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1.
Sheng Wu Gong Cheng Xue Bao ; 37(8): 2813-2824, 2021 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-34472299

RESUMO

Squalene is widely used in pharmaceutical, nutraceutical, cosmetics and other fields because of its strong antioxidative, antibacterial and anti-tumor activities. In order to produce squalene, a gene ispA encoding farnesyl pyrophosphate synthase was overexpressed in a previously engineered Escherichia coli strain capable of efficiently producing terpenoids, resulting in a chassis strain that efficiently synthesizes triterpenoids. Through phylogenetic analysis, screening, cloning and expression of squalene synthase derived from different prokaryotes, engineered E. coli strains capable of efficiently producing squalene were obtained. Among them, squalene produced by strains harboring squalene synthase derived from Thermosynechococcus elongatus and Synechococcus lividus reached (16.5±1.4) mg/g DCW ((167.1±14.3) mg/L broth) and (12.0±1.9) mg/g DCW ((121.8±19.5) mg/L broth), respectively. Compared with the first-generation strains harboring the human-derived squalene synthase, the squalene synthase derived from T. elongatus and S. lividus remarkably increased the squalene production by 3.3 times and 2.4 times, respectively, making progress toward the cost-effective heterologous production of squalene.


Assuntos
Esqualeno , Synechococcus , Clonagem Molecular , Escherichia coli/genética , Humanos , Filogenia
2.
Sheng Wu Gong Cheng Xue Bao ; 37(8): 2915-2923, 2021 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-34472308

RESUMO

Antimicrobial peptides are the most promising alternatives to antibiotics. However, the strategy of producing antimicrobial peptides by recombinant technology is complicated and expensive, which is not conducive to the large-scale production. Oxysterlin 1 is a novel type of cecropin antimicrobial peptide mainly targeting on Gram-negative bacteria and is of low cytotoxicity. In this study, a simple and cost-effective method was developed to produce Oxysterlin 1 in Escherichia coli. The Oxysterlin 1 gene was cloned into a plasmid containing elastin-like polypeptide (ELP) and protein splicing elements (intein) to construct the recombinant expression plasmid (pET-ELP-I-Oxysterlin 1). The recombinant protein was mainly expressed in soluble form in E. coli, and then the target peptide can be purified with a simple salting out method followed by pH changing. The final yield of Oxysterlin 1 was about 1.2 mg/L, and the subsequent antimicrobial experiment showed the expected antimicrobial activity. This study holds promise for large-scale production of antimicrobial peptides and the in-depth study of its antimicrobial mechanism.


Assuntos
Elastina , Escherichia coli , Escherichia coli/genética , Inteínas , Peptídeos/genética , Peptídeos/farmacologia , Proteínas Citotóxicas Formadoras de Poros , Proteínas Recombinantes de Fusão/genética
3.
Arch Esp Urol ; 74(7): 645-651, 2021 Sep.
Artigo em Espanhol | MEDLINE | ID: mdl-34472432

RESUMO

INTRODUCTION: Urinary tract infections (Uti) are one of the most common infections that affec thumans throughout their lives and are a common healthproblem both at the community and at the nosocomial level. Knowing microbiological characteristics, sensitivity profile and risk factors allow to optimize the management of Utis minimizing the increase of antibiotic resistance (AR) and establishing early treatments to reduce the morbidity and severity of infection. This study aims to establish which microorganisms are responsible for urinary tract infections in our community and determine their AR. PATIENTS AND METHODS: An observational, descriptive, cross-sectional, retrospective study of all patients with the first episode of UTI recorded at the Sanatorio Allende in the city of Cordoba, Argentina, who were requested to under go urine culture (URC), from January 2016 to December 2017. RESULTS: 3636 positive URC were analyzed, of which1740 met the inclusion criteria. Of the total analyzed 90.2 % (n=1570) were female. The average age was 37.8 years (SD=15.2). Escherichia coli was the microorganism most frequently isolated in 80.3% followed by S. saprophyticus in 8.0%. The age group of 18-30 years (40.1%) showed the highest proportion of microorganisms, where we observed the highest prevalence of E. coli and S. saprophyticus. The following acquired resistances were obtained from the total isolations: 47.6% of the microorganisms were resistant to ampicillin, 29.6% to cotrimoxazole, 15.2% to ciprofloxacin, 4.6% to first generation of cephalosporins, 3.4% to cefixime, 2.3% to amoxicillin-clavulanic, 1,2% to gentamicin and 1% to nitrofurantoin. CONCLUSION: E. Coli was the most prevalent pathogenin our environment, with high rates of resistance to ampicillin, fluoroquinolones and trimethoprim-sulfamethoxazole, confirming the need for periodic studiesto determine the most optimal empirical antibiotic treatment.


