First record of Perkinsus marinus infecting Crassostrea sp. in Rio Grande do Norte, Brazil, using real-time PCR.

A pathogen with high virulence potential in some host species, Perkinsus marinus remains a challenge for the ecological integrity of marine ecosystems and the health of bivalve molluscs. This study investigates the occurrence of P. marinus in Crassostrea sp. in estuaries of the Potengi River and the Guaraíras lagoon in Rio Grande do Norte, Brazil. A total of 203 oyster samples that tested positive for Perkinsus sp. in Ray's fluid thioglycollate medium (RFTM) were subjected to species-specific quantitiative PCR, where 61 animals (30.05 %) presented amplification graphs with a melting temperature of 80.1 ± 0.6 °C matching the positive control. This was the first record of P. marinus in oysters in these estuaries using qPCR as a diagnostic tool.

Antibacterial and cytotoxicity activity in macroalgae extracts: perspectives for the use against pathogenic bacteria from shrimp farms (Litopenaeus vannamei) / Atividade antibacteriana e citotóxica em extratos de macroalgas: perspectivas de uso contra bactérias patogênicas de ambiente de cultivo de camarões (Litopenaeus vannamei)

Some infections caused by pathogenic microorganisms might shows high prevalence in farmed shrimp environments, compromising production and causing economic losses. Therefore, the search for compounds with antibiotic activity has become intensive, following the record of new antimicrobial-resistant bacteria. The study of those bioactive compounds in marine macroalgae has produced satisfactory results, such as the discovery of antibacterial activity against multiresistant strains. Accordingly, this study aims to research antibiotic activity in macroalgae extracts of Chlorophyta, Phaeophyta and Rhodophyta found in the coast of Ceará and also to evaluate the cytotoxicity activity against bacterial strains (Vibrio sp.) from shrimp farms (Litopenaeus vannamei). The extracts cytotoxicity was also evaluated. The results prove that there was antibacterial activity in ethanolic, acetonic, hexanic and methanolic extracts against bacterial strains of Vibrio with multiple resistance profile as well as displaying low cytotoxicity.

Algumas infecções causadas por micro-organismos patogênicos podem apresentar alta prevalência em ambientes de cultivo de camarões marinhos, comprometendo a produção e causando prejuízos econômicos aos aquicultores. Assim, tem-se tornado intensa a busca por compostos com atividade antibiótica pelo registro cada vez mais frequente de bactérias com perfil de resistência a antimicrobianos. A presença desses compostos com bioatividade em macroalgas marinhas tem revelado resultados satisfatórios, como a descoberta de ação antibacteriana contra cepas multirresistentes. Desta forma, decidiu-se pesquisar as propriedades antibióticas dos extratos de macroalgas das classes Chlorophyta, Phaeophyta e Rhodophyta, coletadas no litoral cearense, bem como avaliar a citotoxicidade destes extratos, frente a cepas bacterianas (Vibrio sp.) isoladas e provenientes de ambientes de cultivo de camarões marinhos (Litopenaeus vannamei). Os resultados comprovaram que houve atividade antibacteriana dos extratos etanólicos, acetônicos, hexânicos e metanólicos contra cepas bacterianas de Vibrio, além de apontar que os extratos de todas as espécies apresentaram baixa citotoxicidade.

Antibacterial and cytotoxicity activity in macroalgae extracts: perspectives for the use against pathogenic bacteria from shrimp farms (Litopenaeus vannamei) / Atividade antibacteriana e citotóxica em extratos de macroalgas: perspectivas de uso contra bactérias patogênicas de ambiente de cultivo de camarões (Litopenaeus vannamei)

Some infections caused by pathogenic microorganisms might shows high prevalence in farmed shrimp environments, compromising production and causing economic losses. Therefore, the search for compounds with antibiotic activity has become intensive, following the record of new antimicrobial-resistant bacteria. The study of those bioactive compounds in marine macroalgae has produced satisfactory results, such as the discovery of antibacterial activity against multiresistant strains. Accordingly, this study aims to research antibiotic activity in macroalgae extracts of Chlorophyta, Phaeophyta and Rhodophyta found in the coast of Ceará and also to evaluate the cytotoxicity activity against bacterial strains (Vibrio sp.) from shrimp farms (Litopenaeus vannamei). The extracts cytotoxicity was also evaluated. The results prove that there was antibacterial activity in ethanolic, acetonic, hexanic and methanolic extracts against bacterial strains of Vibrio with multiple resistance profile as well as displaying low cytotoxicity.(AU)

