Evaluación de la calidad del agua envasada para consumo humano en la ciudad de Villavicencio (Colombia) / Assessment of quality of sachet water for human consumption in Villavicencio (Colombia)

RESUMEN En Colombia, las empresas de acueducto deben garantizar que el agua que suministran se pueda consumir directamente; sin embargo, la percepción de la población es que su calidad no es la adecuada para su ingesta directa. Esta situación es más notoria en algunas ciudades, como es el caso de Villavicencio, Meta, donde la mayoría de la población consume agua envasada en diferentes presentaciones, debido a la poca confianza en el agua que suministra la empresa de acueducto, por lo tanto, este producto se ha convertido en un artículo de primera necesidad en la canasta familiar de los hogares de Villavicencio. El objetivo de este trabajo fue evaluar la calidad del agua envasada de diez empresas, por un periodo de 8 meses. La calidad se evaluó mediante el análisis de los siguientes parámetros fisicoquímicos: cloruro, dureza total, hierro, manganeso, nitrato, nitrito, pH, sodio, sólidos totales y turbiedad y los siguientes parámetros microbiológicos: bacterias coliformes totales, bacterias coliformes fecales y Pseudomonas aeruginosa. Los parámetros fisicoquímicos estuvieron dentro de los valores admisibles, de acuerdo con la norma de referencia; no obstante, se evidenció la presencia de microorganismos en el 33 % de las muestras analizadas, por lo que su consumo representa un riesgo para la salud humana.

ABSTRACT In Colombia, water companies must guarantee that the water they supply can be consumed directly. However, the population's perception is that the quality of this water is not adequate for direct consumption. This situation is more noticeable in some cities, such as Villavicencio, Meta, where most of the population consumes packaged water in different presentations due to little confidence in the water supplied by the water company. Therefore, this product has become a staple item of Villavicencio households. The aim of this work was to assess the quality of packaged water from ten companies for a period of 8 months. Quality was assessed by analyzing the following physicochemical parameters: chlorides, total hardness, iron, manganese, nitrate, nitrite, pH, sodium, total solids, and turbidity; and the following microbiological parameters: total coliform bacteria, fecal coliform bacteria, and Pseudomonas aeruginosa. The physicochemical parameters were within the admissible values in accordance with the reference standard. However, the presence of microorganisms was evident in 33 % of the samples analyzed, so its consumption represents a risk to human health.

Integrating field and satellite monitoring for assessing environmental risk associated with bacteria in recreational waters of a large reservoir.

In a large South American Reservoir (750 km2, limit between Uruguay and Argentina), we characterized the environmental risk posed by cyanobacteria proxies (abundance, toxin concentration, chlorophyll-a) and Escherichia coli abundances, integrating field (six sites, summers 2011-2015) and satellite (750 km2, summers 2011-2017) monitoring. We further assessed how well field cyanobacteria quantitative proxies (abundance, toxin concentration, chlorophyll-a and scum formation) used to build a local risk communication system for recreational (bathing) use of waters named "cyano-traffic-light", ongoing since 2011, reflected its outcome. Cyanobacteria abundance in the field ranged from moderate (>20,000 to <100,000 cells mL-1) to high-risk (>100,000 cells mL-1), and its abundance was positively related to toxin (microcystin) concentration. Mean microcystin concentrations was within the low (≤2 µg L-1, 50% sites) or moderate (>2 < 10 µg L-1, 50% sites) risk categories. On rare occasions, toxin concentration posed a high-risk for human health. E. coli abundance was within the high-risk category (>126 CFU 100 mL-1) for human health, mostly in the northern part of the reservoir. Cyanobacteria proxies (abundance and toxins) and E. coli abundance were, however, unrelated. The predictive model showed that, out of the four cyanobacteria proxies used to construct the cyano-traffic-light only cyanobacteria abundance (p < 0.05) explained the outcome of the reports, yet with low explanatory power (41%). The satellite monitoring allowed delimiting the extent and magnitude of the environmental risk posed by cyanobacteria at landscape scale (highest risk in the meander parts of the Argentinean side of the reservoir) and producing risk maps that can be used by water management agencies. Based upon our results we propose including E. coli abundances and satellite derived cyanobacteria abundances in the building of the cyano-traffic-light, among other modifications.

Microbiological Quality of High-Demand Food from Three Major Cities in Ecuador.

