RESUMO
Fish pasteurellosis is a bacterial disease causing important losses in farmed fish, including gilthead sea bream, a teleost fish of great relevance in marine aquaculture. We report in this study a QTL analysis for resistance to fish pasteurellosis in this species. An experimental population of 500 offspring originating from eight sires and six dams in a single mass-spawning event was subjected to a disease challenge with Photobacterium damselae subsp. piscicida (Phdp), the causative agent of fish pasteurellosis. A total of 151 microsatellite loci were genotyped in the experimental population, and half-sib regression QTL analysis was carried out on two continuous traits, body length at time of death and survival, and for two binary traits, survival at day 7 and survival at day 15, when the highest peaks of mortality were observed. Two significant QTLs were detected for disease resistance. The first one was located on linkage group LG3 affecting late survival (survival at day 15). The second one, for overall survival, was located on LG21, which allowed us to highlight a potential marker (Id13) linked to disease resistance. A significant QTL was also found for body length at death on LG6 explaining 5-8% of the phenotypic variation.
Assuntos
Resistência à Doença/genética , Doenças dos Peixes/imunologia , Infecções por Pasteurella/veterinária , Locos de Características Quantitativas/genética , Dourada/genética , Animais , Aquicultura , Sequência de Bases , Mapeamento Cromossômico/veterinária , Doenças dos Peixes/microbiologia , Ligação Genética , Marcadores Genéticos/genética , Genótipo , Repetições de Microssatélites/genética , Dados de Sequência Molecular , Infecções por Pasteurella/imunologia , Infecções por Pasteurella/microbiologia , Photobacterium/fisiologia , Dourada/imunologia , Análise de Sequência de DNA/veterináriaRESUMO
INTRODUCTION: The authors report on an ultrasound (US) outreach program for the nomadic people living in Yushu, a remote area of Qinghai, Tibet, People's Republic of China (PRC) about 4800 m above sea level. The program was carried out in cooperation with ROKPA INTERNATIONAL, a non-profit organization (NGO) that aims at helping the poorest peoples living in remote regions of the world. MATERIALS AND METHODS: A hand-held US scanner (Sonosite 180 Plus, Sonosite Inc., Bothell, WA, USA) equipped with a 3.5-5 MHz convex probe was used at a local clinic for 21 days in 2007 and for 32 days in 2009. RESULTS: A total of 1128 US examinations were performed (578 in 2007 and 550 in 2009). The main diagnoses were: Echinococcal cysts (66 cases; 6.23%) - Biliary tract and intrahepatic gallstones (10% of patients examined) - Ascariasis - Acute and chronic hepatitis, liver cirrhosis, abdominal masses - Abdominal tuberculosis - Miscellaneous (trophoblastic tumor, megacalicosis, splenomegaly in acute leukemia). After the first experience in 2007, collaboration with the local hospital was established for the treatment of patients affected by active echinococcal cysts using albendazole and puncture, aspiration and injection of scolicidal agent and re-aspiration (PAIR) and subsequent follow-up. DISCUSSION AND CONCLUSIONS: US scanning was well accepted by the local population and allowed diagnosis, classification and choice of treatment of the echinococcal cysts according to recent criteria based on a stage-specific approach. Percutaneous treatment was also introduced, but more training of local healthcare providers is needed to secure continuation of this practice. Further experience may help improve the standard of health care services offered to the nomadic populations in this remote area.