Algumas infecções causadas por micro-organismos patogênicos podem apresentar alta prevalência em ambientes de cultivo de camarões marinhos, comprometendo a produção e causando prejuízos econômicos aos aquicultores. Assim, tem-se tornado intensa a busca por compostos com atividade antibiótica pelo registro cada vez mais frequente de bactérias com perfil de resistência a antimicrobianos. A presença desses compostos com bioatividade em macroalgas marinhas tem revelado resultados satisfatórios, como a descoberta de ação antibacteriana contra cepas multirresistentes. Desta forma, decidiu-se pesquisar as propriedades antibióticas dos extratos de macroalgas das classes Chlorophyta, Phaeophyta e Rhodophyta, coletadas no litoral cearense, bem como avaliar a citotoxicidade destes extratos, frente a cepas bacterianas (Vibrio sp.) isoladas e provenientes de ambientes de cultivo de camarões marinhos (Litopenaeus vannamei). Os resultados comprovaram que houve atividade antibacteriana dos extratos etanólicos, acetônicos, hexânicos e metanólicos contra cepas bacterianas de Vibrio, além de apontar que os extratos de todas as espécies apresentaram baixa citotoxicidade.(AU)

Multidrug-resistant Vibrio associated with an estuary affected by shrimp farming in Northeastern Brazil.

Bacteria of genus Vibrio with multidrug resistance in shrimp farm environment were recurrent. Thus, the aim of this study was to evaluate the antimicrobial resistance profile of 70 strains of Vibrio isolated from water and sediment of Acaraú estuary, Ceará, Brazil. In order to achieve this goal, disk diffusion technique was used with the following antimicrobial agents: ampicillin (Amp), aztreonam (Atm), cephalothin (Cef), cefotaxime (Ctx), ceftriaxone (Cro), ciprofloxacin (Cip), chloramphenicol (Clo), florfenicol (Flo), nitrofurantoin (Nit), gentamicin (Gen), oxytetracycline (Otc), tetracycline (Tet), streptomycin (Str), nalidixic acid (Nal), and sulfazotrim (Sut). All Vibrio strains were resistant to at least one antimicrobial agent, being verified as 17 multidrug-resistant profiles. All strains resistant to Otc and Tet were characterized to exhibit plasmidial resistance. Therefore, Vibrio strains from Acaraú estuary pose a risk to public health and aquatic culture.

Antimicrobial Susceptibility of Escherichia coli Isolated from Fresh-Marketed Nile Tilapia (Oreochromis niloticus).

The contamination of seafood by bacteria of fecal origin, especially Escherichia coli, is a widely documented sanitary problem. The objective of the present study was to isolate E. coli strains from the gills, muscle, and body surface of farmed Nile tilapias (Oreochromis niloticus) fresh-marketed in supermarkets in Fortaleza (Ceará, Brazil), to determine their susceptibility to antibiotics of different families (amikacin, gentamicin, imipenem, cephalothin, cefotaxime, ciprofloxacin, aztreonam, ampicillin, nalidixic acid, tetracycline, and sulfametoxazol-trimetoprim), and to determine the nature of resistance by plasmid curing. Forty-four strains (body surface = 25, gills = 15, muscle = 4) were isolated, all of which were susceptible to amikacin, aztreonam, cefotaxime, ciprofloxacin, gentamicin, and imipenem. Gill and body surface samples yielded 11 isolates resistant to ampicillin, tetracycline, and sulfametoxazol-trimetoprim, 4 of which of plasmidial nature. The multiple antibiotic resistance index was higher for strains isolated from body surface than from gills. The overall high antibiotic susceptibility of E. coli strains isolated from fresh-marketed tilapia was satisfactory, although the occasional finding of plasmidial resistance points to the need for close microbiological surveillance of the farming, handling, and marketing conditions of aquaculture products.

