The use of 35S-labelled Toxocara canis to determine larval numbers in tissues

1992 ◽  
Vol 66 (4) ◽  
pp. 279-287 ◽  
Author(s):  
K. C. Carter
Keyword(s):  
Post Infection ◽  
Half Life ◽  
Toxocara Canis ◽  
Second Stage ◽  
Infective Larvae ◽  
Secretory Products ◽  
Formed Part ◽  
Antibody Levels ◽  
The Brain

ABSTRACTThe potential of using 35S-labelled larvae to determine the number of second-stage Toxocara canis larvae present in the tissues of infected animals was assessed. Infective larvae were labelled by in vitro culture with medium containing 35S-methionine. The amount of radiolabel attached to larvae decayed exponentially with time and had an in vitro mean half life of 3·54±0·65 days. The ‘lost’ radiolabel was incorporated into proteins which formed part of the worm's excretory/secretory products. The levels of radioactivity present in different organs of BALB/c mice, infected with 35S-labelled T. canis larvae, varied over the course of infection. Initially most of the radioactivity was present in liver, but over the course of infection 35S liver levels gradually decreased and brain levels increased. By day 14 post-infection the majority of the isotope was present in the brain (p<0·01). Assessment of antibody levels on day 14 post-infection showed that infection with 35S labelled T. canis larvae induced the production of parasite-specific IgM, IgG and IgG1 antibodies.

scholarly journals Influence of mouse strain, infective dose and larval burden in the brain on activity in Toxocara-infected mice

2001 ◽  
Vol 75 (1) ◽  
pp. 23-32 ◽  
Author(s):  
D.M. Cox ◽  
C.V. Holland
Keyword(s):  
Mouse Strain ◽  
Post Infection ◽  
Home Cage ◽  
Brain Activity ◽  
Toxocara Canis ◽  
Cage Activity ◽  
Home Cage Activity ◽  
The Brain ◽  
Larval Recovery ◽  
Larval Burden

Outbred LACA mice and inbred NIH mice were administered low (100 ova), medium (1000 ova), high (3000 ova) and trickle (4×250 ova) doses ofToxocara canisova and the effect of infection on activity was examined with respect to: (i) the dose of ova administered and (ii) the number of larvae recovered from the brain. Larval recovery from the brain was significantly reduced in NIH mice compared to LACA mice for the 1000, 3000 and trickle doses. Mice from each strain were divided into larval intensity groupings based upon the number of larvae recovered from their brain. Activity for each mouse was measured pre- and post-infection by observing its behaviour in the home cage. Activity was assessed by monitoring six different independent categories of murine behaviour – ambulation, grooming, rearing, digging, climbing and immobility. Within each behavioural category, the duration of time spent at each behaviour per mouse within one thousandth of a second, the number of short bouts performed and the number of long bouts of behaviour performed were recorded over a 20 min period. Activity of LACA and NIH mice differed prior to infection. LACA mice spent more time immobile compared to NIH mice, which ambulated and climbed more. Variations in activity were also observed between groups of mice prior to infection. The effect of infection differed by strain, by dose and by larval intensity. Post-infection LACA mice became more immobile and ambulated less. NIH mice showed reduced immobility, but while ambulation decreased digging and climbing increased post-infection. Short bouts of activity remained unchanged among LACA mice post-infection but showed an increase for some behaviours in NIH mice.

Identification of a new C-type lectin, TES-70, secreted by infective larvae of Toxocara canis, which binds to host ligands

Parasitology ◽  
2000 ◽  
Vol 121 (5) ◽  
pp. 545-554 ◽  
Author(s):  
A. LOUKAS ◽  
A. DOEDENS ◽  
M. HINTZ ◽  
R. M. MAIZELS
Keyword(s):  
Immune Cell ◽  
Sequence Similarity ◽  
Mannose Receptor ◽  
Toxocara Canis ◽  
Dependent Manner ◽  
Expression Screening ◽  
Lectin Domain ◽  
Calcium Dependent ◽  
Infective Larvae

Infective larvae of the dog roundworm Toxocara canis survive in the tissues of their hosts for extended periods in a state of developmental arrest, successfully evading immune destruction. This survival strategy is thought to be mediated by T. canis excretory/secretory (TES) products which downregulate or divert the immune response. We purified one of the major TES products, TES-70 and gained amino acid sequence from 4 tryptic peptides. These peptides were matched to a predicted protein from a cDNA that was isolated by expression screening a T. canis cDNA library with mouse anti-TES serum. The predicted protein (Tc-CTL-4) is similar to, but larger than, Tc-CTL-1, a 32-kDa C-type lectin secreted by T. canis larvae. Tc-CTL-4 has a signal peptide, 2 Cys-rich domains and a C-terminal calcium-dependent C-type lectin domain that shares sequence similarity with host immune cell receptors such as macrophage mannose receptor and CD23. The lectin domain was expressed in bacteria and antiserum to the purified recombinant protein was used to confirm that Tc-ctl-4 did encode the native TES-70 glycoprotein. TES-70 selectively bound to ligands on the surface of Madin–Darby Canine Kidney cells in vitro in a calcium-dependent manner, inhibitable by mammalian serum, indicating that a host glycan is the native ligand for this new parasite lectin.