Assuntos
Infecções por Escherichia coli , Infecções Urinárias , Adolescente , Adulto , Antibacterianos/uso terapêutico , Argentina/epidemiologia , Estudos Transversais , Farmacorresistência Bacteriana , Escherichia coli , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/epidemiologia , Feminino , Humanos , Estudos Retrospectivos , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/epidemiologia , Adulto Jovem
4.
Appl Microbiol Biotechnol ; 105(18): 7023-7034, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34477938

RESUMO

In the current study, the polyurethane acrylate (PUA) polymer was synthesized by the addition reaction between an isophorone diisocyanate (IPDI) and 2-hydroxyethyl acrylate and cured by polyol. Different properties of the synthesized PUA were determined through diverse analysis methods. The polyurethane acrylate (PUA)/natural filler-based composite (rhizome water extract of Costus speciosus) was prepared as an antifouling agent. The results revealed that the lowest weight loss percentages were detected at 2 wt% PUA/natural filler composite loadings with Escherichia coli (ATCC 23,282) and Pseudomonas aeruginosa (ATCC 10,145). The decreased weight loss percentage may be attributed to the well dispersed natural composite resulting in a slippery surface that can prevent fouling adhesion. It was concluded that the PUA/natural filler composite might be considered an eco-friendly and economical solution to the biofouling problem. KEY POINTS: • A novel strategy for anti-biofouling. • A new composite reduced Gram-negative bacteria.


Assuntos
Incrustação Biológica , Acrilatos , Incrustação Biológica/prevenção & controle , Escherichia coli , Poliuretanos , Pseudomonas aeruginosa
5.
Appl Microbiol Biotechnol ; 105(18): 6793-6803, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34477943

RESUMO

Some microbial-associated molecular patterns (MAMPs), like glucan oligosaccharides, can be recognized by pattern recognition receptors (PRRs) of plant to elicit further immunity response. In this study, a novel glycoside hydrolase family 55 ß-1,3-glucanase (AcGluA) from Archangium sp. strain AC19 was cloned and expressed in Escherichia coli. Among the reported ß-1, 3-glucanases from the glycoside hydrolase 55 family, the purified AcGluA exhibited the highest activity on laminarin at pH 6.0 and 60 °C with 112.3 U/mg. Activity of AcGluA was stable in the range of pH 4.0-9.0 and at temperatures below 60 °C. The Km and Vmax of AcGluA for laminarin were 3.5 mg/ml and 263.5 µmol/(ml·min). AcGluA hydrolyzed laminarin into a series of oligosaccharides, suggesting it was an endo-ß-1,3-glucanase. The high dose of oligosaccharides (1600 mg/l) had conspicuous biocontrol efficacy on the defense of rice seedlings to Magnaporthe oryzae, which provided a new idea for the development of green biopesticide.Key points• The AcGluA was determined bacteria-derived ß-1,3-glucanases in the GH55 family.• The AcGluA showed the highest activity towards laminarin among reported GH55 family.• The hydrolysates of laminarin showed conspicuous biocontrol efficacy to M. oryzae.


