scholarly journals Copro-PCR in the detection and confirmation of Toxoplasma gondii oocysts in feces of stray and domiciled cats

2021 ◽  
Vol 30 (2) ◽  
Author(s):  
Jaqueline Ataíde Silva Lima da Igreja ◽  
Hanstter Hallison Alves Rezende ◽  
Jade de Oliveira Melo ◽  
João Luís Garcia ◽  
Felippe Danyel Cardoso Martins ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Toxoplasma Gondii ◽  
Genetic Material ◽  
High Sensitivity ◽  
Molecular Techniques ◽  
Molecular Methods ◽  
Chain Reaction ◽  
Highly Sensitive ◽  
Polymerase Chain ◽  
Fecal Tests

Abstract Molecular methods such as Copro-PCR stand out in the diagnosis of T. gondii, because they are highly sensitive and specific, and can distinguish T. gondii from other morphologically similar coccids. The purpose was the detection of Toxoplasma gondii copro-prevalence by polymerase chain reaction in 149 fecal samples from stray and domiciled cats, using three distinct markers (B5-B6, 18S and 529bp RE). Oocysts of T. gondii/H. hammondi were detected in 15.4% by parasitology fecal tests (PFT), and 4% of these oocysts were positively identified as T. gondii by Copro-PCR. The presence of T. gondii genetic material was detected in 16.1%, but 12% of the samples that tested positive by Copro-PCR were negative in PFT. Samples with discordant results were subjected to a new Copro-PCR with 18S marker and a 529, and of the 17 samples, 9 contained T. gondii genetic material. A comparison of the PFT and the molecular methods showed the latter was more sensitive, since it detected 22.1% while the PFT detected 15.4%. Demonstrating the high sensitivity and specificity of the Copro-PCR, particularly with the association of primers (k=0.809), but also confirms the importance of using molecular techniques in laboratories, since Copro-PCR was able to detect samples considered negative by PFT.

scholarly journals Analysis and validation of a highly sensitive one-step nested quantitative real-time polymerase chain reaction assay for specific detection of severe acute respiratory syndrome coronavirus 2

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Yang Zhang ◽  
Chunyang Dai ◽  
Huiyan Wang ◽  
Yong Gao ◽  
Tuantuan Li ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
Quantitative Polymerase Chain Reaction ◽  
Clinical Samples ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Qrt Pcr ◽  
Highly Sensitive ◽  
One Step ◽  
Polymerase Chain

Abstract Background Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, is posing a serious threat to global public health. Reverse transcriptase real-time quantitative polymerase chain reaction (qRT-PCR) is widely used as the gold standard for clinical detection of SARS-CoV-2. Due to technical limitations, the reported positive rates of qRT-PCR assay of throat swab samples vary from 30 to 60%. Therefore, the evaluation of alternative strategies to overcome the limitations of qRT-PCR is required. A previous study reported that one-step nested (OSN)-qRT-PCR revealed better suitability for detecting SARS-CoV-2. However, information on the analytical performance of OSN-qRT-PCR is insufficient. Method In this study, we aimed to analyze OSN-qRT-PCR by comparing it with droplet digital PCR (ddPCR) and qRT-PCR by using a dilution series of SARS-CoV-2 pseudoviral RNA and a quality assessment panel. The clinical performance of OSN-qRT-PCR was also validated and compared with ddPCR and qRT-PCR using specimens from COVID-19 patients. Result The limit of detection (copies/ml) of qRT-PCR, ddPCR, and OSN-qRT-PCR were 520.1 (95% CI: 363.23–1145.69) for ORF1ab and 528.1 (95% CI: 347.7–1248.7) for N, 401.8 (95% CI: 284.8–938.3) for ORF1ab and 336.8 (95% CI: 244.6–792.5) for N, and 194.74 (95% CI: 139.7–430.9) for ORF1ab and 189.1 (95% CI: 130.9–433.9) for N, respectively. Of the 34 clinical samples from COVID-19 patients, the positive rates of OSN-qRT-PCR, ddPCR, and qRT-PCR were 82.35% (28/34), 67.65% (23/34), and 58.82% (20/34), respectively. Conclusion In conclusion, the highly sensitive and specific OSN-qRT-PCR assay is superior to ddPCR and qRT-PCR assays, showing great potential as a technique for detection of SARS-CoV-2 in patients with low viral loads.

