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1.
Food Funct ; 13(9): 5166-5176, 2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-35421887

RESUMO

Berry fruits are rich in polyphenolic compounds (PCs) and may promote health benefits. Anthocyanin (ACN) concentrations of red raspberry (RR) (Rubus idaeus) extracts were 887.6 ± 262.8 µg g-1, consisting mainly of cyanidin-3-sophoroside (C3S) equivalents. To test the efficacy of RR in diabetes treatment, seven patients with type 2 diabetes mellitus (T2DM) were given one oral RR serving (123 g per day) for two weeks. Blood samples were drawn at the baseline (BSL) and post-feeding (PF) periods for phenolic metabolite, inflammation and insulin resistance (IR) biomarker analysis. Two urolithin conjugates, urolithin A glucuronide (Uro-A glur) and urolithin A sulphate (Uro-A sulf) were identified in the PF period in 5 of the 7 patients in nanomolar concentrations (1.6 ± 0.7-63.2 ± 31.2 nM). ACN-derived metabolites such as protocatechuic acid (PCA) and 3,4-dihydroxyphenylacetic acid (DOPAC) were at micromolar levels and were higher during the PF period for diabetics and the levels were as follows: BSL: PCA = 0.6 ± 0.4, DOPAC = 1.2 ± 0.5; PF: PCA = 0.6 ± 0.4, DOPAC = 1.1 ± 0.6. The results revealed significant reductions in high sensitivity C-reactive protein, hsCRP (p = 0.01) and there was a downward trend in IR measured by the homeostatic model assessment of insulin resistance (HOMA-IR, p = 0.0584) in T2DM patients. DOPAC (1-100 µM) failed to stimulate insulin secretion in pancreatic ß-cells. The multiplex assay showed variations in the cytokine levels between patients, but differences were not significant. This study demonstrates a potential use of RR in the treatment of inflammation and possibly IR as well in patients with type 2 diabetes.


Assuntos
Diabetes Mellitus Tipo 2 , Resistência à Insulina , Rubus , Ácido 3,4-Di-Hidroxifenilacético , Biomarcadores , Diabetes Mellitus Tipo 2/tratamento farmacológico , Promoção da Saúde , Humanos , Inflamação/tratamento farmacológico , Insulina , Projetos Piloto , Polifenóis/farmacologia
2.
AIMS Public Health ; 7(3): 574-586, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32968679

RESUMO

Human norovirus (HuNoV) is one of the leading causes of acute gastroenteritis globally. HuNoV outbreaks have been recently reported during air travels. Contaminated surfaces are known as a critical transmission route at various settings. The aim of this study was to provide key information about the survival and the decontamination of HuNoV on three commonly touched airplane cabin surfaces. In this study, we monitored the survival of HuNoV on seat leather, plastic tray table, and seatbelt for 30 days, with and without additional organic load (simulated gastric fluid). The efficacy of two EPA registered anti-norovirus disinfectants were also evaluated. Results showed that HuNoV was detected at high titers (>4 log10 genomic copy number) for up to 30 days when additional organic load was present. Both tested disinfectants were found highly ineffective against HuNoV when the surface was soiled. The study showed that when the organic load was present, HuNoV was highly stable and resistant against disinfectants. Findings from this study indicated that appropriate procedures should be developed by airline companies with the help of public health authorities to decrease passengers' exposure risk to HuNoV.

3.
Foods ; 9(9)2020 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-32911767

RESUMO

Sodium hypochlorite (NaOCl) is a commonly used sanitizer in the produce industry despite its limited effectiveness against contaminated human pathogens in fresh produce. Aqueous chlorine dioxide (ClO2) is an alternative sanitizer offering a greater oxidizing potency with greater efficacy in reducing a large number of microorganisms. We investigated the effect of aqueous chlorine dioxide treatment against human pathogens, Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes seeded on sweet potatoes. Sweet potatoes were spot inoculated (4.2 to 5.7 log CFU/cm2) with multi-strain cocktails of Salmonella spp., E. coli O157:H7, and L. monocytogenes and treated for 10-30 min with 5 ppm aqueous ClO2 or water. Aqueous ClO2 treatment was significantly (p < 0.05) effective in reducing Salmonella with a reduction of 2.14 log CFU/cm2 within 20 min compared to 1.44 log CFU/cm2 for water treatment. Similar results were observed for L. monocytogenes with a 1.98 log CFU/cm2 reduction compared to 0.49 log CFU/cm2 reduction observed after 30 min treatment with aqueous ClO2 the water respectively. The maximum reduction in E. coli O157: H7 reached 2.1 Log CFU/cm2 after 20 min of treatment with aqueous ClO2. The level of the pathogens in ClO2 wash solutions, after the treatment, was below the detectable limit. While in the water wash solutions, the pathogens' populations ranged from 3.47 to 4.63 log CFU/mL. Our study indicates that aqueous ClO2 is highly effective in controlling cross-contamination during postharvest washing of sweet potatoes.

