Total coliforms, microbial diversity and multiple characteristics of Salmonella in soil-irrigation water-fresh vegetable system in Shaanxi, China.

Global occurrences of foodborne disease outbreaks have been documented, involving fresh agricultural produce contaminated by various pathogens. This contamination can occur at any point in the supply chain. However, studies on the prevalence of total coliforms, Salmonella and microbial diversity in vegetable and associated environments are limited. This study aimed to assess 1) the number of total coliforms (n = 299) and diversity of microbial communities (n = 52); 2) the prevalence, antibiotic susceptibility, genomic characteristics, and potential transmission relationships of Salmonella in soil-irrigation water-vegetable system (n = 506). Overall, 84.28 % samples were positive to total coliforms, with most frequently detected in soil (100 %), followed by irrigation water (79.26 %) and vegetables (62.00 %). A seasonal trend in coliform prevalence was observed, with significantly higher levels in summer (P < 0.05). Detection rates of Salmonella in soil, vegetable and irrigation water were 2.21 %, 4.74 % and 9.40 %. Fourteen serotypes and sequence types (STs) were respectively annotated in 56 Salmonella isolates, ST13 S. Agona (30.36 %, 17/56), ST469 S. Rissen (25.00 %, 14/56), and ST36 S. Typhimurium (12.50 %, 7/56) were dominant serotypes and STs. Thirty-one (55.36 %) isolates were multi-drug resistant, and the resistance was most frequently found to ampicillin (55.36 %, 31/56), followed by to sulfamethoxazole (51.79 %, 29/56) and tetracycline (50.00 %, 28/56). The genomic characteristics and antibiotic resistance patterns of Salmonella isolates from soil, vegetables, and irrigation water within a coherent geographical locale exhibited remarkable similarities, indicating Salmonella may be transmitted among these environments or have a common source of contamination. Microbial alpha diversity indices in soil were significantly higher (P < 0.05) than that in vegetable and irrigation water. The microbial phylum in irrigation water covered that in the vegetable, demonstrating a significant overlap in the microbial communities between the vegetables and the irrigation water.

Efecto de la actividad truchícola sobre la concentración de coliformes totales y Escherichia coli en aguas de la cuenca alta del río Savegre, Costa Rica

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.

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.

The efficacy of hydrogen sulfide (H2S) tests for detecting microbial contamination in rooftop-harvested rainwater.

As climate change strains the world's freshwater resources, access to safe and clean water becomes limited. The use of alternative water sources, such as rooftop-harvested rainwater, has become one mechanism to address freshwater scarcity in the American Southwest, particularly when it comes to home gardening. The University of Arizona's Project Harvest, in partnership with the Sonora Environmental Research Institute, Inc., is a multi-year, co-created citizen science project aimed at increasing current understanding of harvested rainwater quality. Citizens in four Arizona, USA, communities (Hayden/Winkelman, Globe/Miami, Dewey-Humboldt, and Tucson) submitted harvested rainwater samples over 3 years. The harvested rainwater samples were then analyzed using IDEXX Colilert® for total coliforms and E. coli and using Hach PathoScreen™ test for sulfate-reducing bacteria (SRB). This study design allows for the validation of a low-cost, at-home alternative methodology for testing rainwater for bacteria that may indicate fecal contamination. In total, 226 samples were tested using both methodologies, revealing a positive correlation (r=0.245; p<0.002) between total coliform MPN and SRB MPN, but no discernable correlation between E. coli MPN and SRB MPN. This work indicates a potential value of SRB testing for harvested rainwater if cost, laboratory access, and fecal contamination are of concern.

Microbiological quality of water samples obtained from water sources in Ishaka, Uganda.