Diagnostic Accuracy of a Direct Panfungal Polymerase Chain Reaction Assay Performed on Stained Cytology Slides

2021 ◽  
pp. 030098582199156
Author(s):  
Alexandra N. Myers ◽  
Unity Jeffery ◽  
Zachary G. Seyler ◽  
Sara D. Lawhon ◽  
Aline Rodrigues Hoffmann
Keyword(s):  
Polymerase Chain Reaction ◽  
Diagnostic Accuracy ◽  
Molecular Techniques ◽  
Fungal Culture ◽  
Chain Reaction ◽  
Identification Of Fungi ◽  
Fungal Dna ◽  
Polymerase Chain ◽  
Panfungal Pcr ◽  
Pcr Targeting

Molecular techniques are increasingly being applied to stained cytology slides for the diagnosis of neoplastic and infectious diseases. Such techniques for the identification of fungi from stained cytology slides have not yet been evaluated. This study aimed to assess the diagnostic accuracy of direct (without nucleic acid isolation) panfungal polymerase chain reaction (PCR) followed by sequencing for identification of fungi and oomycetes on stained cytology slides from dogs, cats, horses, and other species. Thirty-six cases were identified with cytologically identifiable fungi/oomycetes and concurrent identification via fungal culture or immunoassay. Twenty-nine controls were identified with no cytologically or histologically visible organisms and a concurrent negative fungal culture. Direct PCR targeting the internal transcribed spacer region followed by sequencing was performed on one cytology slide from each case and control, and the sensitivity and specificity of the assay were calculated. The sensitivity of the panfungal PCR assay performed on stained cytology slides was 67% overall, 73% excluding cases with oomycetes, and 86% when considering only slides with abundant fungi. The specificity was 62%, which was attributed to amplification of fungal DNA from control slides with no visible fungus and negative culture results. Direct panfungal PCR is capable of providing genus- or species-level identification of fungi from stained cytology slides. Given the potential of panfungal PCR to amplify contaminant fungal DNA, this assay should be performed on slides with visible fungi and interpreted in conjunction with morphologic assessment by a clinical pathologist.

PCR BY THERMAL CONVECTION

2004 ◽  
Vol 18 (16) ◽  
pp. 775-784 ◽  
Author(s):  
DIETER BRAUN
Keyword(s):  
Polymerase Chain Reaction ◽  
Thermal Convection ◽  
Dna Amplification ◽  
Reaction Vessel ◽  
Cold Region ◽  
Chain Reaction ◽  
Heating And Cooling ◽  
Highly Sensitive ◽  
Specific Amplification ◽  
Polymerase Chain

The Polymerase Chain Reaction (PCR) allows for highly sensitive and specific amplification of DNA. It is the backbone of many genetic experiments and tests. Recently, three labs independently uncovered a novel and simple way to perform a PCR reaction. Instead of repetitive heating and cooling, a temperature gradient across the reaction vessel drives thermal convection. By convection, the reaction liquid circulates between hot and cold regions of the chamber. The convection triggers DNA amplification as the DNA melts into two single strands in the hot region and replicates into twice the amount in the cold region. The amplification progresses exponentially as the convection moves on. We review the characteristics of the different approaches and show the benefits and prospects of the method.

scholarly journals Detection of Toxoplasma gondii DNA by polymerase chain reaction in experimentally desiccated tissues

2004 ◽  
Vol 99 (2) ◽  
pp. 185-188 ◽  
Author(s):  
Márcia Andreia Barge Loução Terra ◽  
Alexandre Ribeiro Bello ◽  
Otilio Machado Bastos ◽  
Regina Reis Amendoeira ◽  
Janice Mary Chicarino de Oliveira Coelho ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Toxoplasma Gondii ◽  
Chain Reaction ◽  
Polymerase Chain

scholarly journals Molecular diagnosis and biochemical studies of tick-borne diseases (anaplasmosis and babesiosis) in Aberdeen Angus Cattle in New Valley, Egypt

2020 ◽  
Vol 13 (9) ◽  
pp. 1884-1891
Author(s):  
Nani Nasreldin ◽  
Rania M. Ewida ◽  
Hatem Hamdon ◽  
Yasser F. Elnaker
Keyword(s):  
Oxidative Stress ◽  
Polymerase Chain Reaction ◽  
Molecular Techniques ◽  
Babesia Bovis ◽  
Blood Parasites ◽  
Chain Reaction ◽  
Infected Female ◽  
Angus Cattle ◽  
Polymerase Chain ◽  
Female Cattle

