Decaimiento de coliformes fecales en lagunas aireadas de plantas de tratamiento de aguas residuales en Lima metropolitana / Decay of fecal coliforms in aerated lagoons of wastewater treatment plants in metropolitan Lima

A nivel mundial, el 44% de las aguas residuales domésticas no se tratan de forma segura, la recolección y tratamiento de aguas residuales, se ha convertido en un desafío, particularmente en áreas urbanas de bajos ingresos dentro de los países en desarrollo, donde las aguas residuales pueden fluir sin tratar a transportes de aguas pluviales o canales de drenaje informales. No es raro encontrar efluentes, desechos sólidos, excretas humanas y descargas líquidas de industrias y hospitales en las aguas superficiales de muchas zonas urbanas de los países en desarrollo. El proceso de tratamiento de aguas residuales puede ser llevado en lagunas mediante reacciones tanto oxidativas como reductoras. En la capa superior de la laguna, donde las aguas residuales son aeróbicas, ocurre el mecanismo convencional de la demanda bioquímica de oxígeno aeróbico (DBO) y se produce la oxidación del amoníaco. La capa inferior de la laguna es anaerobia, y en esta zona tiene lugar la digestión de los sólidos del lodo, un intermedio, la zona facultativa permite la respiración con aceptores de electrones terminales distintos del oxígeno, esto permite reacciones como la desnitrificación. Los gases producidos en las zonas inferiores se estabilizan en la zona aeróbica por disolución oxígeno, y esto reduce los problemas de olores. Este estudio tiene como objetivo, estudiar el descenso de coliformes fecales en lagunas aireadas de plantas de tratamiento de aguas residuales en la ciudad de Lima, Perú. Los resultados señalan que la separación diferencial de las aguas tratadas, experimentó un descenso del 13 al 26% de coleiformes fecales en todas las lagunas de tratamiento(AU)

Globally, 44% of domestic wastewater is not treated safely, and wastewater collection and treatment has become a challenge, particularly in low-income urban areas within developing countries, where wastewater may flow untreated into stormwater conveyances or informal drainage channels. It is not uncommon to find effluents, solid wastes, human excreta, and liquid discharges from industries and hospitals in the surface waters of many urban areas in developing countries. The wastewater treatment process can be carried out in lagoons through both oxidative and reductive reactions. In the upper layer of the lagoon, where the wastewater is aerobic, the conventional mechanism of aerobic biochemical oxygen demand (BOD) occurs and ammonia oxidation occurs. The lower layer of the lagoon is anaerobic, and in this zone the digestion of the sludge solids takes place, an intermediate, the facultative zone allows respiration with terminal electron acceptors other than oxygen, and this allows reactions such as denitrification. The gases produced in the lower zones are stabilized in the aerobic zone by dissolving oxygen, and this reduces odor problems. The objective of this study is to study the decrease of fecal coliforms in aerated lagoons of wastewater treatment plants in the city of Lima, Peru. The results indicate that the differential separation of the treated waters experienced a decrease from 13 to 26% of fecal coleiforms in all treatment lagoons(AU)

Evaluación de la calidad del agua de la vereda Río Suárez de Puente Nacional, Santander / Water quality evaluation ot the rural area of Río Suárez of Puente Nacional, Santander

Resumen Objetivo. Determinar la calidad del agua que abastece a la población de la Vereda Rio Suarez del municipio de Puente Nacional por medio del cálculo del índice de riesgo de la calidad del agua (IRCA). Métodos. Se tomaron 10 muestras de diferentes puntos de la red de distribución del agua veredal, se realizó análisis físico-químico y microbiológico por técnica de filtración por membrana bajo parámetros del Instituto Nacional de Salud. Resultados. El análisis físico-químico mostró cuantificación de hierro elevado y nivel de turbiedad inadecuado lo que puede afectar el sabor y el aspecto del agua. El recuento de coliformes totales fue >300 UFC/100ml., con identificación de Escherichia coli, Klebsiella oxytoca, Pseudomonas aeruginosa y Enterococcus entre otras, habitantes de suelo y aguas que pueden ser causantes de infecciones gastrointestinales e infecciones urinarias, resultados que indican que el agua no es apta para consumo humano.

Abstract Objective. To determine the quality of the water that supplies the population of the Vereda Rio Suarez of the municipality of Puente Nacional through the calculation of the risk index of water quality (IRCA). Methods. 10 samples were taken from different points of the water distribution network, physical-chemical and microbiological analysis was performed by membrane filtration technique under parameters of the National Institute of Health. Results. The physical-chemical analysis showed high iron quantification and inadequate turbidity level that can affect the taste and appearance of the water. The total coliform count> 300 CFU / 100ml., with identification of Escherichia coli, Klebsiella oxytoca, Pseudomonas aeruginosa and Enterococcus among others that inhabit soils and waters and can cause gastrointestinal infections and urinary infections and is not suitable for human consumption.

First detection of Shiga toxin producing Escherichia coli O157:H7 (HlyA gene) and enumeration of most probable number (MPN) of fecal coliforms and Escherichia coli in cage cultured oysters (Crassostrea iredalei) and water from southern Malaysia

Aims@#Escherichia coli O157:H7 is known to be transmitted via fecal-oral route, where water plays a role in the transmission process. Oysters as bivalves, bio accumulate pathogens from the water through filter feeding and are suspected to play a role as disease transmission vector. In Malaysia, the data on oyster’s microbiological quality are limited. Hence, it was vital to conduct oyster related studies in Malaysia. The main objectives of this study include the enumeration of most probable number (MPN) of fecal coliforms and E. coli and isolation of E. coli from oyster (Crassostrea iredalei) and water sample for the detection of 16S rRNA and HlyA (Hemolysin A) genes of E. coli O157:H7. @*Methodology and results@#A total of 120 oysters and water samples (n=6) were collected from a fisherman village located in southern Malaysia. Total fecal coliforms and E. coli were determined using the MPN procedure. Colonies of E. coli were identified based on Gram staining, biochemical test, and PCR detection for the presence of 16S rRNA and HlyA gene of E. coli O157:H7. The enumeration results showed that the MPN of the fecal coliforms and E. coli found in the collected oyster samples do not meet the standard to be directed for human consumption (0.72 ± 0.19 × 104 MPN/100 g and 0.13 ± 0.03 × 10 4 MPN/100 g, respectively). The PCR assays showed that 16 out of the 104 (15.38%) of E. coli isolated from water and oysters showed the presence of HlyA gene. The phylogenetic tree analysis showed there were genetic relationships between the HlyA gene of the E. coli isolated in this study with the ones isolated from calf and human faeces.@*Conclusion, significance and impact of study@#The detection of Shiga toxin producing E. coli O157:H7 (HlyA gene) in cage cultured oysters (C. iredalei) and water from southern Malaysia was first time reported here. In the future, more study can be conducted to study the expression of the HlyA gene and confirm of its identity as E. coli O157:H7 using different target genes such as eaeA (encodes a 94 kD outer membrane protein called intimin) and Stx1 (Shiga toxin, Shigella dysenteriae type 1).

