Aislamientos de bacterias post tratamiento con gasoil - agua y centrifugación de fondo de tanques petroleros / Oil tank bottoms, bacteria isolate after diesel treatment - water and centrifugation

Resumen En la industria petrolera se almacenan grandes cantidades de hidrocarburos en tanques en las diferentes etapas de extracción y procesamiento del crudo hasta su refinamiento. Esto genera un residuo denominado fondo de tanque, es una emulsión estable de sedimentos agua e hidrocarburos. Este trabajo tuvo como objeto estudiar las bacterias que están presentes en el sedimento después de la primera etapa de tratamiento con gasoil, agua, temperatura y posterior centrifugación. El sedimento, considerado por la legislación como residuo peligroso se le realizo un estudio bacteriológico, que consistió en recuento, aislamiento e identifican de bacterias. Se obtuvieron 34 cepas de las cuales 86.1% pertenecieron al género Bacillus. Las mismas presentaron capacidad para desarrollar en alguno de los siguientes hidrocarburos o mezclas de hidrocarburos gasoil, kerosene, hexadecano y ciclohexano.

Abstract In the oil industry, large quantities of hydrocarbons are stored in tanks, in the different stages of extraction and processing of crude oil until it is refined. This generates a residue called a tank bottom, which is a stable emulsion of water and hydrocarbon sediments. The objective of this work was to study the bacteria that are present in the sediment after treating the bottom of the tank with diesel oil, water, and subsequent centrifugation. A bottom and tank were treated with diesel, water and centrifugation, the sediment was obtained, which was counted, isolated and bacteria were identified. 34 strains were obtained, of which 86.1% belonged to the genus Bacillus. The same capacity capabilities to develop diesel, kerosene, hexadecane, and cyclohexane hydrocarbons.

Detection of Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli in Brazilian mastitic milk goats by multiplex-PCR / Detecção de Staphylococcus aureus, Streptococcus agalactiae e Escherichia coli em leite caprino mastítico no Brasil, por multiplex-PCR

This study evalueted the prevalence of Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli in milk samples from 257 goats (513 half-udders) and ten bulk tanks, from ten dairy goat farms of São Paulo State, Brazil, by multiplex-PCR. The samples were screened by microbiological culture (gold-standard), and tested by different multiplex-PCR protocols for the detection of each bacterium. A total of 178 half-udders resulted positive by microbiological culture, with coagulase-negative staphylococci (70%), S. aureus (13.5%), S. intermedius (7.9%), and Enterobacteriaceae (4%) the prevalent pathogens. In other way, multiplex-PCR detected 173 pathogens in 151/523 (28.9%; CI95% 25.2-32.9%) milk samples 144/513 (28.1%) half-udders and 7/10 (70%) bulk tanks, with E. coli (86/162, 51.9%) and S. aureus (50/162, 30.9%) the prevalent ones in half-udders, and S. aureus (6/10, 60%) and E. coli (4/5, 36.4%) in bulk tanks. Multiplex-PCR showed a high performance for the detection of three bacteria at a time in mastitic goat milk direct from half-udders or bulk tanks. Thus, this multiplex-PCR protocol proved to be an adequate tool for the identification of the most common mastitis pathogens, independent of their phenotypic characteristics in the diagnosis of clinical mastitis in goats, allowing a continuous and better vigilance and monitoring the herd, being included in quality programs.(AU)

Este estudo avaliou por multiplex-PCR a prevalência de Staphylococcus aureus, Streptococcus agalactiae e Escherichia coli em amostras de leite de 257 caprinos (513 tetos) e dez tanques de expansão, em dez fazendas leiteiras do estado de São Paulo, Brasil. As amostras foram triadas por cultura microbiológica (padrão-uro) e testadas por diferentes protocolos multiplex-PCR para a detecção de cada bactéria. Um total de 178 amostras de leite foram positivos na cultura microbiológica, com estafilococos coagulase-negativos (70%), S. aureus (13,5%), S. intermedius (7,9%) e Enterobacteriaceae (4%) como patógenos prevalentes. Por outro lado, a PCR multiplex detectou 173 patógenos em 151/523 (28,9%, IC95% 25,2-32,9%) amostras de leite, 144/513 (28,1%) amostras de tetos e 7/10 (70%) em tanques de expansão, E. coli (86/162, 51,9%) e S. aureus (50/162, 30,9%) foram identificados nas amostras de tetos e S. aureus (6/10, 60%) e E. coli (4/5, 36,4%) em tanques expansão. Multiplex-PCR mostrou um alto desempenho para a detecção das três bactérias em leite de cabra com mastite ou em tanques de expansão. Dessa forma, este protocolo multiplex-PCR provou ser uma ferramenta adequada para a identificação dos patógenos mais comuns da mastite, independentemente de suas características fenotípicas no diagnóstico de mastite clínica em caprinos, permitindo uma vigilância contínua e melhor acompanhamento do rebanho, sendo incluído em programas de qualidade.(AU)