Influence of environmental color on zootechnical performance and feeding behavior during masculinization of Nile tilapia / Influência das cores ambientais sobre o desempenho zootécnico e comportamento alimentar durante a masculinização da Tilápia do Nilo

The rise of tilapia in Brazil and the world increasingly needs the best growing conditions. Despite the Nile tilapia has diurnal, your vision is considered a strong sensory stimulus, and as the perception of the color contrast of medium, production losses may be evidence due to stress caused too. Thus, an experiment was conducted at Biotechnology Aquaculture Applied Center (CEBIAQUA), The Fishing Engineering Department, Federal University of Cearل, with the aim of evaluating the influence of the background color translucent on zootechnical performance and feeding behavior of Nile tilapia during masculinization. We used 200 post-larvae (average weight = 0:02 ± 0.01g; mean initial length = 1.10 ± 0.01 cm) of Nile tilapia, packed in 40 L aquarium, covered with cellophane, for 28 days. Fish were distributed in a completely randomized in two treatments (blue and green) and five replications. Environmental variables analyzed were dissolved oxygen, temperature, pH and photoperiod and productive performance was evaluated weight, total length, condition factor and lot uniformity. Behavioral observations occurred twice daily, immediately before the first feeding and 2 minutes after each feeding treatment. We found no significant difference in water parameters in two treatments. We found no significant difference in water parameters in two treatments. The weight, length and condition factor did not differ between treatments. There was a higher survival rate, more lot uniformity, and an obvious grouped behavior during feeding in aquaria translucent greens than blues. So for the masculinization of Nile tilapia, it is recommended to translucent green, because the results were most satisfactory.

A ascensão da tilapicultura no Brasil e no mundo necessita cada vez mais de melhores condições ambientais de cultivo. Apesar da tilápia do Nilo possuir hábito diurno, sua visão é considerada um forte estímulo sensorial, e conforme a percepção do contraste das cores do meio, perdas produtivas podem ser evidencias devido ao estresse demasiadamente causado. Assim, foi conduzido um experimento no Centro de Biotecnologia Aplicada a Aquicultura (CEBIAQUA), da Universidade Federal do Ceará com o objetivo de avaliar a influência da cor doambiente translúcido sobre o desempenho produtivo e comportamento alimentar da tilápia do Nilo durante a masculinização. Foram utilizadas 200 pós-larvas (pesomédio inicial = 0.02 ± 0.01 g; comprimento médio inicial = 1.10 ± 0.01 cm) de tilápia do Nilo, acondicionadas em aquários de 40 L, recobertos com papel celofane, por 28 dias. Os peixes foram distribuídos em delineamento inteiramentecasualizado em dois tratamentos (azul e verde) e cinco repetições. As variáveis ambientais analisadas foram oxigênio dissolvido, temperatura, pH e fotoperíodo e para o desempenho produtivo foi avaliado o peso, comprimento total, sobrevivência, fator de condição e uniformidade do lote. As observações ocorreram duas vezes ao dia, de forma imediata antes de alimentar e durante dois minutos após última refeição, totalizando em média 56 observações focais e visuais. Não houve diferença significativa nos parâmetros da água nos dois tratamentos, e estes se encontravam dentro do recomendável. O peso, comprimento e fator de condição não diferiram entre os tratamentos. Houve maior índice de sobrevivência e lotes mais uniformes nos aquários translúcidos verdes do que nos azuis. Portanto, para a masculinização da tilápia do Nilo, recomenda-se a cor verde translúcida, pois os resultados foram mais satisfatórios.

Influence of environmental color on zootechnical performance and feeding behavior during masculinization of Nile tilapia / Influência das cores ambientais sobre o desempenho zootécnico e comportamento alimentar durante a masculinização da Tilápia do Nilo

