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1.
J Appl Microbiol ; 132(3): 1788-1801, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34637587

RESUMO

AIMS: This study aimed to investigate the physiological responses of two gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and two gram-positive bacteria (Enterococcus faecalis and Bacillus sphaericus) to ultraviolet (UV) and chlorine disinfection. METHODS AND RESULTS: Bacterial inactivation by UV and chlorine disinfection were evaluated with a plate count method for culturability, FCM and PMA-qPCR for membrane integrity and DyeTox13-qPCR for enzymatic activity, respectively. Both UV and chorine disinfection caused complete loss of culturability while membrane integrity remained intact after UV disinfection. Both DyeTox13-qPCR and PMA-qPCR showed high ΔCt values up to 8.9 after chlorine disinfection, indicating that both methods were able to distinguish non-treated from chlorine-treated cells. Although PMA-qPCR could not differentiate membrane integrity of cells on UV exposure, DyeTox13-qPCR showed significant differences in ΔCt values of 5.05 and 10.4 for gram-negative (E. coli) and gram-positive (Enterococcus) bacteria, respectively. However, DyeTox13-qPCR for gram-negative bacteria displayed relatively small differences in ΔCt values compared with gram-positive bacteria. CONCLUSION: UV and chlorine disinfection led to changes in physiological state of gram-negative and gram-positive bacteria. Particularly, UV disinfection could induce active but non-culturable (ABNC) for gram-negative bacteria and dormant cell for gram-positive bacteria where intact cells no longer showed the enzymatic activity. SIGNIFICANCE AND IMPACT OF THE STUDY: UV and chlorine are commonly used to disinfect water, food and fomites to inactivate pathogenic bacteria. However, a viable but non-culturable (VBNC) state of bacteria induced by disinfection may underestimate the health risks because of the potential resuscitation of VBNC cells. This study highlighted that bacteria could undergo different physiological (ABNC or dormant) states during UV and chlorine disinfection. In addition, viability PCR techniques could provide insight into the changes in physiological states during disinfection processes.


Assuntos
Cloro , Desinfecção , Bactérias/genética , Cloro/farmacologia , Desinfecção/métodos , Escherichia coli , Citometria de Fluxo , Viabilidade Microbiana , Reação em Cadeia da Polimerase em Tempo Real/métodos
2.
Graefes Arch Clin Exp Ophthalmol ; 256(10): 1895-1903, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30078141

RESUMO

PURPOSE: To investigate the effect of titanium dioxide (TiO2) nanoparticles on the inhibition of the in vitro cellular activity of human Tenon's fibroblasts (HTFs) under UVA exposure. METHODS: The effects of TiO2 nanoparticles on human Tenon's fibroblasts were evaluated after 1, 4, 6, and 24 h of exposure to UVA at levels of 2.5, 5.0, and 10 J/cm2. The methyl thiazolyl tetrazolium (MTT) assay was performed to measure the suppression of cellular metabolic activity. The lactate dehydrogenase (LDH) assay was performed to determine the extent of cell membrane damage. Flow cytometric analysis and inverted phase-contrast and electron microscopy were performed. The scratch wound assay was performed to visualize suppression of cellular migration. RESULTS: MTT assay values were similar between the UVA-exposed groups and the control group without UVA exposure. However, the combined exposure of TiO2 nanoparticles and UVA exposure induced significant dose-dependent inhibition of cellular viability and damage to HTFs, especially at concentrations of TiO2 equal to or greater than 100 µg/mL and 2.5 J/cm2 of UVA irradiation. Changes in cellular morphology increased in a dose-dependent pattern with a TiO2 concentration greater than 100 µg/mL under UVA exposure. At a TiO2 concentration of 150 µg/mL, damage to the cellular morphology of the HTFs was significantly increased, and nanoparticles were seen inside of the cytoplasm in the affected HTFs exposed to UVA. There was a significant reduction of cellular migration at TiO2 concentrations higher than 150 µg/mL. CONCLUSION: TiO2 nanoparticles inhibited the cellular activity of HTFs under UVA irradiation and showed potential for use to prevent the wound scarring of Tenon's fibroblasts. Further studies will be necessary to determine the optimal concentration of TiO2 nanoparticles and UVA exposure dose for clinical applications.


