Resumen: La presencia de bacterias coliformes en el agua presenta una amenaza potencial a la salud pública, ya que puede incrementar el riesgo de enfermedades infecciosas en la población más vulnerable. El asunto resulta más complicado cuando se desconoce la calidad fisicoquímica y microbiológica del agua que se consume. El presente estudio tiene la finalidad de evaluar el estado actual de la calidad de agua de consumo en tres Organizaciones Territoriales de Base (OTB’s) del Municipio de Vinto-Cochabamba y la relación de dependencia de los parámetros microbiológicos con las OTB’s. Los análisis de laboratorio de 30 muestras tomadas en los diferentes domicilios (10 muestras por OTB) muestran el cumplimiento de los límites máximos permisibles de los parámetros fisicoquímicos (pH, conductividad, alcalinidad y dureza) según la Norma Boliviana 512 (NB 512). Respecto a los parámetros microbiológicos para coliformes totales, de las 30 muestras analizadas solo 11 cumplieron con el límite máximo permisible, a diferencia del parámetro de coliformes termorresistentes, donde 25 de las 30 muestras cumplieron con el límite máximo permisible. Los parámetros microbiológicos fueron sometidos al análisis de chi-cuadrado, dando evidencia suficiente para afirmar con un 95% de confianza que los resultados de coliformes totales y termorresistentes no depende de la OTB (p=0.36). Al contrastar los resultados de agua de consumo domiciliario con la del agua suministrada, puede especularse que la contaminación de origen microbiológico ocurre ya sea en las tuberías de distribución, tanques domiciliarios y/o las prácticas de uso del agua de cada domicilio

Abstract:The presence of coliform bacteria in water presents a potential threat to public health, as it can increase the risk of infectious diseases in the most vulnerable population. The matter is more complicated when the physicochemical and microbiological quality of the water consumed is unknown. The purpose of this study is to evaluate the current state of the quality of drinking water in three Territorial Base Organizations (OTB’s) of the Municipality of Vinto-Cochabamba and the relationship of dependence of the microbiological parameters with the OTB’s. Laboratory analyzes of 30 samples taken from different homes (10 samples per OTB) show compliance with the maximum permissible limits of physicochemical parameters (pH, conductivity, alkalinity and hardness) according to Bolivian Standard 512 (NB 512). Regarding the microbiological parameters for total coliforms, of the 30 samples analyzed, only 11 met the maximum permissible limit, unlike the total coliform parameter, where 25 of the 30 samples met the maximum permissible limit. The microbiological parameters were subjected to chi-square analysis, providing sufficient evidence to affirm with 95% confidence that the results of total and heat-resistant coliforms do not depend on the OTB (p=0.36). By contrasting the results of household water consumption with that of water supplied, it can be speculated that contamination of microbiological origin occurs either in the distribution pipes, household tanks and/or the water use practices of each household.

Abstract Surveillance indicators of the quality of water for human consumption in the Amazon were analysed from 2016 to 2020 using 185,528 samples from 11 microregions. Of the samples analysed, 93.20% were from urban areas, 66.65% were from the public water supply system (WSS), 31.02% were from the Collective Alternative Solution-CAS, and 2.33% from the Individual Alternative Solution-IAS. There was an increase in the number of records by the WSS, with a downwards trend and fluctuations in records for the CAS and the IAS. The quality indicators of chemical and physical parameters for urban areas were higher than those for rural areas and traditional communities. Most of the samples presented pH values below the recommended level. In the quantification of microbiological parameters, a higher presence of total coliforms and E. coli was identified in samples from rural areas and in traditional communities. In conclusion, there were inadequacies in the chemical, physical and microbiological parameters as well as problems related to the supply, storage and surveillance of water distributed for human consumption. These findings indicate the need to build an agenda for public management to address water insecurity and its likely effects on food insecurity in the region. 201 202 185528 185 528 185,52 1 microregions 9320 93 20 93.20 6665 66 65 66.65 WSS , (WSS) 3102 31 02 31.02 SolutionCAS, SolutionCAS Solution CAS, Solution-CAS 233 2 33 2.33 SolutionIAS. SolutionIAS IAS Solution-IAS communities level E conclusion region 18552 18 52 185,5 932 9 93.2 666 6 66.6 (WSS 310 3 0 31.0 23 2.3 1855 5 185, 93. 66. 31. 2.