4.
Food Sci Nutr ; 8(2): 1237-1243, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32148829

RESUMO

Produce growers using surface or well water to irrigate their crops may require an appropriate water treatment system in place to meet the water quality standard imposed by FSMA Produce Safety Rule. This study evaluated the potential of using ultraviolet (UV-C) treatment in reducing the microbial population in agricultural water. Waters with turbidity levels ranging from 10.93 to 23.32 Nephelometric Turbidity Units (NTU) were prepared by mixing pond water and well water. The waters were inoculated with a cocktail of generic Escherichia coli (ATCC 23716, 25922, and 11775) and then treated with UV-C light (20-60 mJ/cm2). All tested doses of the UV-C treatment reduced the E. coli levels significantly (p < .05) in the water samples with the turbidity levels up to 23.32 NTU. The decrease in the turbidity from 23.32 to 10.93 NTU increased the level of reduction by more than 2.15 log most probable number (MPN)/100 ml). UV-C treatment effectively reduces microbial load in agriculture water; however, turbidity of water may significantly affect the disinfection efficacy. The study also demonstrated that sprinkler system resulted in a higher level of contamination of cantaloupes compared with drip irrigation. The results indicated that UV-C treatment could be a promising strategy in reducing the produce safety risks associated with irrigation water.

5.
ACS Omega ; 5(8): 4125-4132, 2020 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-32149241

RESUMO

A facile method was used to synthesize biocomposites containing differing ratios of hyaluronic acid (HA) and cellulose (CEL). Based on the properties of the individual polymers, the resultant composite materials may have potentially great wound care properties. In the method outlined here, 1-butyl-3-methylimidazolium chloride ([Bmim][Cl]), a simple ionic liquid, was used as the sole solvent without chemical modifiers to dissolve the biopolymers at ratios of 1:1 and 2:1 HA to CEL. This method was completely recyclable since the ionic liquid, [Bmim][Cl], can be recovered. Results from spectroscopic measurements [Fourier transform infrared (FT-IR) and X-ray diffraction (XRD)] confirm the interaction between HA and CEL. Scanning electron microscopy (SEM) images reflect differing biopolymer ratios and the resulting impact on the texture and porosity of these composite materials. The composites exhibited high swelling capacity in various media. These composites were also drug-loaded to examine drug release properties for greater potential in combating Staphylococcus aureus infections.

6.
Food Microbiol ; 84: 103272, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31421761

RESUMO

One of the most important transmission routes of foodborne pathogens is through contaminated food contact surfaces. In this study, we investigated the survival and inactivation of Salmonella enterica serovar Typhimurium on frequently used food contact surfaces in household settings, including plastic cutting board (CB), formica laminate (LA), and stainless steel (SS) surfaces. S. Typhimurium at log (6 h), stationary (24 h), or long-term stationary (LTS) (14 days) phases were evaluated. Results showed that, at medium and high microbial loads, LTS phase cells had significantly higher survivor population compared to log and stationary phase cells at 24 h after inoculation (p < 0.05). Disinfection study showed that LTS phase cells were very resilient to sodium hypochlorite when the initial microbial load was high with disinfection efficacy ranging from 26 to 35%. Scanning electron microscopy of these surfaces at 24 h after inoculation with a high microbial load revealed an early biofilm structure.