Assuntos
Nanopartículas , Cápsula de Tenon/patologia , Titânio/farmacologia , Raios Ultravioleta , Western Blotting , Movimento Celular/efeitos dos fármacos , Movimento Celular/efeitos da radiação , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Células Cultivadas , Fibroblastos/metabolismo , Fibroblastos/patologia , Fibroblastos/efeitos da radiação , Citometria de Fluxo , Humanos , Fármacos Fotossensibilizantes/farmacologia , Cápsula de Tenon/metabolismo , Cápsula de Tenon/efeitos da radiação
3.
Asian-Australas J Anim Sci ; 30(2): 160-166, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27492349

RESUMO

OBJECTIVE: This study identifies single-nucleotide polymorphisms (SNP) or gene combinations that affect the flavor and quality of Korean cattle (Hanwoo) by using the SNP Harvester method. METHODS: Four economic traits (oleic acid [C18:1], saturated fatty acids), monounsaturated fatty acids, and marbling score) were adjusted for environmental factors in order to focus solely on genetic effects. The SNP Harvester method was used to investigate gene combinations (two-way gene interactions) associated with these economic traits. Further, a multifactor dimensionality reduction method was used to identify superior genotypes in gene combinations. RESULTS: Table 3 to 4 show the analysis results for differences between superior genotypes and others for selected major gene combinations using the multifactor dimensionality reduction method. Environmental factors were adjusted for in order to evaluate only the genetic effect. Table 5 shows the adjustment effect by comparing the accuracy before and after correction in two-way gene interactions. CONCLUSION: The g.3977-325 T>C and (g.2988 A>G, g.3977-325 T>C) combinations of fatty acid-binding protein4 were the superior gene, and the superior genotype combinations across all economic traits were the CC genotype at g.3977-325 T>C and the AACC, GACC, GGCC genotypes of (g.2988 A>G, g.3977-325 T>C).

4.
Asian-Australas J Anim Sci ; 30(6): 765-772, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28183167

RESUMO

OBJECTIVE: This study examines the genetic factors influencing the phenotypes (four economic traits:oleic acid [C18:1], monounsaturated fatty acids, carcass weight, and marbling score) of Hanwoo. METHODS: To enhance the accuracy of the genetic analysis, the study proposes a new statistical model that excludes environmental factors. A statistically adjusted, analysis of covariance model of environmental and genetic factors was developed, and estimated environmental effects (covariate effects of age and effects of calving farms) were excluded from the model. RESULTS: The accuracy was compared before and after adjustment. The accuracy of the best single nucleotide polymorphism (SNP) in C18:1 increased from 60.16% to 74.26%, and that of the two-factor interaction increased from 58.69% to 87.19%. Also, superior SNPs and SNP interactions were identified using the multifactor dimensionality reduction method in Table 1 to 4. Finally, high- and low-risk genotypes were compared based on their mean scores for each trait. CONCLUSION: The proposed method significantly improved the analysis accuracy and identified superior gene-gene interactions and genotypes for each of the four economic traits of Hanwoo.

5.
Zoolog Sci ; 33(1): 73-7, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26853871

RESUMO

Chicken is one of the most popular domesticated species worldwide, as it can serve an important role in agricultural as well as biomedical research fields. Because it inhabits almost every continent and presents diverse morphology and traits, the need of genetic markers for distinguishing each breed for various purposes has increased. The whole genome sequencing of three different breeds (White Leghorn, Korean domestic, and Araucana) that show similar coloring patterns, with the exception of the White Leghorn breed, have confirmed previously reported genomic alterations and identified many novel variants. Additionally, the Whole Genome Re-Sequencing (WGRS) approach identified an approximately 4 kb insert within SLCO1B3 responsible for blue egg shell color. Targeted investigation of pigment-related genes corroborated previously reported non-synonymous mutations, and provided deeper insight into chicken coloring, where not a single but a combination of non-synonymous mutations in the MC1R gene is likely to be responsible for altered feather coloring.