Resumo Analisaram-se indicadores de vigilância da qualidade da água para consumo humano no Amazonas, de 2016 a 2020, utilizando 185.528 amostras provenientes de 11 microrregiões. Das amostras analisadas, 93,20% são da área urbana, 66,65% provinham do sistema público (SAA), 31,02% da Solução Alternativa Coletiva (SAC) e 2,33% da Solução de Alternativa Individual (SAI). Observou-se aumento do número de registros pelo SAA, com tendência de queda e oscilações de registros para a SAC e a SAI. Os indicadores de qualidade dos parâmetros químicos e físicos da área urbana foram superiores aos das áreas rurais e de comunidades tradicionais. A maior parte das amostras apresentou valores de pH abaixo do recomendado. Na quantificação dos parâmetros microbiológicos, identificou-se maior presença de coliformes totais e E.coli na área rural e em comunidades tradicionais. Em conclusão, verificaram-se inadequações nos parâmetros químicos, físicos e microbiológicos, assim como problemas relativos ao abastecimento, armazenamento e à vigilância da água distribuída para consumo humano. Tais achados indicam a necessidade de construir uma agenda, pela gestão pública, para o enfrentamento da insegurança hídrica e seus prováveis efeitos sobre a insegurança alimentar existente na região. Analisaramse Analisaram se Amazonas 201 2020 185528 185 528 185.52 1 microrregiões analisadas 9320 93 20 93,20 6665 66 65 66,65 SAA , (SAA) 3102 31 02 31,02 (SAC 233 2 33 2,33 SAI . (SAI) Observouse Observou tradicionais recomendado microbiológicos identificouse identificou Ecoli E coli conclusão verificaramse verificaram abastecimento agenda pública região 202 18552 18 52 185.5 932 9 93,2 666 6 66,6 (SAA 310 3 0 31,0 23 2,3 (SAI 1855 5 185. 93, 66, 31, 2,

ABSTRACT The paper analyzes the quality of the water supplied by the potable water treatment plant Altos of Quintero to the city of Santiago de Cuba through the study of five consumers. The quality of the parameters analyzed was determined for pH, color, turbidity, residual free chlorine and determination of total and fecal coliforms, resulting in La Colonia, La Cervecería Hatuey and the Combined Milk, which residual free chlorine and turbidity are outside the norm in some occasions. The effects of the quality of drinking water coming from the potabilizer were mainly the deterioration of the infrastructure of the supply networks and poor storage conditions of the liquid in the above mentioned institutions. Options are presented to ensure that water quality is maintained in the different consumption centers and a predictable model is proposed that allows the maximum time that guarantees the minimum level of allowable residual chlorine that a consumer source should have.

RESUMEN El trabajo analiza la calidad del agua que suministra la potabilizadora Altos de Quintero a la ciudad de Santiago de Cuba mediante el estudio de cinco consumidores. Al agua de los seis centros analizados se les determinó su calidad por la medición de los parámetros: pH, color, turbidez, cloro libre residual y determinación de coliformes totales y fecales, resultando La Colonia, La Cervecería Hatuey y el Combinado Lácteo las entidades en las cuales el cloro libre residual y la turbidez se encuentran fuera de norma en algunas ocasiones. Las afectaciones de la calidad del agua potable procedente de la potabilizadora se deben fundamentalmente al deterioro de la infraestructura de las redes de abastecimiento y a las malas condiciones de almacenamiento del líquido en las instituciones antes mencionadas. Se presentan opciones para garantizar que se mantenga la calidad del agua en los diferentes centros de consumo y se propone un modelo predictivo que posibilita determinar el tiempo máximo que garantiza el mínimo nivel de cloro residual libre permisible que debe disponer una fuente consumidora.

