Can the parasitic fauna on Nile tilapias be affected by different production systems?

This study compared the parasitic fauna on Nile tilapias kept with swine dejects and tilapia from fee fishing fed commercial ration. A total of 360 fish were analyzed from August 2003 to July 2004 in a facility situated in Nova Trento, Santa Catarina, Brazil. No significant difference was observed in both systems. The parasite fauna in both systems were slightly similar, with the presence of the following parasites: Trichodina magna and T compacta (Ciliophora); Cichlidogyrus sclerosus and Cichlidogyrus sp. (Monogenoidea); and Lamproglena sp. (Lernaeidae). Parasitological analyzes did not differ among fishes kept with swine dejects and in fee fishing with commercial diet (P >0.05). The total prevalence of trichodinids in the gills of fish kept with swine dejects was 1.7 percent as compared to the one kept in fee fishing with commercial diet (0.6 percent). The Monogenoidea prevalence and mean intensity in the gills and body of fish from fee fishing was 16.5 percent and 2.6, and compared to other system was 13.2 percent and 0.8, respectively. This study showed that low stocking density and low water temperature in that region were responsible for the maintenance of good health and lower parasitism rate.

Este estudo comparou a fauna parasitária de tilápia do Nilo mantida em consorciação com suínos e alimentada com ração comercial mantida em pesque-pague. Um total de 360 peixes foi analisado, entre agosto de 2003 ejulhode2004, em uma propriedade de Nova Trento, Santa Catarina, Brasil. Não houve diferença significativa entre os dois sistemas de cultivo. A fauna parasitária em ambos foi ligeiramente semelhante com a presença de Trichodina magna e T compacta (Ciliophora); Cichlidogyrus sclerosus e Cichlidogyrus sp. (Monogenoidea) e Laproglena sp. (Lernaeidae). A análise parasitológica não mostrou diferença entre os peixes dos dois sistemas. A prevalência total de tricodinídeos nas brânquias dos peixes mantidos com dejetos de suínos foi de 1,7 por cento quando comparada com os do pesque-pague de 0,6 por cento. A taxa de prevalência e a intensidade média de Monogenoidea nas brânquias dos peixes do pesque-pague foi de 16,5 por cento e 2,6, respectivamente comparada com os mantidos com suínos de 13,2 por cento e 0,8, respectivamente. Este estudo demonstrou que a baixa densidade de estocagem de peixes nesta propriedade e a baixa temperatura na região colaboraram para que a saúde dos animais fosse mantida e o nível de parasitismo baixo.

Contaminação da pastagem com larvas infectantes de nematoides gastrintestinais após o pastejo de ovelhas resistentes ou susceptíveis à verminose / Pasture contamination with infective larvae of gastrointestinal nematodes after grazing by sheep resistant or susceptible to parasitic infection

O grau de contaminação da pastagem por larvas de terceiro estágio (L3) de nematoides gastrintestinais foi avaliado em piquetes pastejados por ovelhas resistentes ou susceptíveis à verminose. O experimento foi realizado de 23 de novembro de 2007 a 22 de julho de 2008. Inicialmente, realizou-se a contagem de ovos por grama de fezes (OPG) de amostras individuais de 130 ovelhas adultas da raça Bergamácia. Dessas, foram selecionadas as nove ovelhas com contagens mais elevadas de OPG (susceptíveis) e as 10 com as menores contagens (resistentes). As ovelhas resistentes apresentaram menor contagem de OPG, maiores valores de volume globular, de proteína plasmática total e de eosinófilos sanguíneos, do que as ovelhas susceptíveis. O peso também foi maior no grupo resistente. Na pastagem, foram identificadas larvas de Haemonchus spp., Trichostrongylus spp. e Oesophagostomum spp. Em média, as quantidades de L3 de Haemonchus spp. e de Trichostrongylus spp., na pastagem, foram 2,19 e 2,31 vezes, respectivamente, maiores nos piquetes pastejados pelo grupo susceptível do que nos do grupo resistente. Portanto, os animais susceptíveis devem ser eliminados do rebanho a fim de reduzir a contaminação da pastagem e otimizar a profilaxia das infecções por nematoides gastrintestinais.