Assuntos
Galinhas/genética , Variação Genética , Genoma , Animais , Plumas/fisiologia , Regulação da Expressão Gênica/fisiologia , Transportadores de Ânions Orgânicos Sódio-Independentes/genética , Transportadores de Ânions Orgânicos Sódio-Independentes/metabolismo , Filogenia , Pigmentos Biológicos , Receptor Tipo 1 de Melanocortina/genética , Receptor Tipo 1 de Melanocortina/metabolismo
6.
Clin Exp Ophthalmol ; 44(6): 481-7, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26661832

RESUMO

BACKGROUND: The aim of this study was to determine whether implantable collamer lens (ICL) implantation to correct myopia is an effective and safe surgical option even after long-term follow up. DESIGN: A retrospective observational study was carried out. PARTICIPANTS: A total of 281 eyes of 145 myopic patients were included in the study. METHODS: Patients underwent ICL implantation and had the follow-up period of at least 5 years (87 ± 18.9 months). MAIN OUTCOME MEASURES: Outcome measures included uncorrected and corrected distance visual acuities, refraction for the evaluation of efficacy, safety, stability and predictability, ICL vault and adverse events. RESULTS: The final mean logMAR uncorrected and corrected distance visual acuities were 0.02 ± 0.19 and -0.12 ± 0.13, respectively. The mean efficacy and safety indices were 1.04 ± 0.32 and 1.20 ± 0.26. The mean spherical equivalent decreased from -8.74 ± 2.27 diopter (D) to -0.58 ± 0.72 D, and there was high predictability with 69.8% and 87.2% having a postoperative refraction within 0.5 D and 1.0 D, respectively. The mean postoperative vault was changed from 2.53 ± 0.6 to 2.00 ± 0.7. Six (2.1%) eyes developed cataract, and the mean endothelial cell loss was 7.8 ± 8.3%. Increased intraocular pressure was found in two (0.7%) eyes that required the exchange of lenses with different sizes. CONCLUSIONS: Implantable collamer lens implantation to correct myopia was an effective and safe surgery with high predictability and stability during long-term follow up. Slight myopic shift and cataract formation related with change in vault should be further evaluated.


Assuntos
Implante de Lente Intraocular , Miopia/cirurgia , Lentes Intraoculares Fácicas , Adulto , Feminino , Seguimentos , Humanos , Masculino , Miopia/fisiopatologia , Segmento Posterior do Olho/cirurgia , Refração Ocular/fisiologia , Estudos Retrospectivos , Acuidade Visual/fisiologia , Adulto Jovem
7.
Asian-Australas J Anim Sci ; 29(2): 184-94, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26732443

RESUMO

The peroxisome proliferator-activated receptor gamma (PPARγ) gene plays an important role in the biosynthesis process controlled by a number of fatty acid transcription factors. This study investigates the relationships between 130 single-nucleotide polymorphisms (SNPs) in the PPARγ gene and the fatty acid composition of muscle fat in the commercial population of Korean native cattle. We identified 38 SNPs and verified relationships between 3 SNPs (g.1159-71208 A>G, g.42555-29812 G>A, and g.72362 G>T) and the fatty acid composition of commercial Korean native cattle (n = 513). Cattle with the AA genotype of g.1159-71208 A>G and the GG genotype of g.42555-29812 G>A and g.72362 G>T had higher levels of monounsaturated fatty acids and carcass traits (p<0.05). The results revealed that the 3 identified SNPs in the PPARγ gene affected fatty acid composition and carcass traits, suggesting that these 3 SNPs may improve the flavor and quality of beef in commercial Korean native cattle.