Assuntos
Desinfetantes/farmacologia , Viabilidade Microbiana , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/fisiologia , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/fisiologia , Hipoclorito de Sódio/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Contagem de Colônia Microbiana , Desinfecção/métodos , Microbiologia de Alimentos
7.
J Food Sci ; 83(10): 2560-2570, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30184253

RESUMO

Sensory acceptability, purchase intent (PI), consumer emotional profile, and fatty acid profile of rib-eye steaks from four different biological types of grass-fed cattle (Angus, Brangus, Pineywoods, and Holstein) were evaluated. The effects of health benefit information (HBI) pertaining to grass-fed beef on the overall liking (OL), emotional profile, and PI were also studied. Consumers rated steaks from the two nontraditional beef biological types (Pineywoods and Holstein) equally or higher than conventional biological types (Angus and Brangus) in several hedonic (9-point scale) categories. Mean OL scores were 6.1 for Pineywoods and 6.3 for Holstein steaks, versus 5.5 for Angus and 6.0 for Brangus. Hedonic attributes, especially OL and liking of beef flavor, accounted for most of the differences between treatments based on Wilks' Lambda Multivariate Analysis of Variance (MANOVA) and descriptive discriminant analysis. After knowledge of HBI, OL of all treatments increased, particularly Angus with OL mean score significantly increasing from 5.5 to 6.2. Positive PI increased significantly for Angus (from 48% to 65.33%), Brangus (from 50.67% to 66.67%), and Holstein (from 61.33% to 76%) steaks. Angus steaks, which initially received the lowest beef flavor liking (5.1) showed the most improvement for OL after HBI. Likewise, emotional profiles were improved after HBI, particularly the "Interested" emotion with a 0.5 unit increased. PRACTICAL APPLICATION: Providing consumers with health benefit information (HBI) can enhance acceptability of grass-fed beef. Fatty acid analyses of steaks from four biological types of steers showed favorable n-6/n-3 ratios. Although some sensory attributes of cooked rib-eye steaks were scored differently among biological types, knowledge of grass-feeding and healthier fatty acids increased overall liking and purchase intent (PI) across products. Emotional profiles improved after HBI was given to consumers, with some emotions being significantly related to PI odds ratios. This research demonstrated the usefulness of HBI in improving hedonic perceptions of grass-fed steaks and the importance of consumer emotions in predicting PI.


Assuntos
Ração Animal/análise , Comportamento do Consumidor , Emoções , Percepção , Carne Vermelha/análise , Animais , Bovinos , Culinária , Ácidos Graxos/análise , Análise de Alimentos , Humanos , Masculino , Especificidade da Espécie , Paladar
8.
Microbiol Spectr ; 5(1)2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-28185612

RESUMO

Fresh fish and seafood are highly perishable, and microbiological spoilage is one of the important factors that limit their shelf life and safety. Fresh seafood can be contaminated at any point from rearing or harvesting to processing to transport or due to cross-contamination by consumer mishandling at home. With the increase in the demand for fish and seafood, aquaculture production is increasing, which could lead to new risks that will need to be addressed in the future to control foodborne pathogens.


Assuntos
Manipulação de Alimentos/métodos , Doenças Transmitidas por Alimentos/epidemiologia , Doenças Transmitidas por Alimentos/prevenção & controle , Alimentos Marinhos/microbiologia , Animais , Humanos , Risco
9.
Mol Nutr Food Res ; 61(3)2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27794202

RESUMO

SCOPE: Antibiotics ampicillin 1 g/L and neomycin 0.5 g/L were added to drinking water before or during feeding of resistant starch (RS) to rats to inhibit fermentation. METHODS AND RESULTS: In a preliminary study, antibiotics and no RS were given prior to rats receiving a transplant of cecal contents via gavage from donor rats fed RS (without antibiotics) or a water gavage before feeding resistant starch to both groups. Antibiotics given prior to feeding RS did not prevent later fermentation of RS regardless of either type of gavage. In the second study, antibiotics were given simultaneously with feeding of RS. This resulted in inhibition of fermentation of RS with cecal contents pH >8 and low amounts of acetate and butyrate. Rats treated with antibiotics had reduced Bifidobacteria spp., but similar Bacteroides spp. to control groups to reduce acetate and butyrate and preserve the production of propionate. Despite reduced fermentation, rats given antibiotics had increased glucagon-like peptide 1 (GLP-1) and cecum size, measures that are usually associated with fermentation. CONCLUSIONS: A simultaneous delivery of antibiotics inhibited fermentation of RS. However, increased GLP-1 and cecum size would be confounding effects in assessing the mechanism for beneficial effects of dietary RS by knocking out fermentation.