Aislamiento e identificación de levaduras degradadoras de hidrocarburos aromáticos, presentes en tanques de gasolina de vehículos urbanos / Isolation and identification of aromatic hydrocarbon degrading yeasts present in gasoline tanks of urbans vehicles

RESUMEN Se obtuvieron aislamientos de levaduras a partir de muéstreos en tanques de combustible de vehículos urbanos, con el objeto de evaluar su potencial actividad de degradación de hidrocarburos aromáticos derivados del petróleo. Se realizaron ensayos de crecimiento en medio mínimo mineral sólido utilizando distintos hidrocarburos (benceno, tolueno, naftaleno, fenantreno, y pireno). Los aislamientos que presentaron crecimiento notorio en alguno de los hidrocarburos aromáticos policíclicos fueron identificados mediante secuenciación Sanger de los marcadores moleculares ITS1 e ITS2 del ARNr. Se obtuvieron 16 aislados de levaduras, de las cuales tres presentaron crecimiento conspicuo con hidrocarburos aromáticos como única fuente de carbono. Las cepas identificadas pertenecen al género Rhodotorula y corresponden a las especies Rhodotorula calyptogenae (99,8% de identidad) y Rhodotorula dairenensis (99,8% de identidad). Dichas cepas presentaron crecimiento en benceno, tolueno, naftaleno, fenantreno. En este estudio se reporta por primera vez la presencia de levaduras del género Rhodotorula que habitan los ductos y tanques de gasolina de vehículos urbanos, así como su capacidad para utilizar distintos hidrocarburos aromáticos que son contaminantes para el medio ambiente. Estos resultados sugieren que dichas levaduras constituyen potenciales candidatos para la degradación de éstos compuestos, como parte de estrategias de biorremediación.

ABSTRACT Yeast isolates were obtained from fuel tanks of vehicles in order to assess their potential use in the degradation of aromatic hydrocarbons. Growth assays were performed in minimum mineral medium using different aromatic hydrocarbons (benzene, toluene, naphthalene, phenanthrene, and pyrene) as the sole carbon source. Isolates that showed growth in any of the tested polycyclic aromatic hydrocarbons were identified by Sanger sequencing of the ITS1 and ITS2 rDNA molecular markers. A total of 16 yeasts strains were isolated, and three showed remarkable growth in media with aromatic hydrocarbons as the sole carbon source. These strains belong to the genus Rhodotorula, and correspond to the species Rhodotorula calyp-togenae (99,8% identity) and Rhodotorula dairenensis (99,8% identity). These strains grew in benzene, toluene, naphthalene, phenanthrene and pyrene. This study demonstrates for the first time that yeasts of the genus Rhodotorula inhabit pipelines and fuel tanks of vehicles and that remove aromatic hydrocarbons that are environmental pollutants. Our results suggest that these yeasts are potential candidates for aromatic hydrocarbon degradation as part of bioremediation strategies.

Pseudomonas spp: contamination sources in bulk tanks of dairy farms / Pseudomonas spp: fontes de contaminação em tanques de expansão em fazendas leiteiras

This study focused on isolating Pseudomonas spp. during milking process in ten dairy farms with manual and mechanical milking systems during dry and rainy seasons, and evaluating DNA homology and patterns of distribution between isolates, in order to identify main sources of milk contamination by Pseudomonas spp. A total of 167 isolates of Pseudomonas spp. were obtained from water, milkers' hands, cows' teats, teat cups, cooling tanks and raw milk. Bacteria of Pseudomonas spp. genus were isolated from 85 and 82 sampling points in dairy farms with manual and mechanical milking system, respectively. A significant difference (p=0.02) on Pseudomonas spp. isolation was observed among samples of surface of cows' teats before and after pre-dipping, but no significant difference (p>0.05) was observed among milking systems or seasons. The possibility of the same Pseudomonas spp. patterns are distributed in different farms and seasons using Amplified Fragment Length Polymorphism (AFLP) technique was demonstrated. Milkers' hands, surface of cows' teats, teat cups and cooling tanks were associated with raw milk contamination with Pseudomonas spp. on farms with manual and mechanical milking system, showing that regardless of the type of milking system and season, proper hygiene procedures of equipment, utensils and workers' hands are essential to avoid contamination of the milk and, therefore, improve milk quality.(AU)