Objectives: This study aimed to evaluate the microbiological quality of water sources in Ishaka division, Bushenyi district. Methods: Water from taps, wells and springs were sampled for the cross-sectional investigation. The enumeration and identification of microbes (Escherichia coli, Salmonella, Shigella, Proteus, Staphylococcus aureus and total coliforms) in water samples were carried out using a variety of methods. Escherichia coli was enumerated using the membrane filtration method; Salmonella, Shigella and Proteus using a two-step enrichment method; Staphylococcus aureus using the surface spread method and total coliforms using the most probable number technique. Mannitol salt agar was used for enumeration of Staphylococcus Aureus and violet red bile agar was used for enumeration of total coliforms and Escherichia coli; xylose lysine deoxycholate agar was used for both Salmonella spp. and Shigella spp. API-20E was used to phenotypically identify the Enterobacteriaceae contaminants in water. These included Escherichia coli, Proteus mirabilis, Proteus vulgaris, Salmonella spp. and Staphylococcus aureus. Results: Escherichia coli counts in the water from springs and wells ranged from 0 to 314 cfu/mL (p = 0.173) and 0 to 3 cfu/mL (p = 0.269), respectively, while tap water had no incidence of Escherichia coli. Highest level of bacterial contamination in water sources, beyond acceptable WHO (0 cfu/100 mL) limits for drinking water, was reported: Proteus spp., 34 (54.8%), followed by total coliforms, 24 (38.7%), Shigella spp., 22 (35.5%) and least were Salmonella spp. (8.1%) and Staphylococcus aureus spp. (8.1%). Conclusion: It is therefore concluded that spring and well community water sources in Ishaka division, Uganda, are significantly contaminated with pathogenic bacteria and thus unsafe for drinking without adequate water treatment (disinfection and filtration).

Effect of Type of Mulch on Microbial Food Safety Risk on Cucumbers Irrigated with Contaminated Water.

Mulches are used to block light and retain soil moisture which may affect the survival of bacterial pathogens on soil. This study examined the effectiveness of different types of mulches to minimize microbial risk from contaminated water used for irrigation of cucumbers. A production bed of 120 ft2 with 18 beds (30 ft long) covered with five different types of mulch (paper, paper with fertilizer incorporated (PF), maize-based mulch, biodegradable plastic covering, and conventional plastic) including three beds with no cover was planted with Dasher 2 Variety cucumber. Soil samples from each bed were collected for the first five weeks to examine natural E. coli and coliforms. Well water contaminated with or without nalidixic acid-resistant mutant of E. coli (8 Log CFU/mL) was used for drip irrigation for 7 days before harvesting. Prior to irrigation with contaminated water, naturally present E. coli and coliform in the soil samples with or without mulch were in the range of 3.45-3.78 Log CFU/g and 4.18-5.31 Log CFU/g, respectively. E. coli levels on cucumbers harvested from mulched beds and irrigated with contaminated irrigation water had significantly higher (P < 0.05) levels of E. coli as compared with samples from similar beds irrigated with noncontaminated water. However, Cucumber, harvested within each irrigation water quality were not significantly different regardless of the type of mulch with E. coli levels from 1.72 to 3.30 Log CFU/cm2 (contaminated water) and 0.28-1.86 Log CFU/cm2 (noncontaminated water). A significant die-off of inoculated E. coli was observed on cucumber within 3 days (>1.17 Log CFU/cm2) and >1.38 Log CFU/cm2 after 4 days. Beds with maize mulch were effective on minimizing E. coli contamination on cucumber from contaminated irrigation water.

Physical, chemical and microbiological assessments of drinking water of small-layer farms.

Water quality is critical for poultry farming. This study assessed the physical, chemical and microbiological quality of drinking water in small-layer farms in Southern Mozambique and identified potential risk factors for total coliform (TC) and Escherichia coli contamination of drinking water. In 20 farms, 57 samples were collected and examined for pH, nitrate content (NC), nitrite level (NL) and total hardness contents (TH). Furthermore, TC and E. coli growth were assessed at 37 °C. One hundred per cent of the drinking water was of acceptable quality in terms of pH (6.5-8.5), NC (50 mg/L) and NL (3 mg/L). Total hardness contents exceeded the recommended standard in 37.5% of borehole water samples and 91.7% of tap water samples, respectively. Total coliform and E. coli were found in 40% and 15% of water samples. Tap water samples had the greatest contamination, with TC and E. coli levels of 41.7% and 16.7%, respectively. Although not statistically significant, sampling from the beginning of the nipple line (p = 0.101, OR = 7.357, 95% confidence interval [CI]: 0.678-79.886) and not cleaning the rearing equipment regularly (p = 0.098, OR = 3.966, 95% CI: 0.766-20.280) were factors affecting the TC growth. Sampling from the tank water source (p = 0.001, OR = 0.005, 95% CI: 0.000-0.121) and borehole water source (OR = 13 585) and not cleaning the equipment consistently (p = 0.073, OR = 9.682, 95% CI: 0.810-115.68) were all factors affecting E. coli growth. It is concluded that the TH and microbiological quality of the drinking water of the study region are inadequate. Regular water quality assessments should be incorporated into Mozambican layer farm management to limit the potential for health concerns, and farmers should thoroughly clean and disinfect their rearing equipment.Contribution: We should incorporate regular water quality assessments into Mozambican layer farm management to limit the potential for health concerns, and farmers should thoroughly clean and disinfect their rearing equipment.