ABSTRACT: Bacterial foodborne diseases are among the most important public health issues worldwide, but in Ecuador, reports on the microbiological quality of food are scarce. In this cross-sectional study, 450 samples of high-demand Ecuadorian food, including bolon, encebollado, sauces, ceviche, fruit, fruit juice, fruit salad, cheese, raw chicken, and ground beef, were collected from popular street markets in the cities of Guayaquil, Quito, and Cuenca. Populations of total aerobic mesophilic bacteria, total coliforms, fecal coliforms, Escherichia coli, Salmonella enterica, and Listeria monocytogenes were examined on composited samples by plate count following the local regulations (Norma Tecnica Ecuatoriana, Instituto Ecuatoriano de Normalización) for each kind of food. The individual and interaction effects of the city and food type on the levels of each bacterial group were assessed by two-way analysis of variance. Selected colonies from each culture were identified using Biolog OmniLog ID and sequencing of the V3 to V4 region on the 16S rRNA gene. Average total aerobic mesophilic bacteria, total coliform, fecal coliform, and E. coli levels were 5.10 ± 0.12, 2.50 ± 0.16, 1.09 ± 0.12, and 0.83 ± 0.12 log CFU/g or mL, respectively, with significant variations among the cities. The prevalence of Salmonella in chicken and sauces and L. monocytogenes in cheese and fruit salad was greater than 20%. Opportunistic pathogens including Klebsiella pneumoniae, Staphylococcus sciuri, and Enterococcus spp. were frequently identified in the samples from all three cities. High prevalence of spoilage microorganisms such as Bacillus amyloliquefaciens and biocontrol bacteria such as Lactococcus lactis was also observed. This is the first report on the microbiological quality of food from Ecuador.

Pre-ozonation of surface water: An effective water treatment process to reduce the risk of infection by Giardia in drinking water.

Giardia is a protozoan parasite of primary concern for the drinking water industry. High contact times are required for Giardia inactivation by chlorination, while ozonation may be effective at much lower Ct products. In this study, we have assessed the occurrence of Giardia cysts in raw water, and in chlorinated or ozonated water from a drinking water treatment plant (DWTP) in Brazil, over a 16-month period. Moreover, we analyzed the effects of primary disinfection on cysts, and calculated the infection risk caused by the occurrence of Giardia cysts in raw water, chlorinated or ozonated water. Furthermore, we assessed the correlation of Giardia cysts with indicator bacteria in raw water. Data referring to concentration of Giardia cysts in raw water showed adherence to a gamma distribution at a significance level α = 0.05. The detection frequency and the mean concentration of Giardia cysts were higher in raw water (86.6%, 26 cysts∙L-1), than in chlorinated (46.1%, 15.7 cysts·L-1) or ozonated water (43.5%, 11.1 cysts·L-1). Overall, Giardia non-viable cysts were detected more frequently in ozonated water (80%) than in chlorinated water (68.2%) or raw water (37.7%). Ozonation and chlorination resulted, respectively, in ≈27.5- and ≈13- fold reduction of Giardia infection risk, when compared to the risk calculated for raw water. Total coliform and Escherichia coli proved to be suitable surrogates to predict the occurrence of Giardia cysts in raw surface water, however, the indicator bacteria may not be suitable surrogates to predict the disinfection of Giardia cysts, as no correlation was found between indicator bacteria and Giardia cysts in treated water. To our knowledge, this is the first study reporting the efficacy of chlorine and ozone at Ct products actually applied at a full-scale drinking water treatment plant against Giardia cysts naturally occurring in the source water, i.e. real situation. Ozonation has proven more efficient than chlorination against Giardia cysts in surface water. Escherichia coli proved to be suitable surrogate to predict Giardia cysts in raw surface water.

Biomarkers (glutathione S-transferase and catalase) and microorganisms in soft tissues of Crassostrea rhizophorae to assess contamination of seafood in Brazil.

The goal of this study was to evaluate biomarkers (glutathione S-transferase and catalase) and microorganisms in soft tissues of Crassostrea rhizophorae to assess possible contamination of seafood in Brazil. The oysters were sampled from a reference area (Ports 1 and 2) and an impacted area (Ports 3 and 4) in Brazil (São Luís Island, Maranhão). Six attributes were examined in sampled oysters: glutathione S-transferase activity, catalase activity, concentrations of total coliforms and thermotolerant coliforms, and levels of Escherichia coli and Aeromonas hydrophila. Water samples were analysed for aluminium, cadmium, iron, manganese, lead, mercury, phenolics, and polychlorinated biphenyls. We found that Ports 3 and 4 are impacted by several contaminants (mercury, phenolics, and polychlorinated biphenyls), while Ports 1 and 2 are still relatively free of these contaminants. Changes in enzymes activity as well as the highest tissue bacterial concentrations were recorded in oysters from Ports 3 and 4 during the rainy season.

Dental Unit Waterlines in Quito and Caracas Contaminated with Nontuberculous Mycobacteria: A Potential Health Risk in Dental Practice.

Three cases of severe odontogenic infections due to nontuberculous mycobacteria (NTM) in Venezuela that were directly associated with dental procedures and the finding of dental unit waterlines (DUWLs) in dental offices that were colonized with mycobacteria species was the reason for assessing the water quality of DUWLs in dental offices in two capital cities in South America, namely, Quito and Caracas. The main water supplies and the water from 143 DUWLs in both cities were sampled and especially checked for contamination with NTM. To measure the overall bacteriological quality of the water also the presence of heterotrophic bacteria, coliform bacteria, and Pseudomonas was determined. Results showed that respectively 3% and 56% of the DUWLs in Quito and Caracas yielded NTM species (up to 1000 colony-forming units (CFU)/mL). Furthermore, high and unacceptable total viable counts of heterotrophic bacteria and/or coliform bacteria and Pseudomonas were detected in 73% of the samples. We conclude that, in both cities, the water in the majority of DUWLs was contaminated with NTM and other potential pathogens, presenting a risk to human health. The detection of NTM in DUWL water with acceptable heterotrophic bacteria counts shows the need to include NTM in water quality testing. Mycobacteria are more resistant to disinfection procedures than other types of vegetative bacteria, and most testing protocols for DUWLs do not assess mycobacteria and thus do not guarantee risk-free water.