Assuntos
Ampicilina/farmacologia , Antibacterianos/farmacologia , Neomicina/farmacologia , Amido/farmacocinética , Gordura Abdominal/efeitos dos fármacos , Ampicilina/administração & dosagem , Animais , Antibacterianos/administração & dosagem , Ceco/química , Dieta Hiperlipídica , Digestão/efeitos dos fármacos , Água Potável/química , Interações Medicamentosas , Fermentação/efeitos dos fármacos , Microbioma Gastrointestinal/efeitos dos fármacos , Peptídeo 1 Semelhante ao Glucagon/sangue , Concentração de Íons de Hidrogênio , Masculino , Neomicina/administração & dosagem , Ratos Sprague-Dawley
10.
J Virol Methods ; 235: 1-8, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27150045

RESUMO

Hepatitis A virus (HAV) infection is the leading worldwide cause of acute viral hepatitis, and outbreaks caused by this virus often occur in fecal polluted waters. Rapid concentration and detection of viral contamination in water environments can prevent economic loss and can identify the source of contamination within a short time. However, conventional methods for virus concentration are often laborious, time consuming, and subject to clogging. Furthermore, most methods require a secondary concentration step to reduce the final volume of samples. We developed a method to concentrate HAV from seawater using zeolite in aid of rapid detection. In this method,artificial seawater was inoculated with HAV (7-8 log TCID50) and filtered with zeolite. The viruses were then eluted from zeolite with sodium dodecyl sulfate and detected via real-time PCR (qPCR). Zeolite was able to concentrate HAV from artificial seawater with ∼99% efficiency in less than 5min and was more efficient in seawater than in fresh water. The entire concentration and detection can be done in approximately 2h. Compared to existing methods, this method eliminated the need for a secondary concentration step as well as the necessity to modify the pH or salinity of the seawater during concentration, and was simple and inexpensive.


Assuntos
Vírus da Hepatite A/isolamento & purificação , Água do Mar/virologia , Zeolitas , Filtração , RNA Viral/análise , Reação em Cadeia da Polimerase em Tempo Real/economia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Salinidade , Sensibilidade e Especificidade , Dodecilsulfato de Sódio
11.
J Food Prot ; 79(1): 75-81, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26735032

RESUMO

Campylobacter jejuni has been recognized as one of the most prevalent causes of foodborne bacterial illnesses in humans. Previous studies have focused on the transmission routes of C. jejuni from commercial flock farms to the final retail product. The objective of this study was to determine the prevalence of C. jejuni and Campylobacter spp. in eggshells, live birds, feed, drinking water, and the rearing environment in a small-scale broiler operation. Broilers were raised under two different production systems: (i) environmentally controlled housing and (ii) open-air housing with two replications. Each week, samples were collected from eggshells, bird feces, feed, drinking water, enclosures (vertical walls of bird housing), and feed troughs for enumeration and isolation testing. All samples were plated on modified charcoal-cefoperazone-deoxycholate agar to determine the log CFU per gram and percent prevalence of Campylobacter spp. Isolation of C. jejuni was verified with latex agglutination and hippurate hydrolysis tests. The results from this study suggest that vertical transmission of these bacteria from egg surfaces to newly hatched chicks is not a significant risk factor. The results also suggest that the prevalence of C. jejuni at time of harvest (week 6) was significantly higher (P < 0.05) in the open-air housing broilers than in those in the environmentally controlled housing. Elevated levels of cross-contaminants, especially water and feed, may have played a role in this outcome.


Assuntos
Infecções por Campylobacter/veterinária , Campylobacter jejuni/isolamento & purificação , Doenças das Aves Domésticas/microbiologia , Animais , Infecções por Campylobacter/epidemiologia , Infecções por Campylobacter/microbiologia , Campylobacter jejuni/classificação , Campylobacter jejuni/genética , Galinhas/crescimento & desenvolvimento , Galinhas/microbiologia , Fezes/microbiologia , Prevalência
12.
J Food Sci ; 80(10): S2287-95, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26408954