Peligros microbiológicos relacionados con alimentos fermentados de elaboración artesanal comercializados en Tunja, Nariño y Cauca / Microbiological risks related to artisanal fermented foods marketed in Tunja, Nariño and Cauca

RESUMEN Varios factores intervienen en la calidad de los alimentos, como los físicos, químicos, nutricionales, sensoriales y microbiológicos. Este último es importante, ya que, afecta las propiedades organolépticas del producto terminado y, además, puede ocasionar riesgos de salud pública asociados a peligros microbiológicos. Colombia es un país rico en gastronomía, incluyendo alimentos fermentados de elaboración artesanal (AFEA), los cuales son una alternativa actual para sistemas agroalimentarios que buscan alimentos más naturales. El objetivo de este estudio fue evaluar los criterios microbiológicos en AFEA y el cumplimiento de requisitos sanitarios para sensibilizar a productores de bebidas artesanales y revalorizar los productos. Se tomaron en cuenta 11 productores artesanales de Masato, Champús y Almidón agrio de yuca en zonas rurales del país, que voluntariamente aceptaron participar. Se midieron los parámetros de pH, humedad, sólidos solubles y recuentos microbiológicos. Con estos resultados, se pudo calcular el porcentaje de conformidad de los alimentos, de los cuales el 36 % de productos evaluados fueron aptos para el consumo. Se incumplieron los límites establecidos para Escherichia coli, Staphylococcus aureus, Bacillus cereus y Salmonella sp. Los análisis fisicoquímicos mostraron que el Masato y el Champús aportan condiciones abióticas para el crecimiento microbiano. Además, los productores Almidón agrio de yuca tuvieron mayor valoración en el cumplimiento de requisitos sanitarios y menor cumplimiento que los productores de Champús. Los análisis realizados indican que la mayoría de los alimentos incumplieron los límites permitidos por lo cual se debe capacitar a los productores en buenas prácticas de manufactura.

ABSTRACT Several factors intervene in the quality of the food, such as physical, chemical, nutritional, sensory, and microbiological. The latter is important as it affects the sensory properties of the finished product, and it can also cause public health risks associated with microbiological hazards. Colombia is a country rich in gastronomy, including artisanal fermented foods (AFEA), which are a current alternative for agri-food systems seeking for more natural foods. The objective of this study was to evaluate the microbiological criteria in AFEA and its compliance with the sanitary requirements to raise the awareness among crafted beverages producers and revalue the products. Eleven artisan producers of masato, champús and sour cassava starch in rural areas of the country, who voluntarily agreed to participate, were considered. The parameters of pH, humidity, soluble solids, and microbiological counts were measured. With these results, it was possible to calculate the compliance rate of the food, from which 36% of the products evaluated were fit for consumption. The limits established for Escherichia coli, Staphylococcus aureus, Bacillus cereus and Salmonella spp were breached. Physicochemical analysis showed that Masato and Champús provide abiotic conditions for microbial growth. In addition, the Sour cassava starch producers had higher compliance ratings regarding sanitary requirements but lower compliance ratings than champús producers. The performed analysis indicates that most of the food did not comply with the permitted limits, which is why producers must be trained in good manufacturing practices.

Chlorination of secondary treated wastewater with sodium hypochlorite (NaOCl): An effective single alternate to other disinfectants.

The present study provides details about the usefulness of chlorination in the recovery effluents of sewage, and to make it useable for irrigation purposes. Chlorination is one of the effective simplified, and cost-effective traditional methods for disinfection. The study was done for the period of March, 2019 to February, 2020. The disinfection process was optimized by adding sodium hypochlorite to the secondary treated effluents with the help of jar apparatus at a mixing speed of 100 rpm. To optimize the various process variables such as dose, and contact time, several concentrations of NaOCl (0.5, 1, 1.5, 2, 2.5, 3.0) ppm were carefully chosen at different time intervals of 15, 30, and 60 min respectively, which were centered on the foregoing studies. The factors like seasonal variation on MPN index of total coliforms (TCs), CR ∗ T concept, and effect of pH on log elimination of TCs, outcome of pH with rate constant (k), and results of pH against dilution coefficient (n) was also studied. The Chick-Watson, Rennecker-Marinas, Collin-Selleck, and modified Selleck models have shown good reliability to the experimental data of chlorine disinfection to be fit into these kinetic models for the treatment of sewage wastewater. The upgraded CR ∗ T values were attained by using disinfection models. Among these four models, the kinetic modeling by Collin-Selleck, and Selleck-White was investigated as the best modeling to be fitted more finely to the chlorination experimental data to count for the effectiveness of NaOCl. The selected indicator organism in the optimization process of chlorine was Total coliforms (TCs). The residual chlorine and most probable number per log unit (Log) for TCs were measured before the start and after the termination of the disinfection process. The World Health Organization (WHO) standard for pathogenic removal from wastewater, and to irrigate the crops is 3- to 4-log and the chlorine residual under 1 mg/l limit was accomplished.