Effects of bathing intensity, rainfall events, and location on the recreational water quality of stream pools in southern Ecuador.

Bathing in natural waters is a highly demanded recreational activity in tropical countries because of climatic conditions and availability of bathing sites; but, do users know the water quality of these sites? We determined the physicochemical and microbiological water quality of a highly used bathing site in southern Ecuador. We assessed how bather attendance, rainfall events, and pool location alters the recreational water quality (RWQ). Most of the parameters measured in the stream pools did not accomplish the Ecuadorian and international regulations for recreational water quality. Microbiological water quality diminishes from upstream to downstream pools because of human activities and bathing intensity having potential effects on bather health and eco-touristic development. We found that an increase of bathers is strongly associated with a growing concentration of Escherichia coli. It is suggested better land-use practices and review thoroughly the Ecuadorian regulation to assure a healthy RWQ. Further efforts are needed to identify more risky bathing sites, determine pollution sources, and establish a long-term monitoring program to support the touristic development in countries looking for diversifying their economy.

Virulence genes in Escherichia coli isolates from commercialized saltwater mussels Mytella guyanensis (Lamarck, 1819) / Presença de genes de virulência em isolados de Escherichia coli provenientes de sururu Mytella guyanensis (Lamarck, 1819) comercializado

Abstract The isolation of Escherichia coli from food is a major concern. Pathogenic strains of these bacteria cause diseases which range from diarrhea to hemolytic-uremic syndrome. Therefore the virulence genes in E. coli isolates from the mussel ( Mytella guyanensis) commercialized in Cachoeira, Bahia, Brazil were investigated. Samples were purchased from four vendors: two from supermarkets and two from fair outlets. They were conditioned into isothermal boxes with reusable ice and transported to the laboratory for analysis. E. coli strains were isolated in eosin methylene blue agar, preserved in brain-heart infusion medium with 15% glycerol and stored at -20 °C, after microbiological analysis. Virulence genes in the isolated strains were identified by specific primers, with Polymerase Chain Reaction. Twenty-four isolates were obtained, with a prevalence of elt gene, typical from enterotoxigenic infection, in 75% of the isolates. The stx and bfpA genes, prevalent in enterohemorragic and enteropathogenic E. coli, respectively, were not detected. The occurrence of elt virulence-related gene in the E. coli isolates of Mytella guyanensis reveals urgent improvement in food processing, including good handling practices, adequate storage and cooking before consumption, to ensure consumer's health.

Resumo O isolamento de Escherichia coli a partir de alimentos é uma grande preocupação, pois cepas patogênicas desta bactéria podem causar desde diarreia até síndrome hemolítico-urêmica. Diante do exposto, o objetivo do trabalho foi pesquisar genes de virulência em isolados de Escherichia coli provenientes do sururu Mytella guyanensis comercializado na cidade de Cachoeira, Bahia, Brasil. As amostras foram adquiridas de quatro comerciantes, sendo duas de mercados e duas em pontos de venda na feira livre da cidade de Cachoeira, acondicionadas em caixas isotérmicas com gelo reutilizável e transportadas até o laboratório para a análise. Após a análise microbiológica, as cepas de Escherichia coli foram isoladas em ágar Eosina Azul de Metileno e preservadas em caldo Brian Heart Infusion e glicerol a 15% e mantidas a - 20° C. A identificação dos genes de virulência nas cepas isoladas foi realizada utilizando primers específicos, por meio da Reação em Cadeia da Polimerase. Foram obtidos 24 isolados de Escherichia coli, destes a prevalência do gene elt , característico de Escherichia coli enterotoxigênica, foi de 75% dos isolados. Não houve a detecção dos genes stx e bfpA nos isolados, os quais são prevalentes nas cepas de Escherichia coli enterohemorrágica e Escherichia coli enteropatogênica, respectivamente. A presença do gene elt relacionado à virulência de Escherichia coli nos isolados de Mytella guyanensis revela a necessidade da melhoria no processamento, incluindo boas práticas de manipulação, armazenamento adequado e cocção previa ao consumo, visando a garantia da saúde do consumidor.

Virulence factors of Escherichia coli: an overview of animal and human infections with emphasis in bovine mastitis / Fatores de virulência de Escherichia coli: revisão de infecções em humanos e animais com ênfase na mastite bovina

Escherichia coli is a normal inhabitant of the enteric microflora of human and animal. Intestinal and extra-intestinal infections caused by E. coli in mammals are characterized by the presence of diversity of virulence factors. In addition it can be isolated from environment surrounding human and animal farms. E. coli is the main environmental pathogen causing clinical mastitis in dairy cattle. It causes a wide range of disease severity, from changes seen exclusively in milk to severe systemic signs. The severity of clinical mastitis has been conventionally classified into three levels: mild (grade 1), moderate (score 2), and severe (score 3). Recently, reports of cases of bovine mastitis caused by environmental agents have been on the rise, in particular in countries that have succeeded in controlling contagious microorganisms. Unlike enteric and certain extra-enteric conditions in domestic animals and humans, the impact of virulence factors on the occurrence of bovine mastitis due to E. coli, as well as the clinical severity of the cases, is not fully understood. In this regard, the present study reviewed the most relevant virulence factors of E. coli in human and animals, with emphasis in bovine mastitis.