8.
Circulation ; 129(3): 304-12, 2014 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-24097439

RESUMO

BACKGROUND: The risks and benefits of long-term dual antiplatelet therapy remain unclear. METHODS AND RESULTS: This prospective, multicenter, open-label, randomized comparison trial was conducted in 24 clinical centers in Korea. In total, 5045 patients who received drug-eluting stents and were free of major adverse cardiovascular events and major bleeding for at least 12 months after stent placement were enrolled between July 2007 and July 2011. Patients were randomized to receive aspirin alone (n=2514) or clopidogrel plus aspirin (n=2531). The primary end point was a composite of death resulting from cardiac causes, myocardial infarction, or stroke 24 months after randomization. At 24 months, the primary end point occurred in 57 aspirin-alone group patients (2.4%) and 61 dual-therapy group patients (2.6%; hazard ratio, 0.94; 95% confidence interval, 0.66-1.35; P=0.75). The 2 groups did not differ significantly in terms of the individual risks of death resulting from any cause, myocardial infarction, stent thrombosis, or stroke. Major bleeding occurred in 24 (1.1%) and 34 (1.4%) of the aspirin-alone group and dual-therapy group patients, respectively (hazard ratio, 0.71; 95% confidence interval, 0.42-1.20; P=0.20). CONCLUSIONS: Among patients who were on 12-month dual antiplatelet therapy without complications, an additional 24 months of dual antiplatelet therapy versus aspirin alone did not reduce the risk of the composite end point of death from cardiac causes, myocardial infarction, or stroke. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT01186146.


Assuntos
Angioplastia Coronária com Balão , Aspirina/administração & dosagem , Doença da Artéria Coronariana/tratamento farmacológico , Stents Farmacológicos , Ticlopidina/análogos & derivados , Idoso , Aspirina/efeitos adversos , Clopidogrel , Terapia Combinada , Doença da Artéria Coronariana/mortalidade , Quimioterapia Combinada , Feminino , Seguimentos , Hemorragia/induzido quimicamente , Hemorragia/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Inibidores da Agregação Plaquetária/administração & dosagem , Inibidores da Agregação Plaquetária/efeitos adversos , Estudos Prospectivos , Fatores de Risco , Ticlopidina/administração & dosagem , Ticlopidina/efeitos adversos , Resultado do Tratamento
9.
Appl Environ Microbiol ; 81(8): 2808-18, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25681177

RESUMO

Many bacteria convert bicyclic compounds, such as indole and naphthalene, to oxidized compounds, including hydroxyindoles and naphthols. Pseudomonas aeruginosa, a ubiquitous bacterium that inhabits diverse environments, shows pathogenicity against animals, plants, and other microorganisms, and increasing evidence has shown that several bicyclic compounds alter the virulence-related phenotypes of P. aeruginosa. Here, we revealed that hydroxyindoles (4- and 5-hydroxyindoles) and naphthalene derivatives bearing hydroxyl groups specifically inhibit swarming motility but have minor effects on other motilities, including swimming and twitching, in P. aeruginosa. Further analyses using 1-naphthol showed that this effect is also associated with clinically isolated hyperswarming P. aeruginosa cells. Swarming motility is associated with the dispersion of cells from biofilms, and the addition of 1-naphthol maintained biofilm biomass without cell dispersion. We showed that this 1-naphthol-dependent swarming inhibition is independent of changes of rhamnolipid production and the intracellular level of signaling molecule cyclic-di-GMP (c-di-GMP). Transcriptome analyses revealed that 1-naphthol increases gene expression associated with multidrug efflux and represses gene expression associated with aerotaxis and with pyochelin, flagellar, and pilus synthesis. In the present study, we showed that several bicyclic compounds bearing hydroxyl groups inhibit the swarming motility of P. aeruginosa, and these results provide new insight into the chemical structures that inhibit the specific phenotypes of P. aeruginosa.


Assuntos
Indóis/toxicidade , Naftalenos/toxicidade , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/fisiologia , Perfilação da Expressão Gênica , Radical Hidroxila , Dados de Sequência Molecular , Pseudomonas aeruginosa/genética , Análise de Sequência de DNA , Transdução de Sinais
10.
J Environ Manage ; 128: 941-8, 2013 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-23892135

