In vivo fluorescent cercariae reveal the entry portals of Cardiocephaloides longicollis (Rudolphi, 1819) Dubois, 1982 (Strigeidae) into the gilthead seabream Sparus aurata L.
Abstract Background Despite their complex life-cycles involving various types of hosts and free-living stages, digenean trematodes are becoming recurrent model systems. The infection and penetration strategy of the larval stages, i.e. cercariae, into the fish host is poorly understood and informatio...
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| Format: | Article |
| Language: | English |
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BMC
2019-03-01
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| Series: | Parasites & Vectors |
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| Online Access: | http://link.springer.com/article/10.1186/s13071-019-3351-9 |
| _version_ | 1819261818762166272 |
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| author | Gabrielle S. van Beest Mar Villar-Torres Juan Antonio Raga Francisco Esteban Montero Ana Born-Torrijos |
| author_facet | Gabrielle S. van Beest Mar Villar-Torres Juan Antonio Raga Francisco Esteban Montero Ana Born-Torrijos |
| author_sort | Gabrielle S. van Beest |
| collection | DOAJ |
| description | Abstract Background Despite their complex life-cycles involving various types of hosts and free-living stages, digenean trematodes are becoming recurrent model systems. The infection and penetration strategy of the larval stages, i.e. cercariae, into the fish host is poorly understood and information regarding their entry portals is not well-known for most species. Cardiocephaloides longicollis (Rudolphi, 1819) Dubois, 1982 (Digenea, Strigeidae) uses the gilthead seabream (Sparus aurata L.), an important marine fish in Mediterranean aquaculture, as a second intermediate host, where they encyst in the brain as metacercariae. Labelling the cercariae with in vivo fluorescent dyes helped us to track their entry into the fish, revealing the penetration pattern that C. longicollis uses to infect S. aurata. Methods Two different fluorescent dyes were used: carboxyfluorescein diacetate succinimidyl ester (CFSE) and Hoechst 33342 (NB). Three ascending concentrations of each dye were tested to detect any effect on labelled cercarial performance, by recording their survival for the first 5 h post-labelling (hpl) and 24 hpl, as well as their activity for 5 hpl. Labelled cercariae were used to track the penetration points into fish, and cercarial infectivity and later encystment were analysed by recording brain-encysted metacercariae in fish infected with labelled and control cercariae after 20 days of infection. Results Although the different dye concentrations showed diverse effects on both survival and activity, intermediate doses of CFSE did not show any short-term effect on survival, permitting a brighter and longer recognition of cercariae on the host body surface. Therefore, CFSE helped to determine the penetration points of C. longicollis into the fish, denoting their aggregation on the head, eye and gills region, as well as on the dorsal fin and the lower side. Only CFSE-labelled cercariae showed a decreased number of encysted metacercariae when compared to control. Conclusions Our study suggests that CFSE is an adequate labelling method for short-term in vivo studies, whereas NB would better suit in vivo studies on long-term performance. Cardiocephaloides longicollis cercariae seem to be attracted to areas near to the brain or those that are likely to be connected to migration routes to neuronal canals. |
| first_indexed | 2024-12-23T19:47:51Z |
| format | Article |
| id | doaj.art-fb06e00e23264110a84b252c7807c953 |
| institution | Directory Open Access Journal |
| issn | 1756-3305 |
| language | English |
| last_indexed | 2024-12-23T19:47:51Z |
| publishDate | 2019-03-01 |
| publisher | BMC |
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| series | Parasites & Vectors |
