The ability of thick-lipped grey mullet to mount both humoral and cellular immune responses to Cryptocotyle lingua has been demonstrated here for the first time. Of the 3 procedures for immunisation investigated, namely exposure to live cercariae, intraperitoneal (ip) injection of whole killed cercariae and ip injection of a cercarial sonicate, the former gave the highest primary antibody titres with a peak response at 4 weeks post infection. Peak titres occurred at 5 and 7 weeks after immunisation by ip injection of sonicated cercariae and whole killed cercariae respectively. An enhanced secondary antibody response was observed following challenge by ip injection of sonicated cercariae. Cercariacidal activity, apparently involving complement, was detected in normal serum and enhanced in immune serum. However, the mechanism for complement activation remains uncertain. Parasite antigens were identified following separation by SOS-PAGE and immunoblotting using mullet and rabbit antisera. Mullet failed to respond to certain parasite proteins recognised by rabbit antiserum and in situ immunogold-silver staining demonstrated that mullet. immunised by exposure to live cercariae, were unable to recognise the metacercarial cyst wall. Migration and polarisation of pronephric leucocytes in vitro was enhanced following immunisation but cellular adherence to encysted and unencysted parasites was not observed. In vitro studies further demonstrated a possible role for fish serum in stimulating metacercarial encystment. The intensity of melanisation of the host capsule in metacercarial infections was increased in fish held in total darkness and with increased temperature. The rate of development of the metacercarial tegument and cyst wall and the associated host response was similarly affected by temperature and initial development was inhibited by prior immunisation via ip injection of sonicated cercariae. There was however, no evidence of protection against cercarial infection following such immunisation. These results are discussed in relation to mechanisms of immunity, metacercarial survival strategies and control of metazoan infections in fish.

Orientador: Reinaldo José da Silva / Coorientador: Sérgio Henrique Canello Schalch / Banca: Eduardo Makoto Onaka / Banca: Maurício Laterça Martins / Resumo: O desenvolvimento das atividades relacionadas à aquicultura tem aumentado consideravelmente a relevância dos estudos sobre parasitas e outros patógenos de organismos aquáticos, principalmente, daqueles hospedeiros com potencial para o cultivo e comercialização. O objetivo deste estudo foi avaliar a ocorrência de infecções parasitárias e microbianas na produção de pacu Piaractus mesopotamicus e do híbrido "patinga" (P. mesopotamicus x Piaractus brachypomus) procedentes da região Noroeste do Estado de São Paulo, Brasil. Três pisciculturas foram amostradas bimestralmente, de fevereiro de 2010 a fevereiro de 2011: A - Reprodução e Larvicultura (pacu/patinga), B - Engorda (patinga) e C - Pesque-pague (pacu/patinga), das quais 35 peixes foram submetidos à análise parasitológica e 21 à análise microbiológica. Foram encontrados os parasitas: dactilogirídeos (Monogenea); Trichodina spp., Ichthyophthirius multifiliis, Chilodonella sp. (Protozoa); Myxobolus spp. e Henneguya spp. (Myxozoa); Rondonia rondoni e Contracaecum sp. (Nematoda); e Dolops carvalhoi (Crustacea). Dentre os peixes analisados, 62,9% de "A" e 100% de "B" e "C" estavam infectados/infestados por pelo menos uma espécie de parasita. Pacus (n=44) apresentaram maior suscetibilidade a infestações por Anacanthorus penilabiatus, e as patingas (n=61), por Mymarothecium viatorum (p<0,05). Na análise microbiológica, 23,8% dos peixes de "A" e "B" e 33,3% da propriedade "C" estavam infectados com pelo menos um gênero de bactéria. A sazonalidade influenciou as infestações por Trichodina spp., A. penilabiatus e infecções pela bactéria Enterobacter sp. em patingas (p<0,05). No antibiograma, cepas de Pseudomonas sp., Stenotrophomonas maltophilia e Aeromonas sp. apresentaram resistência a todos antibióticos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The development of activities related to aquaculture has considerably increased the relevance of studies on parasites and other pathogens of aquatic organisms, especially those with potential for production and marketing. The aim of this study was to evaluate the occurrence of parasitic and microbial infections in the "pacu" Piaractus mesopotamicus and hybrid "patinga" (P. mesopotamicus x Piaractus brachypomus) from the Northwest of São Paulo State, Brazil. Fishes from three fish farms were evaluated every two months: A - Reproduction and larviculture (pacu / patinga), B - Growout (patinga) and C - Fee-fishing property (pacu / patinga). Fishes from each fish farm were collected from February 2010 to February 2011 for parasitological (n = 35 per property) and microbiological (n = 21 per property) analysis. The