Assuntos
Ascomicetos , Glicosídeo Hidrolases , Ascomicetos/metabolismo , Clonagem Molecular , Escherichia coli/genética , Escherichia coli/metabolismo , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Hidrólise , Especificidade por Substrato
6.
J Hazard Mater ; 416: 126125, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492919

RESUMO

The ongoing COVID-19 pandemic increases the consumption of antimicrobial substances (ABS) due to the unavailability of approved vaccine(s). To assess the effect of imprudent consumption of ABS during the COVID-19 pandemic, we compare the 2020 prevalence of antidrug resistance (ADR) of Escherichia coli (E. coli) with a similar survey carried out in 2018 in Ahmedabad, India using SARS-CoV-2 gene detection as a marker of ABS usage. We found a significant ADR increase in 2020 compared to 2018 in ambient water bodies, harbouring a higher incidence of ADR E.coli towards non-fluoroquinolone drugs. Effective SARS-CoV-2 genome copies were found to be associated with the ADR prevalence. The prevalence of ADR depends on the efficiency of WWTPs (Wastewater Treatment Plants) and the catchment area in its vicinity. In the year 2018 study, prevalence of ADR was discretely distributed, and the maximum ADR prevalence recorded was ~60%; against the current homogenous ADR increase, and up to 85% of maximum ADR among the incubated E.coli isolated from the river (Sabarmati) and lake (Chandola and Kankaria) samples. Furthermore, wastewater treatment plants showed less increase in comparison to the ambient waters, which eventually imply that although SARS-CoV-2 genes and faecal pollution may be diluted in the ambient waters, as indicated by low Ct-value and E.coli count, the danger of related aftermath like ADR increase cannot be nullified. Also, Non-fluoroquinolone drugs exhibited overall more resistance than quinolone drugs. Overall, this is probably the first-ever study that traces the COVID-19 pandemic imprints on the prevalence of antidrug resistance (ADR) through wastewater surveillance and hints at monitoring escalation of other environmental health parameters. This study will make the public and policyholders concerned about the optimum use of antibiotics during any kind of treatment.


Assuntos
COVID-19 , Escherichia coli/genética , Humanos , Pandemias , SARS-CoV-2 , Águas Residuárias
7.
Braz J Biol ; 83: e245585, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34495157

RESUMO

Many soil microorganisms' i.e., bacteria and fungi produce secondary metabolites called antibiotics. These are used for the treatment of some of the bacterial, fungal and protozoal diseases of humans. There is a need for isolation of a broad spectrum of antibiotics from microorganisms due to the emergence of antibiotic resistance. In the present study two antibiotic producing bacteria Klebsiella pneumoniae and Bacillus cereus were isolated from pharmaceutical and poultry feed industry of Hattar, Haripur Pakistan. Total 10 waste samples were collected from different industries (Marble, Ghee, Soap, Mineral, Steel, Poultry Feed, Pharmaceutical, Qarshi, Cosmetic and Glass). Thirty-three bacterial strains were isolated from industrial wastes of these ten different industries. Fourteen out of thirty-three bacterial strains exhibited antimicrobial activities against at least one of the test microbes considered in this study including Escherchia coli, Staphylococcus aureus and Salmonella typhi. The bacteria were isolated by standard serial dilution spread plate technique. Morphological characterization of the isolates was done by Gram staining. Nine bacterial isolates out of fourteen were initially identified as B. cereus and five as K. pneumoniae through biochemical characterization. The antibacterial activities were tested by well diffusion method. Maximum number of antibiotic producing bacteria were isolated from pharmaceutical and poultry feed industry based on the results of primary screening, the most potential isolates S9, S19, S20, S22 and S23 were selected for secondary screening. The maximum activity against E. coli and S. aureus was recorded by bacterial isolate S19 i.e zones of inhibition of 6.5mm and 9mm while S20 showed 7.5mm and 6mm zones respectively. Molecular identification was carried out on the basis of 16S rRNA sequence analysis. Finally, the isolates were identified as B. cereus accession number LC538271and K. pneumoniae accession number MT078679. Analysis of bacterial extract S20 through GC-MS indicated the presence of 8 compounds of diverse nature and structure. Present study suggests that wastes of pharmaceutical and poultry feed industry may have antibiotic producing bacteria. These bacteria could be utilized for the production of antibiotics. B. cereus and K. pneumoniae isolated from wastes of poultry feed and pharmaceutical industries have the potential to produce antibiotics and could be used to control the microbial growth.


