The infectivity and antigenicity of Toxocara canis eggs can be retained after long-term preservation
Suspensions of fertilized eggs of Toxocara canis were mixed with 2% neutral formalin and preserved at 4°C. When, after storage for 0, 12, 18, 21 and 24 months, samples of the eggs were incubated at 30°C for 12 days, 96.8%, 92.6%, 74.1%, 51.0% and 19.3% of the eggs in the samples were found to embryo...
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Published in | Annals of tropical medicine and parasitology Vol. 98; no. 3; pp. 251 - 260 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Leeds
Taylor & Francis
01.04.2004
Maney Publishing |
Subjects | |
Online Access | Get full text |
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Summary: | Suspensions of fertilized eggs of Toxocara canis were mixed with 2% neutral formalin and preserved at 4°C. When, after storage for 0, 12, 18, 21 and 24 months, samples of the eggs were incubated at 30°C for 12 days, 96.8%, 92.6%, 74.1%, 51.0% and 19.3% of the eggs in the samples were found to embryonate.
The embryonated eggs produced from the fertilized eggs preserved (in 2% neutral formalin at 4°C) for 0, 12, 18 and 21 months were then tested for their infectivity to BALB/c mice, each mouse being given 800 embryonated eggs. The numbers of larvae recovered from the mice and the sites from which they were recovered, 2 or 14 days post-infection, appeared unaffected by the length of storage of the eggs. The infected mice all had similar eosinophil counts in their peripheral blood and similar serum titres of Toxocara-specific IgM and IgG antibodies, and cultures of their spleen cells produced similar amounts of interleukin-4, interleukin-5 and interferon-γ when stimulated with concanavalin A. The results of SDS-PAGE indicated that egg preservation for at least 21 months had no effect on the excretory-secretory antigens in samples of medium from cultures of infective larvae released from the eggs. In summary, at least 50% of the fertilized eggs preserved in 2% neutral formalin at 4°C for 21 months could fully embryonate and then had the same infectivity and antigenicity as embryonated fresh eggs. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0003-4983 1364-8594 |
DOI: | 10.1179/000349804225003280 |