The rise of tilapia in Brazil and the world increasingly needs the best growing conditions. Despite the Nile tilapia has diurnal, your vision is considered a strong sensory stimulus, and as the perception of the color contrast of medium, production losses may be evidence due to stress caused too. Thus, an experiment was conducted at Biotechnology Aquaculture Applied Center (CEBIAQUA), The Fishing Engineering Department, Federal University of Cearل, with the aim of evaluating the influence of the background color translucent on zootechnical performance and feeding behavior of Nile tilapia during masculinization. We used 200 post-larvae (average weight = 0:02 ± 0.01g; mean initial length = 1.10 ± 0.01 cm) of Nile tilapia, packed in 40 L aquarium, covered with cellophane, for 28 days. Fish were distributed in a completely randomized in two treatments (blue and green) and five replications. Environmental variables analyzed were dissolved oxygen, temperature, pH and photoperiod and productive performance was evaluated weight, total length, condition factor and lot uniformity. Behavioral observations occurred twice daily, immediately before the first feeding and 2 minutes after each feeding treatment. We found no significant difference in water parameters in two treatments. We found no significant difference in water parameters in two treatments. The weight, length and condition factor did not differ between treatments. There was a higher survival rate, more lot uniformity, and an obvious grouped behavior during feeding in aquaria translucent greens than blues. So for the masculinization of Nile tilapia, it is recommended to translucent green, because the results were most satisfactory.(AU)

A ascensão da tilapicultura no Brasil e no mundo necessita cada vez mais de melhores condições ambientais de cultivo. Apesar da tilápia do Nilo possuir hábito diurno, sua visão é considerada um forte estímulo sensorial, e conforme a percepção do contraste das cores do meio, perdas produtivas podem ser evidencias devido ao estresse demasiadamente causado. Assim, foi conduzido um experimento no Centro de Biotecnologia Aplicada a Aquicultura (CEBIAQUA), da Universidade Federal do Ceará com o objetivo de avaliar a influência da cor doambiente translúcido sobre o desempenho produtivo e comportamento alimentar da tilápia do Nilo durante a masculinização. Foram utilizadas 200 pós-larvas (pesomédio inicial = 0.02 ± 0.01 g; comprimento médio inicial = 1.10 ± 0.01 cm) de tilápia do Nilo, acondicionadas em aquários de 40 L, recobertos com papel celofane, por 28 dias. Os peixes foram distribuídos em delineamento inteiramentecasualizado em dois tratamentos (azul e verde) e cinco repetições. As variáveis ambientais analisadas foram oxigênio dissolvido, temperatura, pH e fotoperíodo e para o desempenho produtivo foi avaliado o peso, comprimento total, sobrevivência, fator de condição e uniformidade do lote. As observações ocorreram duas vezes ao dia, de forma imediata antes de alimentar e durante dois minutos após última refeição, totalizando em média 56 observações focais e visuais. Não houve diferença significativa nos parâmetros da água nos dois tratamentos, e estes se encontravam dentro do recomendável. O peso, comprimento e fator de condição não diferiram entre os tratamentos. Houve maior índice de sobrevivência e lotes mais uniformes nos aquários translúcidos verdes do que nos azuis. Portanto, para a masculinização da tilápia do Nilo, recomenda-se a cor verde translúcida, pois os resultados foram mais satisfatórios.(AU)

Vibrio na água e sedimento de viveiros de quatro fazendas de carcinicultura no estado do Ceará, Brasil / Vibrio in pond water and sediment from four shrimp farms in Ceará state, Brazil

Foram realizadas 16 coletas, oito no período chuvoso e oito no período de estio, em quatro fazendas de carcinicultura do Estado do Ceará, nos estuários dos rios Jaguaribe (fazendas A e B) e Acaraú (fazendas C e D), totalizando 32 amostras. O objetivo da pesquisa foi quantificar e identificar Vibrio spp. nas amostras de água e sedimento. Os valores máximos da Contagem Padrão em Placas (CPP) de Vibrio spp. encontrados para as amostras de água, no período chuvoso, foram de 5.103 UFC/mL est. e, para o sedimento, de 7,5.103 UFC/g est. No período de estio, a CPP máxima para água foi de 4,35.102 UFC/mL est. e de 3,55.103 UFC/g est. para as amostras de sedimento. Foram obtidos 36 isolados de Vibrio: Vibrio spp. (17), V. vulnificus B1(3); V. calviensis (2), V. cholerae (2), V. litoralis (2), V. metschnikovii (2), V. agarivorans (1), V. alginolyticus (1), V. campbellii (1), V. coralliilyticus (1), V. diazotrophicus (1), V. logei (1), V. mediterranei (1), V. vulnificus B2 (1). O conhecimento da presença de espécies, nunca anteriormente isoladas em viveiros de fazendas de carcinicultura, tais como o V. coralliilyticus, V. agarivorans, V. litoralis e V. calviensis são importantes para o monitoramento microbiológico contínuo desses ambientes.