RESUMO

UNLABELLED: Rib-eye steaks, from 3 forage-finished systems (S1, S2, and S3) and 1 commercial steak (C), either cooked by 1-sided-grilling or 2-sided-grilling, were evaluated for sensory acceptability [overall appearance (ORA) and overall appearance of fat (OAF) for raw steaks; overall appearance (OCA), overall beef aroma (OBA), overall beef flavor (OBF), juiciness, tenderness and overall liking (OL) for cooked steaks] and purchase intent by Hispanic, Asian and U.S. consumers. They also indicated preferred degree of doneness and cooking methods. Cross-cultural differences in preferences and consumer acceptability of rib-eye steaks were observed. Grilling was the most preferred cooking method. Hispanics and Asians preferred medium and/or medium well, while U.S. consumers preferred medium and/or medium rare. For cooked steaks, the population effect was significant for all sensory attributes; Asians generally scored lower than did Hispanics and U.S. consumers. C and S3 generally had higher scores for all sensory attributes across 3 populations. Purchase intent for all forage-finished steaks was higher for Hispanics and U.S. consumers compared to Asians (50.0% to 77.8% compared with 43.2% to 65.9%). Attributes influencing purchase intent of forage-finished steaks differed among populations: tenderness (odds ratio = 1.4) for Hispanics, OCA (odds ratio = 1.5) for Asians, and OBF (odds ratio = 1.3) for U.S. consumers. Overall, this study demonstrated that the type of forage-finished system and ethnic differences influenced sensory acceptability and purchase intent of forage-finished rib-eye steaks. PRACTICAL APPLICATION: Demand for forage-finished beef has increased worldwide due to its potential health benefits. Little is known regarding the cross-cultural effects on the consumer acceptance of forage-finished beef. We evaluated sensory acceptance and purchase intent of raw and cooked forage-finished rib-eye steaks using Hispanic, Asian, and U.S. (White and African American) populations. This study demonstrated that consumer acceptability and purchase intent of forage-finished rib-eye steaks differed among Hispanic, Asian, and U.S. populations. This information can be used to guide development and marketing strategies for beef products.


Assuntos
Ração Animal , Criação de Animais Domésticos/métodos , Comportamento do Consumidor , Dieta , Etnicidade , Carne Vermelha , Paladar , Negro ou Afro-Americano , Animais , Povo Asiático , Bovinos , Comércio , Culinária , Comparação Transcultural , Aromatizantes , Hispânico ou Latino , Humanos , Intenção , Odorantes , Costelas , Estados Unidos , População Branca
13.
Appl Environ Microbiol ; 81(18): 6436-45, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26162869

RESUMO

Pathogenic enteric viruses are responsible for a wide range of infections in humans, with diverse symptoms. Raw and partially treated wastewaters are major sources of environmental contamination with enteric viruses. We monitored a municipal secondary wastewater treatment plant (New Orleans, LA) on a monthly basis for norovirus (NoV) GI and GII and enterovirus serotypes using multiplex reverse transcription-quantitative PCR (RT-qPCR) and microbial indicators of fecal contamination using standard plating methods. Densities of indicator bacteria (enterococci, fecal coliforms, and Escherichia coli) did not show monthly or seasonal patterns. Norovirus GII was more abundant than GI and, along with enterovirus serotypes, increased in influent during fall and spring. The highest NoV GI density in influent was in the fall, reaching an average of 4.0 log10 genomic copies/100 ml. Norovirus GI removal (0.95 log10) was lower than that for GII, enterovirus serotypes, and male-specific coliphages (1.48 log10) or for indicator bacteria (4.36 log10), suggesting higher resistance of viruses to treatment. Male-specific coliphages correlated with NoV GII densities in influent and effluent (r = 0.48 and 0.76, respectively) and monthly removal, indicating that male-specific coliphages can be more reliable than indicator bacteria to monitor norovirus GII load and microbial removal. Dominant norovirus genotypes were classified into three GI genotypes (GI.1, GI.3, and GI.4) and four GII genotypes (GII.3, GII.4, GII.13, and GII.21), dominated by GI.1 and GII.4 strains. Some of the seasonal and temporal patterns we observed in the pathogenic enteric viruses were different from those of epidemiological observations.