Influence of different sources of contamination on the microbiological quality of lettuce in the Teresópolis region, RJ, Brazil / Influência de diferentes fontes de contaminação na qualidade microbiológica de alface na região de Teresópolis, RJ

ABSTRACT Irrigation water and cultivated soil have been identified as possible sources of contamination in several crops. In certain vegetables that are eaten raw, such as lettuce, this contamination can lead to public health problems. Aiming to evaluate the influence of these sources on the quality of lettuce grown in the Córrego Sujo Basin, Teresópolis, RJ, an important agricultural pole whose production services the metropolitan region of Rio de Janeiro, water from different sources (spring, weir and river) was collected in this region, as well as samples of soil and lettuce irrigated with these waters, to carry out conventional microbiological analyzes (counts of total heterotrophic bacteria and thermotolerant coliforms) and molecular analyzes (PCR-DGGE). The count of fecal coliforms in lettuce suggests that there is an influence of irrigation water and the cultivated soil on the contamination of these vegetables. The grouping of bacterial communities in the different samples obtained by the PCR-DGGE technique shows that irrigation water has a greater influence on the contamination of these vegetables in relation to the soil where they are grown. These results corroborate the need to monitor water bodies used for irrigation and demonstrate that the PCR-DGGE technique is of great value for the study of microbial communities and, when associated with specific primers, can help in the detection of pathogens in food.

RESUMO A água de irrigação e o solo de cultivo têm sido apontados como possíveis fontes de contaminação em diversas culturas. Em determinadas hortaliças consumidas cruas, como a alface, essa contaminação pode causar problemas de saúde pública. Objetivando avaliar a influência dessas fontes na qualidade das alfaces cultivadas na Bacia do Córrego Sujo, Teresópolis, RJ; importante polo agrícola com produção voltada à região metropolitana do Rio de Janeiro, coletou-se nesta região águas proveniente de diferentes fontes (nascente, açude e rio); solos e alfaces irrigados com essas águas, para realização de análises microbiológicas convencionais (contagens de bactérias heterotróficas totais e coliformes termotolerantes) e moleculares (PCR-DGGE). A contagem de coliformes fecais na alface sugere que existe influência da água de irrigação e do solo na contaminação desses vegetais. O agrupamento das comunidades bacterianas nas diferentes amostras obtido pela técnica de PCR-DGGE mostra que a água de irrigação tem influência maior na contaminação dessas hortaliças em relação ao solo onde são cultivadas. Esses resultados corroboram a necessidade de monitoramento de corpos d'água utilizados para irrigação e demonstram ser a técnica do PCR-DGGE de grande valia para o estudo das comunidades microbianas e, quando associada a iniciadores específicos podem ajudar na detecção de patógenos em alimentos.

Análise microbiológica da água do Rio Bacacheri, em Curitiba (PR) / Microbiological analysis of Bacacheri River water, Curitiba (PR), Brazil

RESUMO O planeta terra é constituído por uma grande porcentagem de água, sendo apenas 3% doce. Dessa água doce, aproximadamente 0,3% está disponível para ser utilizada pelos habitantes do planeta. Para a avaliação das condições sanitárias da água, utilizam-se bactérias do grupo coliforme, cuja presença no ambiente aquático configura um potencial indicativo de poluição, bem como do risco da presença de organismos patogênicos. O Brasil possui a maior disponibilidade hídrica do planeta, porém, em várias regiões do país, muitos rios encontram-se poluídos. Dessa forma, o objetivo deste estudo foi realizar a análise microbiológica da água do Rio Bacacheri, localizado na cidade de Curitiba (PR) e incluído na seção das águas doces destinadas à preservação do equilíbrio natural das comunidades aquáticas, a fim de determinar o nível de poluição em cinco pontos pré-determinados, acompanhando o crescimento de colônias de coliformes fecais e coliformes totais através da técnica de membrana filtrante. Os resultados permitem verificar que, em todos os pontos de coleta, foi observada a proliferação de coliformes fecais e totais em valores acima do limite proposto pela resolução CONAMA nº 357/2005. Adicionalmente, nota-se que os pontos #P1, #P2 e #P5 são os mais afetados, enquanto #P3 e #P4 parecem ser os menos impactados, provavelmente pela presença de mata ciliar, bem como pela canalização de margens e fundo do rio.

ABSTRACT The planet Earth is made up of a large percentage of water, being only 3% of fresh water. Of this fresh water, approximately 0.3% is available to be used by the planet's inhabitants. For the evaluation of the health conditions of the water, bacteria of the coliform group are use, being their presence in the aquatic environment a potential indicative of pollution, as well as of the risk for presence of pathogenic organisms. Brazil has the highest availability of water on the planet, but in several parts of the country, many rivers are polluted. The objective of the study was to perform the microbiological analysis of the Bacacheri River water, located in the city of Curitiba, Paraná, which is included in the section of fresh waters, aimed at preserving the natural balance of aquatic communities, in order to determine the level of pollution in five pre-determined points, following the growth of colonies of fecal coliforms and total coliforms, through the membrane filter technique. The results show proliferation of fecal and total coliforms in values above the limit proposed by CONAMA no. 357/2005 Brazilian determination in all harvest points observed. In addition, points # P1, # P2, and # P5 are the most affected ones, whereas points # P3 and # P4 seem to be less affected, probably due to the presence of ciliary forest, as well as the channeling of the banks and the bottom of the river.

Avaliação da qualidade microbiológica do queijo artesanal serrano / Evaluation of microbiological quality of serrano artisanal cheese

O queijo artesanal tem boa aceitação, consumo e produção em quase todo país. O Queijo Artesanal Serrano (QAS) é um produto tradicional da região dos Campos de Cima da Serra, no Rio Grande do Sul, com mais de 200 anos de história. Ele é feito à mão a partir do leite de bovinos de raças de corte, sem utilizar processos de refrigeração e pasteurização. O objetivo deste estudo foi avaliar a qualidade microbiológica do QAS, produzido na cidade de Cambará do Sul, com diferentes estágios de maturação. Analisaram-se 27 queijos produzidos em onze unidades produtivas, sendo dez com até 15 dias de maturação e oito e nove queijos amostras com 30 e 60 dias de maturação, respectivamente. Verificou-se ausência de L. monocytogenes e Salmonella spp em todas as amostras e contagens de Staphylococcus coagulase positiva em acordo com a legislação. Entretanto, dois queijos maturados (22%) foram considerados impróprios para consumo por apresentarem elevada contagem de coliformes termotolerantes (104 e 3,6x103 UFC.g-1). Visando à qualidade do produto, os produtores têm introduzido boas práticas agropecuárias (BPA) que, na ordenha tem mostrado melhora na qualidade do leite utilizado na produção do QAS. Por outro lado, boas práticas de fabricação (BPF) e tecnificação adequada deverão ser introduzidas nas unidades de produção. O QAS tem grande importância social e econômica para a população local e a produção com qualidade é de suma importância para a perpetuação deste produto centenário.

