bachelorThesis
Identificación de estadios larvarios de Taenia solium y T. asiatica en muestras de tejidos de cerdos (Sus scrofa ssp domestica) mediante LAMP
Fecha
2021-10-22Autor
Carpio Sánchez, Jonnathan Xavier
Coello Miranda, Dorian Javier
Institución
Resumen
The taeniasis/cysticercosis complex is a worldwide zoonotic parasitic disease
caused by the tapeworm Taenia solium, T. saginata and T. asiatica. The species
that affect pigs and humans are T. solium and T. asiatica. The natural cycle of the
parasite includes the pig as an intermediate host and the human as the final host
and/or in some cases as an intermediate host due to fecal-oral contamination.
Ecuador is considered an endemic country to human taeniasis and hyper-endemic
to Neurocysticercosis. While in pigs, studies and prevalence figures do not report
on the evolution of the number of cases over time and estimates of the incidence
rate of cysticercosis are lacking, causing great economic losses and being a
serious health problem. The objective of the present study was to identify larval
stages of T. solium and T. asiatica in tissue samples from pigs (Sus scrofa ssp.
domestica) using the LAMP biomolecular technique; to generate a first information
on its use and viability. A total of 76 samples of cysts with lesions were collected in
different tissues of the pig suspected of larval stages of Taenia spp. with a greater
location in the liver (52), followed by masseter muscle (5,) shoulder butt (4), tongue
(4), biceps (3), heart (2), diaphragm (2), thigh (2), neck muscle (1) and intestine
(1). The viability of the samples (process control) was determined by a LAMP
assay for Sus scrofa spp. domestica with a set of primers for the COXII gene, while
a LAMP assay was used to identify the samples of T. solium and T. asiatica with a
set of primers for the COXI genes. As a result, it was observed that, of the total
samples collected, 36.84% were valid for process control, while for the LAMP test
for T. solium, 15.79% of positive samples were obtained; to finally have a total of
10.53% positive samples and also valid for process control, on the contrary, for T.
asiatica all the samples were negative. The LAMP technique is capable of
detecting larval stages positive to T. solium and valid for the control of the process,
such as the case of intestine and various liver tissue samples, which could easily
be confused with E. granulosus or T. hydatigena. However, it is evident that
several of the samples that coincide with lesions characteristic of cysticercosis,
were negative in the test for T. solium and not valid in the control of the process.
Being necessary to adapt the tests for the reactives used, improve the protocols in
the extraction method or even take into account the amount of porcine tissue that
covers the cysts and seek more evidence that may suggest whether or not the
viability of these may affect the way in which DNA is preserved.