Stormwater harvesting is a promising solution for global freshwater depletion, particularly in tropical regions with abundant rainfall. However, it is not widely used due to the lack of suitable treatment technologies for domestic applications. Multi-stage filtration (MSF) is an effective integrated treatment technology that provides a cost-effective alternative for stormwater treatment. This study investigated MSF's capacity for treating stormwater at different stages. The MSF designed and built comprised the down-flow roughing filter (DRF) and slow sand filter (SSF). The results achieved by the MSF for the treated effluents were: pH (7.1-8.1), temperature (27.6-29.4°C), electrical conductivity (EC) (100-190 µS/cm) and total dissolved solids (TDS) (70-130 mg/L). Turbidity removal efficiency of the MSF was in the range of 36-99% (5.825-164.05 NTU) and the overall average removal efficiency of the MSF was 74%, 90% and 86% for total coliforms (TC) (360-11 800 CFU/ 100 mL), faecal coliforms (FC) (0-1 300 CFU/100 mL) and Enterococcus spp. (120- 1 400 CFU/100 mL), respectively. The study identified stormwater reuse potentials based on international guidelines and benchmarks. For the treated effluent, pH, temperature, EC and TDS were all within the permissible limits for toilet, laundry, bathing, recreational and agricultural water reuse, while turbidity suited agricultural (non-food crop) and restricted urban reuse. 46% of the effluent was suitable for recreational purposes as this satisfied the 50 NTU standard. 62.5% of the effluent satisfied the FC standard for toilets and urinals and agricultural reuse (non-food crop) purposes, while 87.5 % of the effluent satisfied urban reuse purposes (restricted access). 66.67% of the effluent satisfied the Enterococcus spp. standard for agricultural reuse (non-food crop). All treated effluents satisfied the TC bathing standard. This study shows that after minimal disinfection, stormwater effluents offer potential reuse in household applications, thereby reducing potable water demand.

Resumo O presente estudo envolve a análise química e bacteriológica de água de diferentes fontes, ou seja, furo, poços, garrafa e torneira, dos distritos de Peshawar, Mardan, Swat e Kohat da província de Khyber Pakhtunkhwa (KP), Paquistão. De cada distrito, 50 amostras de água (10 amostras de cada fonte), independentemente do status urbano e rural, foram coletadas dessas fontes e analisadas para sulfatos, nitratos, nitritos, cloretos, sólidos solúveis totais e coliformes (E. coli). Os resultados indicaram que a maioria das fontes de água tinha uma contagem inaceitável de E. coli, ou seja, > 34 UFC / 100 mL. As amostras positivas para E. coli foram elevadas no distrito de Mardan, seguido por Kohat, Swat e distrito de Peshawar. Além disso, algumas fontes de água também foram contaminadas quimicamente por diferentes fertilizantes inorgânicos (nitratos/nitritos de sódio, potássio), mas em níveis seguros, enquanto os resíduos agrícolas e industriais (compostos de cloreto e sulfato) estavam em níveis inseguros. Entre todos os distritos, a qualidade da água foi considerada comparativamente mais deteriorada nos distritos de Kohat e Mardan do que nos distritos de Peshawar e Swat. Essas fontes de água química e bacteriologicamente impróprias para beber podem causar problemas à saúde humana.

Abstract The present study involves the chemical and bacteriological analysis of water from different sources i.e., bore, wells, bottle, and tap, from Peshawar, Mardan, Swat and Kohat districts of Khyber Pakhtunkhwa (KP) province, Pakistan. From each district, 50 water samples (10 samples from each source), regardless of urban and rural status, were collected from these sources and analysed for sulphates, nitrates, nitrites, chlorides, total soluble solids and coliforms (E. coli). Results indicated that majority of the water sources had unacceptable E. coli count i.e.> 34 CFU/100mL. E. coli positive samples were high in Mardan District, followed by Kohat, Swat and Peshawar district. Besides this, the some water sources were also chemically contaminated by different inorganic fertilizers (nitrates/nitrites of sodium, potassium) but under safe levels whereas agricultural and industrial wastes (chloride and sulphate compounds) were in unsafe range. Among all districts, the water quality was found comparatively more deteriorated in Kohat and Mardan districts than Peshawar and Swat districts. Such chemically and bacteriologically unfit water sources for drinking and can cause human health problems.

Leachate from a composting plant was characterized and applied as a biofertilizer in lettuce crops. Characteristics of untreated (UE) and anaerobically treated (TE) leachate samples were compared. The pH of TE (8.2) increased in relation to the UE (5.2) due to an increase in ammonia nitrogen in TE (1197 mg L-1) compared to UE (859 mg L-1). Anaerobic treatment was efficient in the removal of organic matter from the leachate, evaluated by the decrease of dissolved organic carbon, biochemical oxygen demand, total organic carbon and total solids. K presented the highest concentration (1743 mg L-1) in TE, followed by Mg (135 mg L-1). Cd, Pb and Cr were present at low concentrations in the samples, 0.047, 0.206 and 0.081 mg L-1, respectively. Salmonella, thermotolerant coliforms and viable helminth eggs were not present in TE, which was applied as a biofertilizer in a lettuce crop and compared to mineral fertilization based on fresh matter and dry matter production. Lettuce production using TE was statistically equivalent to mineral fertilization. Toxic metals were not detected in the lettuce shoots. It was concluded that the anaerobically treated leachate from the composting company has the potential to be used as a biofertilizer. crops (UE (TE 8.2 82 8 2 (8.2 5.2 52 5 (5.2 1197 (119 L1 L 1 L-1 859 (85 L1. . demand solids 1743 (174 135 (13 Cd 0047 0 047 0.047 0206 206 0.20 0081 081 0.08 L1, 1, respectively Salmonella shoots 8. (8. 5. (5. 119 (11 L- 85 (8 174 (17 13 (1 004 04 0.04 020 20 0.2 008 08 0.0 (5 11 ( 17 00 02 0.