RESUMO

The management of waste electrical and electronic equipment (WEEE) or electronic waste (e-waste) has become a major issue of concern for solid waste communities due to the large volumes of waste being generated from the consumption of modern electrical and electronic products. In 2003, Korea introduced the extended producer responsibility (EPR) system to reduce the amount of electronic products to be disposed and to promote resource recovery from WEEE. The EPR currently regulates a total of 10 electrical and electronic products. This paper presents the results of the application of the Delphi method and analytical hierarchy process (AHP) modeling to the WEEE management tool in the policy-making process. Specifically, this paper focuses on the application of the Delphi-AHP technique to determine the WEEE priority to be included in the EPR system. Appropriate evaluation criteria were derived using the Delphi method to assess the potential selection and priority among electrical and electronic products that will be regulated by the EPR system. Quantitative weightings from the AHP model were calculated to identify the priorities of electrical and electronic products to be potentially regulated. After applying all the criteria using the AHP model, the results indicate that the top 10 target recycling products for the expansion of the WEEE list were found to be vacuum cleaners, electric fans, rice cookers, large freezers, microwave ovens, water purifiers, air purifiers, humidifiers, dryers, and telephones in order from the first to last. The proposed Delphi-AHP method can offer a more efficient means of selecting WEEE than subjective assessment methods that are often based on professional judgment or limited available data. By providing WEEE items to be regulated, the proposed Delphi-AHP method can eliminate uncertainty and subjective assessment and enable WEEE management policy-makers to identify the priority of potential WEEE. More generally, the work performed in this study is an example of how Delphi-AHP modeling can be used as a decision-making process tool in WEEE management.


Assuntos
Técnicas de Apoio para a Decisão , Resíduo Eletrônico , Reciclagem , Gerenciamento de Resíduos/métodos
12.
Cardiovasc Drugs Ther ; 24(2): 181-8, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20383571

RESUMO

BACKGROUND: This study was designed to evaluate the safety and efficacy of algorithm-based atorvastatin therapy initiated at different starting doses of 10, 20, and 40 mg in Korean dyslipidemic patients. METHODS: Five hundred seventy-four patients were screened, and 425 were enrolled (low risk, n = 29; intermediate risk, n = 45; high risk, n = 351). The starting dose depended on a patient's cardiovascular risk and LDL-cholesterol (LDL-C) levels. RESULTS: Of the patients, 253 (59.5%), 63 (14.8%) and 109 (25.6%) patients were assigned at baseline to 10 mg, 20 mg and 40 mg atorvastatin, respectively. 390 patients (91.8%) completed the study, and 35 discontinued prematurely. No patient in the low or intermediate risk groups was titrated to 80 mg at Week 4, whereas, 26 in the high risk group were. 81.9% of patients achieved their LDL-C target at Week 4, which was sustained through to Week 8 (86.0%). 89.1% of patients who were not titrated achieved their LDL-C target at Week 8, and 82.1% of patients who were titrated 1 step up achieved their LDL-C target at Week 8. Overall, about 40% reduction in LDL-C, non-HDL-C levels, and LDL-C/HDL-C ratio was observed during the follow-up. Triglyceride was reduced by approximately 10% by Week 8. HDL cholesterol was slightly increased over 8 weeks (2.6%). Atorvastatin was well tolerated at all dose levels. CONCLUSIONS: Patient-tailored statin therapy according to an individual's risk category and LDL-C levels was safe and effective with a quick achievement of LDL-C target in Korean dyslipidemic patients.


Assuntos
LDL-Colesterol/efeitos dos fármacos , Dislipidemias/tratamento farmacológico , Ácidos Heptanoicos/administração & dosagem , Ácidos Heptanoicos/uso terapêutico , Pirróis/administração & dosagem , Pirróis/uso terapêutico , Adulto , Idoso , Algoritmos , Anticolesterolemiantes/administração & dosagem , Anticolesterolemiantes/efeitos adversos , Anticolesterolemiantes/farmacologia , Anticolesterolemiantes/uso terapêutico , Atorvastatina , Proteína C-Reativa/metabolismo , Doenças Cardiovasculares/prevenção & controle , Quimiocina CCL2/sangue , Colesterol/sangue , HDL-Colesterol/sangue , HDL-Colesterol/efeitos dos fármacos , LDL-Colesterol/sangue , Projetos de Pesquisa Epidemiológica , Feminino , Ácidos Heptanoicos/efeitos adversos , Ácidos Heptanoicos/farmacologia , Humanos , Interleucina-6/sangue , Coreia (Geográfico) , Masculino , Pessoa de Meia-Idade , Pirróis/efeitos adversos , Pirróis/farmacologia , Fatores de Risco , Resultado do Tratamento , Triglicerídeos/sangue , Fator de Necrose Tumoral alfa/sangue , Adulto Jovem
13.
Harmful Algae ; 88: 101638, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31582154

