, 2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34162783

RESUMO

For broad detection of pestivirus A (bovine viral diarrhea virus 1: BVDV1) and pestivirus B (BVDV2) by a reverse transcription loop-mediated isothermal amplification (RT-LAMP) test, the P25 primer set was designed using nucleotide sequences of 5'-UTR region of 1454 BVDVs. The base coverage of each primer against diverse BVDVs were more than 99% in each base position. The one step LAMP test with the P25 primer set could detect both BVDV1 (TK) and BVDV2 (KZ), but did not amplify 5 other bovine viruses. Detection limit of the LAMP test was 103 copies of synthesized DNAs, and 10-3 and 10-4 dilutions of viral RNAs of TK and KZ strains, respectively, whereas that with current Aebischer's primer set was 10-2 dilution and negative of these RNAs, respectively. All of the 63 viral RNA samples of persistently infected (PI) cattle, consisting of the 1a (12), 1b (31), 1c (11), and 2a (9) subgenotypes, were broadly detected with the P25, while only 65% of them were positive with Aebischer's primer set. The validation study showed that the RT-LAMP test with the P25 had 100% sensitivity and 100% specificity against that with updated Vilcek's PCR primers. Also, by using the P26 primer set which contained 3 species-specific primers, all 63 RNA samples were clearly distinguished from BVDV1 or BVDV2 by the typing RT-LAMP test. These results indicate that the one step RT-LAMP test using P25 or P26 primer sets would be useful for broad detection and rapid differentiation of BVDV1 and BVDV2.


Assuntos
Vírus da Diarreia Viral Bovina Tipo 1 , Transcrição Reversa , Animais , Bovinos , Vírus da Diarreia Viral Bovina Tipo 1/genética , Técnicas de Diagnóstico Molecular/veterinária , Técnicas de Amplificação de Ácido Nucleico/veterinária
14.
J Fish Dis ; 44(10): 1595-1607, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34170523

RESUMO

Tilapia is one of the major aquaculture species with a global economic significance. Despite a high scale of production worldwide, mortality in many tilapia cultures has recently become a problem concerned with not only intensive farming but also the prevalence of infectious pathogens. Tilapia lake virus (TiLV) has emerged as a serious single-stranded RNA disease agent that thus far has continued to cause a number of incidences across the continents. Conventional PCR-based molecular detection techniques, despite having high sensitivity for TiLV, are not best suited for the onsite identification of infected fish mainly due to their requirement of laboratory resources and extended assay turnaround time. To address this practical limitation, we have developed a novel colorimetric assay based on reverse transcription-loop-mediated isothermal amplification (RT-LAMP) and gold nanoparticle (AuNP)-labelled oligonucleotide reporter probe targeting the viral genomic segment 9 that enables the assay to be completed within an hour. This technique has been shown to be compatible with a rapid nucleic extraction method that does not demand centrifugation steps or any benchtop laboratory equipment. When validated with field-acquired tilapia samples, our RT-LAMP-AuNP assay exhibited a near-perfect agreement with the semi-nested RT-PCR assay recommended by OIE with Cohen's κ coefficient of .869, yet requiring significantly less time to perform.


Assuntos
Aquicultura/métodos , Ciclídeos , Colorimetria/veterinária , Doenças dos Peixes/diagnóstico , Nanopartículas Metálicas/uso terapêutico , Técnicas de Diagnóstico Molecular/veterinária , Técnicas de Amplificação de Ácido Nucleico/veterinária , Infecções por Vírus de RNA/veterinária , Vírus de RNA/isolamento & purificação , Animais , Doenças dos Peixes/virologia , Ouro/uso terapêutico , Infecções por Vírus de RNA/diagnóstico , Infecções por Vírus de RNA/virologia , Transcrição Reversa , Sensibilidade e Especificidade
15.
Res Vet Sci ; 137: 144-149, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33975193

RESUMO

Feline Vector-Borne Diseases show increased global prevalence and some Anaplasma and Ehrlichia species may pose a risk to human health. The diagnosis of Anaplasma and Ehrlichia species infection in cats is achieved by the combined use of different methods as cytologic examination evidencing intracytoplasmic morulae, serologic tests and molecular assays. The peripheral whole blood is considered the sample of choice for Anaplasma and Ehrlichia species DNA detection in cats, but false negative results are reported leading to underestimation of infection prevalence. In order to have a more accurate assessment of the spread of feline vector-borne pathogens, the presence of Anaplasma spp. and Ehrlichia spp. DNA in 37 owner and shelter cats subjected to necropsy were prospectively investigated by testing in end-point PCR spleen, bone marrow, blood clot and hair samples. The bacteria identified were genetically characterised. Three shelter cats tested positive for A. phagocytophilum DNA in spleen (one cat) or in hair samples (two cats). None of the cats tested positive in bone marrow and blood samples. From the results obtained, it can be assumed that the use of spleen or hair samples could allow a more reliable detection of A. phagocytophilum DNA in cats with blood tested negative. In the phylogeny constructed with a fragment of the heat shock (groEL) gene nucleotide sequences, all the identified A. phagocytophilum clustered with bacteria infecting a wide range of hosts, including humans, showing a potential zoonotic role.