Abstract The implementation of effective cleaning and disinfection procedures is crucial to ensure quality control and food safety in food services. This study aimed to evaluate the hygienic conditions in the gastronomy laboratories of a university in Colombia. The study conducted ATP bioluminescence detection and microbiological analysis on various surfaces and food handler's hands. The results indicated the presence of aerobic mesophilic bacteria and total coliforms on the surfaces, but no Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, or Salmonella spp. The cutting-board had the highest microbial counts, while the countertop and serving dish had the lowest. Total coliform counts exceeded the acceptable limits on most surfaces. Correlations between ATP levels and microbial counts were not significant. ATP measurements indicated organic contamination, but not necessarily high microbial loads. The findings emphasize the importance of proper cleaning, disinfection protocols, and personal hygiene practices to prevent cross-contamination and ensure food safety. services Colombia handlers handler s hands coli aureus monocytogenes spp cuttingboard cutting board lowest significant contamination loads protocols crosscontamination cross

Abstract Solar Water Disinfection, known as SODIS, is a treatment method involving the exposure of water to solar radiation (UVA light and heat) to eliminate pathogenic microorganisms. Organic coagulants extracted from Moringa oleifera (T1) and Salvia hispanica (T2) were used in conjunction with the filtration process as auxiliaries. This process included sand filters with particle sizes ranging from 0.25 mm to 0.850 mm and a non-woven geotextile placed at its base. After undergoing the coagulation/flocculation/sedimentation/filtration process, the samples were exposed to sunlight in a solar concentrator using bottles painted on half of their surface (PR) and unpainted bottles (BR). The analyzed parameters included physicochemical properties such as pH, electrical conductivity, turbidity, and apparent color, as well as microbiological parameters, including E. coli and total coliforms. The results of physicochemical analyses demonstrated the superiority of T1 in terms of turbidity and apparent color. Regarding microbiological analyses, they showed the effective removal of E. coli and total coliforms, with 100% inactivation observed in the samples. It was observed that the applied treatment sequence significantly reduced the microbiological load of the samples; however, it cannot be stated with certainty whether the coagulants exerted any influence on this result. Disinfection SODIS UVA heat microorganisms T (T1 T2 (T2 auxiliaries 025 0 25 0.2 0850 850 0.85 nonwoven non woven base coagulationflocculationsedimentationfiltration coagulation flocculation sedimentation PR (PR BR. BR . (BR) pH conductivity color E coliforms 100 however result (T 02 2 0. 085 85 0.8 (BR 10 08 8 1

Resumo O sistema de desinfecção solar, conhecido como SODIS (Solar Water Disinfection), é um método que envolve a exposição da água à radiação solar (luz UVA e calor) para eliminar microrganismos patogênicos. Coagulantes orgânicos extraídos da Moringa oleifera (T1) e Salvia hispanica (T2) foram usados em conjunto com o processo de filtração como auxiliares. Esse processo incluiu filtros de areia com tamanhos de partícula variando de 0,25 mm a 0,850 mm e uma manta geotêxtil não tecida colocada em sua base. Após passarem pelo processo de coagulação/floculação/sedimentação/filtração, as amostras foram expostas ao sol em um concentrador solar usando garrafas pintadas na metade de sua superfície (PR) e garrafas não pintadas (BR). Os parâmetros analisados incluíram propriedades físico-químicas como pH, condutividade elétrica, turbidez e cor aparente, bem como parâmetros microbiológicos, incluindo E. coli e coliformes totais. Os resultados das análises físico-químicas demonstraram a superioridade de T1 em termos de turbidez e cor aparente. Em relação às análises microbiológicas, as análises demostraram a remoção eficaz de E. coli e coliformes totais, com 100% de inativação observada nas amostras. Portanto, foi observado que a sequência de tratamento aplicada reduziu significativamente a carga microbiológica das amostras; contudo, não se pode afirmar com certeza se os coagulantes exerceram alguma influência nesse resultado. Solar Disinfection, Disinfection , Disinfection) luz calor patogênicos T (T1 T2 (T2 auxiliares 025 0 25 0,2 0850 850 0,85 base coagulaçãofloculaçãosedimentaçãofiltração coagulação floculação sedimentação coagulação/floculação/sedimentação/filtração PR (PR BR. BR . (BR) físicoquímicas físico químicas pH elétrica aparente microbiológicos E totais microbiológicas 100 Portanto contudo resultado (T 02 2 0, 085 85 0,8 (BR 10 08 8 1