RESUMO

A sudden increase of algae and their associated toxins in aquatic ecosystems can detrimentally affect the quality of the water, causing serious socio-economic and public health problems. To prevent the spread of harmful algae in aquatic ecosystems, it is essential to track the water's quality through rapid and in-situ monitoring systems. Conventional methods of algae quantification such as microscopy, hemocytometry, and UV-vis spectroscopy, however, are often unsuitable or inconvenient for in-situ assessment as they require skilled labor and expensive equipment. In this study, we developed a three-dimensional (3D)-printed smartphone platform integrated with a light-driven microfluidic chip operated by optoelectrowetting (OEW). This OEW-driven microfluidic chip not only allows multiplexed drop-wise functions such as droplet transportation, merging, mixing, immobilization on a detection zone, for on-chip water sample preparation but also fluorescent detection and counting of target algae cells using a commercially-available smartphone. Two freshwater algae (C. reinhardtii and M. aeruginosa) and two marine water algae (Amphiprora sp and C. closterium) were employed to validate the 3D-printed smartphone platform in this study. The fluorescence images of viable algae and the cell counting from the microfluidic chip were comparable to the results from a hemocytometer (P > 0.05). We have further conducted tests with spiked samples using freshwater and marine water that were directly collected from environmental samples, showing the same order of magnitude of cell numbers in the spiked and control cultures of algae cells (106 cell/mL, P > 0.05). Unlike traditional quantification methods, the 3D-printed smartphone platform integrated with the OEW offers a highly portable, user-friendly, low-cost tool that enables simple on-chip sample preparation and detection of viable algae. Thus, this stand-alone technology has the potential for rapid and in-situ monitoring of water quality, while using the smartphone's wireless communication capabilities to report the quality of the water in real-time.


Assuntos
Microfluídica , Smartphone , Ecossistema , Impressão Tridimensional , Água
14.
Water Res ; 160: 371-379, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31163314

RESUMO

Contamination of water by fecal matter and potential human enteric pathogens is a serious health concern. Microbiological water quality has been assessed by conventional culture-based methods of fecal indicator bacteria (FIB). Recently, molecular techniques for FIB have been introduced as alternative tools for rapid detection. However, such molecular techniques require a modern laboratory setting, expensive equipment, and skilled personnel. In this study, we developed a simple and rapid DNA extraction method based on a syringe filter without any specialized equipment. Furthermore, loop-mediated isothermal amplification (LAMP) PCR for fecal indicator bacteria (FIB) (i.e. E. coli and E. faecalis) was carried out using the DNA extracts from the syringe-filter based DNA extraction method. The efficiency of the extracted DNA from the syringe-filter based method was comparable to the results of the commercial kit method. We also tested fresh and marine-water collected directly from different locations in Singapore that were spiked with E. coli or E. faecalis. The LAMP assays combined with our DNA extraction method showed higher sensitivity and more tolerance to PCR inhibitors than that of conventional PCR methods. We further developed a portable LAMP device to conduct isothermal PCR reactions for rapid on-site measurement of FIB. As the color changes in the end point of the LAMP reaction can be observed with the naked eye, the portable LAMP device was easily operated and quick, obtaining results in 30 min. The simple, portable and user-friendly platform can be used as an initial screening for the rapid detection of the presence FIB in lower-resource settings. In conclusion, the portable LAMP device coupled with a syringe-filter based DNA extraction method enables us to detect the presence of FIB for assessing microbial water quality within 1 h without any sophisticated laboratory equipment or highly trained personnel.