Assuntos
Enterovirus/isolamento & purificação , Norovirus/isolamento & purificação , Águas Residuárias/microbiologia , Águas Residuárias/virologia , Microbiologia da Água , Bactérias/genética , Bactérias/isolamento & purificação , Colífagos/genética , Enterovirus/classificação , Enterovirus/genética , Monitoramento Ambiental , Fezes/microbiologia , Fezes/virologia , Genoma Viral , Genótipo , Humanos , Nova Orleans , Norovirus/classificação , Norovirus/genética , Reação em Cadeia da Polimerase , RNA Viral/genética , Estações do Ano , Sorogrupo , Vírus/genética , Vírus/isolamento & purificação , Purificação da Água
14.
J Food Sci ; 80(5): M1075-82, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25899121

RESUMO

Noroviruses are the most common causative agent of viral gastroenteritis in humans, and are responsible for major foodborne illnesses in the United States. Filter-feeding molluscan shellfish exposed to sewage-contaminated waters bioaccumulate viruses, and if consumed raw, transmit the viruses to humans and cause illness. We investigated the occurrence of norovirus GI and GII and microbial indicators of fecal contamination in the eastern oysters (Crassostrea virginica) and water from commercial harvesting areas along the Louisiana Gulf Coast (January to November of 2013). Microbial indicators (aerobic plate count, enterococci, fecal coliforms, Escherichia coli, male-specific coliphages, and somatic coliphages) were detected at the densities lower than public health concerns. Only one oyster sample was positive for norovirus GII at 3.5 ± 0.2 log10 genomic equivalent copies/g digestive tissues. A stool specimen obtained from an infected individual associated with a norovirus outbreak and the suspected oysters (Cameron Parish, La., area 30, January 2013) were also analyzed. The norovirus strain in the stool belonged to GII.4 Sydney; however, the oysters were negative and could not be linked. In general, no temporal trend was observed in the microbial indicators. Low correlation among bacterial indicators was observed in oysters. Strongest correlations among microbial indicators were observed between enterococci and fecal coliforms (r = 0.63) and between enterococci and E. coli (r = 0.64) in water (P < 0.05); however, weak correlations were found in oysters (r < 0.45) and between oysters and harvest water (r ≤ 0.36, P > 0.05). Our results emphasize the need for regular monitoring of pathogenic viruses in commercial oyster harvesting areas to reduce the risks of viral gastroenteritis incidences.


Assuntos
Crassostrea/microbiologia , Crassostrea/virologia , Norovirus/isolamento & purificação , Microbiologia da Água , Animais , Infecções por Caliciviridae/epidemiologia , Infecções por Caliciviridae/virologia , Enterobacteriaceae/isolamento & purificação , Escherichia coli/isolamento & purificação , Fezes/microbiologia , Doenças Transmitidas por Alimentos , Gastroenterite/virologia , Golfo do México , Humanos , Louisiana , Esgotos/microbiologia , Frutos do Mar/microbiologia , Vírus , Poluição da Água
15.
J Virol Methods ; 196: 86-92, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24211298

RESUMO

Bacteriophage MS2 is used widely as a model organism to estimate pathogenic virus survival in various environments, and is usually quantified by plaque assay. Although current plaque assays work well in enumeration of MS2 in environmental samples, quantification of MS2 calls for better visibility and higher consistency. In an attempt to improve the visibility and consistency of the current plaque assay, spread plate technique was introduced, instead of the pour plate technique used commonly in existing methods. Other parameters that influence the outcome of the plaque assay were also compared. Using spread plate technique resulted in an increase of plaque size by approximately 50% and contributed to a better visibility. Addition of supplements (glucose, CaCl2 and thiamine); reduction of agar thickness and hardness, also contributed to enhanced plaque visibility and increased plaque count. Among all the conditions tested, a supplemented thin bottom agar (10ml 1% agar) and a supplemented thin top agar (10ml 0.45% agar) with spread plate technique gave the maximum countable plaques with a minimum standard deviation. When compared to other methods, it produced significantly higher plaque count and lower variation. The optimized plaque assay significantly improved visibility and consistency of the existing plaque assay methods and could be used in quantification of MS2.


Assuntos
Levivirus/isolamento & purificação , Carga Viral/métodos , Ensaio de Placa Viral/métodos , Meios de Cultura/química , Reprodutibilidade dos Testes
16.
J Virol Methods ; 196: 212-8, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24269798