Assuntos
Resíduos Industriais , Staphylococcus aureus , Antibacterianos/farmacologia , Escherichia coli , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Testes de Sensibilidade Microbiana , Extratos Vegetais , RNA Ribossômico 16S
8.
Sensors (Basel) ; 21(17)2021 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-34502797

RESUMO

Inappropriate use of antibiotics is one of the leading causes of the increasing numbers of resistant bacteria strains, resulting in 700,000 deaths worldwide each year. Reducing unnecessary use of antibiotics and choosing the most effective antibiotics instead of broad-spectrum drugs will slow the arms race between germs and humans. Urinary tract infections (UTIs) are among the most common bacterial infections. Currently, accurate diagnosis of UTI requires approximately 48 h from the time of urine sample collection until antibiotic susceptibility test (AST) results. This work presents a rapid bacterial detection device that integrates a centrifuge, microscope, and incubator. Two disposable microfluidic chips were developed. The first chip was designed for bacteria concentration, detection, and medium exchange. A second multi-channel chip was developed for AST. This chip contains superhydrophobic and hydrophilic coatings to ensure liquid separation between the channels without the need for valves. The designed chips supported the detection of E. coli at a concentration as low as 5 × 103 cells/mL within 5 min and AST in under 2 h. AST was also successfully performed with Klebsiella pneumonia isolated from a human urine sample. In addition, machine-learning-based image recognition was shown to reduce the required time for AST and to provide results within 1 h for E. coli cells. Thus, the BactoSpin device can serve as an efficient and rapid platform for UTI diagnostics and AST.


Assuntos
Escherichia coli , Infecções Urinárias , Antibacterianos/farmacologia , Bactérias , Humanos , Testes de Sensibilidade Microbiana , Microfluídica , Infecções Urinárias/diagnóstico , Infecções Urinárias/tratamento farmacológico
9.
Nat Commun ; 12(1): 5206, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34471126

RESUMO

CRISPR base editing is a powerful method to engineer bacterial genomes. However, it restricts editing to single-nucleotide substitutions. Here, to address this challenge, we adapt a CRISPR-Prime Editing-based, DSB-free, versatile, and single-nucleotide resolution genetic manipulation toolkit for prokaryotes. It can introduce substitutions, deletions, insertions, and the combination thereof, both in plasmids and the chromosome of E. coli with high fidelity. Notably, under optimal conditions, the efficiency of 1-bp deletions reach up to 40%. Moreover, deletions of up to 97 bp and insertions up to 33 bp were successful with the toolkit in E. coli, however, efficiencies dropped sharply with increased fragment sizes. With a second guide RNA, our toolkit can achieve multiplexed editing albeit with low efficiency. Here we report not only a useful addition to the genome engineering arsenal for E. coli, but also a potential basis for the development of similar toolkits for other bacteria.


Assuntos
Sistemas CRISPR-Cas , Escherichia coli/genética , Edição de Genes/métodos , Engenharia Genética/métodos , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , DNA Bacteriano , Genoma Bacteriano , Plasmídeos , RNA Guia/genética
10.
Nat Commun ; 12(1): 5216, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34471137

RESUMO

Bacterial biosensors, or bactosensors, are promising agents for medical and environmental diagnostics. However, the lack of scalable frameworks to systematically program ligand detection limits their applications. Here we show how novel, clinically relevant sensing modalities can be introduced into bactosensors in a modular fashion. To do so, we have leveraged a synthetic receptor platform, termed EMeRALD (Engineered Modularized Receptors Activated via Ligand-induced Dimerization) which supports the modular assembly of sensing modules onto a high-performance, generic signaling scaffold controlling gene expression in E. coli. We apply EMeRALD to detect bile salts, a biomarker of liver dysfunction, by repurposing sensing modules from enteropathogenic Vibrio species. We improve the sensitivity and lower the limit-of-detection of the sensing module by directed evolution. We then engineer a colorimetric bactosensor detecting pathological bile salt levels in serum from patients having undergone liver transplant, providing an output detectable by the naked-eye. The EMeRALD technology enables functional exploration of natural sensing modules and rapid engineering of synthetic receptors for diagnostics, environmental monitoring, and control of therapeutic microbes.