Resumo Analisaram-se indicadores de vigilância da qualidade da água para consumo humano no Amazonas, de 2016 a 2020, utilizando 185.528 amostras provenientes de 11 microrregiões. Das amostras analisadas, 93,20% são da área urbana, 66,65% provinham do sistema público (SAA), 31,02% da Solução Alternativa Coletiva (SAC) e 2,33% da Solução de Alternativa Individual (SAI). Observou-se aumento do número de registros pelo SAA, com tendência de queda e oscilações de registros para a SAC e a SAI. Os indicadores de qualidade dos parâmetros químicos e físicos da área urbana foram superiores aos das áreas rurais e de comunidades tradicionais. A maior parte das amostras apresentou valores de pH abaixo do recomendado. Na quantificação dos parâmetros microbiológicos, identificou-se maior presença de coliformes totais e E.coli na área rural e em comunidades tradicionais. Em conclusão, verificaram-se inadequações nos parâmetros químicos, físicos e microbiológicos, assim como problemas relativos ao abastecimento, armazenamento e à vigilância da água distribuída para consumo humano. Tais achados indicam a necessidade de construir uma agenda, pela gestão pública, para o enfrentamento da insegurança hídrica e seus prováveis efeitos sobre a insegurança alimentar existente na região.

Abstract Surveillance indicators of the quality of water for human consumption in the Amazon were analysed from 2016 to 2020 using 185,528 samples from 11 microregions. Of the samples analysed, 93.20% were from urban areas, 66.65% were from the public water supply system (WSS), 31.02% were from the Collective Alternative Solution-CAS, and 2.33% from the Individual Alternative Solution-IAS. There was an increase in the number of records by the WSS, with a downwards trend and fluctuations in records for the CAS and the IAS. The quality indicators of chemical and physical parameters for urban areas were higher than those for rural areas and traditional communities. Most of the samples presented pH values below the recommended level. In the quantification of microbiological parameters, a higher presence of total coliforms and E. coli was identified in samples from rural areas and in traditional communities. In conclusion, there were inadequacies in the chemical, physical and microbiological parameters as well as problems related to the supply, storage and surveillance of water distributed for human consumption. These findings indicate the need to build an agenda for public management to address water insecurity and its likely effects on food insecurity in the region.

PEO/TiP fibers were obtained using the Solution Blow Spinning (SBS) apparatus and heat treated to produce TiO2 fibers. The morphological and structural characteristics were assessed using SEM and X-ray diffraction. The fibers, with a thickness of 12 μm, showed a change in crystalline structure with heat treatment. At temperatures as low as 800 °C, only the anatase phase was identified, while at 900 °C, both anatase and rutile phases coexisted. The addition of TiP to the polymer matrix reduced the initial breakdown temperature, and the DSC curves showed exothermic peaks due to the amorphous phase transition to TiO2/anatase. The fibers' photocatalytic capacity was tested, revealing that TiO2-fibers in the anatase phase achieved 97% degradation of Rhodamine-B dye in 40 minutes. The study found that the biocide efficacy of TiO2-fibers depends on their heat treatment. Fibers with anatase/rutile or pure rutile phases did not show significant efficiency. However, fibers treated at 600°C with pure anatase phase were more effective in eliminating E. coli and total coliforms. Finally, we can state that the TiO2 fibers obtained in this work using the SBS technique can be used to produce filters to purify water contaminated by pathogens dangerous to human health or even to purify the air. PEOTiP PEO (SBS TiO Xray X ray diffraction 1 μm treatment 80 C °C identified 90 coexisted temperature TiO2anatase TiOanatase TiO2/anatase tested TiO2fibers TiOfibers 97 RhodamineB Rhodamine B 4 minutes anataserutile efficiency However 600C 600 E coliforms Finally air 8 9 60 6