RESUMO

Fecal contamination of shellfish growing seawater with enteric viruses is often associated with human outbreaks of gastroenteritis. Male specific bacteriophage MS2 is correlated with those of enteric viruses in a wide range of water environments and has been used widely as a surrogate for pathogenic waterborne viruses. Since viruses in contaminated water are usually at low levels, the development of methods to concentrate viruses from water is crucial for detection purposes. In the present study, granular activated carbon was evaluated for concentration of MS2 from artificial seawater, and different parameters of the seawater were also compared. Recovery of MS2 from warm seawater (37°C) was found to be significantly greater than from cold seawater (4 and 20°C), and even greater than from fresh water (4, 20 and 37°C); the difference between seawater and fresh water became less profound when the temperatures of both were below 37°C. Although not of statistical significance, recovery of MS2 from low salinity seawater (10 and 20 parts per thousand, ppt) was greater than from high salinity seawater (30 and 40ppt). One gram of granular activated carbon was able to extract 6-log plaque forming units (PFU) of MS2 from 500ml seawater at 37°C. This study demonstrated that granular activated carbon can concentrate an enteric virus indicator from shellfish growing seawater effectively.


Assuntos
Carvão Vegetal , Levivirus/isolamento & purificação , Água do Mar/virologia , Virologia/métodos , Poluição da Água , Animais , Água Doce/virologia , Humanos , Modelos Teóricos , Salinidade , Água do Mar/química , Temperatura
17.
J Tissue Eng Regen Med ; 8(5): 386-95, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-22700366

RESUMO

Nationally, nearly 1.5 million patients in the USA suffer from ailments requiring bone grafts and hip and other joint replacements. Infections following internal fixation in orthopaedic trauma can cause osteomyelitis in 22-66% of cases and, if uncontrolled, the mortality rate can be as high as 2%. We characterize a procedure for the synthesis of antimicrobial and biocompatible poly-l-lactic acid (PLLA) and poly-ethyleneglycol (PEG) bioscaffolds designed to degrade and absorb at a controlled rate. The bioscaffold architecture aims to provide a suitable substrate for the controlled release of silver nanoparticles (SNPs) to reduce bacterial growth and to aid the proliferation of human adipose-derived stem cells (hASCs) for tissue-engineering applications. The fabricated bioscaffolds were characterized by scanning transmission microscope (SEM) and it showed that the addition of tncreasing concentrations of SNPs results in the formation of dendritic porous channels perpendicular to the axis of precipitation. The antimicrobial properties of these porous bioscaffolds were tested according to a modified ISO 22196 standard across varying concentrations of biomass-mediated SNPs to determine an efficacious antimicrobial concentration. The bioscaffolds reduced the Staphylococcus aureus and Escherichia coli viable colony-forming units by 98.85% and 99.9%, respectively, at an antimicrobial SNPs concentration of 2000 ppm. Human ASCs were seeded on bioscaffolds and cultured in vitro for 20 days to study the effect of SNPs concentration on the viability of cells. SEM analysis and the metabolic activity-based fluorescent dye, AlamarBlue®, demonstrated the growth of cells on the efficacious antimicrobial bioscaffolds. The biocompatibility of in vitro leached silver, quantified by inductively coupled plasma optical emission spectroscopy (ICP-OES), proved non-cytotoxic when tested against hASCs, as evaluated by MTT assay.


Assuntos
Anti-Infecciosos/farmacologia , Materiais Biocompatíveis/farmacologia , Ortopedia , Próteses e Implantes , Alicerces Teciduais/química , Tecido Adiposo/citologia , Morte Celular/efeitos dos fármacos , Força Compressiva/efeitos dos fármacos , Módulo de Elasticidade/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Humanos , Ácido Láctico/farmacologia , Nanopartículas Metálicas/ultraestrutura , Testes de Sensibilidade Microbiana , Poliésteres , Polietilenoglicóis/farmacologia , Polímeros/farmacologia , Prata/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Células-Tronco/citologia , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo , Células-Tronco/ultraestrutura
18.
J Biomater Appl ; 28(7): 1028-38, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23775239

RESUMO

Herein we report a facile layer-by-layer method for creating an antimicrobial coating composed of silver nanoparticles on medical grade titanium test discs. Nanoscale silver nanoparticle layers are attached to the titanium orthopedic implant material via aminopropyltriethoxy silane crosslinker that reacts with neighboring silane moieties to create an interconnected network. A monolayer of silane, followed by a monolayer of silver nanoparticles would form one self-assembled layer and this process can be repeated serially, resulting in increased silver nanoparticles deposition. The release rate of silver ion increases predictably with increasing numbers of layers and at appropriate thicknesses these coatings demonstrate 3-4 log reduction of viable Escherichia coli and Staphylococcus aureus bacteria. Increasing the thickness of the coatings resulted in reduced bacterial colonization as determined by fluorescent staining and image analysis. Interestingly, the cytotoxicity of murine 3T3 cells as quantified by fluorescent staining and flow cytometry, was minimal and did not vary significantly with the coating thickness. Additionally, these coatings are mechanically stable and resist delamination by orthogonal stress test. This simple layer-by-layer coating technique may provide a cost-effective and biocompatible method for reducing microbial colonization of implantable orthopedic devices.