Assuntos
Bactérias/metabolismo , Biomarcadores/metabolismo , Técnicas Biossensoriais , Proteínas de Transporte/metabolismo , Patologia Molecular/métodos , Bactérias/genética , Ácidos e Sais Biliares/sangue , Técnicas Biossensoriais/métodos , Proteínas de Transporte/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Regulação Bacteriana da Expressão Gênica , Humanos , Transplante de Fígado , Engenharia Metabólica/métodos , Sensibilidade e Especificidade , Alinhamento de Sequência , Vibrio , Vibrioses/diagnóstico
12.
Mater Sci Eng C Mater Biol Appl ; 128: 112296, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474847

RESUMO

Hydroxyapatite is widely utilized for different biomedical applications because of its outstanding biocompatibility and bioactivity. Cuttlefish bones, which are available aplenty, are both inexpensive and eco-friendly sources for calcium carbonate. In the present study, cuttlefish bones-derived HAp nanorods have been utilized to fabricate HAp nanocomposites incorporating 1, 3 and 5 wt% each of GO, MWCNTs, GONRs and Ag NPs. Characterization using such techniques as XRD, FTIR, HRSEM and EDS was performed to analyze the physicochemical properties of nanocomposites, and MTT assay, hemolysis, bioactivity and drug release to evaluate the biological properties. The XRD and HRSEM results reveal that crystallite and particle size increase with increasing wt% of carbon nanomaterials and Ag NPs. However, the addition of nanomaterials did not modify the shape of HAp. The MTT assay and hemolysis results suggest GONRs possess better biocompatibility than GO and CNTs due to their smooth edge structure. While adding carbon materials up to 3 wt% caused an increase in the hardness, adding up to 5 wt% of them caused a decrease in the hardness due to the agglomeration of the particles. Biocompatibility and Vicker's hardness studies show that adding carbon nanomaterials up to 3 wt% caused significant improvement in biocompatibility and mechanical properties. Antibacterial activity test was performed to analyze the ability to preclude the formation of biofilms. The results showed better activity for silver-incorporated nanocomposites in the presence of E. coli and S. aureus bacteria. Drug release studies were performed using lidocaine drug and the results showed nearly similar drug release profile for all the samples except HAg3. Finally, nanocomposite HRA3 could be a suitable candidate for biomedical applications since it shows better biological and mechanical properties than GO and MWCNTs nanocomposites.


Assuntos
Durapatita , Nanocompostos , Antibacterianos/farmacologia , Carbono , Escherichia coli , Teste de Materiais , Prata/farmacologia , Staphylococcus aureus
13.
Mater Sci Eng C Mater Biol Appl ; 128: 112320, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474871

RESUMO

This study aimed to fabricate cinnamon essential oil (CO)-laden 45S5 bioactive glass (BG)/soy protein (SP) scaffolds exhibiting antioxidant and antibacterial activity. In this regard, 45S5 BG-based scaffolds were produced by the foam replica method, and subsequently the scaffolds were coated with various concentrations of CO (2.5, 5 and 7 (v/v) %) incorporated SP solution. Scanning electron microscopy images revealed that the CO-laden SP effectively attached to the 45S5 BG scaffold struts. The presence of 45S5 BG, SP and CO was confirmed using Fourier transform infrared spectroscopy. Compressive strength results indicated that SP based coatings improved the scaffolds' mechanical properties compared to uncoated BG scaffolds. The loading efficiency and releasing behaviour of the different CO concentrations were tested by gas chromatography-mass spectroscopy and UV-Vis spectroscopy. The results showed that CO incorporated scaffolds have controlled releasing behaviour over seven days. Furthermore, the coating on the scaffold surfaces slightly retarded, but it did not inhibit, the in vitro bioactivity of the scaffolds. Moreover, the antioxidant and antibacterial activity of CO was studied. The free radical scavenging activity measured by DPPH was 5 ± 1, 41 ± 3, 44 ± 1 and 43 ± 1 % for BGSP, CO2.5, CO5 and CO7, respectively. The antioxidant activity was thus enhanced by incorporating CO. Agar diffusion and colony counting results indicated that the incorporation of CO increased the antibacterial activity of scaffolds against S. aureus and E. coli. In addition, cytotoxicity of the scaffolds was investigated using MG-63 osteoblast-like cells. The results showed that the BG-SP scaffold was non-toxic under the investigated conditions, whereas dose-dependent toxicity was observed in CO-laden scaffolds. Considered together, the developed phytotherapeutic agent laden 45S5 BG-based scaffolds are promising for bone tissue engineering exhibiting capability to combat bone infections and to protect against oxidative stress damage.


