{"id":{"repo_id":"ghent","oai_identifier":"oai:archive.ugent.be:2065469"},"canonical_url":"https://search.dev.ndltd.org/etd/ghent/oai:archive.ugent.be:2065469","repository":{"repo_id":"ghent","name":"Ghent University","base_url":"https://biblio.ugent.be/oai"},"display":{"title":"Single and dual experimental infection of specific pathogen-free Litopenaeus vannamei shrimp with White Spot Syndrome Virus and Vibrio species","abstract":"Infectious diseases, especially white spot syndrome virus (WSSV) and vibriosis, have caused huge economic loss in shrimp culture in many countries. The availability of specific pathogen-free (SPF) is now facilitating the development of standardized protocols for pathogen challenge, as established recently for WSSV. Hence, a protocol for Vibrio challenge in SPF shrimp was standardized. Shrimp from postlarve to juvenile were challenged with five different Vibrio strains namely V. campbellii, V. harveyi 642, V. harveyi E022, V. harveyi E2 and V. penaeicida. Many stress factors were applied such as starvation, salinity and ammonium stress. In absence of stress, SPF shrimp were not susceptible to Vibrio neither by immersion nor by injection. Only under ammonium stress, SPF shrimp became susceptible to infection by Vibrio through injection of 106 CFU shrimp-1 after an initial ammonium stress of 50 mgL-1 during 12 h, followed by a continuous ammonium exposure to 20 mgL-1. Another factor, namely WSSV burden, was used as interfering factor in testing the susceptibility of SPF shrimp to Vibrio. Shrimp were first injected with 30 SID50 (SID50 = Shrimp Infectious Dose with 50% endpoint) of WSSV and 24 h later with 106 CFU shrimp-1 of V. campbellii. Shrimp injected with only WSSV started to die at 60 hours post injection (hpi) and cumulative mortality reached 100% at 168-336 hpi. On the other hand, shrimp in the dual treatment died earlier (36 hpi) and cumulative mortality reached 100% at 72-96 hpi. In WSSV-compromised shrimp, the proliferation capacity of V. campbellii is enhanced considerably. The density of V. campbellii in the haemolymph of WSSV-compromised shrimp collected 6 and 10 hours after V. campbellii injection was between 102 and 103-fold higher than in shrimp injected with V. campbellii only (p<0.01). In contrast, there was no difference in WSSV replication between shrimp inoculated with WSSV only compared to dually inoculated groups. A dose of 104 CFU shrimp-1 of V. campbellii can be considered as the threshold needed for accelerated mortality of WSSV-compromised shrimp. Shrimp which were first inject with WSSV and 24 h (or 48 h) later exposed to 106, 107, or 108 CFU mL-1 of V. campbellii by immersion did not show any accelerated mortality. It was verified that the clinical outcome of WSSV and V. campbellii co-infection in SPF L. vannamei shrimp depends on the bacterial dose, strain and challenge routes. In conclusion, the outcome from this study revealed that SPF shrimp were not susceptible to Vibrio neither by immersion nor by injection in absence of stress. However, they can be made more susceptible by abiotic stress (NH3) and biotic stress (WSSV burden). This study is the first to experimentally reproduce synergistic effect between a viral and a bacterial pathogen in shrimp. The results corroborate findings of polymicrobial diseases in the field.","abstract_html":"Infectious diseases, especially white spot syndrome virus (WSSV) and vibriosis, have caused huge economic loss in shrimp culture in many countries. The availability of specific pathogen-free (SPF) is now facilitating the development of standardized protocols for pathogen challenge, as established recently for WSSV. Hence, a protocol for Vibrio challenge in SPF shrimp was standardized. Shrimp from postlarve to juvenile were challenged with five different Vibrio strains namely V. campbellii, V. harveyi 642, V. harveyi E022, V. harveyi E2 and V. penaeicida. Many stress factors were applied such as starvation, salinity and ammonium stress. In absence of stress, SPF shrimp were not susceptible to Vibrio neither by immersion nor by injection. Only under ammonium stress, SPF shrimp became susceptible to infection by Vibrio through injection of 106 CFU shrimp-1 after an initial ammonium stress of 50 mgL-1 during 12 h, followed by a continuous ammonium exposure to 20 mgL-1. Another factor, namely WSSV burden, was used as interfering factor in testing the susceptibility of SPF shrimp to Vibrio. Shrimp were first injected with 30 SID50 (SID50 = Shrimp Infectious Dose with 50% endpoint) of WSSV and 24 h later with 106 CFU shrimp-1 of V. campbellii. Shrimp injected with only WSSV started to die at 60 hours post injection (hpi) and cumulative mortality reached 100% at 168-336 hpi. On the other hand, shrimp in the dual treatment died earlier (36 hpi) and cumulative mortality reached 100% at 72-96 hpi. In WSSV-compromised shrimp, the proliferation capacity of V. campbellii is enhanced considerably. The density of V. campbellii in the haemolymph of WSSV-compromised shrimp collected 6 and 10 hours after V. campbellii injection was between 102 and 103-fold higher than in shrimp injected with V. campbellii only (p&lt;0.01). In contrast, there was no difference in WSSV replication between shrimp inoculated with WSSV only compared to dually inoculated groups. A dose of 104 CFU shrimp-1 of V. campbellii can be considered as the threshold needed for accelerated mortality of WSSV-compromised shrimp. Shrimp which were first inject with WSSV and 24 h (or 48 h) later exposed to 106, 107, or 108 CFU mL-1 of V. campbellii by immersion did not show any accelerated mortality. It was verified that the clinical outcome of WSSV and V. campbellii co-infection in SPF L. vannamei shrimp depends on the bacterial dose, strain and challenge routes. In conclusion, the outcome from this study revealed that SPF shrimp were not susceptible to Vibrio neither by immersion nor by injection in absence of stress. However, they can be made more susceptible by abiotic stress (NH3) and biotic stress (WSSV burden). This study is the first to experimentally reproduce synergistic effect between a viral and a bacterial pathogen in shrimp. The results corroborate findings of polymicrobial diseases in the field.","abstract_has_math":false,"creators":["Le, Hong Phuoc"],"institution":"Ghent University. Faculty of Bioscience Engineering","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Bossier, Peter","Nauwynck, Hans"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2008,"date_issued":"2008","date_published":"2008","updated_at":"2026-07-24T02:23:00Z","subjects":["Veterinary Sciences","Litopenaeus vannamei","white spot syndrome","shrimp"],"languages":["eng"],"rights":["info:eu-repo/semantics/openAccess"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://biblio.ugent.be/publication/2065469","urn:isbn:9789059892507","https://biblio.ugent.be/publication/2065469/file/2065472"],"render_values":[{"text":"https://biblio.ugent.be/publication/2065469","href":"https://biblio.ugent.be/publication/2065469","code":true},{"text":"urn:isbn:9789059892507","href":null,"code":true},{"text":"https://biblio.ugent.be/publication/2065469/file/2065472","href":"https://biblio.ugent.be/publication/2065469/file/2065472","code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/1854/LU-2065469","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Bossier, Peter","Nauwynck, Hans"]},{"key":"dc:creator","label":"Author","values":["Le, Hong Phuoc"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2008"]},{"key":"dc:publisher","label":"Institution","values":["Ghent University. 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The availability of specific pathogen-free (SPF) is now facilitating the development of standardized protocols for pathogen challenge, as established recently for WSSV. Hence, a protocol for Vibrio challenge in SPF shrimp was standardized. Shrimp from postlarve to juvenile were challenged with five different Vibrio strains namely V. campbellii, V. harveyi 642, V. harveyi E022, V. harveyi E2 and V. penaeicida. Many stress factors were applied such as starvation, salinity and ammonium stress. In absence of stress, SPF shrimp were not susceptible to Vibrio neither by immersion nor by injection. Only under ammonium stress, SPF shrimp became susceptible to infection by Vibrio through injection of 106 CFU shrimp-1 after an initial ammonium stress of 50 mgL-1 during 12 h, followed by a continuous ammonium exposure to 20 mgL-1. Another factor, namely WSSV burden, was used as interfering factor in testing the susceptibility of SPF shrimp to Vibrio. Shrimp were first injected with 30 SID50 (SID50 = Shrimp Infectious Dose with 50% endpoint) of WSSV and 24 h later with 106 CFU shrimp-1 of V. campbellii. Shrimp injected with only WSSV started to die at 60 hours post injection (hpi) and cumulative mortality reached 100% at 168-336 hpi. On the other hand, shrimp in the dual treatment died earlier (36 hpi) and cumulative mortality reached 100% at 72-96 hpi. In WSSV-compromised shrimp, the proliferation capacity of V. campbellii is enhanced considerably. The density of V. campbellii in the haemolymph of WSSV-compromised shrimp collected 6 and 10 hours after V. campbellii injection was between 102 and 103-fold higher than in shrimp injected with V. campbellii only (p<0.01). In contrast, there was no difference in WSSV replication between shrimp inoculated with WSSV only compared to dually inoculated groups. A dose of 104 CFU shrimp-1 of V. campbellii can be considered as the threshold needed for accelerated mortality