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1.
Environ Monit Assess ; 192(11): 681, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-33025312

RESUMO

Genotypic diversity among multi-drug-resistant (MDR) aquatic E. coli isolated from different sites of Yamuna River was analyzed using repetitive element PCR (rep-PCR) methods viz. ERIC-PCR and (GTG)5-PCR and compared with the MDR animal fecal isolates. The 97 E. coli isolates belonging to different serotypes, phylogroups, and multi-drug resistance patterns were analyzed. High genetic diversity was observed by both the methods; however, (GTG)5 typing showed higher discriminating potential. Combination of ERIC types (E1-E32) and (GTG)5 types (G1-G46) generated 77 genotypes. The frequency of genotypes ranged from 0.013 to 0.065. The genotype composition of E. coli isolates was highly diverse at all the sampling sites across Yamuna River except at its entry site in Delhi. The sampling sites under the influence of high anthropogenic activities showed an increase in number of unique genotype isolates. These sites also exhibited high multiple antibiotic resistance (MAR) indexes (above 0.25) suggesting high risk of contamination. Principal coordinate analysis (PCoA) showed limited clustering of genotypes based on the sampling sites. The most frequent genotypes were grouped in the positive zone of both the principal coordinates (PC1 and PC2). The genotypes of most of the animal fecal isolates were unique and occupied a common space in the negative PC1 area forming a separate cluster. High genotypic diversity among the aquatic E. coli and the drain isolates, discharging the untreated municipal waste in the river, was observed, suggesting that the sewage effluents contribute substantially to contamination of this river system than animal feces. The presence of such a high diversity among the MDR E. coli isolates in the natural river systems is of great public health significance and highlights the need of an efficient surveillance system for better management of Indian natural water bodies.


Assuntos
Escherichia coli , Rios , Animais , Monitoramento Ambiental , Escherichia coli/genética , Fezes , Genótipo , Índia , Reação em Cadeia da Polimerase
2.
Mol Cell ; 80(1): 1-2, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33007252

RESUMO

Wang et al. (2020) show that binding of the second messenger ppGpp to inosine-guanosine kinase (Gsk) in E. coli modulates the levels of the key metabolite phosphoribosyl pyrophosphate (pRpp), decreasing purine synthesis to favor amino acid synthesis during stress adaptation.


Assuntos
Escherichia coli , Nucleotídeos , Bactérias , Guanosina Pentafosfato , Guanosina Tetrafosfato
3.
Nat Commun ; 11(1): 4915, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33004811

RESUMO

A phenotype of Escherichia coli and Klebsiella pneumoniae, resistant to piperacillin/tazobactam (TZP) but susceptible to carbapenems and 3rd generation cephalosporins, has emerged. The resistance mechanism associated with this phenotype has been identified as hyperproduction of the ß-lactamase TEM. However, the mechanism of hyperproduction due to gene amplification is not well understood. Here, we report a mechanism of gene amplification due to a translocatable unit (TU) excising from an IS26-flanked pseudo-compound transposon, PTn6762, which harbours blaTEM-1B. The TU re-inserts into the chromosome adjacent to IS26 and forms a tandem array of TUs, which increases the copy number of blaTEM-1B, leading to TEM-1B hyperproduction and TZP resistance. Despite a significant increase in blaTEM-1B copy number, the TZP-resistant isolate does not incur a fitness cost compared to the TZP-susceptible ancestor. This mechanism of amplification of blaTEM-1B is an important consideration when using genomic data to predict susceptibility to TZP.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Infecções por Escherichia coli/tratamento farmacológico , Proteínas de Escherichia coli/genética , Escherichia coli/genética , beta-Lactamases/genética , Antibacterianos/uso terapêutico , Cromossomos Bacterianos/genética , Elementos de DNA Transponíveis/genética , DNA Bacteriano/genética , Quimioterapia Combinada/métodos , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Amplificação de Genes , Regulação Bacteriana da Expressão Gênica , Genoma Bacteriano/genética , Humanos , Testes de Sensibilidade Microbiana , Piperacilina/farmacologia , Piperacilina/uso terapêutico , Polimorfismo de Fragmento de Restrição , RNA Ribossômico 16S/genética , Tazobactam/farmacologia , Tazobactam/uso terapêutico , Sequenciamento Completo do Genoma
4.
Nat Commun ; 11(1): 5065, 2020 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-33033237