The artisanal cheese has good acceptance, consumption and production in almost all country. The Serrano Handmade Cheese (SHC) is a traditional product from the region of Campos de Cima da Serra, state of Rio Grande do Sul (Brazil), with more than 200 years of history. It is handmade from the milk from mixed breed beef cattle, without using refrigeration and pasteurization processes. The objective of this study was to assess the microbiological quality of Serrano Handmade Cheese, produced in the city of Cambará do Sul, with different stages of maturation. Eleven SHC producers provided 27 cheeses. Ten samples with up to 15 days of production and 8 and 9 samples with 30 and 60 days old, respectively. In all samples analyzed in this study were verify absence of L. monocytogenes and Salmonella spp. The same was observed in the Staphylococcus coagulase positive counting that was in according to the legislation recommendations. Two maturated cheese samples (22%) were considered unfit for human consumption because their termotolerant coliform count was 104 and 3.6x103 cfu.g-1. Aiming the product quality the producers started the implementation of good agricultural practices (GAP) that in the milking has shown improvement in the quality of the milk used in the production of SHC. On the other hand, good manufacturing practices should also be introduced in the production units of handmade cheese. Therefore, producers have invested in SHC technification adequacy and the legal criteria. The Serrano Handmade Cheese has a great social and economical importance for the local population and the such, the orientation of producers regarding the production of a high quality cheese is of paramount importance for the perpetuation of this centennial product, which walks hand in hand with the history of the region.

Physico-Chemical and Thermotolerant Fecal Coliforms Analysis of Commercial Bottled Water in Dar es Salaam City in Tanzania.

Background: There is currently an increased demand and consumption of bottled water in Tanzania especially among the middle and high income earners as it is generally perceived to be pure, clean and of good quality. This has led to the sale of different brands of bottled water on the Tanzanian market. Due to increased demand and consumption of bottled water in Tanzania, there has been a growing concern about the microbiological quality of this product. The objective of this study was to assess the physico-chemical quality parameters and microbial contamination level with thermotolerant fecal coliform bacteria commercial bottled water Dar es Salaam city in Tanzania. Materials and Methods: This cross sectional study was done in randomly selected ten different commercial brand of bottled water available in commercial market of Dar es Salaam city in Tanzania. Tap water from Dar es Salaam Water Supply Company (DAWASCO) was also sampled for comparison. Fecal coliform were enumerated by the membrane filtration and commercial field testing DelAgua®kit. The physicochemical examination of the water samples was done to determine pH, turbidity and Total Dissolved Solids (TDS) of the water samples using a Hach spectrophotometer (Hach Company, Loveland, Colorado, USA). Results and Discussion: All samples of bottled water (100%) analyzed did not show the presence of thermotolerant faecal coliform bacteria and thus meet the World Health Organization (WHO) acceptable value of zero cfu/ml. All the surveyed brands of bottled water were safe for drinking as they were devoid of any thermotolerant fecal coliforms bacteria. Tap water from DAWASCO revealed thermotolerant fecal coliforms contamination with mean CFU counts of 4.0/100ml. Coliform organisms found in tap water in this study were above the recommended levels by regulatory agencies such as Tanzania Bureau Standard (TBS), International Bottled Water Association (IBWA), Food and Drug Administration (FDA), United States Environmental Protection Agency for (USEPA), World Health Organization (WHO) and the European Community (EC). The overall mean results of the physicochemical parameters of bottled water brands and tap water studied were within the recommended limits by TBS and WHO. Conclusions: The absence of thermotolerant fecal coliform bacteria in the bottled water is indicative of safety for public consumption. Tap water from DAWASCO is unfit for human consumption and it needs to be treated to render it safe for human drinking. Physicochemical parameters revealed that the pH, TDS and turbidity were within the required levels by TBS and WHO. This indicates that, the manufacturers of bottled water brands and DAWASCO are conforming to the TBS and WHO standards on physicochemical requirements for drinking water.

Efecto de medios de cultivo preparados con agua de mar sobre indicadores sanitarios en aguas marinas de balnearios de Chichiriviche, estado Falcón, Venezuela / Effect of culture media prepared with sea water over health indicators in sea water of the Chichiriviche resort, Falcon State, Venezuela

Debido a su uso por humanos y para preservar la salud pública, los ambientes marinos recreacionales, deberían cumplir requisitos de calidad fisico-química y microbiológica. Sin embargo, actividades antropogénicas, tales como agricultura, ganadería, industriales, turísticas y domésticas, pueden descargar aguas servidas en playas marinas. La metodología vigente para evaluar la carga bacteriana de aguas recreacionales, no pareciera satisfactoria, particularmente en la detección de microorganismos patógenos debido a la presencia, en aguas marinas, de bacterias viables pero no cultivables (VBNC). Este estudio evaluó la carga bacteriana de aerobios mesófilos, coliformes totales/fecales y enterococos, en playas de Chichiriviche, Falcón, Venezuela y el efecto de concentraciones de agua marina sobre las densidades bacterianas. Las determinaciones se efectuaron en agar nutritivo, Mac Conkey y KF, preparados con agua destilada (MAD) o con agua de mar 10% v/v, (MAM). La carga bacteriana se incrementó entre 20 y 47 veces cuando los medios de cultivo se suplementaron con agua de mar. Las diferencias en las cargas bacterianas entre MAD y MAM, para aerobios mesófilos, coliformes totales y fecales fueron estadísticamente significativas (p≤0,05). El oxígeno disuelto y pH, en ambos medios presentaron valores permisibles.