In vitro trapping capability of Arthrobotrys spp. on infective larvae of Haemonchus contortus and Nacobbus aberrans

1994 ◽  
Vol 68 (3) ◽  
pp. 223-229 ◽  
Author(s):  
P. Mendoza-de Gives ◽  
E. Zavaleta-Mejia ◽  
D. Herrera-Rodriguez ◽  
H. Quiróz-Romero
Keyword(s):  
Microscopic Examination ◽  
Haemonchus Contortus ◽  
Three Dimensional ◽  
Arthrobotrys Oligospora ◽  
Second Stage ◽  
Infective Larvae ◽  
Third Stage ◽  
Nacobbus Aberrans

AbstractThe trapping capability of Arthrobotrys oligospora and A. conoides (Hyphomycetales) against third stage larvae (L3) of Haemonchus contortus (Trichostrongylidae) was evaluated in an in vitro trial. Arthrobotrys oligospora showed a 35.87% and 25.71% trapping effectiveness against H. contortus infective larvae at 18 and 25°C, respectively; whereas the trapping capability of A. conoides was 92.17% and 90.40% at the same temperatures, respectively. Microscopic examination demonstrated that A. conoides spontaneously developed a large quantity of three-dimensional loops before the nematodes were added. Neither of the two species studied developed three-dimensional adhesive loops at 30°C, consequently no trapped nematode was observed. In a second trial, the trapping capability of A. conoides against H. contortus (L3) and second stage larvae (J2) of Nacobbus aberrans (Pratylenchidae), was evaluated at 25°C. The trapping capability shown by A. conoides was higher than 90% for both kinds of nematode. The possible use of A. conoides to control ovine haemonchosis is discussed.

Toxocara canis: Potential activity of natural products against second-stage larvae in vitro and in vivo

2010 ◽  
Vol 126 (2) ◽  
pp. 191-197 ◽  
Author(s):  
Mariana Reis ◽  
Alcione Trinca ◽  
Maria José U. Ferreira ◽  
Ana R. Monsalve-Puello ◽  
Maria Amélia A. Grácio
Keyword(s):  
Natural Products ◽  
Toxocara Canis ◽  
Second Stage ◽  
Potential Activity

Changing chemosusceptibility in the second-stage larvae of Toxocara canis by long-term incubation

1993 ◽  
Vol 67 (2) ◽  
pp. 145-150 ◽  
Author(s):  
Nobuaki Akao ◽  
Yoshihisa Goto ◽  
Kaoru Kondo ◽  
Yoshisuke Tsuda
Keyword(s):  
Decanoic Acid ◽  
Toxocara Canis ◽  
Second Stage ◽  
One Year

AbstractSecond-stage larvae of Toxocara canis were maintained in vitro for one year. Susceptibility of the larvae to drugs was evaluated by means of minimal larvicidal concentration (MLC) and larval bursting percentage. MLCs of citral and decanoic acid were almost constant throughout all stages of incubation. However, bursting percentage markedly varied within the first 20 weeks of incubation. Therefore, while larvae are available for use in the MLC assay at any stage of incubation, those beyond the first 20 weeks after incubation should be used for the bursting assay to obtain reproducible results.

scholarly journals Proteinases in Excretory-Secretory Products ofToxocara canisSecond-Stage Larvae: Zymography and Modeling Insights

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Gonzalo Ernesto González-Páez ◽  
Fernando Alba-Hurtado ◽  
Carlos Gerardo García-Tovar ◽  
Raúl Argüello-García
Keyword(s):  
Serine Proteinase ◽  
Toxocara Canis ◽  
Serine Proteinases ◽  
Bodily Fluids ◽  
Multiple Components ◽  
Proteolytic Activities ◽  
Secretory Products ◽  
Ph Range ◽  
Physiological Substrates