RESUMO

The type VI protein secretion system (T6SS) is a powerful needle-like machinery found in Gram-negative bacteria that can penetrate the cytosol of receiving cells in milliseconds by physical force. Anchored by its membrane-spanning complex (MC) and a baseplate (BP), the T6SS sheath-tube is assembled in a stepwise process primed by TssA and terminated by TagA. However, the molecular details of its assembly remain elusive. Here, we systematically examined the initiation and termination of contractile and non-contractile T6SS sheaths in MC-BP, tssA and tagA mutants by fluorescence microscopy. We observe long pole-to-pole sheath-tube structures in the non-contractile MC-BP defective mutants but not in the Hcp tube or VgrG spike mutants. Combining overexpression and genetic mutation data, we demonstrate complex effects of TssM, TssA and TagA interactions on T6SS sheath-tube dynamics. We also report promiscuous interactions of TagA with multiple T6SS components, similar to TssA. Our results demonstrate that priming of the T6SS sheath-tube assembly is not dependent on TssA, nor is the assembly termination dependent on the distal end TssA-TagA interaction, and highlight the tripartite control of TssA-TssM-TagA on sheath-tube initiation and termination.


Assuntos
Proteínas de Bactérias/metabolismo , Sistemas de Secreção Tipo VI/metabolismo , Vibrio cholerae/metabolismo , Proteínas de Bactérias/química , Membrana Celular/metabolismo , Escherichia coli/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Proteínas de Membrana/metabolismo , Viabilidade Microbiana , Modelos Biológicos , Mutação/genética , Ligação Proteica , Domínios Proteicos
5.
Nat Commun ; 11(1): 5078, 2020 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-33033266

RESUMO

Metabolic engineering facilitates chemical biosynthesis by rewiring cellular resources to produce target compounds. However, an imbalance between cell growth and bioproduction often reduces production efficiency. Genetic code expansion (GCE)-based orthogonal translation systems incorporating non-canonical amino acids (ncAAs) into proteins by reassigning non-canonical codons to ncAAs qualify for balancing cellular metabolism. Here, GCE-based cell growth and biosynthesis balance engineering (GCE-CGBBE) is developed, which is based on titrating expression of cell growth and metabolic flux determinant genes by constructing ncAA-dependent expression patterns. We demonstrate GCE-CGBBE in genome-recoded Escherichia coli Δ321AM by precisely balancing glycolysis and N-acetylglucosamine production, resulting in a 4.54-fold increase in titer. GCE-CGBBE is further expanded to non-genome-recoded Bacillus subtilis to balance growth and N-acetylneuraminic acid bioproduction by titrating essential gene expression, yielding a 2.34-fold increase in titer. Moreover, the development of ncAA-dependent essential gene expression regulation shows efficient biocontainment of engineered B. subtilis to avoid unintended proliferation in nature.


Assuntos
Acetilglucosamina/metabolismo , Bacillus subtilis/crescimento & desenvolvimento , Vias Biossintéticas , Escherichia coli/crescimento & desenvolvimento , Ácido N-Acetilneuramínico/metabolismo , Bacillus subtilis/metabolismo , Proliferação de Células , Escherichia coli/metabolismo , Código Genético , Proteínas de Fluorescência Verde/metabolismo , Engenharia Metabólica , Análise do Fluxo Metabólico , Regiões Promotoras Genéticas/genética , RNA de Transferência/genética , Tirosina/metabolismo
6.
Wei Sheng Yan Jiu ; 49(5): 785-822, 2020 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-33070825