Due to their use by humans and to preserve public health, recreational marine environments should fulfill physico-chemical and microbiological quality prerequisites. Nevertheless, anthropogenic activities such as agriculture, cattle raising, industrial, touristic and domestic, can discharge contaminated water at marine beaches. The present methods for evaluating the bacterial load of recreational waters does not appear satisfactory, especially concerning the detection of pathogenic microorganisms due to the presence, in marine waters, of viable but not cultivable bacteria (VNCB). This study evaluated the bacterial load of mesophilic aerobials, total and fecal coliforms, and enterococci at the Chichiriviche beaches, Falcon State, Venezuela, and the effect of marine water concentrations over the bacterial densities. The determinations were done in nutrient, Mac Conkey and KF agar prepared with distilled water (MAD) or with sea water (MSW). The bacterial load increased between 27 and 47 times when the culture media were supplement with sea water. The differences of the bacterial loads between MAD and MSW for mesophilic aerobials, total and fecal coliforms were statistically significant (p≤0.05). Dissolved oxygen and pH presented permissible values in both media.

The influence of ripening period length and season on the microbiological parameters of a traditional Brazilian cheese

The ripening process of Serro Minas cheese, one of the most popular cheeses produced with raw milk in Brazil, was studied over the course of 60 days of ripening during dry and rainy seasons. Brazilian legislation prohibits the production of cheese from raw milk unless it was submitted to a maturation period greater than 60 days. However Minas Serro cheese is sold within a few days of ripening. A total of 100 samples of Serro cheese were obtained from five farms; 50 samples were collected during the dry season (winter in Brazil) and 50 samples were collected during the rainy season (summer in Brazil). From each farm, ten cheeses were collected during each season after two days of ripening. Our results showed high levels of total and fecal coliforms at the beginning of the ripening period (approximately 4 Log MPN/g with 3 days of ripening) that decreased with 60 days of ripening reaching almost 1.5 Log MPN/g. Contamination by coagulase-positive staphylococci was reduced by the end of the ripening period. Salmonella spp. was not detected. The staphylococcal enterotoxins B and C were detected in 1% and 4% of the cheeses, respectively, after 30 days of ripening. These results suggest that the ripening process was not effective in eliminating staphylococcal enterotoxins from the cheese. However, none of the investigated strains of Staphylococcus spp. isolated from Serro cheese produced enterotoxins A, B, C or D. The high pathogen and coliform levels at the beginning of the ripening process for the cheese produced during both seasons indicate the need for improvement of the sanitation of the manufacturing conditions.

Incidencia de histamina y de bacterias indicadoras de calidad higiénica, en filetes, ruedas y trozos de pescado de especies pelágicas comercializadas en un mercado de pescado de la isla de Margarita (Venezuela) / Incidence histamine and hygienic quality indicators´s bacteria in fillets, slice and pieces pelagic fish´s marketing in one fish´s market of Margarita´s Island (Venezuela)

Se estudió la incidencia de histamina y de bacterias indicadoras de manejo higiénico en filetes, ruedas y trozos de diez especies de pescado en estado fresco, (Euthynnus alletteratus; Caranx latus; Ophisthonema oglinum; Alectis crinitus; Sardinella aurita; Thunnus alalunga; Sarda sarda; Scomberomorus cavalla; Coryphaena hippurus y Xyphias gladius), comercializadas en un mercado de pescado de Isla de Margarita (Venezuela). Según normas COVENIN se enumeraron (UFC g-1) aerobios a 25 y 32 °C, coliformes fecales y Escherichia coli (NMP g-1); histamina (mg/100 g) y pH. También recuentos (UFC g-1) de enterobacterias (ICMSF) y bacterias descarboxiladoras de histidina (Niven y otros). Todos los recuentos de aerobios a 25 °C excedieron el valor m (Log10 = 5,70 UFC g-1) fijado por ICMSF (1986). La prueba r de Pearson indicó que los recuentos a 25 y 32 °C estuvieron altamente relacionados (n = 90; r = 0,89; p < 0,01). E. coli superó en el 76% de las muestras el valor m (Log10 = 1,04 NMP g-1). Las mayores cifras de histamina se detectaron en T. alalunga (promedio 43,5 mg/100 g en uno de tres muestreos); seguido por S. aurita (promedios de 23,7 y 28,0 mg/100 g respectivamente, en dos muestreos). Sólo en muestras de T. alalunga se detectaron olores penetrantes y músculos con elasticidad disminuida. Estos datos y la observación de factores adversos, tales como contacto directo con superficies y utensilios sucios, restos de vísceras, desangrado deficiente, presencia de insectos, utilización de agua no potable y la exposición a temperaturas no apropiadas, reflejan que la manipulación del pescado no fue adecuada. Se recomienda que inspectores sanitarios implementen acciones tendentes a corregir estas deficiencias.

The incidence of histamine and of bacteria that indicate hygienic handling of fillets, slices and pieces of ten pelagic fresh fish (Euthynnus alletteratus; Caranx latus; Ophisthonema oglinum; Alectis crinitus; Sardinella aurita; Thunnus alalunga; Sarda sarda; Scomberomorus cavalla; Coryphaena hippurus and Xyphias gladius), sold in a fish market at Margarita Island (Venezuela) was assessed. According to COVENIN´s norms, total aerobic plate count (FCU g-1) at 25 and 32 °C; fecal coliforms and Escherichia coli (MPN g-1); histamine (mg/100 g) and pH were measured. Also, members of the Enterobacteriaceae family (FCU g-1) and histamine producing bacteria were counted, according to ICMSF and Niven et al respectively. All total aerobic plate count at 25 °C surpassed the m number (Log10 = 5.70 CFU g-1) established by ICMSF (1986). The Pearson test (r) showed that bacteria total counts at 25 and 32 °C were highly related (n = 90; r = 0.89; p < 0.01). E. coli exceeded in 76% of samples the number (Log10 = 1.04 MPN g-1). Histamine biggest numbers were detected in T. alalunga (average 43.5 mg/100 g in one of three samplings), followed by S. aurita (averages of 23.7 and 28.0 mg/100 g respectively, in two samplings). Only in T. alalunga samples were penetrating odors detected and muscles with reduced elasticity. This data and the adverse factors observed, such as: fish in direct contact with dirty areas and utensils, leftover viscera, faulty bleeding, presence of insects, use of non potable water and the exposition of fish at inappropriate temperatures, revealed the handling of fish was not suitable. It is recommended that sanitary officers carry out actions necessary to correct these deficiencies.