Microbiological quality of the water in collection areas and the tissue of Mytella falcata-Cananéia (SP, Brazil).

Changes in fauna and abiotic factors in estuaries are a consequence of their exploitation; thus, bivalve mollusks, as they filter, are widely used as environmental bioindicators. The aim of this study was to analyze the existence of seasonal variation in the concentration of total coliforms (TC) and thermotolerant coliforms (Ct), in addition to correlating the data obtained with the salinity and temperature in collection areas of Mytella falcata and the soft tissue cultivated in the Estuarine Complex of Cananéia. Two biweekly samples of water and tissue were taken, for 12 consecutive months, in nine cultivation areas of M. falcata. The analysis of the water samples showed that the Fisheries Institute, Mosquiteiro, and Itapitangui have high TC densities, with respective annual averages of 772.22, 592.67, and 563.75 most probable number (MPN).100 ml-1 . The highest concentrations of TC and Ct occurred in the summer, in most areas. There was a decrease in both TC and Ct with increasing salinity. However, there was an increase in Ct with increasing temperature. The soft tissue showed TC densities from 9 to 26 MPN.100 ml-1 and Ct densities from 6 to 14 MPN.100 ml-1 , displaying the highest counts in the summer. Places where coliforms were found in high concentrations could indicate contamination, because Ct do not support higher salinities for a long time. PRACTITIONER POINTS: The general mean was 77.64 (total coliforms) and 39.35 (thermotolerant) MPN.100 ml-1 . Annual average (thermotolerant) exceeded the permitted Brazilian limit in five points. Higher concentrations of total and thermotolerant coliforms occurred in the summer. In mollusk's tissue, concentrations of thermotolerant were 6.30 to 26.16 MPN.100 g-1 . Coliforms' MPN varied with increasing salinity and temperature.

Removal of bacterial indicators in on-site two-stage multi-soil-layering plant under arid climate (Morocco): prediction of total coliform content using K-nearest neighbor algorithm.

This study aims to evaluate and monitor the efficacy of a full-scale two-stage multi-soil-layering (TS-MSL) plant in removing fecal contamination from domestic wastewater. The TS-MSL plant under investigation consisted of two units in series, one with a vertical flow regime (VF-MSL) and the other with a horizontal flow regime (HF-MSL). Furthermore, this study attempts to see whether linear model (LM) and K-nearest neighbor (KNN) model can be used to predict total coliform (TC) removal in the TS-MSL system. For 24 months, the TS-MSL system was monitored, with bimonthly measurements recorded at the inlet and outlet of each compartment. Obtained results show removal of 85% of COD, 67% of TP, 27% of TN, and 3 log units of coliforms with good system stability. Thus, the effluent meets the Moroccan water quality code for reuse in the irrigation of green spaces. In addition, as compared to LM, the KNN model (R2 = 0.988) may be considered as an effective method for predicting TC removal in the TS-MSL system. Finally, sensitivity analysis has shown that TC and dissolved oxygen level in the influent were the most influential parameters for predicting TC removal in the TS-MSL system.

A preliminary evaluation of microbial water quality in the irrigation pond.

This study aimed to determine the microbial water quality of Imrahor Pond by enumerating the coliform bacteria levels in the area. Water samples were collected biweekly from the surface and bottom waters at seven points in the pond. Samples were analyzed for total coliforms, Escherichia coli, physicochemical parameters (water temperature, conductivity, pH, turbidity, dissolved oxygen, nitrate) and 1-day rainfall. The average values of TC and E. coli were 1487.4 and 36.3 MPN/100 ml, respectively. TC concentrations/physicochemical parameters were met at least 2nd class water quality class and E. coli results were met "guideline value" (E. coli < 250 MPN/100 ml) of national regulation. Overall, among measured physicochemical parameters, rainfall had the strongest positive correlation (r = 0.377 for total coliforms and r = 0.466 for E. coli, p < 0.05) with both indicators, indicted that surface runoff due to rainfall is the main factor which effects microbial water quality in the study area. This study demonstrated the preliminary microbial water quality results (TC and E. coli) in the Imrahor Pond and can serve as a basis for developing more precise water quality monitoring and management studies in the future. PRACTITIONER POINTS: Prevalence of TC and E. coli in the surface and bottom waters of Imrahor Pond were investigated for the first time. Imrahor Pond was met guideline value of national regulations based on E. coli concentrations, in the study period. Surface runoff after rainfall was the main environmental factor which influenced the microbial water quality of the pond.