RESUMO

OBJECTIVE: Establish the prokaryotic expression system of Amuc_1100 protein from Akkermansia muciniphila, and analyze the effects of this protein on the body weight, blood glucose, intestinal barrier function and Akkermansia muciniphila abundance in rats fed with high-fat diet combined streptozotocin(STZ)injection. METHODS: PCR product of Amuc_1100 Gene(Gene ID: 34174504) was linked to the double enzyme-digested pET-26 b plasmid vector. The recombinant expression plasmid pET-26 b-Amuc_1100 then transformed into E. Coli BL21. The verified clones through sequence analysis were induced by the addition of IPTG. High-fat diet rats were interfered with the purified protein at high and low doses. The changes of body weight, blood glucose, intestinal barrier function and Akkermansia muciniphila abundance were analyzed. RESULTS: The recombinant expression plasmid pET-26 b-Amuc_1100 was successfully constructed. The sequencing result showed 100% similarity to the Amuc_1100 gene in GenBank. The molecular weight of the protein obtained was 42 kDa. The intervention of Amuc_1100 protein can reduce the weight of rats fed with high-fat diet combined STZ injection to some extent, improve barrier function and increase the abundance of Akkermansia muciniphila in intestine. CONCLUSION: The prokaryotic expression system of Amuc_1100 protein was successfully constructed, which has a certain regulatory effect on rats fed with high-fat diet combined STZ injection.


Assuntos
Dieta Hiperlipídica , Escherichia coli , Animais , Dieta Hiperlipídica/efeitos adversos , Escherichia coli/genética , Ratos , Estreptozocina/toxicidade , Verrucomicrobia
7.
Nat Commun ; 11(1): 5001, 2020 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-33020480

RESUMO

To perform their computational function, genetic circuits change states through a symphony of genetic parts that turn regulator expression on and off. Debugging is frustrated by an inability to characterize parts in the context of the circuit and identify the origins of failures. Here, we take snapshots of a large genetic circuit in different states: RNA-seq is used to visualize circuit function as a changing pattern of RNA polymerase (RNAP) flux along the DNA. Together with ribosome profiling, all 54 genetic parts (promoters, ribozymes, RBSs, terminators) are parameterized and used to inform a mathematical model that can predict circuit performance, dynamics, and robustness. The circuit behaves as designed; however, it is riddled with genetic errors, including cryptic sense/antisense promoters and translation, attenuation, incorrect start codons, and a failed gate. While not impacting the expected Boolean logic, they reduce the prediction accuracy and could lead to failures when the parts are used in other designs. Finally, the cellular power (RNAP and ribosome usage) required to maintain a circuit state is calculated. This work demonstrates the use of a small number of measurements to fully parameterize a regulatory circuit and quantify its impact on host.


Assuntos
RNA Polimerases Dirigidas por DNA/metabolismo , Redes Reguladoras de Genes , Ribossomos/metabolismo , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Modelos Teóricos , Biossíntese de Proteínas , RNA-Seq , Biologia Sintética , Transcrição Genética
8.
J Environ Qual ; 49(1): 27-37, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33016358

RESUMO

The United States, particularly the southern portion, has recently suffered drastic population expansion of wild pigs causing destruction of prime farmland. An associated concern, which has been understudied, is the potential transfer of nutrients and pathogens to surface water. This study aimed to identify the abiotic and biotic impacts of captive wild pigs on water quality, including nutrients, fecal indicator and pathogenic bacteria, and antimicrobial resistance. Overall, the study demonstrated that wild pigs harbored Salmonella spp., Campylobacter spp., Escherichia coli, and Clostridium perfringens, which were found in water runoff collected directly beneath the hog paddock, often 2 log10 greater than above-paddock levels. However, the impacts to downstream water quality were limited, perhaps because of a relatively large riparian buffer between the paddock and surface water. A higher rate of ammonium concentration changes over time was detected in the runoff water below the paddock; additionally, microbial releases detected in runoff were also time dependent, possibly associated with increasing pig numbers. Antibiotic resistance was generally not associated with the wild pigs. Antibiotic resistance genes were found in upstream as well as downstream surface water, suggesting that nonpoint sources of microbial contamination were present. Interestingly, intI1 levels were greater in below-paddock runoff by nearly 2 log10 . Overall, it appears that wild pigs potentially pose a threat to water quality but only if they have direct access to the water. Pathogen, fecal indicator bacteria, and some nutrient release were significantly associated with wild pigs, but riparian buffers limited water quality impairment.