Este estudo se propôs a isolar Pseudomonas spp. durante o processo de ordenha em dez fazendas com sistemas manuais e mecanizados, durante as estações seca e chuvosa, além de avaliar a homologia do DNA e seus padrões de distribuição entre os isolados, a fim de se determinar as principais fontes de contaminação do leite. Cento e sessenta e sete isolados de Pseudomonas spp. foram obtidos a partir de amostras de água, mãos de ordenhadores, tetos, teteiras, tanques de resfriamento e leite cru armazenado, sendo 85 e 82 pontos de amostragem em fazendas com sistemas de ordenha manual e mecânico, respectivamente. Diferença estatisticamente significativa foi encontrada entre os isolados observados entre a superfície dos tetos antes e após o pré-dipping (p=0,02), mas nenhuma diferença foi encontrada entre sistemas de ordenha ou estações (p>0,05). A possibilidade do mesmo padrão de Pseudomonas spp. estar distribuído em diferentes fazendas ou estações foi avaliada pela técnica de Polimorfismo do Tamanho de Fragmento Amplificado (AFLP). As mãos de ordenhadores, superfície dos tetos das vacas, teteiras e tanques de resfriamento foram associados com a contaminação do leite cru, demonstrando que independente do tipo de ordenha e estação, a higiene adequada de equipamentos, utensílios e mãos dos ordenhadores é essencial para evitar contaminação do leite, e consequentemente aumentar sua qualidade.(AU)

Presencia de Legionella spp. en depósitos domiciliarios de agua potable en Resistencia, Chaco, Argentina. Informe preliminar / Presence of Legionella spp. in household drinking water reservoirs in Resistencia, Chaco, Argentina. Preliminary report

Legionella spp. es una bacteria ambiental capaz de sobrevivir en un amplio intervalo de condiciones fisicoquímicas y puede colonizar los sistemas de distribución y almacenamiento del agua potable. Legionella pneumophila es el principal patógeno trasmitido por el agua y produce el 90% de los casos de legionelosis. El objetivo del presente trabajo fue detectar por cultivo la presencia de Legionella spp. en depósitos domiciliarios de agua potable de la ciudad de Resistencia, Chaco. La detección de Legionella en las muestras de agua se realizó por cultivo según lo establecido en la norma ISO 11731:1998. Se analizaron 32 muestras de agua y de 12 (37,5%) de ellas se recuperaron cepas de Legionella spp. La vigilancia de este microorganismo en el agua de consumo humano representa el primer paso para controlar su diseminación hacia huéspedes susceptibles.

Legionella spp. is an environmental bacterium that can survive in a wide range of physicochemical conditions and may colonize distribution systems of drinking water and storage tanks. Legionella pneumophila is the major waterborne pathogen that can cause 90% of Legionnaires' disease cases. The aim of this study was to detect the presence of Legionella spp. in household drinking water tanks in the city of Resistencia, Chaco. The detection of Legionella in water samples was performed by culture methods as set out in ISO 11731:1998. Thirty two water samples were analyzed and Legionella spp. was recovered in 12 (37.5%) of them. The monitoring of this microorganism in drinking water is the first step towards addressing the control of its spread to susceptible hosts.

Avaliação da implantação de fossas sépticas na melhoria na qualidade de águas superficiais em comunidades rurais / Evaluation of the implementation of septic tanks improving the quality of surface waters in rural communities

Na maioria dos municípios brasileiros, as comunidades rurais são núcleos populacionais agrupados em torno de córregos que fornecem a água e recebem seus efluentes. Buscou-se nesta pesquisa avaliar as condições dos corpos d'água na bacia hidrográfica do córrego Pau Grande, Ouro Branco, Minas Gerais, antes e depois da instalação de 20 fossas sépticas na comunidade de Castiliano, construídas em 2006. O monitoramento da bacia foi realizado entre 2005 e 2009, em 6 pontos amostrais, onde foram medidos vazão, oxigênio dissolvido, demanda bioquímica de oxigênio, fósforo total, coliformes fecais totais, turbidez e pH. Os pontos a jusante das fossas apresentaram um aumento de mais de 100% nos valores de oxigênio dissolvido e redução em mais de 800% na quantidade de coliformes fecais. Investimentos relativamente baixos, como a construção das fossas, podem trazer melhorias à qualidade dos recursos hídricos em áreas rurais.

In most Brazilian cities, rural communities are clustered in the surroundings of streams that supply water and receive their effluents. The aim of this study was to evaluate the conditions of the quality water in Pau Grande catchment, located in Ouro Branco, Minas Gerais, Brazil, before and after the construction of 20 septic tanks in the community of Castiliano, build in 2006. The monitoring of the basin was conducted between February 2005 and November 2009, using 6 control points. Several water parameters were evaluated: river flow, dissolved oxygen, biochemical oxygen demand, total phosphorus, total coliform, turbidity and pH. Monitoried points downstream of the construction sites showed an increase of more than 100% in dissolved oxygen and a decrease of fecal coliform bacteria (over 800%). Relatively small investments can bring major improvements to the quality of water resources in rural communities areas.

The Effect of Different Stocking Densities on Growth, Production and Survival rate of Pangas (Pangasius hypophthalmus) Fish in Cemented Tanks at Fish Hatchery Chilya Thatta, Sindh-Pakistan.