Assuntos
Escherichia coli , Água , Humanos , Técnicas de Amplificação de Ácido Nucleico , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade , Singapura
15.
Microb Biotechnol ; 11(6): 1008-1016, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29243404

RESUMO

Nucleic acid amplification-based methods are limited by their inability to discriminate between viable and dead cells. To overcome this drawback, propidium monoazide (PMA) combined with qPCR has been used to differentiate viable from nonviable cells in environmental samples. However, assessing bacterial physiology using PMA-qPCR remains a challenge due to its incapability of detecting metabolic activities, leading to overestimation of the viable bacteria population under an inactivation condition (e.g. antibiotic treatments). A recent advanced technique to amplify ribosomal RNA precursors (pre-rRNA) has been shown to detect viable cells because pre-rRNAs are intermediates in rRNA synthesis. This study investigated the effect of different types of antibiotics on the bacterial viability or viable but non-culturable (VBNC) state using both PMA-qPCR and pre-rRNA analyses with Pseudomonas aeruginosa. This study demonstrated that P. aeruginosa was more sensitive to colistin than it was to carbenicillin, gentamicin and levofloxacin. We could discriminate VBNCP. aeruginosa cells using PMA-qPCR when antibiotic pressure induced the VBNC state. Also, pre-rRNA was able to distinguish viable cells from colistin-inactivated bacteria cells, and it could detect the presence of VBNC and persister cells. Our results showed that these two molecular methods could successfully eliminate false-positive signals derived from antibiotics-inactivated cells.


Assuntos
Antibacterianos/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Azidas/farmacologia , Colistina/farmacologia , Viabilidade Microbiana/efeitos dos fármacos , Propídio/análogos & derivados , Propídio/farmacologia , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/crescimento & desenvolvimento , Reação em Cadeia da Polimerase em Tempo Real
16.
J Microbiol Methods ; 148: 33-39, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29604299

RESUMO

PCR-based methods for enumerating bacteria cells could lead to an overestimation of viable cells due to the amplification of DNA from dead cells. To overcome this disadvantage, DNA intercalating dyes such as Ethidium monoazide (EMA) or Propidium monoazide (PMA) combined with qPCR have been considered promising alternative methods to discriminate between viable and nonviable cells. The drawback of those DNA intercalating dyes, however, could not assess the physiological states of cells. Thus, the objective of this study was to develop a novel molecular viability assay to selectively detect only the cells that exhibit metabolic activity. This study's results showed that DyeTox13 Green C-2 Azide dye coupled with qPCR can be used effectively to distinguish between active and nonactive gram-negative bacteria (P. aeruginosa PAO1) and gram-positive bacteria (E. faecalis v583). In this study, we evaluated the usefulness of the DyeTox13 Green C-2 Azide-qPCR assay for selectively amplifying nucleic acids of microorganisms that have metabolic activities. We conclude that the use of DyeTox13 Green C-2 Azide-qPCR is a promising alternative for discriminating active cells from nonactive cells but the dye's performance might be dependent on the kind of bacterial species.


Assuntos
Carga Bacteriana/métodos , Corantes Fluorescentes/metabolismo , Bactérias Gram-Negativas/fisiologia , Bactérias Gram-Positivas/fisiologia , Viabilidade Microbiana , Reação em Cadeia da Polimerase em Tempo Real/métodos , Coloração e Rotulagem/métodos , Azidas/metabolismo , Inibidores Enzimáticos/metabolismo , Bactérias Gram-Negativas/genética , Bactérias Gram-Positivas/genética
17.
Lab Chip ; 18(3): 532-539, 2018 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-29334390

RESUMO

With the increasing capabilities and ubiquity of smartphones and their associated digital cameras, this study presents a smartphone integrated optoelectrowetting (SiOEW) device as a simple, portable tool capable of on-chip water sample preparation and microscopic detection of the target cells in water samples, which significantly reduce the detection time and the labor cost required for water quality monitoring. A commercially available smartphone is used as a low-intensity portable light source to perform optoelectrowetting (OEW)-based microfluidic operations such as droplet transportation, merging, mixing, and immobilization on a hydrophobic detection zone. Furthermore, a built-in smartphone camera allows on-chip microscopic detection of water quality with a 45× magnification. We have experimentally demonstrated that the SiOEW platform is able not only to automate the sample processing of marine water including the target algae cells (Amphiprora sp.) and staining reagents fluorescein diacetate (FDA) and 5-chloromethylfluorescein diacetate (CMFDA), but also detect the fluorescence signals emitted from the target cells in water samples and count their populations. Using the smartphone, the collected information (e.g. the location of the water sample collected and the time it was detected, the number of the target cells, etc.) can be rapidly and wirelessly shared with a central host such as an environmental regulation agency for real-time monitoring and further management of water quality.

