ABSTRACT
BACKGROUND: The giant kidney worm, Dioctophyme renale, is a debilitating and potentially lethal parasite that inhabits and destroys, typically host's right kidney, and may also be found in ectopic sites. It is circumglobally distributed, mainly in dogs, and is increasingly regarded as a threat to other domestic animals and humans. There is little information on the parasite's true incidence, or immune responses to it, and none on its biochemistry and molecular biology. RESULTS: We characterised the soluble proteins of body wall, intestine, gonads and pseudocelomic fluid (PCF) of adult parasites. Two proteins, P17 and P44, dominate the PCF of both male and females. P17 is of 16,622 Da by mass spectrometry, and accounts for the intense red colour of the adult parasites. It may function to carry or scavenge oxygen and be related to the 'nemoglobins' found in other nematode clades. P44 is of 44,460 Da and was found to associate with fatty acids by thin layer chromatography. Using environment-sensitive fluorescent lipid probes, P44 proved to be a hydrophobic ligand-binding protein with a binding site that is highly apolar, and competitive displacement experiments showed that P44 binds fatty acids. It may therefore have a role in distributing lipids within the parasites and, if also secreted, might influence local inflammatory and tissue responses. N-terminal and internal peptide amino-acid sequences of P44 indicate a relationship with a cysteine- and histidine-rich protein of unknown function from Trichinella spiralis. CONCLUSIONS: The dominant proteins of D. renale PCF are, like those of large ascaridids, likely to be involved in lipid and oxygen handling, although there is evidence of strong divergence between the two groups.
Subject(s)
Dioctophymatoidea/metabolism , Enoplida Infections/veterinary , Helminth Proteins/chemistry , Amino Acid Sequence , Animals , Chromatography, Thin Layer , Dioctophymatoidea/chemistry , Dioctophymatoidea/genetics , Dog Diseases/parasitology , Dogs , Enoplida Infections/parasitology , Fatty Acids/chemistry , Fatty Acids/metabolism , Female , Helminth Proteins/genetics , Helminth Proteins/metabolism , Kidney , Male , Mass Spectrometry , Molecular Sequence Data , Molecular WeightABSTRACT
El objetivo de este trabajo fue analizar la relación entre el comportamiento migratorio larval de Toxocara canis y la eosinofilia en el hospedador paraténico. Utilizando al ratón como modelo experimental, debido a la similitud en la ruta migratoria y en la patogenia de este parásito en roedores y humanos. Se inocularon ratones Balb/c, por vía intragástrica con 250 (ñ 10) huevos larvados. Recuperación de larvas: se eligieron como órganos de referencia ojos y encéfalo. En encéfalo comenzaron a recuperarse larvas al 4º día y en ojo al día 21 post-inoculación. La asociación medida por el coeficiente de correlación, entre el tiempo de observación y larvas recuperadas en cada órgano fue: ojo derecho (OD) r=0,24; ojo izquierdo (OI) r=0,43; encéfalo (E) r=0,60. La recuperación de larvas inoculadas es significativamente mayor en encéfalo que en los globos oculares (chi cuad.: 185; p<0,00001). Los eosinófilos en el 80 por ciento de los ratones superó el 6 por ciento de la fórmula. La correlación entre eosinofilia y la recuperación de larvas en los órganos observados fue: 0,33 para el OD; 0,21 para OI y 0,44 para el encéfalo; estos valores de correlación se califican como bajos, sugiriendo la no asociación entre eosinofilia y la cantidad de larvas de T. canis que se alojen en ojos (toxocarosis ocular) o encéfalo (toxocarosis cerebroespinal)
Subject(s)
Animals , Mice , Cerebrum , Eye , Toxocara canis , Eosinophilia , Larva , Mice , Host-Parasite Interactions , Toxocara canisABSTRACT
This study consisted of a stratified sampling, randomly taken, of the soil from the squares and parks of the city of La Plata, Province de Buenos Aires, in order to establish the prevalence of contamination caused by Toxocara sp. A total 242 soil samples was examined. From each sample a 10 grams aliquot was taken, washed in a 0.2 percent Tween 80 solution, and processed using the technique of concentration by flotation with sugar solution. There was a prevalence of 13.2 percent. In each positive sample, the quantity of eggs varied from 1 to 4. Toxocara sp. eggs were observed in 15 out of 22 squares and parks investigated. The sampling design and the processing method employed were satisfactory for the recovering and identification of Toxocara sp. eggs