Components released in excretory-secretory products ofToxocara canislarvae (TES) include phosphatidylethanolamine-binding proteins (TES26), mucins (TES120, MUC2-5), and C-type lectins (TES32, TES70) and their biochemical, immunological, and diagnostic properties have been extensively studied albeit proteinase activities towards physiological substrates are almost unknown. Proteolytic activities in TES samples were first analyzed by gel electrophoresis with gelatin as substrate. Major activities of ~400, 120, and 32 kDa in TES were relatively similar over a broad pH range (5.5–9.0) and all these were of the serine-type as leupeptin abolished gelatinolysis. Further, the ~400 kDa component degraded all physiological substrates tested (laminin, fibronectin, albumin, and goat IgG) and the 120 kDa component degraded albumin and goat IgG while proteinases of lower MW (45, 32, and 26 kDa) only degraded laminin and fibronectin, preferentially at alkaline pH (9.0). By protein modeling approaches using the known sequences of TES components, only TES26 and MUC4 displayed folding patterns significantly related to reference serine proteinases. These data suggest that most of serine proteinase activities secretedin vitroby infective larvae ofT. canishave intriguing nature but otherwise help the parasite to affect multiple components of somatic organs and bodily fluids within the infected host.

scholarly journals Strongyloses ratti and S. stercoralis: effects of cambendazole, thiabendazole and mebendazole in vitro

1986 ◽  
Vol 28 (2) ◽  
pp. 97-103 ◽  
Author(s):  
David I. Grove ◽  
Carolyn Northern
Keyword(s):  
The Other ◽  
Free Living ◽  
Second Stage ◽  
Infective Larvae ◽  
In Vitro Incubation ◽  
Living Adult

The effects of in vitro incubation of three henzimidazole anthelmintics, thiabendazole, mebendazole and cambendazole on Strongyloides were compared. No drug affected hatching of S. ratti eggs or the viability of infective larvae or parasitic adult worms, but all three inhibited moulting of S. ratti larvae. In addition, cambendazole, but not thiabendazole or mebendazole, impaired the viability of S. ratti first- and second-stage larvae. The three drugs had no effect on isolated S. stercorais free-living adult worms, but they all prevented development of S. stercoralis rhabditiform larvae. Thiabendazole and mebendazole had no effect on the infectivity of either S. ratti or S. stercoralis infective larvae, but infection with these worms was abrogated by prior incubation with cambendazole. These results indicate that cambendazole acts in a different manner to the other two drugs. Since it is active against larvae migrating through the tissues, it is potentially of much greater value than thiabendazole or mebendazole in the therapy of strongyloidiasis.

scholarly journals In vitro cultivation of Toxocara cati adult worms for production of eggs and evaluation of oviposition

2009 ◽  
Vol 46 (1) ◽  
pp. 28-30 ◽  
Author(s):  
M. Zibaei ◽  
S. Sadjjadi ◽  
B. Sarkari ◽  
A. Oryan ◽  
S. Uga
Keyword(s):  
Culture Method ◽  
Toxocara Canis ◽  
Clinical Syndrome ◽  
Egg Laying ◽  
In Vitro Cultivation ◽  
Toxocara Cati ◽  
Second Stage ◽  
Immunological Diagnosis ◽  
The Mean

AbstractToxocariasis is the clinical syndrome caused by infection of zoonotic roundworms of dogs (Toxocara canis) or cats (Toxocara cati). Current research on the immunology and pathology aspects of toxocariasis requires Toxocara second stage larvae and a ready source of excretory-secretory (ES) antigens. We cultured eleven pairs of both sexes of Toxocara cati adult worms maintained in RPMI 1640 medium in order to evaluate the amounts and duration of egg laying. At the first day and last day (day 19), the mean egg counts were 9300 and 250 eggs/ml, respectively. These results showed that this culture method is very appropriate for collection of pure oviposited eggs and/or production of adult ES antigens of Toxocara cati that could be used for immunological diagnosis of toxocariasis.

Variation in the larval recovery ofToxocara canisfrom the murine brain: implications for behavioural studies

1997 ◽  
Vol 71 (3) ◽  
pp. 253-256 ◽  
Author(s):  
H. Skerrett ◽  
C.V. Holland
Keyword(s):  
Post Infection ◽  
Toxocara Canis ◽  
High Dose ◽  
Murine Brain ◽  
The Brain ◽  
Larval Recovery ◽  
Migratory Pathway

AbstractThe migratory pathway ofToxocara canislarvae was determined by infecting mice with a low, medium or high dose of embryonatedT. caniseggs and determining numbers of larvae present in the brain, liver, lungs, kidneys and muscle on days 5, 14 and 26 post infection. Variation was seen in the numbers of larvae recorded in the organs of mice which had received the same number of eggs and were at the same stage of infection. This variation was particularly marked in the brain indicating that, for the purposes of behavioural studies, the actual numbers of larvae found in the brain rather than the number assumed from the dose would have to be taken into account when analysing the behaviour of infected mice.

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