18.
Environ Microbiol Rep ; 8(2): 261-71, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26743211

RESUMO

Bacteria typically form biofilms under natural conditions. To elucidate the effect of the carriage of carbazole-degradative plasmid pCAR1 on biofilm formation by host bacteria, we compared the biofilm morphology, using confocal laser scanning microscopy, of three pCAR1-free and pCAR1-carrying Pseudomonas hosts: P. putida KT2440, P. aeruginosa PAO1 and P. fluorescens Pf0-1. Although pCAR1 did not significantly affect biofilm formation by PAO1 or Pf0-1, pCAR1-carrying KT2440 became filamentous and formed flat biofilms, whereas pCAR1-free KT2440 formed mushroom-like biofilms. pCAR1 contains three genes encoding nucleoid-associated proteins (NAPs), namely, Pmr, Pnd and Phu. The enhanced filamentous morphology was observed in two double mutants [KT2440(pCAR1ΔpmrΔpnd) and KT2440(pCAR1ΔpmrΔphu)], suggesting that these NAPs are involved in modulating the filamentous phenotype. Transcriptome analyses of the double mutants identified 32 candidate genes that may be involved in filamentation of KT2440. Overexpression of PP_2193 in KT2440 induced filamentation and overexpression of PP_0308 or PP_0309 in KT2440(pCAR1) enhanced filamentation of cells over time. This suggests that pCAR1 induces development of an abnormal filamentous morphology by KT2440 via a process involving overexpression of several genes, such as PP_2193. In addition, pCAR1-encoded NAPs partly suppress too much filamentation of KT2440(pCAR1) by repressing transcription of some genes, such as PP_0308 and PP_0309.


Assuntos
Biofilmes/crescimento & desenvolvimento , Carbazóis/metabolismo , Plasmídeos , Pseudomonas putida/fisiologia , Biotransformação , Deleção de Genes , Perfilação da Expressão Gênica , Microscopia Confocal , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/fisiologia , Pseudomonas fluorescens/genética , Pseudomonas fluorescens/fisiologia , Pseudomonas putida/citologia , Pseudomonas putida/genética
19.
Int J Cardiol ; 158(1): 88-92, 2012 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-21256606

RESUMO

BACKGROUND: Several studies have demonstrated that adenosine and nicorandil protect the myocardium against angioplasty-related myocardial injury. We conducted a prospective study to investigate the myocardial protective effects of combination therapy with intracoronary adenosine and nicorandil. METHODS: We enrolled 213 consecutive patients with stable or unstable angina who were scheduled for non-urgent PCI for de-novo coronary lesions. Patients were randomized into group I (control saline, n=55), group II (adenosine 50 µg, n=54), group III (nicorandil 4 mg, n=54), or group IV (adenosine-nicorandil combination, n=50). Serial assessments of CK-MB were used to assess myocardial necrosis before and after PCI. The primary endpoint was the incidence of myocardial necrosis (elevation of CK-MB), and the secondary endpoints were the changes in serum CK-MB and cTnI levels and the incidence of post-procedural myocardial infarction (MI). RESULTS: No significant differences were observed among the four groups with regard to baseline or angiographic characteristics. No major adverse events related to adenosine and nicorandil were observed. There were no significant differences in the incidence of post-procedural myocardial necrosis among the four groups (10.9, 14.8, 14.8, and 14.0%, respectively, p=0.9). There were no significant differences in the incidence of post-procedural MI among groups (p=0.6). In multivariate regression analysis, multivessel stenting, median stent length, and the presence of a compromised side branch were independent predictors of myonecrosis. CONCLUSIONS: Pretreatment with intracoronary adenosine, nicorandil, or the combination of the two drugs did not reduce the incidences of myocardial necrosis or MI after non-urgent PCI in patients with low-risk angina pectoris.


Assuntos
Adenosina/administração & dosagem , Angioplastia Coronária com Balão/efeitos adversos , Cardiopatias/prevenção & controle , Nicorandil/administração & dosagem , Vasodilatadores/administração & dosagem , Idoso , Feminino , Cardiopatias/etiologia , Humanos , Injeções , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
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