| spelling | doaj.art-fb06e00e23264110a84b252c7807c9532022-12-21T17:33:29ZengBMCParasites & Vectors1756-33052019-03-0112111010.1186/s13071-019-3351-9In vivo fluorescent cercariae reveal the entry portals of Cardiocephaloides longicollis (Rudolphi, 1819) Dubois, 1982 (Strigeidae) into the gilthead seabream Sparus aurata L.Gabrielle S. van Beest0Mar Villar-Torres1Juan Antonio Raga2Francisco Esteban Montero3Ana Born-Torrijos4Cavanilles Institute for Biodiversity and Evolutionary Biology, Science Park, University of ValenciaCavanilles Institute for Biodiversity and Evolutionary Biology, Science Park, University of ValenciaCavanilles Institute for Biodiversity and Evolutionary Biology, Science Park, University of ValenciaCavanilles Institute for Biodiversity and Evolutionary Biology, Science Park, University of ValenciaCavanilles Institute for Biodiversity and Evolutionary Biology, Science Park, University of ValenciaAbstract Background Despite their complex life-cycles involving various types of hosts and free-living stages, digenean trematodes are becoming recurrent model systems. The infection and penetration strategy of the larval stages, i.e. cercariae, into the fish host is poorly understood and information regarding their entry portals is not well-known for most species. Cardiocephaloides longicollis (Rudolphi, 1819) Dubois, 1982 (Digenea, Strigeidae) uses the gilthead seabream (Sparus aurata L.), an important marine fish in Mediterranean aquaculture, as a second intermediate host, where they encyst in the brain as metacercariae. Labelling the cercariae with in vivo fluorescent dyes helped us to track their entry into the fish, revealing the penetration pattern that C. longicollis uses to infect S. aurata. Methods Two different fluorescent dyes were used: carboxyfluorescein diacetate succinimidyl ester (CFSE) and Hoechst 33342 (NB). Three ascending concentrations of each dye were tested to detect any effect on labelled cercarial performance, by recording their survival for the first 5 h post-labelling (hpl) and 24 hpl, as well as their activity for 5 hpl. Labelled cercariae were used to track the penetration points into fish, and cercarial infectivity and later encystment were analysed by recording brain-encysted metacercariae in fish infected with labelled and control cercariae after 20 days of infection. Results Although the different dye concentrations showed diverse effects on both survival and activity, intermediate doses of CFSE did not show any short-term effect on survival, permitting a brighter and longer recognition of cercariae on the host body surface. Therefore, CFSE helped to determine the penetration points of C. longicollis into the fish, denoting their aggregation on the head, eye and gills region, as well as on the dorsal fin and the lower side. Only CFSE-labelled cercariae showed a decreased number of encysted metacercariae when compared to control. Conclusions Our study suggests that CFSE is an adequate labelling method for short-term in vivo studies, whereas NB would better suit in vivo studies on long-term performance. Cardiocephaloides longicollis cercariae seem to be attracted to areas near to the brain or those that are likely to be connected to migration routes to neuronal canals.http://link.springer.com/article/10.1186/s13071-019-3351-9Cardiocephaloides longicollisCercarial penetration patternCercarial survival and activityMetacercarial encystmentDigenea |
| spellingShingle | Gabrielle S. van Beest Mar Villar-Torres Juan Antonio Raga Francisco Esteban Montero Ana Born-Torrijos In vivo fluorescent cercariae reveal the entry portals of Cardiocephaloides longicollis (Rudolphi, 1819) Dubois, 1982 (Strigeidae) into the gilthead seabream Sparus aurata L. Parasites & Vectors Cardiocephaloides longicollis Cercarial penetration pattern Cercarial survival and activity Metacercarial encystment Digenea |
| title | In vivo fluorescent cercariae reveal the entry portals of Cardiocephaloides longicollis (Rudolphi, 1819) Dubois, 1982 (Strigeidae) into the gilthead seabream Sparus aurata L. |
| title_full | In vivo fluorescent cercariae reveal the entry portals of Cardiocephaloides longicollis (Rudolphi, 1819) Dubois, 1982 (Strigeidae) into the gilthead seabream Sparus aurata L. |
| title_fullStr | In vivo fluorescent cercariae reveal the entry portals of Cardiocephaloides longicollis (Rudolphi, 1819) Dubois, 1982 (Strigeidae) into the gilthead seabream Sparus aurata L. |
| title_full_unstemmed | In vivo fluorescent cercariae reveal the entry portals of Cardiocephaloides longicollis (Rudolphi, 1819) Dubois, 1982 (Strigeidae) into the gilthead seabream Sparus aurata L. |
| title_short | In vivo fluorescent cercariae reveal the entry portals of Cardiocephaloides longicollis (Rudolphi, 1819) Dubois, 1982 (Strigeidae) into the gilthead seabream Sparus aurata L. |
| title_sort | in vivo fluorescent cercariae reveal the entry portals of cardiocephaloides longicollis rudolphi 1819 dubois 1982 strigeidae into the gilthead seabream sparus aurata l |
| topic | Cardiocephaloides longicollis Cercarial penetration pattern Cercarial survival and activity Metacercarial encystment Digenea |
| url | http://link.springer.com/article/10.1186/s13071-019-3351-9 |
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