The degree of contamination of herbage with third stage larvae of gastrointestinal nematodes was evaluated in paddocks grazed by resistant or susceptible ewes. The trial occurred from November 23, 2007 to July 22, 2008. Initially, fecal egg counts (FEC) were performed with individual samples of 130 adult ewes of the Bergamacia breed. Of those animals, nine ewes with the highest FEC (susceptible group) and 10 with the lowest counts (resistant group) were selected and moved to separate paddocks. The resistant ewes presented lower FEC, higher values of packed cell volume, total plasma protein and blood eosinophils than the susceptible ewes. The weight was also higher in the resistant group. Haemonchus spp., Trichostrongylus spp. and Oesophagostomum spp. third stage larvae were recovered from pasture. In average, the amount of Haemonchus spp. and Trichostrongylus spp. third stage larvae in the pasture were 2.19 and 2.31 times, respectively, higher in the paddocks grazed by susceptible group in comparison with those grazed by the resistant animals. Therefore, the susceptible animals should be eliminated from the flock in order to reduce pasture contamination and optimize the prophylaxis of gastrointestinal nematode infections.

Application of hazard analysis critical control point (HACCP) as a possible control measure for Opisthorchis viverrini infection in cultured carp (Puntius gonionotus).

Opisthorchiasis due to Opisthorchis viverrini and transmitted through infected freshwater cyprinoid fish (carps) affects more than 8 million people in Thailand, People's Democratic Republic of Lao, and Vietnam. The Hazard Analysis Critical Control Point (HACCP)-concept has been recommended by FAO and WHO to be included in programs to control foodborne trematode infections (FBT). HACCP is a multifactorial approach to control food hazards through surveillance of diseases, foods, and operations and education. This study describes the first attempt to apply HACCP to the prevention and control of Opisthorchis viverrini in pond culture carp (Puntius gonionotus). The experiment was designed and carried out by a multidisciplinary "HACCP team" including experts in the field of public health, parasitology, epidemiology, aquaculture, fisheries extension and fish inspection. The investigation was performed in two fish ponds in the District of Sun Pa Tong, Chiang Mai, Thailand. In the experimental pond, fish was cultured according to HACCP principles and compared with the control pond, which followed conventional aquaculture practices. Water supply to the pond, fish fry, fish feed and pond conditions during the growing period were identified as critical control points (CCPs). Hazards were identified and analyzed, as well as control measures, critical limits, monitoring procedures, corrective actions, and record keeping developed for each one of the above CCPs. Complete pond preparation, particularly aiming to eliminate contamination of pond water with O. viverrini eggs, fish infected with parasite meacercariae and the first intermediate host (Bithynia spp), was conducted. After the pond was filled with water, O. viverrini metacercaria-free fry were released into the pond. The preliminary results obtained indicate that HACCP-based principles applied to carp pond culture could be used as a strategy to prevent and control O. viverrini. Further studies should be undertaken aiming to confirm these preliminary results.

Efecto de la adición de la semilla de paprika en la dieta para la infección por Salmonella enteritidis en pollos de engorda / Effect of the administration of dietary paprika seed on Salmonella enteritidis infection in broiler chicks

En el presente trabajo se evaluó el efecto protectivo de la semilla de parpika en la dieta para la colonización e invasión de Salmonella enteritidis en órganos, peso corporal y pH del contenido cecal. Los pollos se pesaron al momento de la llegada y se evaluó el peso a los 7 y 15 días de edad, no encontrándose diferencias estadísticamente significativas (P>0.05). A los 15 días de edad, todas las aves se desafiaron con 10 8 ufc/ml de S. enteritidis resistente a la novobiocina (NO) y al ácido nalidíxico (AN). Las aves fueron sacrificadas 24 horas posinoculación y se tomaron muestras de hígado, bazo y tonsilas cecales. En relación con el número total de aves positivas a S. enteritidis en tonsilas cecales, no se observaron diferencias estadísticamente significativas (P>0.05) en todos los grupos experimentales; sin embargo, en hígado y bazo, la invasión disminuyó significativamente (P<0.05) en los grupos tratados con 18 ppm de ácido cápsico (AC) puro (26/39) y con 18 ppm de AC a partir de semillas de paprika (25/37) comparados con el grupo testigo (34/39). En el grupo con 27 ppm de AC de semilla de paprika (25/39) se observó una diferencia estadísticamente significativa (P<0.025) en relación con el grupo testigo. El pH del contenido cecal decreció significativamente (P<0.05) en todos los grupos tratados con respecto al grupo testigo. Los resultados obtenidos en este trabajo concuerdan con estudios previos y demuestran que el ácido cápsico presente en la semilla de paprika también resultó efectivo en la disminución de la viabilidad de S. enteritidis para colonizar e invadir órganos internos