Calidad bacteriológica del agua de consumo humano de la zona urbana y rural del municipio de Guatavita, Cundinamarca, Colombia / Bacteriological quality of the water for human consumption in urban and rural areas of the municipality of Guatavita, Cundinamarca, Colombia

Guatavita es un municipio ubicado en el Departamento de Cundinamarca, Colombia. Posee recursos hídricos como ríos, quebradas, lagunas y nacimientos, que representan un alto porcentaje del agua con que se abastece. El municipio tiene 16 acueductos en funcionamiento, pero solo el que abastece a la población de la zona urbana cuenta con un sistema de tratamiento de agua. En la zona rural existen 14 acueductos con un sistema básico de pretratamiento. Se analizó la calidad bacteriológica del agua de consumo humano de la zona urbana y rural (veredas Corales, Potrero Largo y Carbonera Alta), por medio de los indicadores de contaminación: coliformes totales y Escherichia coli, mediante la técnica de filtración por membrana. El agua de consumo humano de la zona urbana cumplió con los parámetros establecidos en la Resolución 2115 de 2007 del Ministerio de Protección Social, contrario a la zona rural, donde se encontraron recuentos de los indicadores de contaminación fecal, superiores a lo establecido. Por lo tanto, este recurso debe ser considerado como "agua natural", no apta para consumo humano, según el Decreto 1594 de 1984, por lo que debe ser destinada para potabilización bajo un tratamiento convencional.

Guatavita is a municipality in the department of Cundinamarca, Colombia. Guatavita has water resources such as rivers, streams, lakes and springs, which provide a large proportion of the water consumed by the population. Sixteen water supply systems are in operation, but only the one supplying the urban area is equipped with water treatment facilities. In the rural area there are 14 aqueducts with a basic pretreatment system. An analysis was made of the bacteriological quality of the water for human consumption in urban and rural areas (districts of Corales, Potrero Largo and Carbonera Alta) based on two contamination indicators: total coliforms and Escherichia coli, using membrane filtration technique. The water for human consumption in the urban area complied with the parameters contained in Resolution 2115/2007 of the Ministry of Social Protection. In the rural area, however, fecal contamination indicators were above the established limits. Therefore, this resource should be viewed as "natural water" not suitable for human consumption, according to Decree 1594/1984, and destined for potabilization by conventional treatment.

Estudo fenotípico e molecular de resistência aos antimicrobianos em amostras clínicas e ambientais de enterobactérias / Molecular and phenotypic study of antimicrobial resistance in clinical and environmental samples of enterobacteriaceae

Buscamos detectar evidências da presença de genes envolvidos na produção de Enzimas Modificadoras de Aminoglicosídeos (EMAs), Beta-lactamases de espectro estendido (ESBLs) e Mecanismos Plasmidiais de Resistência a Quinolonas (PMQRs) em cepas de K. pneumoniae, K. ozaenae e E. coli isoladas de amostras de água de rios afluentes da Baía de Guanabara e de materiais clínicos de origem hospitalar, além de avaliar o "status sanitário" dos corpos aquáticos abordados no tocante à contaminação fecal recente e indicações de contaminação hospitalar e por outros ambientes de alta seletividade. As cepas de materiais clínicos foram selecionadas entre Maio e Julho de 2010, a partir da semeadura em meio de cultura contendo 8 ug/mL de gentamicina. As amostras de água foram coletadas em Abril e em Julho de 2009. Realizamos testes de colimetria, empregando para tal, a metodologia convencional e outra, na qual adicionamos 32 ug/mL de cefalotina e 8 ug/mL de gentamicina aos caldos Lactosado e Escherichia coli (caldo EC), a fim de detectar e quantificar coliformes resistentes. Para o isolamento das cepas empregamos meios de cultura contendo 32 ug/mL de cefalotina e 8 ug/mL de gentamicina. As cepas foram identificadas e submetidas a testes de susceptibilidade aos antimicrobianos (TSA), testes presuntivos para presença de ESBLs, extração de DNA plasmidial e ensaios de Reação em Cadeia de Polimerase (PCR) para a detecção dos genes. A utilização de agentes antimicrobianos nos testes de colimetria nos permitiu detectar a presença e quantificar coliformes totais e fecais resistentes nas amostras de água analisadas nos diferentes pontos. O TSA das cepas isoladas de amostras de água exibiu perfis de multirresistência, compatíveis com o de bactérias de origem hospitalar, semelhante ao encontrado nas cepas isoladas de materiais clínicos. Todas as cepas isoladas de amostras de água e 90% das cepas de materiais clínicos apresentaram pelo menos uma banda plasmidial. Os ensaios de PCR...

We seek to detect evidence of the presence of genes involved in the production of Aminoglycoside Modifying Enzymes (AME), Extended-spectrum beta-lactamases (ESBLs) and Plasmid Mechanisms of Resistance to Quinolones (PMQRs) in strains of K. pneumoniae, K. ozaenae and E. coli isolated from water samples from rivers of Guanabara Bay and clinical samples of hospital origin, and to evaluate the "health status" of water bodies addressed in relation to recent fecal contamination and signs of hospital contamination and other environments with high selectivity. The strains from clinical materials were selected between May and July 2010, using culture media containing 8 ug/mL gentamicin. Water samples were collected in April and July 2009. Colimetric assays were performed, using the conventional methodology and other which we added 32 ug/mL cephalothin and 8 ug/mL of gentamicin at Lactose and Escherichia coli broth (EC broth), in order to detect and to count resistant coliforms. For isolation of the strains we employed culture media containing 32 ug/mL cephalothin and 8 ug/mL gentamicin. The strains were identified and submitted to tests for antimicrobial susceptibility (TSA), presumptive tests for the presence of ESBLs, plasmid DNA extraction and tests of the Polymerase Chain Reaction (PCR). The use of antimicrobial agents in colimetric assays allowed us to detect and to count the resistant total and fecal coliforms in the water samples analyzed at different points. The TSA of the isolates recovered from water samples showed multidrug-resistance profiles, compatible with that of nosocomial bacteria, similar to that found in isolates recovered from clinical materials. All isolates from water samples and 90% of the isolates of clinical samples showed at least one plasmid band. PCR assays demonstrated the presence of amplification products to AME, ESBLs and PMQRs, and 7.4% of the isolates recovered of samples of water and 20% of the isolates of clinical materials...

Comparison between the efficiency of two bioindicators for determining surface water quality in an urban environment / Comparação entre a eficiência de dois bioindicadores para a determinação da qualidade de águas superficiais em um ambiente urbano

This study evaluated the efficiency of two bioindicators, fecal coliforms and ecotoxicity tests, set out in CONAMA Resolution 274/00 and CONAMA Resolution 357/05, in assessment of water quality. For this study, Lake Paranoá, Federal District of Brazil, was chosen, since it is a water body directly contaminated by effluents from a sewage treatment plant. Four sampling points were chosen in accordance with the map of recreational water quality published weekly by CAESB/DF, after analysis of fecal coliforms. Samples from these points were collected for 6 months and tested on Danio rerio fish (acute toxicity) and on the microcrustacean Ceriodaphnia dubia (acute and chronic toxicity), besides measuring chemical and physico-chemical parameters. The data obtained show great consistency between the observed biological parameters, suggesting that in this urban aquatic environment, under great anthropogenic pressure, the fecal coliform bioindicator seems to be more restrictive and enough to evaluate the safety of surface water.