Escherichia coli (E. coli) é um micro-organismo que pertence a microbiota entérica de humanos e animais. As afecções entéricas e extra-entéricas causadas por E.coli em mamíferos são caracterizadas pela presença de ampla diversidade de fatores de virulência. Além disso, este micro-organismo também pode ser isolado em ambientes de produção animal. E. coli é o principal agente ambiental que causa mastite clínica em vacas leiteiras, provocando sinais clínicos que podem variar desde mudanças observadas exclusivamente no leite até sinais sistêmicos graves. A gravidade da mastite clínica é convencionalmente classificada em três níveis: leve (grau 1), moderada (grau 2), e grave (grau 3). Atualmente, os relatos de casos de mastite bovina causada por agentes ambientais têm aumentando, principalmente nos países que conseguiram controlar os micro-organismos contagiosos. Diferentemente de infecções entéricas e certas extra-entéricas em humanos e animais, o impacto dos fatores de virulência de E. coli na ocorrência de mastite bovina não é totalmente compreendido, assim como na gravidade clínica dos casos. Neste contexto, o presente estudo revisou os fatores de virulência de E. coli mais relevantes para humanos e animais, com ênfase na mastite bovina.

Virulence factors of Escherichia coli: an overview of animal and human infections with emphasis in bovine mastitis / Fatores de virulência de Escherichia coli: revisão de infecções em humanos e animais com ênfase na mastite bovina

Escherichia coli is a normal inhabitant of the enteric microflora of human and animal. Intestinal and extra-intestinal infections caused by E. coli in mammals are characterized by the presence of diversity of virulence factors. In addition it can be isolated from environment surrounding human and animal farms. E. coli is the main environmental pathogen causing clinical mastitis in dairy cattle. It causes a wide range of disease severity, from changes seen exclusively in milk to severe systemic signs. The severity of clinical mastitis has been conventionally classified into three levels: mild (grade 1), moderate (score 2), and severe (score 3). Recently, reports of cases of bovine mastitis caused by environmental agents have been on the rise, in particular in countries that have succeeded in controlling contagious microorganisms. Unlike enteric and certain extra-enteric conditions in domestic animals and humans, the impact of virulence factors on the occurrence of bovine mastitis due to E. coli, as well as the clinical severity of the cases, is not fully understood. In this regard, the present study reviewed the most relevant virulence factors of E. coli in human and animals, with emphasis in bovine mastitis.(AU)

Escherichia coli (E. coli) é um micro-organismo que pertence a microbiota entérica de humanos e animais. As afecções entéricas e extra-entéricas causadas por E.coli em mamíferos são caracterizadas pela presença de ampla diversidade de fatores de virulência. Além disso, este micro-organismo também pode ser isolado em ambientes de produção animal. E. coli é o principal agente ambiental que causa mastite clínica em vacas leiteiras, provocando sinais clínicos que podem variar desde mudanças observadas exclusivamente no leite até sinais sistêmicos graves. A gravidade da mastite clínica é convencionalmente classificada em três níveis: leve (grau 1), moderada (grau 2), e grave (grau 3). Atualmente, os relatos de casos de mastite bovina causada por agentes ambientais têm aumentando, principalmente nos países que conseguiram controlar os micro-organismos contagiosos. Diferentemente de infecções entéricas e certas extra-entéricas em humanos e animais, o impacto dos fatores de virulência de E. coli na ocorrência de mastite bovina não é totalmente compreendido, assim como na gravidade clínica dos casos. Neste contexto, o presente estudo revisou os fatores de virulência de E. coli mais relevantes para humanos e animais, com ênfase na mastite bovina.(AU)

Surveillance of Enteric Viruses and Thermotolerant Coliforms in Surface Water and Bivalves from a Mangrove Estuary in Southeastern Brazil.

This study was conducted to evaluate the microbiological quality of a mangrove estuary in the Vitória Bay region, Espírito Santo, Brazil. We analyzed the presence and concentration of enteric viruses and thermotolerant coliforms in water, mussels (Mytella charruana and Mytella guyanensis), and oysters (Crassostrea rhizophorae), collected over a 13-month period. Human adenovirus, rotavirus A (RVA), and norovirus genogroup II were analyzed by quantitative PCR. The highest viral load was found in RVA-positive samples with a concentration of 3.0 × 104 genome copies (GC) L-1 in water samples and 1.3 × 105 GC g-1 in bivalves. RVA was the most prevalent virus in all matrices. Thermotolerant coliforms were quantified as colony-forming units (CFU) by the membrane filtration method. The concentration of these bacteria in water was in accordance with the Brazilian standard for recreational waters (< 250 CFU 100 mL-1) during most of the monitoring period (12 out of 13 months). However, thermotolerant coliform concentrations of 3.0, 3.1, and 2.6 log CFU 100 g-1 were detected in M. charruana, M. guyanensis, and C. rhizophorae, respectively. The presence of human-specific viruses in water and bivalves reflects the strong anthropogenic impact on the mangrove and serves as an early warning of waterborne and foodborne disease outbreaks resulting from the consumption of shellfish and the practice of water recreational activities in the region.