Resumen Las tasas de crecimiento y urbanización de las ciudades pronostican el aumento de residuos. En los países en desarrollo la fracción orgánica representa aproximadamente la mitad del total de residuos generados; esta fracción genera lixiviados, gases tóxicos y la aparición de vectores. El compostaje es la alternativa más sencilla y económica para la recuperación de los residuos orgánicos. En este estudio se evaluó la calidad de dos compost elaborados con residuos orgánicos (CRO) y heces de mascota (CM). La pregunta de investigación analizó el efecto de estos abonos en la germinación y crecimiento de hortalizas seleccionadas. Se determinaron los principales parámetros de calidad y se diseñaron tratamientos con diferentes mezclas de CRO y CM. Los abonos evaluados se encuentran en su mayoría dentro de los parámetros de calidad. El porcentaje de germinación del CRO (18 %) y del CM (10 %) fue menor al requerido (80 %); y el CM excedió (1100 NMP/g) el máximo recomendado de coliformes totales (1000 NMP/g). La germinación fue mayor CRO y CM al 25 % (84 % en ambos casos). En los ensayos de crecimiento el control finalizó con mayor altura (13.88 cm), seguido del CRO al 10 % (13.22 cm) y CM al 25 % (11.50cm). Los resultados demuestran el potencial de los residuos orgánicos urbanos, incluyendo los desechos de mascotas, para el compostaje y sus efectos beneficiosos en el crecimiento de las plantas.

Abstract The rates of urban growth and urbanization indicate a projected increase in waste generation. In developing countries, the organic fraction constitutes approximately half of the total waste, leading to the production of leachate, toxic gases, and the emergence of vectors. Composting emerges as a straightforward and cost-effective solution for organic waste recovery. This study focused on evaluating the quality of compost derived from organic waste (CRO) and pet feces (CM). The research aimed to investigate the impact of these composts on the germination and growth of selected vegetables. The primary quality parameters were assessed, and different mixtures of CRO and CM were implemented as experimental treatments. The majority of the fertilizers examined complied with the quality standards. However, the germination percentage of CRO (18 %) and CM (10 %) fell below the required threshold (80 %), and CM surpassed the recommended maximum level of total coliforms (1100 NMP/g compared to the recommended 1000 NMP/g). Notably, a higher germination percentage (84 %) was observed for both CRO and CM at a 25 % compost addition. In terms of growth trials, the control group exhibited the tallest plants (13.88 cm), followed by the 10 % CRO treatment (13.22 cm) and the 25 % CM treatment (11.50 cm). The findings underscore the potential of urban organic waste, including pet waste, for composting and its positive impact on plant growth.

RESUMEN El objetivo fue conocer la calidad e inocuidad del queso fresco que se expende en un mercado de la Ciudad de Riobamba con la finalidad de establecer si es apto para el consumo humano, el nivel de resistencia bacteriana y las repercusiones en la salud del consumidor, siguiendo procedimientos y normativas nacionales e internacionales. Se analizó la presencia de Staphylococcus aureus, Coliformes totales y Escherichia coli, con recuentos en Placas Petrifilm 3M, el procedimiento se manejó con tres diluciones consecutivas, las mismas que se inocularon, incubaron, cuantificaron, se realizaron las pruebas confirmatorias en Placas Petri y antibiograma utilizando el método Kirby Bawer. Los resultados fueron: 1,3x106 UFC/g de Staphylococcus aureus, 7x105 UFC/g de Escherichia coli y 8,5x105 UFC/g de Coliformes totales; después se comparó estadísticamente mediante el Test T de Student, demostrando que los valores sobrepasan los máximos permitidos para el consumo humano, lo cual indica una cadena agroalimentaria deficiente, en donde existe un gran nivel de contaminación del medio en el cual se procesan, transportan y expenden los quesos frescos, por ende se hace un llamado a las entidades municipales y gubernamentales de salud para que incluyan políticas de control y regulación.