Assuntos
Anaplasma phagocytophilum/isolamento & purificação , Doenças do Gato/microbiologia , Ehrlichiose/veterinária , Cabelo/microbiologia , Baço/microbiologia , Doenças Transmitidas por Vetores/veterinária , Anaplasma phagocytophilum/imunologia , Animais , Anticorpos Antibacterianos/sangue , Gatos , DNA Bacteriano/isolamento & purificação , Feminino , Masculino , Técnicas de Diagnóstico Molecular/veterinária , Doenças Transmitidas por Vetores/diagnóstico , Doenças Transmitidas por Vetores/microbiologia
16.
Parasitol Res ; 120(6): 2157-2164, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33855619

RESUMO

Equine piroplasmosis (EP) is a disease of equids caused by Theileria equi and Babesia caballi, members of the order Piroplasmida, transmitted by several species of ticks. As the disease is endemic in many countries, a clinical examination or a serological test are required prior to movement of horses to prove freedom from infection and to avoid the introduction of EP with its sanitary and economic impact, especially in areas where it is absent. Currently, numerous diagnostic PCR protocols are available, some of which are recommended by the World Organisation for Animal Health (OIE). In order to adopt this diagnostic method, the Italian National Reference Centre for Equine Diseases (NRC-ED) conducted a preliminary comparison between an end-point PCR, nested PCR, real-time PCR, and commercial real-time PCR, for the detection of T. equi and B. caballi, respectively. One hundred and three field samples, collected during spring-summer 2013 in Latium and Tuscany regions, were employed for the study, and results discordant between detection assays were confirmed by sequencing. The reference assay was defined as that showing the highest sensitivity, and the relative sensitivity (rSe) and specificity (rSp) of the other methods were estimated referring to this assay. Agreement between methods was estimated by calculating the concordance between each pair of methods. Although no statistical differences were detected among PCR-based methods, the non-commercial real-time PCR assays seemed to be the most suitable for detection of T. equi and B. caballi, respectively. An important advantage of direct PCR detection of the pathogen, in comparison to indirect detection using serological methods, is that it allows specific treatment against the causative pathogen species responsible of the infection as well as for the definition of the infectious status of an animal for international movement.


Assuntos
Babesia/isolamento & purificação , Babesiose/parasitologia , Doenças dos Cavalos/parasitologia , Reação em Cadeia da Polimerase/veterinária , Theileria/isolamento & purificação , Theileriose/parasitologia , Animais , Babesia/genética , Babesiose/epidemiologia , Doenças dos Cavalos/epidemiologia , Cavalos , Itália/epidemiologia , Técnicas de Diagnóstico Molecular/veterinária , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Estudos Retrospectivos , Theileria/genética , Theileriose/epidemiologia
17.
Turkiye Parazitol Derg ; 45(1): 56-75, 2021 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-33685070

RESUMO

Significant numbers of parasites such as protozoa, helminths and arthropods infest equids. Various investigations have been conducted in Turkey to detect these parasites. In this review, all parasites reported in horses, donkeys and mules have been listed. A total of 62, 52 and 21 helminths were recorded in horses, donkeys and mules, respectively. As protozoan parasites, 13 species were detected both in horses and donkeys, and 3 in mules. With regard to arthropods, 40, 23 and 6 species were detected in horses, donkeys and mules, respectively. In the recent years, various molecular diagnostic methods have been developed and especially applied to the protozoan research area. Classical diagnostic methods were incapable of detecting certain protozoan parasites. Such protozoan parasites can be detected at the nucleic acid level with these new techniques. During the last quadranscentennial, a reduction has been recorded in the total number of equids in Turkey, whereby the breeding of sport horses is becoming an important issue. Thus, this review summarises the published research papers in Turkey in order to raise awareness among the animal owners and veterinarians in terms of the prevention of potential hazards resulting from parasitic infections/infestations in equids.


Assuntos
Parasitos/isolamento & purificação , Doenças Parasitárias em Animais/epidemiologia , Doenças Parasitárias em Animais/parasitologia , Animais , Equidae , Cavalos , Técnicas de Diagnóstico Molecular/veterinária , Parasitos/classificação , Parasitos/genética , Doenças Parasitárias em Animais/diagnóstico , Doenças Parasitárias em Animais/prevenção & controle , Turquia/epidemiologia
18.
Arch Virol ; 166(6): 1599-1605, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33755802

RESUMO

Pigeon paramyxovirus-1 (PPMV-1) is a strain of Newcastle disease virus (NDV) that has adapted to infect pigeons and poses a constant threat to the commercial poultry industry. Early detection via rapid and sensitive methods, along with timely preventative and mitigating actions, is important for reducing the spread of PPMV-1. Here, we report the development of a TaqMan loop-mediated isothermal amplification assay (TaqMan-LAMP) for rapid and specific detection of PPMV-1 based on the F gene. This system makes use of six novel primers and a TaqMan probe that targets nine distinct regions of the F gene that are highly conserved among PPMV-1 isolates. The results showed that the limit of detection was 10 copies µL-1 for PPMV-1 cDNA and 0.1 ng for PPMV-1 RNA. The reaction was completed within 25 min and was thus faster than conventional RT-PCR. Moreover, no cross-reactions with similar viruses or with peste des petits ruminants virus (PPRV) or NDV LaSota vaccine strains were observed under the same conditions. To evaluate the applicability of the assay, the TaqMan-LAMP assay and a commercial RT-PCR assay were compared using 108 clinical samples, and the concordance rate between two methods was found to be 96.3%. The newly developed PPMV-1 TaqMan-LAMP assay can therefore be used for simple, efficient, rapid, specific, and sensitive diagnosis of PPMV-1 infections.