Este trabalho comparou a eficiência dos bioindicadores coliformes fecais ou termotolerantes e ensaios de ecotoxicidade, propostos pelas Resoluções Conama 274/00 e Conama 357/05, na avaliação da qualidade de água. Para a realização desse estudo foi escolhido o Lago Paranoá, Brasília, Distrito Federal, por ser um corpo hídrico impactado diretamente pelo lançamento de efluentes de uma estação de tratamento de esgotos. Foram definidos quatro pontos de acordo com o mapa de balneabilidade, publicado semanalmente pela Caesb/DF, em função do teor de coliformes termotolerantes. Amostras desses pontos colhidas durante seis meses foram testadas com o peixe Danio rerio (toxicidade aguda) e o com o microcrustáceo Ceriodaphnia dubia (toxicidade aguda e crônica), além da determinação de parâmetros químicos e físico-químicos. Os resultados obtidos mostraram grande equivalência entre os parâmetros biológicos observados, sugerindo que nesse ambiente sob grande influência antrópica, o bioindicador coliformes termotolerantes foi mais restritivo e suficiente para avaliar a segurança das águas superficiais.

Correlation between Escherichia coli and limnological variables in water samples of the Lagoa da Maraponga, Fortaleza, Ceará State, Brazil / Correlação entre Escherichia coli e variáveis limnológicas em amostras de água da Lagoa da Maraponga, Fortaleza, Estado do Ceará, Brasil

The present work examined possible relationship between the Escherichia coli counts and the concentrations of free CO2, dissolved oxygen, reactive phosphorus, total ammonia, nitrite, pH, transparency and electric conductivity in water samples from the Lagoa da Maraponga (Fortaleza, Ceará State). Eight samplings were carried out every fifteen days to take samples under the water's surface at three sampling stations. Regression analyses were performed with the variable with the greatest Pearson coefficients searching for the best fitted curve to observed data. The correlation between the water pH and E. coli was best represented by the equation y = 7.63 ­ 2.92 * 10-4 x (r² = 0.53; P = 0.06) where x is the E. coli count (MPN 100 mL -1) and y is the water pH. We concluded that the inflow of sewage and other affluent rich in organic matter decreases the lake's alkalinity and make it susceptible to the acidification process.

O presente trabalho teve como objetivo estudar o possível relacionamento existente entre as contagens de Escherichia coli e as concentrações de CO2 livre, oxigênio dissolvido, fósforo reativo, amônia total, nitrito, pH, transparência e condutividade elétrica, em amostras de água da lagoa da Maraponga (Fortaleza, Estado do Ceará). Foram realizadas oito campanhas, com periodicidade quinzenal, nas quais foram coletadas amostras de água subsuperficial, em três pontos de amostragem. Para a variável que apresentou o maior coeficiente de correlação linear em módulo, realizou-se a análise de regressão dos dados. Analisando-se matematicamente a relação entre a concentração de E. coli (NMP 100 mL-1), como variável independente, e a concentração o pH da água da lagoa da Maraponga, como variável dependente, chegou-se à equação y = 7,63 ­ 2,92 * 10-4 x (r² = 0,53; P = 0,06). Concluiu-se que a entrada de esgotos e/ou afluentes ricos em matéria orgânica na lagoa reduz a sua alcalinidade e a torna vulnerável ao processo de acidificação.

Diferentes condimentos vegetais: avaliação sensorial e de atividade antibacteriana em preparação alimentar com frango cozido / Different spice plants: sensorial evaluation and antibacterial activity in chicken broth

A partir da atividade antibacteriana in vitro, predeterminada em doze plantas com indicativo etnográfico condimentar, testou-se este atributo in loco no modelo caldo com frango cozido. Primeiramente, procedeu-se ao treinamento de 10 avaliadores, segundo a legislação vigente quanto ao Consentimento Livre e Esclarecido, oportunizando conhecimentos prévios sobre as plantas salsa (Petroselinum sativum), manjerona branca (Origanum X aplii), manjerona preta (Origanum majorana), manjericão (Ocimum basilicum), sálvia (Salvia officinalis), tomilho (Thymus vulgaris), anis verde (Ocimum selloi), alfavaca (Ocimum gratissimum), alho nirá (Allium tuberosum), alho poró (Allium porrum), cúrcuma (Curcuma longa) e pimenta dedo-de-moça (Capsicum baccatum). Realizou-se, através da adição individualizada desses condimentos ao caldo com frango cozido, um Teste de Aceitação tipo escala hedônica, selecionando, dentre os doze condimentos, quatro deles que se destacaram sensorialmente, a pimenta dedo-de-moça, o alho nirá, o alho poró e o tomilho. Foi feito, então, um Teste de Aceitação de concentrações denominadas pequena, média e grande destes quatro condimentos, para determinação da intensidade sensorialmente melhor aceita. As quantidades eleitas (0,5 g de pimenta dedo-de-moça, 15 g de alho nirá, 15 g de alho poró e 5 g de tomilho) foram acrescidas ao caldo com frango cozido, sendo estes desafiados frente a Escherichia coli (ATCC 11229) em concentração final de 10 UFC mL-1, limite tolerado pela legislação, tendo como grupo-controle o caldo com frango cozido sem condimentos. O crescimento bacteriano foi aferido a cada duas horas após a inoculação, até completar 24 horas de confronto, utilizando-se meio seletivo para coliformes termo-resistentes e incubação constante a 25ºC em DBO, sendo atribuídos valores arbitrários às variações logarítmicas de crescimento. Comparados ao controle, todos os tratamentos condimentados apresentaram, individualmente, atividade antibacteriana significativa, mesmo que sem significância quando comparados entre si. Contudo, em relação ao tempo de início da atividade antibacteriana, destacou-se a pimenta dedo-de-moça, enquanto que, em relação ao prolongamento dessa ação no tempo, destacou-se o alho nirá. As 12 plantas condimentares em estudo tiveram atestada a sensorialidade, sendo que as quatro plantas com destaque tiveram a atividade anti-coliforme termo-resistente comprovada in loco. Diferentes condimentos vegetais foram capazes de fornecer qualificação sensorial e sanitária em caldo com frango cozido, em condições domésticas de manuseio.

