Laboratory-controlled challenges of streptococcosis in Nile tilapia using the oral route (infected-feed) for infection.

Autor: Owatari MS; AQUOS - Aquatic Organisms Health Laboratory, Aquaculture Department, Federal University of Santa Catarina (CCA, UFSC), Rodovia Admar Gonzaga 1346, 88040-900, Florianópolis, SC, Brazil. Electronic address: owatarimarco@hotmail.com., Cardoso L; AQUOS - Aquatic Organisms Health Laboratory, Aquaculture Department, Federal University of Santa Catarina (CCA, UFSC), Rodovia Admar Gonzaga 1346, 88040-900, Florianópolis, SC, Brazil., Pereira SA; AQUOS - Aquatic Organisms Health Laboratory, Aquaculture Department, Federal University of Santa Catarina (CCA, UFSC), Rodovia Admar Gonzaga 1346, 88040-900, Florianópolis, SC, Brazil., Pereira UP; Department of Preventive Veterinary Medicine, Laboratory of Bacteriology in Fish (LABBEP), Universidade Estadual de Londrina, Londrina, Brazil., Tachibana L; Fisheries Institute - APTA - SAA, Aquaculture Research Center, Av. Conselheiro Rodrigues Alves, 1252, CEP 04014-900, São Paulo, SP, Brazil., Martins ML; AQUOS - Aquatic Organisms Health Laboratory, Aquaculture Department, Federal University of Santa Catarina (CCA, UFSC), Rodovia Admar Gonzaga 1346, 88040-900, Florianópolis, SC, Brazil., Mouriño JLP; AQUOS - Aquatic Organisms Health Laboratory, Aquaculture Department, Federal University of Santa Catarina (CCA, UFSC), Rodovia Admar Gonzaga 1346, 88040-900, Florianópolis, SC, Brazil.
Jazyk: angličtina
Zdroj: Fish & shellfish immunology [Fish Shellfish Immunol] 2022 Jan; Vol. 120, pp. 295-303. Date of Electronic Publication: 2021 Dec 03.
DOI: 10.1016/j.fsi.2021.11.039
Abstrakt: The study aimed to evaluate the oral infected-feed, intragastric-gavage, and intraperitoneal routes of the Streptococcus agalactiae infection in Nile tilapia (Oreochromis niloticus). For this purpose, 270 juveniles of Nile tilapia, with an average weight of 2 g, were distributed in 18 experimental units of 90 L, acclimatized, and raised for 55 days, until reaching 50 g (median weight). The experimental design was entirely randomized in six treatments, three of which were composed by bacterial infection routes: intraperitoneal 100 μL fish -1 [10 8  CFU], intragastric 100 μL fish -1 [10 8  CFU], feed inoculum 100 μL g feed -1 [10 9  CFU], and three respective control groups. Clinical signs were observed, and mortalities monitored until reaching 50% in the infected groups. Then, tissue samples from the spleen, liver, intestine, brain, and blood were collected from 20 fish per treatment for histopathological and hemato-immunological analyses. In addition, a related mortality curve was established at the end of the experimental challenge. The intraperitoneal and intragastric routes were more aggressive than the oral inoculum, causing greater brain damage, acute hemato-immunological response, and early mortality. While the orally fed inoculum, fish presented brain lesions with less intensity, and a chronic haemato-immunological response, the mortalities occurred twice as long as the other routes. The present research demonstrated that the S. agalactiae oral (feed inoculum) administration can be an innovative methodology to future experimental challenges in aquaculture research.
(Copyright © 2021 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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