ABSTRACT The objective was to determine the quality and safety of fresh cheese sold in a market in the city of Riobamba in order to establish whether it is suitable for human consumption, the level of bacterial resistance and the repercussions on consumer health, following national and international procedures and regulations. The presence of Staphylococcus aureus, total coliforms and Escherichia coli was analyzed with counts in 3M Petrifilm Plates, The procedure was handled with three consecutive dilutions, which were inoculated, incubated, quantified, and confirmatory tests were performed in Petri Plates and antibiogram using the Kirby Bawer method. The results were: 1.3x106 CFU/g of Staphylococcus aureus, 7x105 CFU/g of Escherichia coli and 8.5x105 CFU/g of total coliforms. Statistical comparisons were then performed using the Student's t-test. It was found that the levels exceed the maximum values allowed for human consumption, which indicates a deficient agri-food chain, where there is a high level of contamination of the environment in which fresh cheeses are processed, transported and sold. In this regard, a call is made to municipal and governmental health entities to include control and regulation policies.

Resumen Introducción: La acuacultura de truchas ha incrementado gradualmente en las tierras altas de Costa Rica. Las aguas residuales de esta actividad son descartadas directamente en los ríos, sin tratamientos previos. Como consecuencia, la actividad truchícola puede contaminar severamente el agua de los ríos con bacterias que pueden afectar la salud humana. Objetivo: Evaluar la contaminación bacteriana por la acuacultura de truchas en el río Savegre, Costa Rica. Métodos: Contamos los coliformes totales y Escherichia coli de muestras mensuales (2015-2018) en tres secciones del proyecto de acuacultura más grande de la cuenca alta del río. Recolectamos las muestras en la entrada de los estanques para las truchas, a la salida, y 200 m hacia abajo. Resultados: Encontramos menos coliformes totales y E. coli en el agua recolectada justo en la salida del agua de los estanques. El número de coliformes totales fue mayor en el 2016 y 2017, y de E. coli en el 2016. Conclusiones: Conteos de coliformes y de E. coli es muy alto en el río, pero inesperadamente, su número disminuye en el agua residual descartada de los estanques. Podría ser que el mucus producido por las truchas o sustancias liberadas del musgo que cubre la pared de los estanques reduzca el crecimiento de bacterias, como se ha sido sugerido en otros estudios. La contaminación del río parece venir de otras fuentes.

Abstract Introduction: The trout aquacultural activity has gradually increased in Costa Rican highlands. Residual waters from this activity are discarded directly in the rivers without any previous treatment process. Consequently, this activity could severely contaminate the river with bacteria that can affect human health. Objective: To evaluate bacterial contamination from trout aquaculture on Río Savegre, Costa Rica. Methods: We counted total coliforms and Escherichia coli from monthly samples (2015-2018) at three sections of the largest aquacultural development in the upper drainage of the river. We collected samples at the fish ponds entrance, exit and 200 m downwards. Results: We found fewer total coliforms and E. coli in the water collected just at the exit of the fish ponds. We counted more total coliforms in 2016 and 2017, and more E. coli in 2016. Conclusions: Coliform and E. coli counts are high in the river, but, unexpectedly, low in the water discarded from the fish tanks. Perhaps the mucus produced by the trouts or substances released by mosses on the fish tank walls reduce bacterial growth, as suggested by other studies. River pollution appears to come from other sources.

Abstract Introduction: Socioeconomic growth has caused pressure on marine ecosystems, and there is little information that can be used for the management of beaches in Nicoya, Costa Rica. Objective: To determine the physicochemical and microbiological quality of marine-coastal water in Nicoya, Costa Rica. Methods: In October 2021, and May and June 2022, we used standard methods to assess physicochemical and microbiological water conditions, in three beaches with different administrations and number of tourists. Results: Water temperature ranged between 26,1°C to 31,2°C, salinity between 22 to 31ups, dissolved oxygen from 3,6 to 7,3mg/L, and total suspended hydrocarbon values were below the detection limit. Higher fecal contamination was found in the rainy season, with maximum values of 3,5x103 NMP/100mL fecal coliforms, 1,1x103 NMP/100mL Escherichia coli and 2,4x103 NMP/100mL Enteroccocus faecalis. Conclusion: While fecal contamination was high during the rainy season, physicochemical parameters were acceptable in the three beaches.