Sixteen collections were taken, eight during rainy season and eight on the draught season in four shrimp farms in Ceará State, from Jaguaribe River (farms A and B) and Acaraú River (farms C and D) estuaries, totalizing 32 samples. The goal of the research was to identify and quantify Vibrio spp. in water and in sediment samples. The maximum Standard Plate Count (SPC) values of Vibrio spp. calculated for the rainy season, from water, was 5.103 CFU/mL est., and for the sediment 7.5.103 CFU/g est.. For the draught season, maximum counting for water was 4.35.102 CFU/mL est. and for sediment 3.55.103 CFU/g est.. Thirty six strains of Vibrio were isolated: Vibrio spp. (17), V. vulnificus B1(3), V. calviensis (2), V. cholerae (2), V. litoralis (2), V. metschnikovii (2), V. agarivorans (1), V. alginolyticus (1), V. campbellii (1), V. coralliilyticus (1), V. diazotrophicus (1), V. logei (1), V. mediterranei (1), V. vulnificus B2 (1). The isolation of species never previously isolated of shrimp farms, such as V. coralliilyticus, V. agarivorans, V. litoralis and V. calviensis are important for the continuous microbiological monitoring these environments.

Vibrio na água e sedimento de viveiros de quatro fazendas de carcinicultura no estado do Ceará, Brasil / Vibrio in pond water and sediment from four shrimp farms in Ceará state, Brazil

Foram realizadas 16 coletas, oito no período chuvoso e oito no período de estio, em quatro fazendas de carcinicultura do Estado do Ceará, nos estuários dos rios Jaguaribe (fazendas A e B) e Acaraú (fazendas C e D), totalizando 32 amostras. O objetivo da pesquisa foi quantificar e identificar Vibrio spp. nas amostras de água e sedimento. Os valores máximos da Contagem Padrão em Placas (CPP) de Vibrio spp. encontrados para as amostras de água, no período chuvoso, foram de 5.103 UFC/mL est. e, para o sedimento, de 7,5.103 UFC/g est. No período de estio, a CPP máxima para água foi de 4,35.102 UFC/mL est. e de 3,55.103 UFC/g est. para as amostras de sedimento. Foram obtidos 36 isolados de Vibrio: Vibrio spp. (17), V. vulnificus B1(3); V. calviensis (2), V. cholerae (2), V. litoralis (2), V. metschnikovii (2), V. agarivorans (1), V. alginolyticus (1), V. campbellii (1), V. coralliilyticus (1), V. diazotrophicus (1), V. logei (1), V. mediterranei (1), V. vulnificus B2 (1). O conhecimento da presença de espécies, nunca anteriormente isoladas em viveiros de fazendas de carcinicultura, tais como o V. coralliilyticus, V. agarivorans, V. litoralis e V. calviensis são importantes para o monitoramento microbiológico contínuo desses ambientes. (AU)

Sixteen collections were taken, eight during rainy season and eight on the draught season in four shrimp farms in Ceará State, from Jaguaribe River (farms A and B) and Acaraú River (farms C and D) estuaries, totalizing 32 samples. The goal of the research was to identify and quantify Vibrio spp. in water and in sediment samples. The maximum Standard Plate Count (SPC) values of Vibrio spp. calculated for the rainy season, from water, was 5.103 CFU/mL est., and for the sediment 7.5.103 CFU/g est.. For the draught season, maximum counting for water was 4.35.102 CFU/mL est. and for sediment 3.55.103 CFU/g est.. Thirty six strains of Vibrio were isolated: Vibrio spp. (17), V. vulnificus B1(3), V. calviensis (2), V. cholerae (2), V. litoralis (2), V. metschnikovii (2), V. agarivorans (1), V. alginolyticus (1), V. campbellii (1), V. coralliilyticus (1), V. diazotrophicus (1), V. logei (1), V. mediterranei (1), V. vulnificus B2 (1). The isolation of species never previously isolated of shrimp farms, such as V. coralliilyticus, V. agarivorans, V. litoralis and V. calviensis are important for the continuous microbiological monitoring these environments. (AU)