Sources of microbial contamination in the watershed and coastal zone of Soufriere, St. Lucia.

The Sustainable Development Goal 6 calls for global progress by 2030 in treating domestic wastewater and providing access to adequate sanitation facilities. However, meeting these goals will be a challenge for most Small Island Developing States, including Caribbean island nations. In the nearshore zone of the Soufriere region on the Caribbean island of St. Lucia, there is a history of high levels of bacteria of fecal origin. Possible land-based sources of microbial contamination in the Soufriere Bay include discharges from the Soufriere River and transport of wastewater, including fecal material from the town of Soufriere. This area is an important tourist destination and supports a local fishery. To identify the sources of microbial contamination in Soufriere Bay, a range of monitoring methods were employed in this study. In grab samples of surface water collected from the Soufriere River, counts of total coliforms and Escherichia coli were elevated above water quality guidelines. However, the spikes in concentrations of these indicator organisms in the river did not necessarily coincide with the spikes in the levels of total coliforms and E. coli detected in samples collected on the same dates in Soufriere Bay, indicating that there are other sources of pollution in the Bay besides discharges from the river. Monitoring for chemical indicators of wastewater (i.e., caffeine, sucralose, fluconazole) in the Soufriere River indicated that there are inputs of sewage or human fecal material throughout the watershed. However, analysis of Bacteroidales 16S rRNA genetic markers for fecal bacteria originating from humans, bovine ruminants, or other warm-blooded animals indicated that the majority of microbial contamination in the river was not from humans. Monitoring for chemical indicators of wastewater using passive samplers deployed in Soufriere Bay indicated that there are two "hot spots" of contamination located offshore of economically depressed areas of the town of Soufriere. This study indicates that efforts to control contamination of Soufriere Bay by fecal microorganisms must include management of pollution originating from both sewage and domestic animals in the watershed.

A multistep enrichment process with custom growth medium improves resuscitation of chlorine-stressed coliforms from secondary sewage effluents.

Resuscitation and detection of stressed total coliforms in chlorinated water samples is needed to assess and prevent health effects from adverse exposure. In this study, we report that the addition of a growth enhancer mix consisting of trehalose, sodium pyruvate, magnesium chloride, and 1× trace mineral supplement improved growth of microorganisms from chlorinated secondary effluent in the base medium with Colilert-18. Improving growth of chlorine stressed microorganisms from secondary effluent is crucial to decreased detection time from 18 to 8 h.

Sanitary sewage disinfection with ultraviolet radiation and ultrasound.

Currently, the world is facing a horrible situation due to SARS-CoV-2. Though its RNA was found in wastewater, there are still no studies on RNA contamination detected in sewage. Hence, a possible treatment of sewage is suggested in this work. The disinfection stage is extremely important in the treatment of effluents, minimizing the impacts on the receiving body of water and promoting public health. In this context, the sequential use of ultrasound and ultraviolet radiation, on a bench scale, was investigated as a way to improve the disinfection of anaerobically treated effluents. Two types of treated effluents were tested, by septic tank and anaerobic filter, for which, two ultrasound frequencies, 25 and 40 kHz, and four doses of UV, 3.6; 9.0; 18 and 36 mJ cm-2 were applied. Physicochemical and microbiological parameters were observed for individual and sequential assays. The better quality of the anaerobic filter effluent influenced the performance of both processes, decreasing the concentration of organic load and turbidity, even though a concentration of total coliforms and Escherichia coli occurred in the lowest quality effluent (septic tank). The application of ultrasound has a positive effect on the inactivation of total coliforms and E. coli up to 1.0 log and provides better conditions for ultraviolet radiation to be sequentially applied. The UV radiation applied for the septic tank and the anaerobic filter inactivates 2.5 log for total coliforms and 3.5 log for E. coli, respectively. It is suggested that the disinfection methods applied in this work to inactivate gram-negative bacteria (E. coli) can also be applied to secondary treatment effluents, as well as being better tested for viruses, protozoa, and helminths. Supplementary Information: The online version contains supplementary material available at 10.1007/s13762-021-03764-7.