Assuntos
Infecções Bacterianas/prevenção & controle , Sobrevivência Celular , Materiais Revestidos Biocompatíveis , Nanopartículas Metálicas/química , Prata/química , Células 3T3 , Animais , Aderência Bacteriana , Infecções Bacterianas/microbiologia , Escherichia coli/isolamento & purificação , Técnicas In Vitro , Camundongos , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Espectrofotometria Ultravioleta , Staphylococcus aureus/isolamento & purificação , Ressonância de Plasmônio de Superfície , Resistência à Tração
19.
Open Microbiol J ; 7: 130-4, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24302976

RESUMO

This study evaluated the antibacterial activity of Biosecur(®) citrus extract surface cleaner against Vibrio vulnificus using plate count method. Two concentrations, 0.5% and 2% of Biosecur(®) surface cleaner were plated on Vibrio vulnificus Agar (VVA) and tested for reduction of Vibrio vulnificus. In order to investigate the lasting residual activity of Biosecur(®), antibacterial activity tests were also performed at time intervals up to 2.5 h after Biosecur(®) was plated on VVA. Biosecur(®) showed 6-log reduction of Vibrio vulnificus at 2%, and 3-log reduction of Vibrio vulnificus at 0.5%. The antibacterial activity of 2% Biosecur(®) against Vibrio vulnificus was shown to be equivalent to that of tetracycline. The residual activity of 2% Biosecur(®) was shown to maintain for at least 2.5 h after application. This study confirmed the high activity and long lasting residual effect of a safe, non-toxic organic food grade surface cleaner.

20.
Obesity (Silver Spring) ; 21(5): 981-4, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23784900

RESUMO

OBJECTIVE: Obesity after menopause is a health concern for older females. Changes in the microbiota are likely to occur with this condition. Modifying the microbiota with a prebiotic is a plausible strategy for improving the health of menopausal females. DESIGN AND METHODS: Resistant starch type 2 from high-amylose maize (HAM-RS2) was used as a prebiotic in rats in a 2 × 2 factorial study with two levels of HAM-RS2 (0 or 29.7% of weight of diet) referred to as energy control (EC) and HAM-RS2 diets, respectively; and two levels of surgery, ovariectomized (OVX) and sham. RESULTS: In a 6-week, postsurgery recovery period, OVX rats gained more body weight with consumption of a similar amount of food. Subsequently, consumption of HAM-RS2 versus EC diets resulted in reduced abdominal fat in both OVX and sham rats; but when normalized for disemboweled body weight (body weight minus GI tract), there was no effect of surgery, only reduction with HAM-RS2. Targeted bacterial populations were estimated that are known to ferment HAM-RS2 or metabolize the products of that initial fermentation. OVX and sham rats demonstrated increased bacterial levels with dietary HAM-RS2 for all bacteria. Additionally, culture techniques and qPCR provided similar results. CONCLUSION: This study shows that, as expected, OVX increases adiposity. However, contrary to previous effects seen in obese mice, this did not prevent fermentation of HAM-RS2 and consequently, the fat gain associated with OVX was attenuated.


Assuntos
Tecido Adiposo/efeitos dos fármacos , Bactérias/efeitos dos fármacos , Trato Gastrointestinal/microbiologia , Obesidade/prevenção & controle , Prebióticos , Amido/análogos & derivados , Zea mays/química , Tecido Adiposo/metabolismo , Animais , Dieta , Fibras na Dieta/farmacologia , Fibras na Dieta/uso terapêutico , Feminino , Fermentação , Menopausa , Microbiota , Obesidade/etiologia , Obesidade/microbiologia , Ovariectomia , Preparações de Plantas/farmacologia , Preparações de Plantas/uso terapêutico , Ratos Sprague-Dawley , Amido Resistente , Amido/farmacologia , Amido/uso terapêutico , Aumento de Peso/efeitos dos fármacos
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