Development of a low-cost copro-LAMP assay for simultaneous copro-detection of Toxocara canis and Toxocara cati

Parasitology ◽  
2021 ◽  
pp. 1-8
Author(s):  
Héctor Gabriel Avila ◽  
Marikena Guadalupe Risso ◽  
Paula Ruybal ◽  
Silvia Analía Repetto ◽  
Marcos Javier Butti ◽  
...  

Abstract

Author(s):  
Eide Dias Camargo ◽  
Paulo Mutuko Nakamura ◽  
Adelaide José Vaz ◽  
Marcos Vinícius da Silva ◽  
Pedro Paulo Chieffi ◽  
...  

The dot-enzyme-linked immunosorbent assay (dot-ELISA) was standardized using somatic (S) and excretory-secretory (ES) antigens of Toxocara-canis for the detection of specific antibodies in 22 serum samples from children aged 1 to 15 years, with clinical signs of toxocariasis. Fourteen serum samples from apparently normal individuals and 28 sera from patients with other pathologies were used as controls. All samples were used before and after absorption with Ascaris suum extract. When the results were evaluated in comparison with ELISA, the two tests were found to have similar sensitivity, but dot-ELISA was found to be more specific in the presence of the two antigens studied. Dot-ELISA proved to be effective for the diagnosis of human toxocariasis, presenting advantages in terms of yield, stability, time and ease of execution and low cost.


2006 ◽  
Vol 54 (3) ◽  
pp. 399-406 ◽  
Author(s):  
Heli Talvik ◽  
Epp Moks ◽  
Erika Mägi ◽  
T. Järvis ◽  
Illa Miller

The aim of the study was to elucidate the distribution and possible transmission routes of Toxocara spp. infection in Estonia. Out of 454 faecal and sand samples collected from park lawns and sandpits in the town of Tartu, 19 were Toxocara positive (4.2%). Out of the 45 sandpit samples 17.8% were Toxocara positive. Cat faeces was found in 21 sandpit samples. Parasitological necropsies were performed on 41 euthanised stray dogs and 27 cats in the Tallinn Dog Home. Additionally, 13 wild free-roaming brown rats (Rattus norvegicus) were captured from the Tallinn Dog Home territory, necropsied and studied for the presence of Toxocara larvae. Toxocara canis adults were found in 14.6% of the dogs and Toxocara cati (syn. mystax) adults in the small intestines of 48.2% of the cats examined. Larval infection was detected in the kidney and liver in 5 dogs (12.2%). Our study demonstrated only low-level larval Toxocara infections in adult dogs. Toxocara larvae were not found in cats and brown rats. According to the results of this study, cats more often carry Toxocara infection than dogs. Under our conditions, stray and free-roaming cats are the main contaminators of the environment with Toxocara eggs. Children playing in sandpits are the main risk group for larval toxocarosis.


Author(s):  
Bo YANG ◽  
zhengwang shi ◽  
Yuan Ma ◽  
Lijuan Wang ◽  
Liyan Cao ◽  
...  

African swine fever (ASF) is one of the most severe infectious diseases of pigs. In this study, a LAMP assay coupled with the CRISPR Cas12a system was established in one tube for the detection of the ASFV p72 gene. The single-strand DNA-fluorophore-quencher (ssDNA-FQ) reporters and CRISPR-derived RNA (crRNAs) were screened and selected for the CRISPR detection system. In combination with LAMP amplification assay, the detection limit for the LAMP-CRISPR assay can reach 7 copies/μl of p72 gene per reaction. Furthermore, this method displays no cross-reactivity with other porcine DNA or RNA viruses. The performance of the LAMP-CRISPR assay was compared with real-time qPCR tests for clinical samples, a good consistency between the LAMP-CRISPR assay and real-time qPCR was observed. In the current study, a LAMP coupled with the CRISPR detection method was developed. The method shed a light on the convenient, portable, low cost, highly sensitive and specific detection of ASFV, demonstrating a great application potential for monitoring on-site ASFV in the field.


Ocular toxocariasis or ocular larva migrans is a parasitic infection via the ingestion of dog nematode Toxocara canis and cat nematode Toxocara cati larvae. It usually affects only one eye of the child under the age of sixteen. The most common clinical findings in ocular toxocariasis are peripheral granuloma, posterior pole chorioretinal eosinophilic granulomas, and endophthalmitis or pars planitis. It is diagnosed with clinical findings in developing countries, ELISA antibody tests, and, if necessary, intraocular fluid analysis can be made. Ocular toxocariasis must be distinguished from retinoblastoma and other congenital and inflammatory eye conditions of childhood. In treatment, besides anthelmintic agents, steroid use and vitreoretinal surgery may be needed.


Author(s):  
Sheelagh Lloyd ◽  
Eric R. Morgan

Toxocara canis and the syndromes of visceral and ocular larva migrans (VLM, OLM), covert toxocarosis, and neurological toxocarosis are described. Other potential agents, particularly Toxocara cati and Baylisascaris procyonis , are described. The transmission dynamics of toxocarosis to humans have never been fully elucidated, but the potential roles of pet and stray dogs, foxes, cats, and the influence of their population densities, and age demographies, are discussed in relation to contamination of the environment with eggs. Routes of infection with eggs by geophagia, poor hygiene outdoors and with dogs, and fly-borne contamination of food, and meat-borne ingestion of larvae are described. The development of prolonged in vitro culture and analyses of T. canis larval excretions/secretions (TES) and surface antigens helped explain the importance of the rapid production and shedding of TES in the prolonged course of infection and pathogenesis of disease. TES also have greatly improved serodiagnosis. However, we still have insufficient understanding of differences in the aetiology of the larvae or differences in immune responses among individuals to account for development of VLM, covert toxocarosis, or OLM in different individuals. Our understanding of the immunopathological response of the host to TES has emphasized the need for anti-inflammatory therapy in treatment; unfortunately, less information is available on the true efficacy of the anthelmintics available. The complexity of the T. canis life cycle in dogs is described and therapeutic regimens to prevent excretion of eggs by pet dogs are given. This, plus adequate control or exclusion of stray or wild canids from a property could prevent most cases of VLM. Control of infection from free-ranging stray dogs, cats and foxes, will be difficult and more data are needed to clarify the importance of these and of fly-borne and meat-borne transfer of infection to humans for control.