Sterol biomarkers and fecal coliforms in a tropical estuary: Seasonal distribution and sources.

The Sergipe River estuary has been subjected to a range of anthropogenic activities including food, plastic, textile, ceramic and metallurgical production plants along with domestic sewage inputs, all of which are of environmental concern. In this study, the levels of fecal coliforms (FC) in surface water samples and sterols in superficial sediment samples collected from the Sergipe River estuary were determined. Based on the FC concentrations, 58% of the water samples were considered Water Potentially Unusable (WPU) according to the United States Environmental Protection Agency (USEPA). Concentrations of coprostanol ranged from 13 to 1072 ng g-1, indicating a significant input of sewage at some points in the estuary. Principal Component Analysis (PCA) showed that there is no clear correlation between the coprostanol and coliform data, which may be due to the high resistance to degradation of coprostanol in sediments and to recent inputs of sewage at the water sample collection points.

Putative virulence factors of extra-intestinal Escherichia coli isolated from bovine mastitis with different clinical scores.

We investigated the genes kpsMTII, iucD, sfaDE, afaBC, papA and papC, (proposed to be involved in extra-intestinal pathogenic Escherichia coli-ExPEC), phylogroup classification and the in vitro swimming and swarming motility in 50 E. coli isolated from bovine mastitis with different clinical severity scores (mild, moderate and severe). The aforementioned genes were detected in 12 (n = 12/50; 24·0%) isolates. kpsMTII and iucD were the most frequent genes identified in six (n = 6/50; 12·0%) and four (n = 4/50; 8·0%) of the isolates, respectively. In only one (n = 1/50; 2·0%) isolate, more than one gene was simultaneously identified: iucD and kpsMTll were detected whereas sfaDE and afaBC were not detected. Mild, moderate and severe clinical signs were observed in 40·0% (n = 20/50), 28·0% (n = 14/50) and 32·0% (n = 16/50) of the cases. Commensal phylogroups B1 (n = 19/50; 38·0%) and A (n = 19/50; 38·0%) were prevalent; whereas pathogenic phylogroups B2 and D were observed in only 10·0% (n = 5/50). Swarming and swimming motilities were observed in 90·0% (n = 45/50) and 68·0% (n = 34/50) of the isolates, respectively; and there was a significant association (P = 0·0036) between swarming motility and severe clinical cases (score 3). To the best of our knowledge, this is the first study where clinical severity of bovine mastitis cases and the genes proposed to classify ExPEC were assessed in relation to swarming and swimming motility. SIGNIFICANCE AND IMPACT OF THE STUDY: Escherichia coli is classified as extra-intestinal (ExPEC) when strains contain at least two of the genes kpsMTII, iucD, sfaDE, afaBC and papA and/or papC. We investigated in vitro motility and the presence of these genes in 50 E. coli isolated from bovine mastitis with different clinical scores (mild, moderate and severe). Clinical severity was not associated with the genes studied. Swarming motility was associated with severe cases (score 3) of clinical mastitis. Results of this study contribute to a better understanding of the factors that determine the severity of clinical mastitis.

Virulence genes in Escherichia coli isolates from commercialized saltwater mussels Mytella guyanensis (Lamarck, 1819) / Presença de genes de virulência em isolados de Escherichia coli provenientes de sururu Mytella guyanensis (Lamarck, 1819) comercializado

The isolation of Escherichia coli from food is a major concern. Pathogenic strains of these bacteria cause diseases which range from diarrhea to hemolytic-uremic syndrome. Therefore the virulence genes in E. coli isolates from the mussel ( Mytella guyanensis) commercialized in Cachoeira, Bahia, Brazil were investigated. Samples were purchased from four vendors: two from supermarkets and two from fair outlets. They were conditioned into isothermal boxes with reusable ice and transported to the laboratory for analysis. E. coli strains were isolated in eosin methylene blue agar, preserved in brain-heart infusion medium with 15% glycerol and stored at -20 °C, after microbiological analysis. Virulence genes in the isolated strains were identified by specific primers, with Polymerase Chain Reaction. Twenty-four isolates were obtained, with a prevalence of elt gene, typical from enterotoxigenic infection, in 75% of the isolates. The stx and bfpA genes, prevalent in enterohemorragic and enteropathogenic E. coli, respectively, were not detected. The occurrence of elt virulence-related gene in the E. coli isolates of Mytella guyanensis reveals urgent improvement in food processing, including good handling practices, adequate storage and cooking before consumption, to ensure consumers health.(AU)