Assuntos
Bactérias , Qualidade da Água , Animais , Antibacterianos , Escherichia coli , Fezes , Suínos , Estados Unidos
9.
J Environ Qual ; 49(5): 1264-1272, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33016462

RESUMO

Leptospirosis is an emerging zoonotic disease in the Caribbean region and the island of Puerto Rico. Information on the presence of pathogenic Leptospira in rivers and streams of Puerto Rico is currently lacking. This study aimed to evaluate seasonal shifts in the presence of pathogenic leptospires and the level of Escherichia coli from 32 coastal locations in Puerto Rico's dry and wet seasons. Physicochemical parameters (temperature, salinity, pH, and dissolved oxygen) were determined at each site. The temperature (25.8 °C) and pH (average 7.6) values were all within acceptable USEPA regulatory standards. Thirty-eight percent of the sites of the dry season and 28% of the wet season sites contained dissolved oxygen levels ≤4 mg L-1 , which is relatively low. In the dry season, 19 sites (59%) and 18 (56%) of the wet season sites had E. coli counts >410 most probable number (MPN) 100 ml-1 and would be considered unsafe for recreational use. The lipl32 gene quantitative polymerase chain reaction assay was used for the detection of pathogenic leptospires in the samples. Low concentrations of pathogenic leptospires (<60 genome copies 100 ml-1 ) at Camuy, Espíritu Santo, Río Guayanilla, Quebrada Majagual, and Río Fajardo were detected during the wet season. Pathogenic leptospires were detected (∼40 genome copies 100 ml-1 ) at only one site, Loíza, during the dry season. There was no predictable relationship between the physicochemical parameters, concentrations of E. coli, and the presence of pathogenic leptospires in water samples.


Assuntos
Escherichia coli , Leptospira , Porto Rico , Rios , Estações do Ano
10.
J Environ Qual ; 49(4): 896-908, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33016491

RESUMO

Recreational water quality is currently monitored at Sandpoint Beach on Lake St. Clair using culture-based enumeration of Escherichia coli. Using water quality and weather data collected over 4 yr, several multiple linear regression (MLR)-based models were developed for near real-time prediction of E. coli concentration and were tested using independent data from the fifth year. Model performance was assessed by the determination of metrics such as RMSE, accuracy, specificity, sensitivity, and area under the receiver operating characteristic curve (AUROC). Each of the developed MLR models described herein resulted in increased correct responses for both exceedance and non-exceedance of the applicable standard as compared to predictions based on E. coli measurements (persistence models, using the previous day's E. coli concentration), which is the method currently being used. The AUROC values for persistence models are between 0.5 and 0.6, as compared to >0.7 for all the MLR models described herein. Among the MLR models, model performance improved when qualitative sky weather condition, which is commonly reported but was not previously used in similar models, was included. To select the best model, a principal coordinate analysis was used to combine multiple model performance metrics and provide a more sensitive tool for model comparison. Although models developed using 2, 3, and 4 yr of monitoring data provided reasonable performance, the model developed using the most recent 2-yr data was marginally better. Thus, data from the most recent 2 yr are likely sufficient as a training dataset for updating the MLR model for Sandpoint Beach in the future.