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.

Composition and microbiological quality of refrigerated raw milk in two seasons of the year in Santa Helena, Western Paraná / Composição e qualidade microbiológica do leite cru refrigerado em duas estações do ano em Santa Helena, oeste do Paraná / Composición y calidad microbiológica de la leche cruda refrigerada en dos estaciones del año en Santa Helena, oeste de Paraná

This study aimed at quantifying the occurrence of proteolytic psychotropic microorganisms and total coliforms in refrigerated raw milk, in addition to assessing the quality through its physical-chemical composition. The samples were collected in 10 dairy farms in the municipality of Santa Helena ­ Western Paraná. Two collections were made, one during the spring and the other during the summer. Samples of refrigerated raw milk were carried out directly from the cooling tank, aseptically, packed in sterile bottles and transported under isothermal conditions (± 4 ºC) to the laboratory where the physical-chemical composition and microbial populations were determined. The levels of fat had great amplitude between the seasons, being higher in the summer, while there was no variation for the contents of protein, lactose, minerals, and non-fat solids. The total coliform count did not differ between seasons. The values obtained for proteolytic psychotropic counts were higher in the summer. A significant positive correlation was found between the total coliform counts, the proteolytic psychotropic counts (r=0.73), the levels of protein (r=0.45), non-fat solids (r=0.45), and minerals (r=0.46). Also, the proteolytic psychotropic counts showed a positive correlation with the cryoscopic index. The milk components met the requirements of NI76. The quality of refrigerated raw milk in the municipality of Santa Helena, Western Paraná was not satisfactory for total coliforms, due to its high incidence, indicating the need for good practices in milking management. Proteolytic psychotropic bacteria presented low proliferation, thus not affecting milk quality.(AU)

O presente estudo teve como objetivo quantificar a ocorrência de microrganismos psicrotróficos proteolíticos e de coliformes totais em leite cru refrigerado além de avaliar a qualidade por meio da sua composição físico-química. As amostras foram coletadas em 10 propriedades leiteiras no município de Santa Helena ­ Oeste do Paraná. Foram realizadas duas coletas, uma durante a primavera e outra no verão. As amostragens do leite cru refrigerado foram realizadas diretamente no tanque de resfriamento, de forma asséptica, acondicionado em frascos esterilizados e transportado sob condições isotérmicas (± 4ºC) ao laboratório onde foram determinadas a composição físico-química e as populações microbianas. Os teores de gordura tiveram grande amplitude entre as estações do ano, sendo superior no verão, enquanto que não houve variação para os teores de proteína, lactose, minerais e sólidos desengordurados. A contagem de coliformes totais não diferiu entre as estações. Os valores obtidos para contagens de psicrotróficos proteolíticos foram superiores no verão. Foi constatada correlação significativa positiva entre as contagens de coliformes totais com as contagens de psicrotróficos proteolíticos (r=0,73) e os teores de proteína (r=0,45), sólidos desengordurados (r=0,45) e minerais (r=0,46). Além disto, as contagens de psicrotróficos proteolíticos apresentaram correlação positiva com o índice crioscópico. Os componentes do leite atenderam as exigências da IN76. A qualidade do leite cru refrigerado no município de Santa Helena, Oeste do Paraná não foi satisfatória em relação aos coliformes totais, devido sua alta incidência, indicando a necessidade de boas práticas no manejo de ordenha. As bactérias psicrotróficas proteolíticas tiveram baixa proliferação, não afetando a qualidade do leite.(AU)

El presente estudio tuvo como objetivo cuantificar la ocurrencia de microorganismos psicrotróficos proteolíticos y de coliformes totales en leche cruda refrigerada, además de evaluar la calidad a través de su composición fisicoquímica. Las muestras fueron recolectadas en 10 granjas lecheras del municipio de Santa Helena ­ Oeste de Paraná. Se realizaron dos colecciones, una en primavera y otra en verano. Las muestras de leche cruda enfriada se realizaron directamente en el tanque de enfriamiento, de forma aséptica, se empacaron en botellas estériles y se transportaron en condiciones isotérmicas (± 4ºC) al laboratorio donde se determinó la composición fisicoquímica y las poblaciones microbianas. Los niveles de grasa tuvieron gran amplitud entre las estaciones, siendo más altos en verano, mientras que no hubo variación para los contenidos de proteínas, lactosa, minerales y sólidos desgrasados. El recuento total de coliformes no difirió entre temporadas. Los valores obtenidos para los recuentos de psicotrópicos proteolíticos fueron mayores en verano. Se encontró una correlación positiva significativa entre los recuentos de coliformes totales y los recuentos de psicrótroficos proteolíticos (r=0.73) y los niveles de proteínas (r=0.45), sólidos desgrasados (r=0.45) y minerales (r=0.46). Además, los recuentos de psicrótroficos proteolíticos mostraron una correlación positiva con el índice crioscópico. Los componentes de la leche cumplieron con los requisitos de IN76. La calidad de la leche cruda refrigerada en el municipio de Santa Helena, Oeste de Paraná no fue satisfactoria en relación a los coliformes totales, debido a su alta incidencia, lo que indica la necesidad de buenas prácticas en el manejo del ordeño. Las bacterias psicrotróficas proteolíticas tuvieron baja proliferación, no afectando la calidad de la leche.(AU)