Assuntos
Antioxidantes , Óleos Voláteis , Antibacterianos/farmacologia , Antioxidantes/farmacologia , Cerâmica , Cinnamomum zeylanicum , Escherichia coli , Vidro , Óleos Voláteis/farmacologia , Estresse Oxidativo , Proteínas de Soja , Staphylococcus aureus , Engenharia Tecidual , Tecidos Suporte
14.
Braz J Biol ; 83: e247061, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34468524

RESUMO

The objective of this study was to evaluate the effectiveness of common antibiotics against different microorganisms in apparently healthy cattle in Shandong province and its suburb. A total of 220 nasal swab samples were collected and cultured for bacteriological evaluation. All the bacteria isolates after preliminary identification were subjected to antibiogram studies following disc diffusion method. It was found in the study that E. coli is the most commonly associated isolate (21%), followed by Klebsiella spp. (18%), Pseudomonas aeruginosa (13%), Salmonella spp. (15%), Shigella spp (12%), and Proteus spp (11%). While the antibiogram studies reveled that highest number of bacterial isolates showed resistance to Ampicillin (95%), followed by Augmentin (91%), Cefuroxime (85%) and Tetracycline (95%) of (Escherichia coli and Klebsiella spp). In the case of pseudomonas spp. and Salmonella the highest resistance was showed by Ampicillin (90%) followed by Amoxicillin + Clavulanic Acid (80%), Cefixime (90%), and Erythromycin (80%). In Shigella spp and Salmonella spp highest resistance was showed by Amoxicillin, Ceftazidime, Augmentin (60%), and Amoxicillin + Clavulanic Acid (50%). It is concluded that in vitro antibiogram studies of bacterial isolates revealed higher resistance for Ampicillin, Augmentin, Cefuroxime, Cefixime, Tetracycline, Erythromycin, and Amoxicillin + Clavulanic Acid. The high multiple Antibiotics resistance indexes (MARI) observed in all the isolates in this study ranging from 0.6 to 0.9. MARI value of >0.2 is suggests multiple antibiotic resistant bacteria and indicate presence of highly resistant bacteria.


Assuntos
Escherichia coli , Bactérias Gram-Negativas , Animais , Bovinos , Resistência a Medicamentos , Lactamas , Fenótipo
15.
Water Sci Technol ; 84(5): 1103-1124, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34534109

RESUMO

Low impact development practices (LID) as alternative measures of urban drainage can be used within the approach of resources recycling and co-management. This study evaluates the potential contribution of a bioretention system to flood control, non-potable water demands (NPD) and resources co-management. Bioretention setups were tested experimentally under variable conditions to identify operational key-factors to multiple purposes. Additionally, the efficiencies obtained for laboratory scale were extrapolated for household and watershed scale, quantifying the indicators of water demand reduction (WDR), energy demand reduction (EDR) and carbon emission reduction (CER) for hybrid systems with LID. The laboratory results indicated that the use of a bioretention with a submerged zone can improve the quality of the water recovered for reuse, while maintaining the efficiency of runoff retention and peak flow attenuation. Comparing the bioretention effluent quality with the Brazilian standards for stormwater reuse, the parameters color, turbidity, E. coli and metals were above the limits, indicating the necessity of a better treatment for solids particles and disinfection. Expanding the analysis to watershed scale, the bioretention helped to reduce NPD demands up to 45%, leading to a reduction in energy demand and carbon emission from the centralized water supply system.