2020 ◽  
Vol 21 (15) ◽  
pp. 5380 ◽  
Author(s):  
Franklin Wang-Ngai Chow ◽  
Tony Tat-Yin Chan ◽  
Anthony Raymond Tam ◽  
Suhui Zhao ◽  
Weiming Yao ◽  
...  

To control the COVID-19 pandemic and prevent its resurgence in areas preparing for a return of economic activities, a method for a rapid, simple, and inexpensive point-of-care diagnosis and mass screening is urgently needed. We developed and evaluated a one-step colorimetric reverse-transcriptional loop-mediated isothermal amplification assay (COVID-19-LAMP) for detection of SARS-CoV-2, using SARS-CoV-2 isolate and respiratory samples from patients with COVID-19 (n = 223) and other respiratory virus infections (n = 143). The assay involves simple equipment and techniques and low cost, without the need for expensive qPCR machines, and the result, indicated by color change, is easily interpreted by naked eyes. COVID-19-LAMP can detect SARS-CoV-2 RNA with detection limit of 42 copies/reaction. Of 223 respiratory samples positive for SARS-CoV-2 by qRT-PCR, 212 and 219 were positive by COVID-19-LAMP at 60 and 90 min (sensitivities of 95.07% and 98.21%) respectively, with the highest sensitivities among nasopharyngeal swabs (96.88% and 98.96%), compared to sputum/deep throat saliva samples (94.03% and 97.02%), and throat swab samples (93.33% and 98.33%). None of the 143 samples with other respiratory viruses were positive by COVID-19-LAMP, showing 100% specificity. Samples with higher viral load showed shorter detection time, some as early as 30 min. This inexpensive, highly sensitive and specific COVID-19-LAMP assay can be useful for rapid deployment as mobile diagnostic units to resource-limiting areas for point-of-care diagnosis, and for unlimited high-throughput mass screening at borders to reduce cross-regional transmission.


2019 ◽  
Vol 13 (9) ◽  
pp. e0007706 ◽  
Author(s):  
Patrick Waindok ◽  
Elisabeth Janecek-Erfurth ◽  
Dimitri Lindenwald ◽  
Esther Wilk ◽  
Klaus Schughart ◽  
...  

1965 ◽  
Vol 39 (2-3) ◽  
pp. 251-256 ◽  
Author(s):  
J. N. Oldham

Using an autopsy method of examination, an incidence of infection withToxocara canisin 250 dogs was 6·4% and withToxascaris leoninait was 2%. Of 100 cats examined, 8% harbouredToxocara catiand 3%Toxascaris leonina. Other British records concerning the incidence of the dog parasites are discussed and attention is drawn to certain reservations that must be placed on their acceptance.


Case reports ◽  
2018 ◽  
Vol 4 (1) ◽  
pp. 4-9 ◽  
Author(s):  
German Santiago Barahona Botache ◽  
Mario Javier Olivera

Introducción. La toxocariasis es una zoonosis producida por las larvas de los nematodos Toxocara canis y Toxocara cati, parásitos intestinales de los cánidos y los félidos, respectivamente.Presentación del caso. Paciente femenino de 22 años de edad, procedente de Caquetá, Colombia, con un cuadro de 3 meses de evolución con pérdida de visión en ojo izquierdo, acompañada de dolor ocular, diplopía, fotofobia y ojo rojo bilateral, quien presenta desprendimiento de retina en ojo izquierdo diagnosticado por ecografía. La mujer asiste a oftalmología, donde se hace diagnóstico diferencial con retinoblastoma y pars planitis. Se inicia manejo sintomático con corticoides orales y tópicos, con mejoría de la sintomatología, pero persistencia de pérdida de la agudeza visual.Discusión. Al revisar historial de antecedentes socioeconómicos, la paciente convive con perros y gatos, por lo que se piensa en toxocariasis ocular. En el cuadro hemático se observa ligera leucocitosis y linfocitosis, sin eosinofilia. La determinación de anticuerpos anti-Toxoplasma gondii y anti-cisticerco de Taenia solium resultaron negativas, al igual que el VDRL. El test de ELISA para T. canis fue positivo, con unos títulos IgG de 1:64 (positivo ≥1:32, especificidad >90%). Se inicia manejo con corticoide oftálmico, sistémico, albendazol y vitrectomía. Con la intervención quirúrgica se libera banda vítrea, logrando la desaparición de la diplopía, pero persiste granuloma periférico residual, el cual será intervenido por oftalmología.Conclusiones. Dada la posibilidad de ser confundida con un retinoblastoma —una neoplasia maligna que puede requerir la enucleación del ojo—, el conocimiento de esta forma de presentación de la toxocariasis es de suma importancia para los clínicos. 


Sign in / Sign up

Export Citation Format

Share Document