Based on the in vitro antibacterial activity predetermined for 12 spice plants with ethnographic indicator, this feature was tested in loco in the model cooked chicken broth. First, ten evaluators were trained, according to the current legislation for Free and Informed Consent, providing previous knowledge about the plants parsley (Petroselinum sativum), marjoram (Origanum X aplii and Origanum majorana), basil (Ocimum basilicum), common sage (Salvia officinalis), thyme (Thymus vulgaris), anis-like spice (Ocimum selloi), african basilicum (Ocimum gratissimum), nirá garlic (Allium tuberosum), leek (Allium porrum), turmeric (Curcuma longa) and "dedo-de-moça" chili (Capsicum baccatum). Those spices were individually added to the chicken broth to perform a Hedonic Scale-like Acceptance Test, selecting four of the twelve spices that had higher sensory acceptance, "dedo-de-moça" chili, nirá garlic, leek and thyme. A new Acceptance Test was then performed using low, medium and high concentrations of those four spices to establish the most acceptable sensory intensities. The elected quantities (0.5 g "dedo-de-moça" chili, 15 g nirá garlic, 15 g leek and 5 g thyme) were added to the chicken broth, then challenged with Escherichia coli (ATCC 11229) at a final 10 concentration of CFU/mL, the tolerated limit according to legislation. The control group was chicken broth without spices. The bacterial growth was measured at every two hours after the inoculation until 24 hours of confront were completed, using a selective medium for thermo-resistant coliforms, under constant incubation at 25ºC in DBO. Arbitrary values were assigned to the logarithmic growth variations. Compared to the control group, all the spiced treatments individually presented significant antibacterial activity, although the latter was not significant when treatments were compared with each other. However, as regards the antibacterial activity starting time, "dedo-de-moça" chili had the best results, whereas nirá garlic had the best results as regard the extension of this activity time. The 12 studied spice plants had their sensorial characteristics attested, and the four plants that had the best results had proved in loco anti-thermo-resistant coliform activity. Different spice plants were capable of providing sensory and sanitary qualification in chicken broth, under domestic conditions of manipulation.

Pressão e temperatura da água de lavagem na população microbiana da superfície de carcaças bovinas / Washing water pressure and temperature on microbial population of cattle carcasses surface

Considerando que a superfície das carcaças bovinas pode se contaminar durante as diferentes etapas do abate e que a lavagem no final do processo tende a reduzir a população microbiana, o presente estudo foi realizado a fim de verificar a influência da temperatura e da pressão da água de lavagem sobre a população de microrganismos heterotróficos mesófilos, psicrotróficos, bolores e leveduras, coliformes totais e coliformes termotolerantes. Para tal, foram coletadas amostras, por suabe de esponja, em quatro pontos da superfície de 80 carcaças (flanco, pescoço, peito e alcatra). Vinte delas foram lavadas com água a 25°C e sem pressão artificial, 20 com água a 25°C sob pressão de 3atm, 20 com água a 40°C e sem pressão artificial e 20 com água a 40°C sob pressão de 3atm. Para efeito de controle, foram coletadas amostras, pelo mesmo método, de 20 carcaças sem lavar, totalizando 100 amostras. Os resultados evidenciaram que a água sob pressão em temperatura de 25oC foi mais eficiente na remoção de microrganismos do que a água aquecida, muito embora esse último caso promovesse uma limpeza mais visível das carcaças.

The aim of this study was to evaluate the influence of washing water temperature and pressure on mesophilic and psychrotrophic aerobic bacterial populations, yeasts and molds, total coliforms and fecal coliforms population, whereas the cattle carcass surface may become contaminated during the different slaughter procedures and the final carcass washing may reduce microbial population. Samples were taken by sponge swabbing in four areas of carcass surface (flank, neck, chest and rump), from which 20 were washed with water at 25°C and without artificial pressure, 20 with water under a pressure of 3atm, 20 with water at 40°C and without artificial pressure and 20 with water at 40°C under a pressure of 3atm. For control purpose and using the same method to collect more 20 carcasses samples were taken without washing,, totaling 100 samples. The results showed that the water at 25°C under 3atm pressure was more efficient to remove microorganisms from carcass surface than the heated water , although this latter promotes a more visible clean carcasses.

Indicadores entéricos en vegetales frescos que se comercializan en mercados populares de Maracaibo / Enteric indicators in fresh vegetables sold at popular food markets in Maracaibo

Se analizó la calidad microbiológica de 300 vegetales (100 lechugas, 100 cilantros y 100 perejiles) en dos mercados de la ciudad de Maracaibo. Se determinó coliformes totales (CT), coliformes fecales (CF) y Escherichia coli por la técnica del número más probable. Los CT oscilaron entre 10³-10(9) NMP/gr en más del 80% de las lechugas adquiridas en ambos mercados; mientras que los CF se ubicaron entre 10¹-10(7) NMP/gr en 90% de las muestras del mercado 2. Para 96% de los cilantros los CT estuvieron entre 10(4)-10(9) NMP/gr. Los CF se ubicaron entre 10(4)-10(9) NMP/gr en 88% y 84% de las muestras del mercado 1 y 2. Los CT oscilaron entre 10(4)-10(9) NMP/gr en 90% o más de los perejiles. Se obtuvieron valores de CF entre 10³-10(9) NMP/gr en 82% y 60% de los especímenes recolectados en el mercado 1 y 2, respectivamente. 52% de las muestras de perejil adquiridas en el mercado 1 presentaron recuentos elevados para E. coli (10(4)-10(7)NMP/gr). Según los criterios microbiológicos para E. coli, 84,7% de los vegetales fueron satisfactorios y 15,3% insatisfactorios. Debido a la variabilidad de los niveles de coliformes y E. coli en los vegetales frescos, es recomendable establecer normas locales para evaluar la calidad microbiológica de estos alimentos.

The microbiological status of 300 vegetables (100 lettuces, 100 corianders, and 100 parsley) from two food markets in Maracaibo city was analyzed. Total coliforms (TC), fecal coliforms (FC) and Escherichia coli were determined by the most probable number technique. TC oscillated between 10³-10(9) MPN/gr in over 80% of the lettuces bought at both markets, while FC oscillated between 10-10(7) MPN/gr in 90% of the samples from Market 2. In 96% of the corianders, TC varied between 10(4)-10(9) MPN/gr, and FC varied between 10(4)-10(9) in 86% and 84% of the samples from Markets 1 and 2 respectively. In parsley, TC oscillated between 10(4)-10(9) in 90% or more of the total samples, and FC varied between 10³-10(9) in 82% and 60% of the samples from Market 1 and 2 respectively. In 52% of the parsley samples obtained from Market 1 there were high E. coli counts (10(4)-10(7) MPN/gr). According to the microbiological criteria for E. coli, 84.7% of the vegetables were satisfactory and 15.3% non satisfactory. Due to the variability of the coliform levels in fresh vegetables, it is advisable to establish local norms to evaluate the microbiological quality of this food.