O isolamento de Escherichia coli a partir de alimentos é uma grande preocupação, pois cepas patogênicas desta bactéria podem causar desde diarreia até síndrome hemolítico-urêmica. Diante do exposto, o objetivo do trabalho foi pesquisar genes de virulência em isolados de Escherichia coli provenientes do sururu Mytella guyanensis comercializado na cidade de Cachoeira, Bahia, Brasil. As amostras foram adquiridas de quatro comerciantes, sendo duas de mercados e duas em pontos de venda na feira livre da cidade de Cachoeira, acondicionadas em caixas isotérmicas com gelo reutilizável e transportadas até o laboratório para a análise. Após a análise microbiológica, as cepas de Escherichia coli foram isoladas em ágar Eosina Azul de Metileno e preservadas em caldo Brian Heart Infusion e glicerol a 15% e mantidas a - 20° C. A identificação dos genes de virulência nas cepas isoladas foi realizada utilizando primers específicos, por meio da Reação em Cadeia da Polimerase. Foram obtidos 24 isolados de Escherichia coli, destes a prevalência do gene elt , característico de Escherichia coli enterotoxigênica, foi de 75% dos isolados. Não houve a detecção dos genes stx e bfpA nos isolados, os quais são prevalentes nas cepas de Escherichia coli enterohemorrágica e Escherichia coli enteropatogênica, respectivamente. A presença do gene elt relacionado à virulência de Escherichia coli nos isolados de Mytella guyanensis revela a necessidade da melhoria no processamento, incluindo boas práticas de manipulação, armazenamento adequado e cocção previa ao consumo, visando a garantia da saúde do consumidor.(AU)

Virulence factors of Escherichia coli: an overview of animal and human infections with emphasis in bovine mastitis / Fatores de virulência de Escherichia coli: revisão de infecções em humanos e animais com ênfase na mastite bovina

Escherichia coli is a normal inhabitant of the enteric microflora of human and animal. Intestinal and extra-intestinal infections caused by E. coli in mammals are characterized by the presence of diversity of virulence factors. In addition it can be isolated from environment surrounding human and animal farms. E. coli is the main environmental pathogen causing clinical mastitis in dairy cattle. It causes a wide range of disease severity, from changes seen exclusively in milk to severe systemic signs. The severity of clinical mastitis has been conventionally classified into three levels: mild (grade 1), moderate (score 2), and severe (score 3). Recently, reports of cases of bovine mastitis caused by environmental agents have been on the rise, in particular in countries that have succeeded in controlling contagious microorganisms. Unlike enteric and certain extra-enteric conditions in domestic animals and humans, the impact of virulence factors on the occurrence of bovine mastitis due to E. coli, as well as the clinical severity of the cases, is not fully understood. In this regard, the present study reviewed the most relevant virulence factors of E. coli in human and animals, with emphasis in bovine mastitis.

Escherichia coli (E. coli) é um micro-organismo que pertence a microbiota entérica de humanos e animais. As afecções entéricas e extra-entéricas causadas por E.coli em mamíferos são caracterizadas pela presença de ampla diversidade de fatores de virulência. Além disso, este micro-organismo também pode ser isolado em ambientes de produção animal. E. coli é o principal agente ambiental que causa mastite clínica em vacas leiteiras, provocando sinais clínicos que podem variar desde mudanças observadas exclusivamente no leite até sinais sistêmicos graves. A gravidade da mastite clínica é convencionalmente classificada em três níveis: leve (grau 1), moderada (grau 2), e grave (grau 3). Atualmente, os relatos de casos de mastite bovina causada por agentes ambientais têm aumentando, principalmente nos países que conseguiram controlar os micro-organismos contagiosos. Diferentemente de infecções entéricas e certas extra-entéricas em humanos e animais, o impacto dos fatores de virulência de E. coli na ocorrência de mastite bovina não é totalmente compreendido, assim como na gravidade clínica dos casos. Neste contexto, o presente estudo revisou os fatores de virulência de E. coli mais relevantes para humanos e animais, com ênfase na mastite bovina.

Virulence factors of Escherichia coli: an overview of animal and human infections with emphasis in bovine mastitis / Fatores de virulência de Escherichia coli: revisão de infecções em humanos e animais com ênfase na mastite bovina

Escherichia coli is a normal inhabitant of the enteric microflora of human and animal. Intestinal and extra-intestinal infections caused by E. coli in mammals are characterized by the presence of diversity of virulence factors. In addition it can be isolated from environment surrounding human and animal farms. E. coli is the main environmental pathogen causing clinical mastitis in dairy cattle. It causes a wide range of disease severity, from changes seen exclusively in milk to severe systemic signs. The severity of clinical mastitis has been conventionally classified into three levels: mild (grade 1), moderate (score 2), and severe (score 3). Recently, reports of cases of bovine mastitis caused by environmental agents have been on the rise, in particular in countries that have succeeded in controlling contagious microorganisms. Unlike enteric and certain extra-enteric conditions in domestic animals and humans, the impact of virulence factors on the occurrence of bovine mastitis due to E. coli, as well as the clinical severity of the cases, is not fully understood. In this regard, the present study reviewed the most relevant virulence factors of E. coli in human and animals, with emphasis in bovine mastitis.