The effect of stocking density on growth performance, production and survival of Pangas, Pangasius hypophthalmus were evaluated in cemented tanks. Fry of Pangas (1.52 ± 0.03 cm in length and 1.08 ± 0.02 g in weight) respectively were stocked into cemented tanks measuring 15 x 6 x 3 ft. Three treatments with two replicates were used: T1- 100; T2-150 and T3-200 fry/ tank. Pangas fry were fed twice daily with formulated feed 35 % protein at 10%, 5%, and 3% body weight for the first, second, and third month, respectively. After 90 days, the Highest growth performances (determined in terms of average weight) were recorded in T1 (27.5±2.5 g) and T2 (22.4±2.8 g) while T3 (18.2±3.5g) recorded the smallest growth. Production differed significantly among treatments (P<0.05). Feed conversion ratio (FCR) of 1.0, 1.02 and 1.05 in T1, T2 and T3, respectively were not significantly different (P>0.05). Survival was significantly different among treatments (P<0.01). Highest survival (100%) was attained in T1 with lower stocking density, followed by T2 (96%) and T3 (90%). Survival was greatly influenced by the stocking densities in all treatments. The water quality parameters and their monthly fluctuations recorded throughout the study period were found within the suitable ranges for the fish culture such as temperature 27.0 to 28.7 °C, dissolved oxygen 5.7 to 6.2 mg/lit, pH 7.2 to 7.5, Ammonia from 0.45 to 0.51mg/L, Hardness 105 to 110 ppm and Nitrite 0.152 to 0.161 mg/.

Qualidade da água utilizada na higienização dos tanques de granelização de leite cru do município de Rio Pomba, MG / Quality of water used in cleaning tanks of raw milk from Rio Pomba, MG

O objetivo deste trabalho foi avaliar a qualidade da água utilizada na higienização dos tanques de resfriamento de leite cru do Município de Rio Pomba, MG. Amostras de água provenientes de 15 tanques de expansão individuais e comunitários foram coletadas as septicamente no período de maio a agosto de 2010 e transportadas para os laboratórios de análise físico-química e microbiologia do IF Sudeste MG, campus Rio Pomba. Foram realizadas análises microbiológicas de micro-organismos mesófilos aeróbios, coliformes termotolerantes e Escherichia coli e análises físico-químicas de pH, dureza, cloro residual, alcalinidade, cloretos, cor e turbidez. Verificou-se que a contagem de micro-organismos mesófilos aeróbios variou entre < 1,0 x 101 UFC/mL estimado e 1,2 x 103 UFC/mL, que 53,3% e 33,3%das amostras apresentaram, respectivamente, coliformes termo tolerantes e E. coli. Constatou-se também que 26,6% das amostras encontravam-se com valores de pH abaixo do recomendado. Além disso, verificou-se que todas as amostras apresentaram valores abaixo de 50 mg/L de CaC03 em relação à dureza e ausência de cloro residual. Em relação à alcalinidade, constatou-se variação entre 8 mg/L e 44 mg/L de CaC03. Na análise de cor, observou-se que todas as amostras de água apresentaram 5 unidades Hansen e em relação à turbidez, constatou-se que todas as amostras apresentaram-se dentro do limite estabelecido pela legislação. Portanto, torna-se imprescindível o tratamento da água a fim de obter leite de qualidade, bem como a implantação de programas que visem o treinamento dos produtores para aplicação de boas práticas higiênicas na propriedade rural.

The aim of this study was to evaluate the quality of water used in cleaning of cooling tanks of rawmilk from Rio Pomba, Minas Gerais, Brazil. Water samples from 15individual and community expansion tanks were aseptically collected during the period from May to August 2010 and transported to the physical chemistry and microbiology laboratories of IF Sudeste MG. It was developed microbiologicalanalysis of mesophilic aerobic microorganisms, coliforms and Escherichia coli and physical chemical analyses of pH, hardness, residual chlorine, alkalinity, chloride, color and turbidity. It was verifiedthat count of mesophilic aerobic micro-organisms ranged from <1.0 x 10' CFU/mL estimated to 1.2 x 103CFU/mL, and that 53.3% and 33.3% of samples presented fecal coliform and E. coli, respectively. It wasalso found that 26.6% of samples presented pH values below recommendation. Besides, it was verifiedthat all samples had values below 50 mg/L CaCO3 in relation to hardness and absence of residual chlorine. In relation to alkalinity, it was detected variation between 8 mg/L to 44 mg/L CaCO3. In color analysis, it was found that all samples of water showed five Hansen units for turbidity, been within the limits of Brazil legislation. Therefore, it is essential to treat water in order to obtain milk of better quality, as well as implementation of programs that provide training to producers to implement good hygienic practices at the farm.