Background and Aim: Anaplasmosis and babesiosis are tick-borne diseases that threaten livestock production with subsequent considerable economic losses. This study was conducted to diagnose Anaplasma and Babesia infection using molecular techniques in imported Aberdeen Angus cattle imported from Uruguay to El-Kharga Oasis in New Valley, Egypt, and to investigate the effects of disease on some serum biochemical and oxidative stress parameters. Materials and Methods: Blood samples were collected from 31 cattle, 21 diseased and ten apparently normal, of varying ages and sex. The blood was used for the preparation of blood smears, polymerase chain reaction assay, and separation of serum for biochemical investigation. The experimental production farm at the Faculty of Agriculture, New Valley University, was infested with ticks and variable clinical manifestations during the period from December 2017 to March 2018. One calf died of a suspected blood parasite infection. Results: The blood film examination revealed infection by blood parasites in 21 samples. Anaplasma marginale and Babesia bovis were identified in 12 and 14 samples, respectively. A total of 14 samples were examined by polymerase chain reaction (PCR) to make these identifications. Biochemical parameters showed significantly elevated serum alanine aminotransferase, aspartate aminotransferase, total bilirubin (T. Bil), and urea in blood from parasite-infected female cattle and male calves compared with controls. Increased serum total protein, globulin, and creatinine were recorded only in infected female cattle. The blood glucose level was significantly decreased in infected female cattle and male calves compared with controls. Furthermore, albumin and albumin/globulin ratio was significantly reduced in the infected female cattle. Oxidative stress profiles of infected animals showed a significant increase in serum nitric oxide and malondialdehyde, and both total antioxidant capacity and reduced glutathione (GSH) were significantly reduced in comparison with control animals. Conclusion: The incidence of A. marginale and B. bovis infection is high in imported Aberdeen Angus cattle in New Valley Province. PCR methods provide a short-term assessment of disease. An extensive epidemiological survey, employing serology together with molecular genetic methods, monitoring of abundance and distribution of tick vectors, availability of vaccination programs, and tracking of animal transport is also needed for control of blood parasites.

scholarly journals Molecular diagnosis of the curly lettuce parasitic contamination from hydroponic cultivation from supermarkets

2020 ◽  
Vol 29 (4) ◽  
Author(s):  
Fernanda Pinto-Ferreira ◽  
Jonatan Batista Reis ◽  
Aline Ticiani Pereira Paschoal ◽  
Letícia Santos Balbino ◽  
Amanda Bertão-Santos ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Toxoplasma Gondii ◽  
Dna Extraction ◽  
Chain Reaction ◽  
Cryptosporidium Spp ◽  
Hydroponic Cultivation ◽  
Polymerase Chain ◽  
Fluctuation Method ◽  
The City ◽  
Commercial Kit

Abstract The consumption of vegetables has increased in recent years due to the search for a healthier diet that is rich in fiber and has fewer calories. To assess the parasitic contamination of lettuce sold in markets, a survey of parasites was carried out from a supermarket chain in the city of Londrina, Paraná. A total of thirty samples of lettuce were purchased in the ten markets visited, three in each, of which ten were conventionally cultivated, ten were hydroponically cultivated, and ten were organically cultivated. All samples were analyzed using the sedimentation methods of Hoffman, Pons and Janer and the fluctuation method of Faust and colleagues and Willis with adaptations. In addition, the samples were subjected to DNA extraction by a commercial kit and polymerase chain reaction to detect Toxoplasma gondii, Cryptosporidium spp. and Giardia spp., which are protozoa that cause food and waterborne parasitic outbreaks. All samples were negative for sedimentation and flotation techniques. One of the hydroponically cultivated samples was positive for T. gondii. The results demonstrate the risk of curly lettuce contamination from hydroponic cultivation and the need for proper cleaning of these foods before consumption.

scholarly journals Occurrence of Toxoplasma gondii DNA in sheep naturally infected and slaughtered in abattoirs in Pernambuco, Brazil

2014 ◽  
Vol 34 (4) ◽  
pp. 329-331 ◽  
Author(s):  
Mauro J.G. Bezerra ◽  
Jefferson A.L.O. Cruz ◽  
Eugênio S. Kung ◽  
José G. Silva ◽  
André S. Santos ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Toxoplasma Gondii ◽  
Genomic Dna ◽  
Reproductive Organs ◽  
Infected Sheep ◽  
Fetal Membranes ◽  
Immunofluorescence Technique ◽  
Chain Reaction ◽  
Indirect Immunofluorescence Technique ◽  
Polymerase Chain

The aim of the present study was to assess the occurrence of antibodies to Toxoplasma gondii and to detect genomic DNA of the parasite in the reproductive organs, fetuses and fetal membranes of sheep in slaughterhouses in the state of Pernambuco, Brazil. The Indirect Immunofluorescence technique (IFA) was used for screening. The Polymerase Chain Reaction (PCR) was used to detect DNA of T. gondii in the animals that were positive in the serology. In the serology, 13/50 samples were positive and genomic DNA of T. gondii was detected in one uterus, tube, ovary, placenta and fetus (heart, brain and umbilical cord) sample from a sheep that was positive in the serology. The present study provides evidence of the occurrence of T. gondii DNA in the organs of the reproductive system, placenta and fetus of a naturally infected sheep.

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