Assuntos
Praias , Escherichia coli , Monitoramento Ambiental , Great Lakes Region , Qualidade da Água
11.
J Contemp Dent Pract ; 21(7): 760-764, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33020359

RESUMO

AIM: One of the most vital characteristics of an ideal root filling material is the capability to inhibit the growth of the microorganisms. Mineral trioxide aggregate (MTA) is one of the most used root repair materials, with approved antibacterial effect. A newly introduced root repair material is nano-fast cement (NFC) which should be investigated. The antibacterial and antifungal activities of NFC were evaluated in the present study. MATERIALS AND METHODS: Enterococcus faecalis (PTCC 1394), Escherichia coli (ATTC 15224), and Candida albicans (PTCC 5027) were employed for the antimicrobial assessment. The following were the steps used to conduct the agar diffusion test (ADT): six agar plates were used. 0.5 McFarland concentration of each strain was cultured on two plates by a sterile cotton-tipped swab. Three holes with 5mm diameter were created on each plate. Freshly mixed cement was placed in the holes of the related plate. After two hours, the plates were incubated at 37°C for 24 hours. Then, the diameter of the growth inhibition zones were measured, and the mean values were used for the analysis. Direct contact test (DCT) was done by using the following steps: Freshly mixed materials were placed in the 96-well microtiter plate. 10 µL of each bacterial suspension was added to the tested cement. After one-hour incubation at 37°C, 245 µL of BHI broth was added to each well, and the plate was vortexed for 2 minutes. About 15 µL of this bacterial suspension was added to a new well which contained 215 µL of fresh medium. The kinetics of the bacterial outgrowth were measured by the microplate spectrophotometer hourly for 12 hours. RESULTS: No significant differences were observed between the diameters of the growth inhibition zones of MTA and NFC groups in ADT. In DCT, the MTA inhibits E. coli more effectively than NFC (p value < 0.001). Both cements had the same inhibitory effect on E. faecalis and C. albicans. CONCLUSION: The MTA and NFC are almost equally effective against the tested microorganisms. CLINICAL SIGNIFICANCE: The antibacterial characteristic of any dental material is an important matter. As well, the antibacterial efficacy of the NFC should be evaluated.


Assuntos
Antifúngicos/farmacologia , Escherichia coli , Compostos de Alumínio , Antibacterianos/farmacologia , Compostos de Cálcio , Combinação de Medicamentos , Óxidos , Materiais Restauradores do Canal Radicular , Silicatos
12.
AAPS PharmSciTech ; 21(7): 286, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33063151

RESUMO

The CoViD-19 pandemic has caused a sudden spike in demand and production of hand sanitisers. Concerns are rising regarding the quality of such products, as the safeguard of consumers is a priority worldwide. We analyse here the ethanolic content of seven off-the-shelf hand sanitiser gels (two biocides and five cosmetics) from the Italian market, using gas chromatography. The WHO recommends that products containing ethanol should have 60-95% (v/v) alcohol. Four of the tested hand gels have ethanolic contents within the recommended range, while three products (all cosmetics) contain < 60% (v/v), i.e. 52.1% (w/w), ethanol. The product with the lowest alcoholic content has 37.1% w/w ethanol. Toxic methanol is not found in any of the hand sanitisers. We show, in addition, that products with the highest ethanolic content have generally greater antibacterial activity. In conclusion, all tested products are complying with the EU regulations, as the three "substandard" products are classified as cosmetics, whose purpose is cleaning and not disinfecting. Nevertheless, if such hand cleaners were inappropriately used as hand disinfectants, they might be ineffective. Thus, consumer safety relays on awareness and ability to distinguish between biocidal and cosmetics hand gels. The obtained results might sensitise the scientific community, health agencies and ultimately consumers towards the risks of using hand sanitisers of substandard alcoholic concentration. If the wrong product is chosen by consumers, public health can be compromised by the inappropriate use of "low-dosed" cosmetic gels as disinfectants, particularly during the period of the CoViD-19 pandemic.