Resumen Introducción: El crecimiento socioeconómico ha causado presión sobre los ecosistemas marinos, y existe poca información que pueda ser utilizada para el manejo de playas en Nicoya, Costa Rica. Objetivo: Determinar la calidad fisicoquímica y microbiológica del agua marino-costera en Nicoya, Costa Rica. Métodos: En octubre de 2021, y mayo y junio de 2022, usamos métodos estándar para evaluar las condiciones fisicoquímicas y microbiológicas del agua, en tres playas con diferentes administraciones y número de turistas. Resultados: La temperatura del agua osciló entre 26,1°C y 31,2°C, la salinidad entre 22 y 31ups, el oxígeno disuelto entre 3,6 y 7,3mg/L y los valores de hidrocarburos totales suspendidos estuvieron por debajo del límite de detección. La mayor contaminación fecal se encontró en época de lluvias, con valores máximos de 3,5x103 NMP/100mL coliformes fecales, 1,1x103 NMP/100mL Escherichia coli y 2,4x103 NMP/100mL Enteroccocus faecalis. Conclusión: Si bien la contaminación fecal fue alta durante la época de lluvias, los parámetros fisicoquímicos fueron aceptables en las tres playas.

Abstract Introduction: Consumption of fresh tomatoes has increased over the years and production systems (conventional or hydroponic), harvest and post-harvest practices, irrigation water and harvest containers, can affect the microbiological quality of the final product. Objective: To compare the microbiological quality of the cultivated or harvested fruit, the irrigation water, and the harvest containers in two tomato production farms (conventional and hydroponic). Methods: We carried out three sampling visits in each farm (repetitions), taking, in each repetition, 3 tomatoes of each type (composite sample), 50 ml of irrigation water and swabbing 50cm2 of the surface of three harvest containers (composite sample). We determined indicator microorganisms such as total aerobic mesophilic count, mold and yeast count, total coliforms, thermotolerant coliforms and E. coli. Presence of Listeria monocytogenes was also analyzed in fruits. We applied student's t-tests at a significance level of 5%. Results: Total aerobic mesophilic and mold and yeast counts of hydroponic tomato were significantly lower than in conventional tomato, while no difference in total coliform counts and E. coli was detected. L. monocytogenes was absent in all samples. The total aerobic mesophilic count was higher in the harvest containers of the conventional farm. In both farms, irrigation water was not considered a source of contamination since it had very low levels of total coliforms, thermotolerant coliforms, and E. coli. Finally, an adequate control during harvesting was presumed, having found no difference in the microbiological indicators between the cultivated and harvested tomato. Conclusion: Hydroponic tomatoes are more likely to have a better microbiological profile and longer shelf life compared to conventionally grown tomatoes, evidencing the importance of environmental control and cleaning and disinfection of all elements used in the farming, harvesting and postharvest processes.

Resumen Introducción: El consumo de tomate fresco ha ido en aumento a través de los años y los sistemas de cultivo (convencional o hidropónico), las prácticas de cosecha y poscosecha, el agua de riego y los contenedores pueden incidir sobre su calidad microbiológica. Objetivo: Comparar la calidad microbiológica de la fruta cultivada o cosechada, del agua de riego y de los contenedores de cosecha en dos fincas de producción de tomate (convencional e hidropónica). Métodos: Realizamos tres muestreos a cada finca (repeticiones), tomando, en cada repetición, 3 tomates de cada tipo que conformaron una muestra compuesta, 50 ml de agua de riego e hisopando 50cm2 de la superficie de tres contenedores de cosecha (muestra compuesta). Determinamos los indicadores microbiológicos de recuento total aerobio mesófilo, recuento de hongos filamentosos y levaduras, coliformes totales, coliformes termotolerantes y E. coli. Además, analizamos la presencia de Listeria monocytogenes en los frutos. Aplicamos pruebas de t-student a un nivel de significancia del 5%. Resultados: Los recuentos total aerobio mesófilo y hongos filamentosos y levaduras del tomate hidropónico fueron significativamente menores que en el tomate convencional, mientras que no hubo diferencia en los recuentos de coliformes totales y E. coli, además L. monocytogenes estuvo ausente en todas las muestras. El recuento total aerobio mesófilo fue mayor en los contenedores de cosecha de la finca convencional. En ambas fincas el agua de riego no se consideró fuente de contaminación pues tuvo niveles muy bajos de coliformes totales, coliformes termotolerantes y E. coli. Finalmente, se presume un control adecuado en las fincas durante la cosecha, al no haber encontrado diferencia en los indicadores microbiológicos entre el tomate cultivado y el cosechado. Conclusión: Los tomates hidropónicos presentan mayor probabilidad de tener un mejor perfil microbiológico y mayor vida útil en comparación con los tomates cultivados de forma convencional, evidenciando la importancia del control ambiental y la limpieza y desinfección de todos los insumos utilizados en los procesos de cultivo, cosecha y poscosecha.