Groundwater contamination in Agbowo community, Ibadan Nigeria: Impact of septic tanks distances to wells

In Nigeria, inadequate supply of pipe borne water is a major concern; hence many homes have wells as a source of water for household uses. The groundwater of forty wells in Agbowo community was assessed for Total Aerobic Bacteria Counts (TABC) and Total Coliform Counts (TCC). The location and distances of wells from septic tanks were determined using the Global Positioning System (GPS) device and a tape rule respectively. All the wells sampled had high TABC (4.76±1.41 log CFU/mL) and TCC (2.29±0.67 log CFU/mL) counts which exceeded the international standard of 0 per 100 mL of potable water. There were no significant differences in the bacterial counts between covered and uncovered wells (p>0.05). The mean distance (8.93±3.61m) of wells from the septic tanks was below the limit (15.24 m or 50 ft) set by United State Environmental Protection Agency (USEPA). TABC increased with a decrease in distance between the wells and septic tanks though not significant (p<0.05). A very weak positive correlation (r2 =0.021) ensued between the distance from septic tank and CC, while a weak negative correlation (r2 = ‒0.261) was obtained between the TCC and TABC. This study accentuates the need to set standards for the siting of wells from septic tanks while considering all possible sources of well contamination as well as treatment of ground water before use.

Investigation of the outbreak of typhoid in a village of Thar Desert Rajasthan, India.

Background & objectives: Outbreaks of typhoid have been reported from Maharashtra, Bangalore, West Bengal and Pondicherry in India but rarely from Rajasthan. We investigated an outbreak of typhoid in a village of Thar Desert of Rajasthan. Methods: A retrospective cohort study was carried out during May-July 2007 in Varkana village, Pali district, Rajasthan, to identify the risk factor for disease. The information on outbreak was collected and then described in time, place and person characteristics to arrive at aetiological hypotheses. Results: There were 219 cases of typhoid in village. Attack rate was 104 cases per 1000 population. Maximum attack rate of 276 cases per 1000 population was noted in persons of 10-14 yr age group. Forty three serum samples were reported positive for Widal agglutination test out of 70 tested. Drinking of water from government overhead tanks was associated with disease significantly (RR= 11.1, 95% CI= 3.7-33). Two of the three water samples from government tanks were found positive for faecal contamination. Interpretation & conclusion: The outbreak of typhoid in a village affected >200 persons of all age groups and both gender. Exposure to the drinking water from government tanks was found significantly associated with the disease. Preventive and control measures undertaken after analytical epidemiological study helped in terminating the outbreak.

Bacterial contamination of automotive fuels in a tropical region: the case of Costa Rica

Microbial contamination of fuel has been the cause of several problems in transportation and storage of these products. Due to the lack of previous studies related to these problems in Costa Rica, bacterial quality was evaluated biannually in automotive fuels stored in the four oil distribution facilities of the Costa Rican Petroleum Refinery (RECOPE). In 12 oil storage tanks, for a total of 96 samples, mesophilic, heterotrophic aerobic/facultative counts (ASTM D6974-04) and identification of bacteria presented in regular gas, premium gas and diesel from the bottom and superior part of the tanks were done; in the samples containing an aqueous phase, sulfate reducing bacteria (SRB) were also quantified by the most probable number technique (MPN), according to the ASTM D4412-84 standard. The higher contamination was shown at the bottom of the tanks (populations up to 10(4) UFC/l), especially if there was accumulated water, in which case populations reached 10(8) UFC/l. The most contaminated fuel was diesel (counts up to 10(4) UFC/l), whereas the less contaminated was premium gas. The less contaminated fuels were from the facilities of La Garita and Barranca, whereas the most contaminated were from Ochomogo. Nevertheless, the quantified populations did not cause significant alteration in quality physicochemical parameters in the samples analyzed. A total of 149 bacterial strains were isolated, 136 (91.3%) Gram positive and 13 (8.7%) Gram negative. The most frequent genera were Staphylococcus (24.0%), Micrococcus (21.9%), Bacillus (18.8%) and Kocuria (11.5%) among Gram positive bacteria and Pseudomonas (7.3%) among Gram negative bacteria. The majority of these genera have been found as fuel contaminants or even as degraders of this kind of products; nevertheless, some species for which their appearance or growth in hydrocarbons have not been described were found with low frequencies. SRB were present in counts up to 10(5) MPN/l in 42.9% of water containing samples (including all from diesel tanks), indicating biocorrosion processes risk in fuel transport and storage systems. From the findings in this study it is recommended to give a frequent maintenance to fuel containers, based on continuous drainage and removal of accumulated water, antimicrobial agent addition and microbial quality monitoring in country’s fuels. Rev. Biol. Trop. 57 (3): 489-504. Epub 2009 September 30.