Assuntos
Infecções por Coronavirus , Higienizadores de Mão/análise , Pandemias , Pneumonia Viral , Antibacterianos/análise , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Cromatografia Gasosa , Cosméticos , Escherichia coli/efeitos dos fármacos , Etanol/análise , Europa (Continente) , Géis , Desinfecção das Mãos , Higienizadores de Mão/farmacologia , Higienizadores de Mão/normas , Metanol/análise , Testes de Sensibilidade Microbiana , Staphylococcus aureus/efeitos dos fármacos
13.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2209-2212, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018446

RESUMO

This is a proof-of-concept study for the development of a field-deployable and low-cost PCR thermocycler (FLC-PCR) to perform Polymerase Chain Reaction (PCR) for the rapid detection of environmental E. coli. Four efficient (77.1 W) peltier modules are used as the central temperature control unit. One 250 W silicone heating pad is used for the heating lid. The PID (proportional-integral-derivative) control algorithm for the thermocycles is implemented by a low-cost 8-bit, 16 MHz microcontroller (ATMEGA328P-PU). ybbW and uidA genes from specific E. coli colonies were used as amplicons for the PCR reactions that were carried out by a commercial PCR machine (Bio-Rad) and our FLC-PCR thermocycler. The heating and cooling speeds averaged 1.11 ± 0.33°C/s which is on a par with the commercial bench-top PCR thermocycler and the efficiency of the heating lid outperformed the Bio-Rad PCR thermocycler. The overall cost of the system is lower than $200 which is more than ten times lower than commercially available units. The heating block can be customized to accommodate different PCR tubes and even microfluidic chambers. An 8000 W portable power generator will be used as the power supply for field studies.


Assuntos
Escherichia coli , Calefação , Fontes de Energia Elétrica , Escherichia coli/genética , Reação em Cadeia da Polimerase , Temperatura
14.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2372-2375, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018483

RESUMO

To advance synthetic biology approaches that utilize S. oneidensis as host for biotechnology applications, we have investigated the variation in plasmid copy number of a modular vector set resulting from distinct origins of replication under different conditions. The replicons yielded a ≈9X-fold range for plasmid copy number variation in S. oneidensis (while the same origins yielded a ≈3X-fold range in Escherichia coli). This provides a sizeable range to control gene expression levels in S. oneidensis for synthetic biology applications. In addition, plasmid harboring the pBBR1 origin resulted in stable copy numbers in S. oneidensis under different conditions (mid-logarithmic, stationary, multi-plasmid). This may enable the realization of synthetic circuits in S. oneidensis where predictable, quantitative behavior is desired (in either single- or double-plasmid contexts).


Assuntos
Variações do Número de Cópias de DNA , Shewanella , Escherichia coli/genética , Plasmídeos/genética , Shewanella/genética
15.
Environ Monit Assess ; 192(11): 714, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33079229

RESUMO

Antibiotic resistance is considered by the countries to be a global health issue and a huge threat to public health. The reduction of resistant microorganisms from water/wastewater is of importance in environmental sciences since they are resistant in the aquatic environment. In this study, a bibliometric analysis of literature from the field of environmental science in water ecosystems from 2015 to 2019 was carried out using the keywords "Antibiotic Resistance (AR)" and "Escherichia coli". Furthermore, using the keywords of "Fresh Water," "Sea Water," and "Waste Water," 155, 52, and 57 studies were discovered, respectively. It is found that 217 studies of the total 2115 studies investigated on AR are mostly performed in the "Waste Water" by considering human health. Given the studies, an up-to-date solution should be proposed since the release of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) from wastewater treatment plants needs to be mitigated. For this reason, it is obvious that working on micro and macro ecosystems will increase the probability of solutions in antibiotic resistance. A discussion of removal techniques for coliform bacteria, particularly antibiotic resistant Escherichia coli, was presented. One of the unique values of this study is to offer an innovative solution that removing them by metal-organic frameworks (MOFs) are emerging crystalline hybrid materials. MOFs are used for environmental, biological, and food antimicrobial substances efficiently. Therefore, we can give inspiration to the future studies of antimicrobial resistance removal via adsorption using MOFs as adsorbents. Graphical Abstract.