Qualidade microbiológica da água e dos mexilhões Perna perna (Linnaeus, 1758) cultivados em Piúma, Espírito Santo, Brasil / Microbiological quality of water and Perna perna (Linnaeus, 1758) mussels cultivated in Piúma, Espírito Santo, Brazil

RESUMO Este estudo objetivou verificar a qualidade microbiológica da água e dos mexilhões cultivados pela Associação dos Maricultores de Piúma (AMPI), Espírito Santo, Brasil. Foram realizadas sete coletas de água e mexilhões, mensalmente, entre outubro de 2016 e maio de 2017. Os mexilhões foram coletados nos long lines da AMPI, e em cada mês foram coletados 40 mexilhões Perna perna e 100 mL de água do local. O material coletado foi destinado ao laboratório para a realização das análises microbiológicas em duplicata, número mais provável de coliformes totais (CT) e termotolerantes (Ctt), presença ou ausência de Salmonella sp e número de unidades formadoras de colônias de Staphylococcus aureus. Os resultados mostraram que o número de Ctt nas amostras de água no mês de janeiro estavam acima do permitido pela Resolução n° 357 do Conselho Nacional do Meio Ambiente (CONAMA). Já os níveis de Ctt e Staphylococcus aureus na carne dos mexilhões mostraram-se dentro do limite aceitável pela RDC n° 12 da Agência Nacional de Vigilância Sanitária (ANVISA). Entretanto, foram encontradas bactérias com características do gênero Salmonella sp nos meses de dezembro e março nos mexilhões, impossibilitando sua comercialização e seu consumo. Durante esses meses, a cidade tem alto fluxo de turistas. Por fim, recomenda-se a realização das análises microbiológicas continuamente, principalmente no período do verão, época que tem grande fluxo de turistas no município de Piúma e que registrou presença de Salmonella na carne dos mexilhões e níveis de Ctt na água acima do permitido pelas legislações vigentes.

ABSTRACT This study aimed to verify the microbiological quality of water and mussels cultivated by the Piúma Farmers Association (Associação dos Maricultores de Piúma — AMPI), Espírito Santo, Brazil. Seven samples of water and mussels were collected monthly from October 2016 to May 2017. The mussels were collected from the long lines of the AMPI, and in each month 40 mussels Perna perna and 100 mL of water were sampled from the site. The collected material was sent to the laboratory for duplicate microbiological analysis, Most Probable Number of Total (CT) and Thermotolerant (Ctt) coliforms, presence or absence of Salmonella sp and number of Staphylococcus aureus colony forming units. The results showed that the number of Ctt in the water samples in January was higher than that allowed by Resolution 357 of the National Environment Council (Conselho Nacional do Meio Ambiente — CONAMA). The levels of Ctt and Staphylococcus aureus in mussel meat were within the acceptable range by the Brazilian National Environment Council (Agência Nacional de Vigilância Sanitária — ANVISA) Resolution RDC No. 12. However, colonies with characteristics of Salmonella sp were found in December and March in the mussels, making it impossible to sell and consume. This period coincides with a high flow of tourists in the municipality. Finally, it is recommended to perform microbiological analyzes continuously, especially in the summer, where there are a lot of tourists in the city of Piúma, period that showed the presence of Salmonella in the meat of mussels and Ctt levels in water above the allowed current legislation.

Microbiological Survey of Wheat Flour Sold at Retail in Canada, 2018 to 2019.