Se evaluó semestralmente durante dos años la calidad bacteriana de los combustibles almacenados en los cuatro planteles de la Refinadora Costarricense de Petróleo (Costa Rica). Para un total de 96 muestras se realizaron recuentos (norma ASTM D6974-04) e identificación de las bacterias presentes en gasolina regular, gasolina súper y diesel en los niveles superior e inferior de los tanques contenedores; en las muestras con fase acuosa se cuantificaron las bacterias reductoras de sulfato (SRB, norma ASTM D4412-84). La mayor contaminación se observó en el fondo de los tanques, sobretodo si se presentó una capa de agua almacenada. El diesel fue el combustible más contaminado, sin embargo, no se observó alteración importante en los parámetros fisicoquímicos de las muestras evaluadas. Se aislaron 149 cepas, 136 (91.3%) Gram positivas y 13 (8.7%) Gram negativas; los géneros más frecuentes fueron Staphylococcus (24.0%), Micrococcus (21.9%), Bacillus (18.8%), Kocuria (11.5%) y Pseudomonas (7.3%). Con bajas frecuencias se encontraron algunas especies para las que no se ha descrito su aparición o crecimiento en hidrocarburos. Las SRB se presentaron con recuentos de hasta 105 MPN/l en un 42.9% de las muestras con agua residual, principalmente en diesel, lo cual es indicativo de alerta por biocorrosión. A partir de los resultados se recomienda dar un mantenimiento frecuente a los contenedores, la adición de compuestos antimicrobianos y el monitoreo de la calidad microbiana de los combustibles del país.

Water quality and zooplankton in tanks with larvae of Brycon Orbignyanus (Valenciennes, 1949)

Due to the importance of water variables conditions and available food in the development and survival of fish larvae, the current research evaluates the effects of two different food treatments (ration + zooplankton and only zooplankton) and water quality in tanks with Brycon orbignyanus larvae. Total water transparency (45 cm) has been mainly associated with short residence time, continuous water flow and shallowness. Dissolved oxygen ranged between 1.32 and 7.00 mg.L-1 in tanks with ration + zooplankton and between 1.82 and 7.60 mg.L-1 in tanks with only zooplankton treatments. Nutrients were directly affected by the addition of ration in water, with the exception of nitrite. Ten Rotifera species were found represented by high densities, ranging between 8.7 x 10(5) and 1.3 x 10(6) org.m-3, throughout the experimental period (January to March/1996). Cladocera had the lowest density in the four tanks under analysis and ranged between 4.7 x 10(4) and 2.1 x 10(5) org.m-3 for the six species. Diaphanosoma birgei has been classified as the most frequent species. Since ration + zooplankton produced better larvae yield, this treatment is recommended for Brycon orbignyanus larvae.

Devido à importância das condições das variáveis da água e do alimento disponível no desenvolvimento e sobrevivência das larvas de peixes, o objetivo deste estudo foi avaliar o efeito do uso de dois tratamentos alimentares (ração + zooplâncton e somente zooplâncton) e a qualidade da água, em tanques de larvicultura de Brycon orbignyanus. A transparência total da água (45 cm) esteve associada principalmente ao curto tempo de residência, fluxo contínuo e baixa profundidade. As concentrações de oxigênio dissolvido variaram de 1,32 a 7,00 mg.L-1 no tratamento contendo ração + zooplâncton, e de 1,82 a 7,60 mg.L-1 no tratamento contendo somente zooplâncton. Os nutrientes foram diretamente influenciados pela adição de ração no meio com exceção do nitrito. Rotifera apresentou a maior densidade, variando ao longo do período experimental de 8,7 x 10(5) a 1,3 x 10(6) org.m-3 entre os quatro tanques estudados, num total de dez espécies. A menor densidade foi observada para Cladocera, variando de 4,7 x 10(4) a 2,1 x 10(5) org.m-3 num total de seis espécies encontradas, sendo Diaphanosoma birgei a única espécie classificada como muito freqüente. O uso de ração junto com zooplâncton proporcionou melhor rendimento para larvas de B. orbignyanus.

Isolamento de Prototheca spp. de vacas com mastite, de leite de tanques de expansão e do ambiente dos animais / Isolation of Prototheca spp. from cows with mastitis, bulk tanks milk and in the environment of the animals

As infecções da glândula mamária de vacas leiteiras acarretam sérios prejuízos ao produtor pela diminuiçãoda produção leiteira, tratamento e descarte de animais com infecções crônicas. Elevada incidência de mastite no rebanho também altera a composição e qualidade do leite. Agentes de mastite podem causar infecções ou intoxicações no homem. Nos últimos anos tem-se dado ênfase às infecções intramamárias por algas do gênero Prototheca, agentes de infecções persistentes e refratárias à terapêutica tradicional além do caráter zoonótico. Este trabalho teve como objetivo o isolamento e identificação de Prototheca spp. de amostras de leite coletadas em tanques de expansão e latões, de vacas com mastite e do ambiente dos animais. Foram coletadas 81 amostras de leite de tanques e latões de 81 propriedades. Prototheca zopfii foi identificada em amostras de tanques de 10 propriedades. Dessas propriedades foram estudadas oito quanto à ocorrência de Prototheca spp. no ambiente do rebanho e em casos de mastite, além da identificação dos principais agentes bacterianos causadores de mastite. Foram isoladas bactérias, algas e leveduras em 324 amostras de leite provenientes de 197 vacas. Em três propriedades foi isolada P. zopfii de onze amostras de leite obtidas de cinco vacas com mastite clínica e subclínica. Nestas propriedades o agente foi isolado do meio ambiente das vacas, fezes de bezerros e teteiras. Os resultados deste trabalho mostram a importância do isolamento no tanque como indicativo da presença de Prototheca spp. em propriedades leiteiras.