Assuntos
Ecossistema , Escherichia coli , Bibliometria , Resistência Microbiana a Medicamentos/genética , Monitoramento Ambiental , Humanos
16.
Water Sci Technol ; 82(6): 1166-1175, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33055406

RESUMO

Escherichia coli (E. coli) first-order decay rates ranging from 3.34 to 11.9 d-1 (25-75% data range, N = 128) were recorded in two outdoor pilot-scale (0.88 m3) high rate algal ponds (HRAPs) continuously fed primary domestic wastewater over two years (influent E. coli cell count of 4.74·106 ± 3.37·106 MPN·100 mL-1, N = 142). The resulting removal performance was relatively constant throughout the year (log10-removal averaging 1.77 ± 0.54, N = 128), apart from a significant performance drop during a cold rainy period. E. coli removal performance was not strongly correlated to any of the meteorological or operational parameters recorded (e.g. sunlight intensity, pH, temperature). Hourly monitoring of E. coli cell count evidenced that E. coli removal, pH, dissolved oxygen (DO) and pond temperature peaked in the late afternoon of sunny summer days. Such improved daytime removal was, however, not evidenced in spring, even under sunny conditions causing milder increases in pH, DO and temperature. Overall, the data confirm the potential of HRAPs to support efficient E. coli removal during secondary domestic wastewater treatment and suggests E. coli decay was mainly caused by dark mechanisms episodically enhanced by indirect sunlight-mediated mechanisms and/or high pH toxicity.


Assuntos
Tanques , Águas Residuárias , Escherichia coli , Luz Solar , Eliminação de Resíduos Líquidos
17.
Water Sci Technol ; 82(6): 1184-1192, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33055408

RESUMO

The influence of CO2 addition and hydraulic retention time (5 and 7 days) on removal of Pseudomonas aeruginosa, Clostridium perfringens, Staphylococcus sp., Enterococcus sp., and Escherichia coli was evaluated in a system with three parallel 21 L high rate algal ponds. Both the addition of CO2 and an increase in HRT had no significant influence on bacterial removal, but bacterial removal was higher than found in previous studies. The removal was 3.4-3.8, 2.5-3.7, 2.6-3.1, 2.2-2.6 and 1.3-1.7 units log for P. aeruginosa, E. coli, Enterococcus sp., C. perfringens, and for Staphylococcus sp., respectively. Although CO2 addition did not increase disinfection, it did significantly increase biomass productivity (by ≈60%) and settleability (by ≈350%). Additionally, even at the lower 5-day hydraulic retention time, CO2 addition improves removal of chemical oxygen demand (COD), total organic carbon (TOC), total organic nitrogen and phosphorus by 97, 91, 12 and 50%, respectively.


Assuntos
Dióxido de Carbono , Eliminação de Resíduos Líquidos , Análise da Demanda Biológica de Oxigênio , Escherichia coli , Nitrogênio
18.
Epidemiol Mikrobiol Imunol ; 69(3): 128-133, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33086854

RESUMO

Úvod: Biomarkery jsou u septických pacientů využívány jak k diagnostice sepse, tak k antibiotickému stewardshipu. Sepse vyvolaná gramnegativními bakteriemi mívá odlišné charakteristiky, především vysoký prokalcitonin vs C-reaktivní protein v porovnání se sepsí vyvolanou grampozitivními bakteriemi. Avšak jednotlivá infekční agens, především Streptococcus pyogenes, nemusí do tohoto schématu zapadat, což může vest k nesprávné iniciální volbě antibiotika. Metody: Retrospektivní analýza biomarkerů, iniciální volby antibiotické léčby a výsledků léčby u pacientů se sepsí vyvolanou S. pyogenes, Escherichia coli a Staphylococcus aureus. Hodnoty biomarkerů byly porovnány pomocí Kruskal-Wallis testu s následným Dunn post-Hoc testem s prahem p < 0,05. Výsledky: Hodnoty prokalcitoninu byly nejvyšší u sepse vyvolané S. pyogenes (12,51 ng/ml, IQR: 6,26-48,38 ng/ml) oproti sepsi vyvolaná E. coli (4,30 ng/ml, IQR: 1,50-10,00 ng/ml, p < 0,001) a S. aureus (0,75 ng/ml, QR: 0,34-1,62 ng/ml, p < 0,001). Poměr neutrofilů a lymfocytů vykazoval stejné charakteristiky jako prokalcitonin. Správná iniciální antibiotická léčba byla v souboru S. pyogenes 11,29 % v porovnání s 99,3 % a 100 % u S. aureus a E. coli skupin. Závěr: Oproti předchozím studiím byly v našem souboru pozorovány nejvyšší hodnoty prokalcitoninu u pacientů se sepsí vyvolanou S. pyogenes spíše než gramnegativními bakteriemi. Vysoké hodnoty prokalcitoninu imitující gramnegativní zánětlivou odpověď přispěli k ovlivnění výběru iniciální antibiotické léčby (bez znalosti původce), což mohlo vést k vyšší mortalitě u této skupiny pacientů. Proto doporučujeme přehodnocení významu prokalcitoninu v diagnostice sepse pro zlepšení přežití i kvality života pacientů.