Escherichia coli (E. coli) é um micro-organismo que pertence a microbiota entérica de humanos e animais. As afecções entéricas e extra-entéricas causadas por E.coli em mamíferos são caracterizadas pela presença de ampla diversidade de fatores de virulência. Além disso, este micro-organismo também pode ser isolado em ambientes de produção animal. E. coli é o principal agente ambiental que causa mastite clínica em vacas leiteiras, provocando sinais clínicos que podem variar desde mudanças observadas exclusivamente no leite até sinais sistêmicos graves. A gravidade da mastite clínica é convencionalmente classificada em três níveis: leve (grau 1), moderada (grau 2), e grave (grau 3). Atualmente, os relatos de casos de mastite bovina causada por agentes ambientais têm aumentando, principalmente nos países que conseguiram controlar os micro-organismos contagiosos. Diferentemente de infecções entéricas e certas extra-entéricas em humanos e animais, o impacto dos fatores de virulência de E. coli na ocorrência de mastite bovina não é totalmente compreendido, assim como na gravidade clínica dos casos. Neste contexto, o presente estudo revisou os fatores de virulência de E. coli mais relevantes para humanos e animais, com ênfase na mastite bovina.

Bacterial Contamination of Drinking Water in Guadalajara, Mexico.

In many regions where drinking water supply is intermittent and unreliable, households adapt by storing water in cisterns or rooftop tanks. Both intermittent supply and stored water can be vulnerable to contamination by microorganisms with deleterious health effects. The Metropolitan Zone of Guadalajara is a rapidly growing urban center with over five million residents where household storage is nearly ubiquitous. This pilot study was conducted in July 2018 to examine the microbiological quality of drinking water in Guadalajara. Samples were tested for free available chlorine residual, total coliform bacteria, and Escherichia coli. A survey on access to water and public perspectives was also conducted. Water exiting rooftop tanks exceeded regulatory limits for total coliform levels in half of the homes studied. Piped water arriving at two homes had total coliform levels that far exceeded regulatory limits. No E. coli were detected in any of the samples. Only 35% of homes had a chlorine residual between the recommended 0.2 and 1.5 mg/L. Many homes reported unpleasant odors and colors. Only 7% of residents drank the piped water. Future studies are needed, especially during April and May when many homes reported a higher disruption to water service.

Qualidade microbiológica do sururu (Mytella charruana) comercializado por catadoras da Baía de Sepetiba, Rio de Janeiro, Brasil / Microbiological quality of sururu (Mytella charruana) marketed by scavengers of the Sepetiba Bay, Rio de Janeiro, Brazil

A preocupação com a qualidade do pescado é de grande importância para todos, pois é um alimento de alto valor nutritivo, mas tem grande susceptibilidade à deterioração e formação de substâncias prejudiciais à saúde, quando as condições de conservação e manipulação não são mantidas. O cultivo de moluscos bivalves além de ser uma fonte alternativa de alimentos, é uma opção para a subsistência das populações ribeirinhas de todo o litoral, à medida que a matriz alimentícia ganha espaço no mercado, principalmente nas regiões nordeste, sul e sudeste. Os sururus são organismos filtradores, capazes de absorver micropartículas em suspensão, as quais podem carrear elevadas concentrações de microrganismos patogênicos, outro fator importante relacionado a este molusco é a má condição de manipulação no beneficiamento, que pode provocar toxinfecções alimentares, ambos provocando danos à saúde. As análises microbiológicas foram realizadas em sururu in natura e após cozimento. Nas amostras analisadas houve ausência de Salmonella spp., com redução na contagem de Staphylococcus coagulase-positiva e de Coliformes Termotolerantes a 45ºC nos produtos cozidos. Os resultados são indicativos de que mesmo havendo redução de contaminação bacteriana, a manipulação das catadoras, após cozimento, é inadequada e que medidas corretivas devem ser adotadas para se obter o produto adequado bacteriologicamente ao consumo.

Fish quality has a great importance concerning to its high nutritional value, due to its great susceptibility to deterioration and occurrence of harmful substances to human health when the storage and handling conditions are not kept properly. The bivalves farming is an alternative source of food and also a source of livelihood for riverside communities, as the product is accepted in the market, mainly in the Northeast, South and Southeast regions. As filter feeders organisms, “sururu” mussels can absorb microparticles which can carry high level of pathogenic micro-organisms. Another important factor is the bad handling conditions both can lead to foodstuff infections. Microbiological analyzes were performed in raw “sururu” mussel and after cooking. The samples analyzed there was no Salmonella sp., a reduction in coagulase-positive Staphylococcus count and thermotolerant coliforms at 45 °C in baked products. Results of the analyzes showed that even with the contamination reduction, the handling of the women staff after cooking is inadequate and corrective measures should be taken to obtain a safe product for the final consumer.