Assuntos
Nitrogênio , Chuva , Escherichia coli , Inundações , Laboratórios
16.
Water Sci Technol ; 84(5): 1182-1189, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34534115

RESUMO

Considering high concentrations of multidrug-resistant bacteria and antibiotic resistance genes (ARGs) in wastewater, agricultural reuse of treated wastewater may be a public health threat due to ARG dissemination in different environmental compartments, including soil and edible parts of crops. We investigated the presence of antibiotic-resistant Escherichia coli as an indicator bacterium from secondary treated wastewater (STWW), water- or wastewater-irrigated soil and crop samples. ARGs including blaCTX-m-32, blaOXA-23, tet-W, sul1, cml-A, erm-B, along with intI1 gene in E. coli isolates were detected via molecular methods. The most prevalent ARGs in 78 E. coli isolates were sul1 (42%), followed by blaCTX-m-32 (19%), and erm-B (17%). IntI1 as a class 1 integrons gene was detected in 46% of the isolates. Cml-A was detected in STWW isolates but no E. coli isolate from wastewater-irrigated soil and crop samples contained this gene. The results also showed no detection of E. coli in water-irrigated soil and crop samples. Statistical analysis showed a correlation between sul1 and cml-A with intI1. The results suggest that agricultural reuse of wastewater may contribute to the transmission of antibiotic-resistant bacteria to soil and crop. Further research is needed to determine the potential risk of ARB associated with the consumption of wastewater-irrigated crops.


Assuntos
Integrons , Águas Residuárias , Antagonistas de Receptores de Angiotensina , Inibidores da Enzima Conversora de Angiotensina , Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla , Escherichia coli/genética , Genes Bacterianos , Integrons/genética
17.
J Agric Food Chem ; 69(36): 10480-10485, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34478293

RESUMO

1,4-Butanediol (1,4-BDO), a significant commodity chemical, is currently manufactured exclusively from a host of energy-intensive processes, accompanied by severe environmental issues, such as the greenhouse effect and air pollution. As a result of the ever-increasing global market demands and increasing applications of 1,4-BDO, attention has turned to the sustainable bioproduction of 1,4-BDO, and several bio-based approaches for 1,4-BDO production have been successfully established in engineered Escherichia coli, including de novo biosynthesis and biocatalysis. Recent achievements in enhancing the accumulation of 1,4-BDO have been achieved by metabolic engineering strategies, such as improving precursor supply, enhancing activities of critical enzymes, and fewer byproduct synthesis. Here, we summarize the primary advances of the biological pathway for 1,4-BDO synthesis and put forward the future development prospect of bio-based 1,4-BDO production.


Assuntos
Butileno Glicóis , Engenharia Metabólica , Biocatálise , Escherichia coli/genética
18.
J Hazard Mater ; 416: 125815, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492781

RESUMO

In this study, seven laccase genes from different bacteria were linked with the signal peptides PelB, Lpp or Ompa for heterologous expression in E. coli. The recombinant strains were applied for the removal of sulfadiazine (SDZ), sulfamethazine (SMZ), and sulfamethoxazole (SMX). The results obtained for different signal peptides did not provide insights into the removal mechanism. The removal ratios of SDZ, SMZ, and SMX obtained with the recombinant strain 6#P at 60 h were around 92.0%, 89.0%, and 88.0%, respectively. The degradation pathways of sulfonamides have been proposed, including SO2 elimination, hydroxylation, oxidation, pyrimidine ring cleavage, and N-S bond cleavage. Different mediators participate in the degradation of antibiotics through different mechanisms, and different antibiotics have different responses to the same mediator. The addition of 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) slightly promoted the removal of sulfonamides by most recombinant strains with different signal peptides, especially for the recombinant strain 2#O. The removal of sulfonamides by 1-hydroxybenzotriazole (HBT) varied with the recombinant strains. Syringaldehyde (SA) had a slight inhibitory effect on the removal of sulfonamides, with the most significant effect on strains 7#L and 7#O.