The dairy cattle mammary gland infections cause serious economic losses to dairy farmers due to the decrease in milk production, therapeutic procedures and culling of chronic infected animals. Highincidence of mastitis in herds also alters both the composition and the quality of the milk. Mastitispathogens can also cause infections and poisoning in humans. In the last years, emphasis has beengiven to intramammary infections caused by the genus Prototheca which, besides their zoonotic characteristics, are considered mastitis pathogens of persistent infection and are refractory to traditional therapeutic procedures. The objective of this work was the isolation and identification of Prototheca spp.from milk samples collected from bulk tanks and milk cans, cows presenting mastitis and the dairy herdenvironment. Milk samples were collected from 81 bulk tanks and milk cans of 81 dairy herds. Protothecazopfii was identified in milk samples in 10 dairy herds. From these, eight dairy herds were studiedregarding Prototheca spp. mastitis and environmental occurrence as well as the main mastitis bacterialagents. Bacteria, algae and yeasts were isolated from 324 milk samples from 197 cows. P. zopfii wasisolated in three dairy herds from eleven milk samples from five cows with clinical and subclinical mastitis. In these dairy herds with positive isolation of P. zopfii the agent was isolated from the herd environment, excrements of the calves and teat cup rubbers. The results of this work demonstrate the importance of isolation in bulk tanks as an indicative of Prototheca spp. presence in dairy herds

Survey of Current Status of Three-Chamber Septic Tanks at a Sampling Point in Chongqing / 环境与健康杂志

Objective To perform a hygienic assessment of the three-chamber septic tanks and analyze the efficiency of non- hazardous treatment of feces and the impact on the environment, so as to provide the reference for the three-chamber septic tanks improvement test. Methods From September 2007 to January 2008, the 20 latrines of residents and the three-chamber septic tanks were selected by simple random sampling method from A village of A town , Chongqing , as the investigation point,with suitable economic conditions,the status of the latrines with three-chamber septic tanks were surveyed, and the hygienic and environmental indicators of the third chamber feces samples were detected. Results After the implementation of the three-chamber septic tanks, the rural ecological environment was improved. The samples test showed that pH value was basically in the range of 8-9, the qualified rate was 85%, as for the other indicators, the qualified rates were generally lower. The qualified rate of chemical oxygen demand, ammonia nitrogen and total nitrogen was only 5% , five-day biochemical oxygen demand and total phosphorus was 10% , SS and the color was 15% , fecal coliform value of the samples were not qualified. Conclusion The management of the three-chamber septic tanks needs to be improved. If the liquid dung of septic tanks was directly discharged, it will cause secondary environmental pollution.So it should be deeply treated.

Policultivo do Camarão Marinho (Litopenaeus Vannamei) com Tilápia do Nilo (Oreochromis Niloticus) / Policulture of Marine Shrimp (Litopenaeus Vannamei) With Nile Tilapia (Oreochromis Niloticus) / Policultivo del camarón marino (Litopenaeus vannamei) con tilapia de nilo (Oreochromis niloticus)

O camarão marinho e a tilápia, no Estado do Ceará, são importantes “commodities” na aquicultura. O desenvolvimento de técnicas de cultivo possibilitou o cultivo do camarão marinho em água doce com a tilápia. O experimento foi realizado com o objetivo de obter informações sobre o policultivo do camarão marinho, Litopenaeus vannamei, com a tilápia do Nilo, Oreochromis niloticus, em tanques. O cultivo teve duração de 120 dias. Foram utilizadas pós-larvas de L. vannamei com pesos e comprimentos médios iniciais de 0,041g e 16,20mm e alevinos machos revertidos sexualmente de tilápia do Nilo, de 1,531g e de 45,27mm, respectivamente, os quais foram cultivados em diferentes densidades, em tanques com capacidade de 1 m3. O pH e a temperatura médios da água dos tanques foram de aproximadamente 8,00 e 27ºC, respectivamente. Os camarões e as tilápias foram alimentados com dieta artificial para peixes. O comprimento e o peso médio final dos animais foram de 127, 129 e 128mm e 13,3; 14,2 e 14,0g para os camarões e de 233, 222 e 236mm e 22,9; 22,1 e 24,6g para as tilápias, nos tratamentos A, B e C, respectivamente. A sobrevivência média da tilápia e do camarão foi de 83,33; 87,50 e 86,11 e 100,00; 83,33 e 100,00 para os tratamentos A, B e C, respectivamente. Os testes estatísticos não mostraram existir diferenças entre os tratamentos. Conclui-se que pós-larvas de L. vannamei podem ser cultivadas juntas com tilápia do Nilo O. niloticus em água doce.