Qualidade microbiológica do sururu (Mytella charruana) comercializado por catadoras da Baía de Sepetiba, Rio de Janeiro, Brasil / Microbiological quality of sururu (Mytella charruana) marketed by scavengers of the Sepetiba Bay, Rio de Janeiro, Brazil

A preocupação com a qualidade do pescado é de grande importância para todos, pois é um alimento de alto valor nutritivo, mas tem grande susceptibilidade à deterioração e formação de substâncias prejudiciais à saúde, quando as condições de conservação e manipulação não são mantidas. O cultivo de moluscos bivalves além de ser uma fonte alternativa de alimentos, é uma opção para a subsistência das populações ribeirinhas de todo o litoral, à medida que a matriz alimentícia ganha espaço no mercado, principalmente nas regiões nordeste, sul e sudeste. Os sururus são organismos filtradores, capazes de absorver micropartículas em suspensão, as quais podem carrear elevadas concentrações de microrganismos patogênicos, outro fator importante relacionado a este molusco é a má condição de manipulação no beneficiamento, que pode provocar toxinfecções alimentares, ambos provocando danos à saúde. As análises microbiológicas foram realizadas em sururu in natura e após cozimento. Nas amostras analisadas houve ausência de Salmonella spp., com redução na contagem de Staphylococcus coagulase-positiva e de Coliformes Termotolerantes a 45ºC nos produtos cozidos. Os resultados são indicativos de que mesmo havendo redução de contaminação bacteriana, a manipulação das catadoras, após cozimento, é inadequada e que medidas corretivas devem ser adotadas para se obter o produto adequado bacteriologicamente ao consumo.(AU)

Fish quality has a great importance concerning to its high nutritional value, due to its great susceptibility to deterioration and occurrence of harmful substances to human health when the storage and handling conditions are not kept properly. The bivalves farming is an alternative source of food and also a source of livelihood for riverside communities, as the product is accepted in the market, mainly in the Northeast, South and Southeast regions. As filter feeders organisms, “sururu” mussels can absorb microparticles which can carry high level of pathogenic micro-organisms. Another important factor is the bad handling conditions both can lead to foodstuff infections. Microbiological analyzes were performed in raw “sururu” mussel and after cooking. The samples analyzed there was no Salmonella sp., a reduction in coagulase-positive Staphylococcus count and thermotolerant coliforms at 45 °C in baked products. Results of the analyzes showed that even with the contamination reduction, the handling of the women staff after cooking is inadequate and corrective measures should be taken to obtain a safe product for the final consumer.(AU)

Influence of packaging on the quality of Brazil nuts / Influência da embalagem na qualidade de castanhas-do-brasil

The Brazil nut is an important commodity that grows in the Amazon rainforest and is notable for its high nutritional value. However, the effect that packaging has on product shelf-life is unclear. This study evaluated the microbiological and nutritional quality of unshelled Brazil nuts packed in (a) nylon and polypropylene under vacuum, and (b) in polyethylene terephthalate and polyethylene aluminized films. The nuts were stored for nine months under natural environmental conditions. The most probable number of total and thermotolerant coliforms and Escherichia coli, and counting of molds and yeast were determined in the unshelled nuts shortly after collection and every three months during storage. Moisture, lipids, ash, neutral detergent fiber, and acid detergent fiber contents were measured by the gravimetric method. Crude protein content was measured using the Kjeldahl method. Coliform levels were within legislated standards in both types of packaging. Mold and yeast growth increased with time in both types of packaging (0.1x10¹ to 9.5x10³ colony forming units g-1), but only nuts packaged in aluminum film showed a significant increase after six months of storage. After nine months of storage, both types of packaged nuts had good nutritional quality. Aluminized packaging resulted in better conservation of the lipid fraction and lower permeability to water vapor, however, vacuum packaging was more effective in controlling fungal growth, possibly due to the lack of oxygen.(AU)

As castanhas-do-brasil são um importante produto da floresta amazônica e destacam-se pelo seu alto valor nutricional. Contudo, os efeitos da embalagem sobre a vida de prateleira das castanhas não estão completamente esclarecidos. Sendo assim, neste estudo, avaliou-se a qualidade microbiológica e nutricional de castanhas-do-brasil descascadas, embaladas em (a) nylon mais polipropileno a vácuo e (b) filmes aluminizados de polietileno tereftalato (PET) e polietileno (PE). As castanhas foram armazenadas por um período de nove meses, sob condições ambientais naturais. Logo após a coleta, e a cada três meses, foram determinados nas castanhas o número mais provável de coliformes totais, coliformes termotolerantes e Escherichia coli, e contagem total de bolores e leveduras. Também foram medidos os teores de umidade, lipídeos, cinzas, fibra em detergente neutro e fibra em detergente ácido por métodos gravimétricos, e os teores de proteína bruta por meio do método de Kjeldahl. Os níveis de coliformes termotolerantes estiveram dentro dos padrões da legislação nos dois tipos de embalagem. A incidência de bolores e leveduras aumentou ao longo do tempo nas duas embalagens (de 0,1x10¹ a 9,5x10³ unidades formadoras de colônia; UFC g-1), porém somente a embalagem aluminizada apresentou aumento significativo após seis meses de armazenamento. Após nove meses, as castanhas nas duas embalagens apresentaram boa qualidade nutricional, porém a embalagem aluminizada apresentou melhor conservação da fração lipídica e menor permeabilidade a vapores de água. Contudo, a embalagem a vácuo foi mais eficiente no controle do crescimento de fungos, possivelmente devido à ausência de oxigênio.(AU)