Assuntos
Antibacterianos , Lacase , Bactérias , Escherichia coli/genética , Lacase/genética , Sulfonamidas
19.
ACS Chem Neurosci ; 12(18): 3445-3455, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34477360

RESUMO

Canavan disease (CD) is a progressive, fatal neurological disorder that begins in infancy resulting from a mutation in aspartoacyclase (ASPA), an enzyme that catalyzes the deacetylation of N-acetyl aspartate (NAA) into acetate and aspartate. Increased NAA levels in the brains of affected children are one of the hallmarks of CD. Interestingly, genetic deletion of N-acetyltransferase-8-like (NAT8L), which encodes aspartate N-aceyltransferase (ANAT), an enzyme responsible for the synthesis of NAA from l-aspartate and acetyl-CoA, leads to normalization of NAA levels and improvement of symptoms in several genetically engineered mouse models of CD. Therefore, pharmacological inhibition of ANAT presents a promising therapeutic strategy for treating CD. Currently, however, there are no clinically viable ANAT inhibitors. Herein we describe the development of fluorescence-based high throughput screening (HTS) and radioactive-based orthogonal assays using recombinant human ANAT expressed in E. coli. In the fluorescence-based assay, ANAT activity was linear with respect to time of incubation up to 30 min and protein concentration up to 97.5 ng/µL with Km values for l-aspartate and acetyl-CoA of 237 µM and 11 µM, respectively. Using this optimized assay, we conducted a pilot screening of a 10 000-compound library. Hits from the fluorescence-based assay were subjected to an orthogonal radioactive-based assay using L-[U-14C] aspartate as a substrate. Two compounds were confirmed to have dose-dependent inhibition in both assays. Inhibitory kinetics studies of the most potent compound revealed an uncompetitive inhibitory mechanism with respect to l-aspartate and a noncompetitive inhibitory mechanism against acetyl-CoA. The screening cascade developed herein will enable large-scale compound library screening to identify novel ANAT inhibitors as leads for further medicinal chemistry optimization.


Assuntos
Doença de Canavan , Acetiltransferases/genética , Acetiltransferases/metabolismo , Animais , Ácido Aspártico , Encéfalo/metabolismo , Doença de Canavan/tratamento farmacológico , Escherichia coli/metabolismo , Ensaios de Triagem em Larga Escala , Humanos , Camundongos
20.
Braz J Biol ; 83: e239323, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34524371

RESUMO

The ß-lactam/lactamase inhibitors (BLBLIs) combination drugs are considered an effective alternative to carbapenems. However, there is a growing concern that the increased use of BLBLIs may lead to increased resistance. This study determined the temporal association between the consumption of BLBLI and the antimicrobial resistance in Gram-negative bacteria. In this retrospective study, electronic data on the Gram-negative bacterial isolates, including A. baumannii, P. aeruginosa, E. coli, and K. pneumoniae from in-patients and susceptibility testing results were retrieved from the medical records of the clinical laboratory. A linear regression and cross-correlation analysis were performed on the acquired data. Increasing trends (p<0.05) in the consumption of BIBLI and carbapenem with a median use of 27.68 and 34.46 DDD/1000 PD per quarter were observed, respectively. A decreased trend (p=0.023) in the consumption of fluoroquinolones with a median use of 29.13 DDD/1000 PD per quarter was observed. The resistance rate of K. pneumoniae was synchronized with the BIBLI and carbapenem consumptions with a correlation coefficient of 0.893 (p=0.012) and 0.951 (p=0.016), respectively. The cross-correlation analysis against the consumption of BIBLI and meropenem resistant K. pneumoniae was peaked at 0-quarter lag (r=951, p=0.016). There was an increasing trend in the consumption of BLBLI and carbapenems. The increasing trend in the rates of resistance to piperacillin/tazobactam, in line with the increasing consumption of BLBLI, suggests that BLBLI has to be used with caution and cannot be directly considered as a long-term alternative to carbapenems.


Assuntos
Antibacterianos , Infecções por Bactérias Gram-Negativas , Antibacterianos/uso terapêutico , Escherichia coli , Bactérias Gram-Negativas , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/epidemiologia , Humanos , Testes de Sensibilidade Microbiana , Estudos Retrospectivos
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