parasites found were: Dactylogyridae (Monogenea), Trichodina spp., Ichthyophthirius multifiliis, Chilodonella sp. (Protozoa), Myxobolus spp., Henneguya spp. (Myxozoa), Rondonia rondonia, third stage larvae of Contracaecum sp. (Nematoda), and Dolops carvalhoi (Crustacea). Among the fishes examined, 62.9% from "A" and 100% from "B" and "C" were infected / infested with at least one parasite species. Pacu (n = 44) showed higher susceptibility to infestations caused by Anacanthorus penilabiatus and patinga (n = 61) by Mymarothecium viatorum (p < 0.05). In the microbiological analysis, 23.8% of fishes from "A" and "B" properties and 33.3% of fish from the property "C" were infected with at least one bacteria species. Seasonality influenced Trichodina spp. and A. penilabiatus infestations and infection caused by Enterobacter sp. in patingas (p < 0.05). In antibiogram test, strains of Pseudomonas sp., Stenotrophomonas maltophilia and Aeromonas sp. were resistant to all beta-lactam antibiotics... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2014-06-11T19:30:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-27Bitstream added on 2014-06-13T19:39:32Z : No. of bitstreams: 1 franceschini_l_me_botib.pdf: 588829 bytes, checksum: 796cb08752fb62d3915ad06ac0d6aa82 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O desenvolvimento das atividades relacionadas à aquicultura tem aumentado consideravelmente a relevância dos estudos sobre parasitas e outros patógenos de organismos aquáticos, principalmente, daqueles hospedeiros com potencial para o cultivo e comercialização. O objetivo deste estudo foi avaliar a ocorrência de infecções parasitárias e microbianas na produção de pacu Piaractus mesopotamicus e do híbrido patinga (P. mesopotamicus x Piaractus brachypomus) procedentes da região Noroeste do Estado de São Paulo, Brasil. Três pisciculturas foram amostradas bimestralmente, de fevereiro de 2010 a fevereiro de 2011: A - Reprodução e Larvicultura (pacu/patinga), B - Engorda (patinga) e C - Pesque-pague (pacu/patinga), das quais 35 peixes foram submetidos à análise parasitológica e 21 à análise microbiológica. Foram encontrados os parasitas: dactilogirídeos (Monogenea); Trichodina spp., Ichthyophthirius multifiliis, Chilodonella sp. (Protozoa); Myxobolus spp. e Henneguya spp. (Myxozoa); Rondonia rondoni e Contracaecum sp. (Nematoda); e Dolops carvalhoi (Crustacea). Dentre os peixes analisados, 62,9% de “A” e 100% de “B” e “C” estavam infectados/infestados por pelo menos uma espécie de parasita. Pacus (n=44) apresentaram maior suscetibilidade a infestações por Anacanthorus penilabiatus, e as patingas (n=61), por Mymarothecium viatorum (p<0,05). Na análise microbiológica, 23,8% dos peixes de “A” e “B” e 33,3% da propriedade “C” estavam infectados com pelo menos um gênero de bactéria. A sazonalidade influenciou as infestações por Trichodina spp., A. penilabiatus e infecções pela bactéria Enterobacter sp. em patingas (p<0,05). No antibiograma, cepas de Pseudomonas sp., Stenotrophomonas maltophilia e Aeromonas sp. apresentaram resistência a todos antibióticos... / The development of activities related to aquaculture has considerably increased the relevance of studies on parasites and other pathogens of aquatic organisms, especially those with potential for production and marketing. The aim of this study was to evaluate the occurrence of parasitic and microbial infections in the “pacu” Piaractus mesopotamicus and hybrid patinga (P. mesopotamicus x Piaractus brachypomus) from the Northwest of São Paulo State, Brazil. Fishes from three fish farms were evaluated every two months: A - Reproduction and larviculture (pacu / patinga), B - Growout (patinga) and C - Fee-fishing property (pacu / patinga). Fishes from each fish farm were collected from February 2010 to February 2011 for parasitological (n = 35 per property) and microbiological (n = 21 per property) analysis. The parasites found were: Dactylogyridae (Monogenea), Trichodina spp., Ichthyophthirius multifiliis, Chilodonella sp. (Protozoa), Myxobolus spp., Henneguya spp. (Myxozoa), Rondonia rondonia, third stage larvae of Contracaecum sp. (Nematoda), and Dolops carvalhoi (Crustacea). Among the fishes examined, 62.9% from A and 100% from B and C were infected / infested with at least one parasite species. Pacu (n = 44) showed higher susceptibility to infestations caused by Anacanthorus penilabiatus and patinga (n = 61) by Mymarothecium viatorum (p < 0.05). In the microbiological analysis, 23.8% of fishes from A and B properties and 33.3% of fish from the property C were infected with at least one bacteria species. Seasonality influenced Trichodina spp. and A. penilabiatus infestations and infection caused by Enterobacter sp. in patingas (p < 0.05). In antibiogram test, strains of Pseudomonas sp., Stenotrophomonas maltophilia and Aeromonas sp. were resistant to all beta-lactam antibiotics... (Complete abstract click electronic access below)