Assuntos
Técnicas de Diagnóstico Molecular/veterinária , Vírus da Doença de Newcastle/genética , Vírus da Doença de Newcastle/isolamento & purificação , Técnicas de Amplificação de Ácido Nucleico/veterinária , Animais , Columbidae , Fezes/virologia , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , RNA Viral , Sensibilidade e Especificidade , Fatores de Tempo
19.
Parasitol Res ; 120(5): 1873-1882, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33712930

RESUMO

The early containment of trypanosomosis depends on early, sensitive, and accurate diagnosis in endemic areas with low-intensity infections. The study was planned to develop a simple read out loop-mediated isothermal amplification (LAMP) assay targeting a partial RoTat1.2 VSG gene of Trypanosoma evansi with naked eye visualization of LAMP products by adding SYBR® Green I dye. The visual results were further confirmed with those of agarose gel electrophoresis, restriction enzyme digestion of LAMP products with AluI, and sequencing of the PCR products using LAMP outer primers. The LAMP primers did not show cross reactivity and non-specific reactions with regional common hemoparasitic DNA revealing high specificity of the assay. The threshold sensitivity level of the LAMP assay was determined to be 0.003 fg compared to 0.03 fg RoTat1.2 amplified DNA fragments of T. evansi by PCR assay. Moreover, assessment of 500 blood samples collected from unhealthy domestic animals in field suspected for various hemoparasitic infections was carried out for the presence of T. evansi by microscopy, RoTat1.2 VSG PCR, and LAMP assay. LAMP could detect T. evansi in 36 samples, while PCR and microscopy could detect 33 and 12 samples, respectively. All the samples positive by microscopy and PCR were also confirmed positive by the LAMP assay. The current LAMP assay has appealing point of care characteristics to visually monitor the results, lessen the need of post DNA amplification procedure, and enable this method to be applied as a rapid and sensitive molecular diagnostic tool in under resourced laboratories and field setup.


Assuntos
Antígenos de Protozoários/genética , Técnicas de Diagnóstico Molecular/veterinária , Técnicas de Amplificação de Ácido Nucleico/veterinária , Proteínas de Protozoários/genética , Trypanosoma/genética , Trypanosoma/isolamento & purificação , Animais , Animais Domésticos/parasitologia , Primers do DNA , DNA de Protozoário/genética , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade , Tripanossomíase/parasitologia
20.
Parasitol Res ; 120(5): 1799-1809, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33649963

RESUMO

Present-day diagnostic tools and technologies for canine diseases and other vector-borne parasitic diseases hardly meet the requirements of an efficient and rapid diagnostic tool, which can be suitable for use at the point-of-care in resource-limited settings. Loop-mediated isothermal amplification (LAMP) technique has been always a method of choice in the development and validation of quick, precise, and sensitive diagnostic assays for pathogen detection and to reorganize point-of-care (POC) molecular diagnostics. In this study, we have demonstrated an efficient detection system for parasitic vector-borne pathogens like Ehrlichia canis and Hepatozoon canis by linking the LAMP assay to a smartphone via a simple, inexpensive, and a portable "LAMP box," All the components of the LAMP box were connected to each other wirelessly. This LAMP box was made up of an isothermal heating pad mounted below an aluminum base which served as a platform for the reaction tubes and LAMP assay. The entire setup could be connected to a smartphone via an inbuilt Wi-Fi that allowed the user to establish the connection to control the LAMP box. A 5 V USB power source was used as a power supply. The sensitivity of the LAMP assay was estimated to be up to 10-6 dilution limit using the amplified, purified, and quantified specific DNA templates. It can also serve as an efficient diagnostic platform for many other veterinary infectious or parasitic diseases of zoonotic origin majorly towards field-based diagnostics.


Assuntos
Coccidiose/veterinária , Doenças do Cão/diagnóstico , Ehrlichiose/veterinária , Técnicas de Diagnóstico Molecular , Smartphone , Doenças Transmitidas por Vetores/diagnóstico , Animais , Coccidiose/diagnóstico , Doenças do Cão/parasitologia , Cães , Ehrlichia canis/genética , Ehrlichiose/diagnóstico , Eucoccidiida , Técnicas de Diagnóstico Molecular/veterinária , Técnicas de Amplificação de Ácido Nucleico/veterinária , Testes Imediatos , Sensibilidade e Especificidade
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