of WSSV-compromised shrimp. Shrimp which were first inject with WSSV and 24 h (or 48 h) later exposed to 106, 107, or 108 CFU mL-1 of V. campbellii by immersion did not show any accelerated mortality. It was verified that the clinical outcome of WSSV and V. campbellii co-infection in SPF L. vannamei shrimp depends on the bacterial dose, strain and challenge routes. In conclusion, the outcome from this study revealed that SPF shrimp were not susceptible to Vibrio neither by immersion nor by injection in absence of stress. However, they can be made more susceptible by abiotic stress (NH3) and biotic stress (WSSV burden). This study is the first to experimentally reproduce synergistic effect between a viral and a bacterial pathogen in shrimp. The results corroborate findings of polymicrobial diseases in the field."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Single and dual experimental infection of specific pathogen-free Litopenaeus vannamei shrimp with White Spot Syndrome Virus and Vibrio species"]}]}],"canonical_facts":{"dc:contributor":["Bossier, Peter","Nauwynck, Hans"],"dc:creator":["Le, Hong Phuoc"],"dc:date":["2008"],"dc:description":["Infectious diseases, especially white spot syndrome virus (WSSV) and vibriosis, have caused huge economic loss in shrimp culture in many countries. The availability of specific pathogen-free (SPF) is now facilitating the development of standardized protocols for pathogen challenge, as established recently for WSSV. Hence, a protocol for Vibrio challenge in SPF shrimp was standardized. Shrimp from postlarve to juvenile were challenged with five different Vibrio strains namely V. campbellii, V. harveyi 642, V. harveyi E022, V. harveyi E2 and V. penaeicida. Many stress factors were applied such as starvation, salinity and ammonium stress. In absence of stress, SPF shrimp were not susceptible to Vibrio neither by immersion nor by injection. Only under ammonium stress, SPF shrimp became susceptible to infection by Vibrio through injection of 106 CFU shrimp-1 after an initial ammonium stress of 50 mgL-1 during 12 h, followed by a continuous ammonium exposure to 20 mgL-1. Another factor, namely WSSV burden, was used as interfering factor in testing the susceptibility of SPF shrimp to Vibrio. Shrimp were first injected with 30 SID50 (SID50 = Shrimp Infectious Dose with 50% endpoint) of WSSV and 24 h later with 106 CFU shrimp-1 of V. campbellii. Shrimp injected with only WSSV started to die at 60 hours post injection (hpi) and cumulative mortality reached 100% at 168-336 hpi. On the other hand, shrimp in the dual treatment died earlier (36 hpi) and cumulative mortality reached 100% at 72-96 hpi. In WSSV-compromised shrimp, the proliferation capacity of V. campbellii is enhanced considerably. The density of V. campbellii in the haemolymph of WSSV-compromised shrimp collected 6 and 10 hours after V. campbellii injection was between 102 and 103-fold higher than in shrimp injected with V. campbellii only (p<0.01). In contrast, there was no difference in WSSV replication between shrimp inoculated with WSSV only compared to dually inoculated groups. A dose of 104 CFU shrimp-1 of V. campbellii can be considered as the threshold needed for accelerated mortality of WSSV-compromised shrimp. Shrimp which were first inject with WSSV and 24 h (or 48 h) later exposed to 106, 107, or 108 CFU mL-1 of V. campbellii by immersion did not show any accelerated mortality. It was verified that the clinical outcome of WSSV and V. campbellii co-infection in SPF L. vannamei shrimp depends on the bacterial dose, strain and challenge routes. In conclusion, the outcome from this study revealed that SPF shrimp were not susceptible to Vibrio neither by immersion nor by injection in absence of stress. However, they can be made more susceptible by abiotic stress (NH3) and biotic stress (WSSV burden). This study is the first to experimentally reproduce synergistic effect between a viral and a bacterial pathogen in shrimp. The results corroborate findings of polymicrobial diseases in the field."],"dc:format":["application/pdf"],"dc:identifier":["https://biblio.ugent.be/publication/2065469","http://hdl.handle.net/1854/LU-2065469","urn:isbn:9789059892507","https://biblio.ugent.be/publication/2065469/file/2065472"],"dc:language":["eng"],"dc:publisher":["Ghent University. Faculty of Bioscience Engineering"],"dc:rights":["info:eu-repo/semantics/openAccess"],"dc:subject":["Veterinary Sciences","Litopenaeus vannamei","white spot syndrome","shrimp"],"dc:title":["Single and dual experimental infection of specific pathogen-free Litopenaeus vannamei shrimp with White Spot Syndrome Virus and Vibrio species"],"dc:type":["dissertation","info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]},"updated_at":"2026-07-24T02:23:00Z"}