ABSTRACT: Following two O121 Shiga toxin-producing Escherichia coli (STEC) outbreaks linked to wheat flour, this study was conducted to gain baseline information on the occurrence of bacterial pathogens and levels of indicator organisms in wheat flour in Canada. A total of 347 prepackaged wheat flour samples were analyzed for Salmonella species, STEC, Listeria monocytogenes, aerobic colony count (ACC), total coliforms, and Escherichia coli. Salmonella spp. and O157 STEC were not detected in any of the samples. L. monocytogenes was identified in two samples (0.6%) at levels below the limit of detection (<0.7 log CFU/g). Non-O157 STEC were isolated from six samples (1.7%) and were characterized for the presence of STEC virulence genes: stx1, stx2, and their subtypes, eae, hlyA, and aggR. One O103:H25 STEC isolate carried virulence genes (stx1a+eae) that are known to be capable of causing diarrhea and/or bloody diarrhea in humans. Of the five remaining non-O157 STEC isolates, four carried single stx2a or stx2c genes and were considered to have the potential of causing diarrhea. The remaining non-O157 STEC isolate (stx2), while not a priority non-O157 STEC, was not available for sequencing; thus, its potential to cause illness is unknown. ACC, total coliforms, and E. coli were detected (≥0.48 log CFU/g) in 98.8, 72.6, and 0.6% of the flour samples. The mean counts of ACC were greater in whole wheat flour compared with the other flour types tested (P < 0.001). The results of this study suggest that the occurrence of O157 STEC and Salmonella is low but that the occurrence of non-O157 STEC in wheat flour with the potential to cause human illness of diarrhea is relatively common. Therefore, the consumption of raw flour could increase the likelihood of STEC infections. Further research is merited for potential risk mitigation strategies within the food production system and with consumers.

Field demonstration of solar-powered electrocoagulation water treatment system for purifying groundwater contaminated by both total coliforms and arsenic.

People who drink groundwater in rural areas of Southeast Asia are exposed to pathogens and arsenic (As)-related health problems. A water treatment system consisting of electrocoagulation reactors, using iron (Fe) electrodes and a filtration tank, was designed to treat complex contaminated groundwater for drinking. Its applicability was demonstrated near the Red River in Vietnam. The water treatment system reduced 10.3 CFU/mL of total coliform and 376 µg/L of As(III) in the groundwater to 0 CFU/mL and 6.68 µg/L, respectively. Total coliforms were attenuated by Fe(II) infiltration or enmeshed during Fe precipitate formation. Of the total As, 43% formed As(III) complexation with the Fe precipitates and the other 57% was oxidized to As(V) then adsorbed to Fe precipitates. The Fe precipitates, containing total coliforms and As, were separated from the discharge water in the filtration tank. The system required 49 W of power to operate, which equates to 423 kWh/year, to continuously purify 0.5 t water/day. This requirement was powered by a 380-750 W solar panel, without external energy supply, making the water treatment system an appropriate option for addressing drinking water problems in rural areas.

Microbiological quality of water from public drinking fountains in northwestern São Paulo, Brazil / Qualidade microbiológica da água de bebedouros públicos no noroeste de São Paulo, Brasil

Objective: The present study aimed to evaluate the microbiological quality of the water and the maintenance and physical structure of public drinking fountains located in the city of Araçatuba ­ SP. Methods: To assess the presence or absence of Escherichia coli and total coliforms in the drinking water 41 samples were randomly collected. Thirteen samples were collected in the year 2018 and 28 samples in 2019. Results: All samples collected in the year 2018 showed no total coliforms and E. coli. However, the samples collected in the year 2019 showed coliforms in 10% (3/28). All the drinking fountains analyzed demonstrated to be inadequate in at least one of the qualitative criteria considered. Conclusion: Our results indicate that are necessary periodic maintenance of the public drinking fountains and the monitoring of its water since these parameters serve as indicators of the integrity of the drinking water distribution system.

Objetivo: O presente estudo teve como objetivo avaliar a qualidade microbiológica da água, a manutenção e estrutura física de bebedouros públicos localizados no município de Araçatuba - SP. Métodos: Para avaliar a presença ou ausência de Escherichia coli e coliformes totais na água de consumo, 41 amostras foram coletadas aleatoriamente. Treze amostras foram coletadas no ano de 2018 e 28 amostras em 2019. Resultados: Todas as amostras coletadas no ano de 2018 não apresentaram coliformes totais e E. coli. Porém, as amostras coletadas no ano de 2019 apresentaram coliformes em 10% (3/28). Todos os bebedouros analisados demonstraram ser inadequados em pelo menos um dos critérios qualitativos considerados. Conclusão: Nossos resultados indicam que são necessários a manutenção periódica dos bebedouros públicos e o monitoramento de sua água, visto que esses parâmetros servem como indicadores da integridade do sistema de distribuição de água potável.