Utilização da análise de coliformes como indicativo de sanidade dos mexilhões Perna perna (Linnaeus, 1758) cultivados na ilha Guaíba, Rio de Janeiro / Coliform enumeration used as a sanitation indicative factor from Perna perna (Linnaeus, 1758) mussels cultivated in Guaíba Island, Rio de Janeiro

O mexilhão Perna perna é a espécie de molusco bivalve predominante nas fazendas marinhas de todo o Brasil. O monitoramento bacteriológico de moluscos comercializados deve ser realizado frequentemente devido aos bivalves serem capazes de bioacumular patógenos presentes na coluna d’água onde crescem. Os mexilhões são animais filtradores utilizados para alimentação humana. Portanto, a contaminação ambiental afeta tanto a sanidade do animal quando a Saúde Coletiva. Os níveis de coliformes totais e termotolerantes presentes nos moluscos foram determinados através da técnica do Número Mais Provável (NMP) de abril de 2007 a março de 2008. Os níveis de coliformes totais nos tecidos dos mexilhões variaram de 0,27 a 160,94 NMP.g-1, enquanto os termotolerantes estiveram entre < 0,18 e 35,73 NMP.g-1. É possível que os coliformes presentes em tais concentrações sejam capazes de tornar os moluscos mais susceptíveis a fatores de estresse durante sua comercialização. Análises específicas para cada organismo patogênico e substâncias tóxicas precisam ser desenvolvidas.

The most predominant species of bivalve mollusc cultivated in Brazil’s marine farms is the brown mussel Perna perna. Bacteriological monitoring of commercialized shellfish has to be carried out frequently due to their ability to concentrate pathogens from the water column where they grow up. Mussels are filter-feeding animals used in human diet. Therefore, environmental contamination not only does affect their own sanitation, but also the public health. Total and fecal coliform levels present in shellfish were determined by the Most Probable Number (MPN) technique from April 2007 to March 2008. Total and thermotolerant coliform mean concentrations varied from 0,27 to 160,94 NMP.g-1 and < 0,18 to 35,73 NMP.g-1, respectively. There is a probability that such coliform concentrations are likely to turn mussels more susceptible to stress factors during their commercialization. Specific analyses for each pathogen and toxic substances are still to be carried out.

Aspectos sanitários do cultivo da alface americana, irrigada com águas recptoras de efluentes urbanos / Sanitary aspects of lectucce (Lactuca sativa L. ) culture irrigated with receiving waters of urban effluent

Avaliou-se a influência da disposição de mangueiras gotejadoras nos canteiros e a injeção ou não de cloro na água de irrigação, nas condições sanitárias do solo e da alface americana irrigada (Lactuca sativa L.) com águas receptoras de efluentes urbanos. Foram realizadas análises microbiológicas de amostras de água do solo e da alface, no decorrer de todo o ciclo de cultivo. Objetivou-se determinar a possível existência de Salmonella spp. e de formas evolutivas de parasitos humanos e a quantidade de coliformes fecais, em pontos e épocas diferentes do experimento, impedindo assim o consumo da alface. Os resultados não indicaram a presença dos dois primeiros em nenhuma das amostras, mas sim de parasitos não humanos (nematóides) de vida livre no solo. Em relação à quantidade de coliformes fecais (NMP ml-1), o valor encontrado na cultura atende às exigências da Secretaria de Vigilância Sanitária do Ministério da Saúde brasileiro, porém a presença dos nematóides em quantidades superiores ao permitido pela Organização Mundial de Saúde (OMS) inviabiliza o seu consumo.

One evaluated the influence of drip tape arrangement and the use of chloride in the irrigation water, on soil sanitary conditions and growing lettuce (Lactuca sativa L.), irrigated with receiving urban waters. Water, soil and lettuce microbiological analyses were performed during crop cycle. The objective was to determine the presence of Salmonella spp., evolutive forms of human parasites and the amount of fecal coliforms in different locations and time, avoiding the lettuce consumption. Although results did not indicate the presence of Salmonella spp. and evolutive forms of human parasites in none of the samples but non human parasites (nematodes) of free life in soil. Total fecal coliforms count (NMP ml-1) met is according to the Brazilian Ministry of Health, Secretary of Health Surveillance requirements. Yet, the lettuce was not good for human consumption as the nematode presence was above the World Health Organization (WHO) guidelines.

Microcistina en plantas de tratamiento de agua para consume humano en un ambiente tropical: el Area Metropolitana de Costa Rica / Microcystin in plants that treat water for human consumption in a tropical environment: the Metropolitan Area of Costa Rica

We measured microcystin levels in water of the Metropolitan Area of Costa Rica by competitive inhibition ELISA and we quantified total coliforms, fecal coliforms, Escherichia coli (by a Most Probable Number method) and aerobic count. We wanted to identify any cyanotoxin correlation with these parameters, as a public health risk. We sampled in the rainy season of 2003 (April-October) and in the dry season of 2004 (February-March) (30 samples/season). We sampled pre-treated, semi-treated and treated water. Microcystin levels < 0.5 ppb were found in the rainy season (and > 0.5 ppb in the dry season). Dry season levels exceeded World Health Organization limits (1.0 ppb). Cyanotoxins occurred in the Tres Rios plant. We did not find a correlation between these microbiologic parameters of water quality and microcystin levels in water.

Se midió la presencia de microcistina en el Área Metropolitana de Costa Rica por la técnica de ELISA de inhibición competitiva y se cuantificó coliformes totales, coliformes termotolerantes, Escherichia coli (por medio de la técnica Numero Más Probable) y recuento total aerobio. Se realizaron dos etapas de muestreo, una durante la estación lluviosa del 2003 (abril-octubre) y otra durante la estación seca del 2004 (febrero-marzo), cada una con 30 muestras de agua. Se muestreó agua pretratada, semitratada y tratada. Se determinaron niveles de microcistina < 0.5 ppb durante la estación lluviosa del 2003, mientras que durante la estación seca, se detectaron concentraciones de microcistina > 0.5 ppb. Se informó la presencia de cianotoxinas en la Planta de Tratamiento de Tres Ríos. No se establece correlación entre los parámetros microbiológicos de calidad del agua y las concentraciones de microcistina en el agua. Los estudios deberían considerar la diversidad y toxicidad de cianobacterias en estas plantas, los efectos del tratamiento, y presencia de otros microorganismos y sustancias (dióxido de carbono, fósforo, Nitrógeno), sobre la presencia, estructura y efecto de estas toxinas.