Assuntos
Antibacterianos/uso terapêutico , Sepse/tratamento farmacológico , Infecções Estreptocócicas/tratamento farmacológico , Streptococcus pyogenes , Biomarcadores , Escherichia coli , Staphylococcus aureus
19.
Sci Total Environ ; 741: 140447, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32887010

RESUMO

Contaminated water resources remain a major global concern regarding public health. The majority of water safety protocols include indicators of microbial contamination to evaluate the potential risk to public health and are key elements of quality guidelines. Among these, markers for total coliforms and fecal coliforms are strong indicators of co-contamination with other pathogens. Traditional methods, recurring to slow and cumbersome culture-based approaches, have been gradually replaced by molecular methods, capable of faster and more specific screening. These are usually PCR-based methods that may allow for multiple pathogen detection but require dedicated laboratory equipment, hindering the rapid on-site assessment. Here, we used a multiplex Loop-Mediated Isothermal Amplification (mLAMP) strategy for the amplification of two markers associated with the contamination by total and fecal coliforms (e.g. Escherichia coli) - lacZ and uidA genes, respectively - thus allowing for single tube multiplex detection. The mLAMP products were then subject to an Au-nanoprobe colorimetric detection assay for precise discrimination of targets. This approach was validated in 22 water samples that were also screened for the presence of lacZ and uidA using standard and quantitative PCR, with the capability for discriminating the contamination level, e.g. a semi-quantitative evaluation of water quality.


Assuntos
Escherichia coli , Técnicas de Amplificação de Ácido Nucleico , Fezes , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade
20.
Zhonghua Liu Xing Bing Xue Za Zhi ; 41(8): 1328-1334, 2020 Aug 10.
Artigo em Chinês | MEDLINE | ID: mdl-32867445

RESUMO

Objective: To understand the characteristics and differences of diarrhea-related symptoms caused by different pathogens, and the clinical features of various pathogens causing diarrhea. Methods: Etiology surveillance program was conducted among 20 provinces of China from 2010 to 2016. The acute diarrhea outpatients were collected from clinics or hospitals. A questionnaire was used to survey demographics and clinical features. VFeces samples were taken for laboratory detection of 22 common diarrhea pathogens, to detect and analyze the clinical symptom pattern characteristics of the patient's. Results: A total of 38 950 outpatients were enrolled from 20 provinces of China. The positive rates of Rotavirus and Norovirus were the highest among the five diarrhea-causing viruses (Rotavirus: 18.29%, Norovirus: 13.06%). In the isolation and culture of 17 diarrhea-causing bacterial, Escherichia coli showed the highest positive rates (6.25%). The clinical features of bacterial diarrhea and viral diarrhea were mainly reflected in the results of fecal traits and routine examination, but pathogenic Vibrio infection was similar to viral diarrhea. Conclusion: Infectious diarrhea presents different characteristics due to various symptoms which can provide a basis for clinical diagnosis.


Assuntos
Disenteria/microbiologia , Disenteria/virologia , Vigilância da População , China/epidemiologia , Disenteria/epidemiologia , Escherichia coli/isolamento & purificação , Fezes/microbiologia , Fezes/virologia , Humanos , Norovirus/isolamento & purificação , Rotavirus/isolamento & purificação
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