The shrimp and tilapia cultures in Ceara are important commodities in aquaculture. The development of aquaculture techniques is making it possible to culture shrimp in freshwater with tilapia. This experiment was carried out to provide more information on the policulture of Litopenaeus vannamei marine shrimp with tilapia Oreochromis niloticus in tanks. They were cultured for 120 days. Post-larvae of L. vannamei an average initial weight and length of 0.041g and 16.20mm, and sex reverted fingerlings of O. niloticus of 1.531g and 45.27mm, respectively, were cultured in different densities, in each 1 m3 tank. The pH and temperature of the water was approximately 8.00 and 27ºC, in the tanks, respectively. The shrimps and tilapia were fed with an artificial fish diet. The final average of length and weight of the shrimp and tilapia were 127, 129 and 128mm and 13.3, 14.2 and 14.0g, and 233, 222 and 236mm and 22.9, 22.1 and 24.6g for the A, B and C treatments, respectively. The survival rate of tilapia and shrimp were 83.33, 87.50 and 86.11 and 100.00; 83.33 and 100.00 for the A, B and C treatments, respectively. The tests showed no statistically differences among the treatments. We concluded that the post-larvae of L. vannamei can be reared with tilapia O. niloticus in freshwater.

El camarón marino y la Tilapia en el estado de Ceará, son importantes commodities en la acuicultura. El desarrollo de técnicas de cultivo posibilitó el cultivo del camarón marino en agua dulce con la tilapia. El experimento fue realizado con el objetivo de obtener informaciones sobre el policultivo del camarón marino, Litopenaeus vannamei con la tilapia del Nilo, Oreochromis niloticus en estanques. El cultivo tuvo duración de120 días. Fueron utilizadas postlarvas de L.vannamei con pesos y extensión medianos iniciales de 0,041g y 16,20 mm y alevinos machos apareados sexualmente de tilapia del Nilo, O.niloticus de 1,531g y de 45,27 mm, respectivamente, donde fueron cultivadas en diferentes densidades, en estanques con capacidad de 1 m³.O pH y la temperatura mediana del agua del estanque fueron de aproximadamente 8,00 y 27ºC respectivamente. Los camarones y las tilapias fueron alimentados con dieta artificial para peces. La extensión y el peso medio final de los animales fueron de 127,129 y 128 mm y 13,3 , 14,2 y 14,0g para los camarones, y de 233, 222 y 236mm y 22,9; 22,1 y 24,6g para las tilapias, en los tratos A,B y C respectivamente. La sobrevivencia media de la tilapia y del camarón fue de 83,33, 87,50 y 86,ll y 100,00, 83,33 y 100,00 para los tratos A, B y C respectivamente. Las pruebas estadísticas no exhibieron existir diferencias entre los tratos. Se deduce que postlarvas de L.vannamei pueden ser cultivadas juntas con Tilapia del Nilo O.niloticus en agua dulce.

EVALUATION ON FUNCTIONING STATUS OF MODIFIED SLUICES IN DONGTING LAKE REGIONS / 中国血吸虫病防治杂志

Objective To evaluate the fun ct ioning status and the effects of snail control in the different kinds of sluices in Dongting Lake regions. Methods Field invest igation was conducted for 85 modified sluices which aimed to preventing snails f rom spreading from 2000 to 2001 in Dongting Lake regions. The survey was used fo r the collection of data in terms of snails' situation in the irrigation canals and ditches inside the embankments where those modified sluices served as the in tervention of schistosomiasis control. The field trials of 85 sluices in 4 kinds (the abandoned, the equipped with lengtlened and lowered underwater pipes, the affiliated by snails retention tanks and the equipped with nets). were carried out to observe their effects of filtering snails, during which a g iven number of snails were cast in the front of the projects and recollected in the rear of the ones by means of the nets framed 40 holes per 25.4 mm.Results Eight sluices with the lengthened an d lowered underwater pipes were on trial for 22-28 hours and during which 2000 dyed snails was cast, yet no snails were detected in the rear. In 10 abandoned s luices, 9 were firmly sealed according to their design, and their functions of d rainage and irrigation inside embankment were replaced by other water conservanc y facilities. Up to 2003, 67 of 85 modified sluices have shown an effect on tra pping snails after 4-10 years of the running, and its effective rate arr ived at 78.8%. Conclusion Three kinds of sluices, i .e. the abandoned, the equipped with the lengthened and lowered underwater pipes , and the affiliated by snails retention tanks, show the capacity of trapping sn ail s, yet the one equipped with nets was unsuitable for application because of its difficulties in the long term maintenance. [