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1.
ACS Synth Biol ; 13(6): 1879-1892, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38847341

RESUMO

Aromatic d-amino acids (d-AAs) play a pivotal role as important chiral building blocks and key intermediates in fine chemical and drug synthesis. Meso-diaminopimelate dehydrogenase (DAPDH) serves as an excellent biocatalyst in the synthesis of d-AAs and their derivatives. However, its strict substrate specificity and the lack of efficient engineering methods have hindered its widespread application. Therefore, this study aims to elucidate the catalytic mechanism underlying DAPDH from Proteus vulgaris (PvDAPDH) through the examination of its crystallographic structure, computational simulations of potential energies and molecular dynamics simulations, and site-directed mutagenesis. Mechanism-guided computational design showed that the optimal mutant PvDAPDH-M3 increased specific activity and catalytic efficiency (kcat/Km) for aromatic keto acids up to 124-fold and 92.4-fold, respectively, compared to that of the wild type. Additionally, it expanded the substrate scope to 10 aromatic keto acid substrates. Finally, six high-value-added aromatic d-AAs and their derivatives were synthesized using a one-pot three-enzyme cascade reaction, exhibiting a good conversion rate ranging from 32 to 84% and excellent stereoselectivity (enantiomeric excess >99%). These findings provide a potential synthetic pathway for the green industrial production of aromatic d-AAs.


Assuntos
Aminoácido Oxirredutases , Aminoácidos Aromáticos , Simulação de Dinâmica Molecular , Mutagênese Sítio-Dirigida , Aminoácido Oxirredutases/metabolismo , Aminoácido Oxirredutases/genética , Aminoácido Oxirredutases/química , Especificidade por Substrato , Aminoácidos Aromáticos/metabolismo , Aminoácidos Aromáticos/biossíntese , Proteus vulgaris/enzimologia , Proteus vulgaris/genética , Biocatálise , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química
2.
Org Lett ; 25(23): 4400-4405, 2023 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-37284758

RESUMO

Herein, we report the first total synthesis of the trisaccharide and tetrasaccharide repeating units of P. penneri 26 and P. vulgaris TG155, respectively, having a common disaccharide unit, 3-α-l-QuipNAc-(1 → 3)-α-d-GlcpNAc-(1 →. Striking features of the targets are the presence of rare sugar units, l-quinovosamine and l-rhamnosamine, all joined through α-glycosidic linkages. Major challenges in the formation of 1,2-cis glycosidic linkages in the case of d-glucosamine, l-quinovosamine, and d-galactosamine have been addressed.


Assuntos
Proteus penneri , Proteus vulgaris , Sequência de Carboidratos , Antígenos O , Dissacarídeos
3.
J Infect Chemother ; 29(6): 631-633, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36996937

RESUMO

A hemin-requiring Proteus vulgaris small-colony variant (SCV) was isolated from a urine culture. This isolate was grown on 5% sheep blood agar but not on modified Drigalski agar. The single nucleotide substitution was found in the SCV of the hemC gene (c.55C > T), and this substitution caused a nonsense mutation (p.Gln19Ter). Porphyrin test results showed that the biosynthesis of δ-aminolevulinic acid stopped up to porphobilinogen and not pre-uroporphyrinogen due to a mutation in the hemC gene. To our knowledge, this is the first report of hemin-requiring P. vulgaris.


Assuntos
Hemina , Porfirinas , Animais , Ovinos , Proteus vulgaris/genética , Ágar , Meios de Cultura
4.
Can J Microbiol ; 68(11): 703-710, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36214343

RESUMO

Iron is essential for almost all bacteria, and iron homeostasis is precisely controlled by the ferric uptake regulator (Fur). The Fur regulons have been well characterized in some model bacteria, yet little is known in the common opportunistic pathogen Proteus vulgaris. In this study, Fur regulon and iron-responsive genes in P. vulgaris were mainly defined by in silico and proteomic analyses. The results showed that about 250 potential Fur-regulated operons including 14 transcriptional factors were predicted, while 559 proteins exhibited differential expression in response to iron deficiency, not all being directly regulated by Fur, such as transcriptional factors lexA, recA, narL, and arcA. Collectively, these results demonstrated that Fur functioned as a global regulatory protein to repress or activate expression of a large repertoire of genes in P. vulgaris; besides, not all the iron-responsive genes were directly regulated by Fur, whereas indirectly regulated through other mechanisms such as additional transcriptional regulatory proteins.


Assuntos
Regulação Bacteriana da Expressão Gênica , Ferro , Ferro/metabolismo , Proteus vulgaris/genética , Proteus vulgaris/metabolismo , Proteínas Repressoras/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteômica , Regulon , Fatores de Transcrição/genética
5.
Enzyme Microb Technol ; 160: 110073, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35689963

RESUMO

Regarding the existence of similar helices on the structure of different proteins, recently, novel variants of Chondroitinase ABC I (cABC I) have been constructed, where a representative helix between two structural motifs in Chondroitinase ABC I from Proteus vulgaris has been replaced by similar versions of helices found in other proteins. The previous study has revealed that the structural features and the activity of double mutants M886A/G887E (inspired by the 30 S ribosomal protein S1 from Geminocystis herdmanii) and M889I/Q891K (inspired by the chondroitin lyase from Proteus mirabilis) is comparable with that of wild-type (WT) cABC I. Here, the kinetic parameters of the enzyme activity for the WT and double mutants were determined. Of the recombinant double mutants, M889I/Q891K gave the highest catalytic efficiency with the kcat/Km value of approximately 2.3-fold increase, as compared with the WT and M886A/G887E. Modeling of experimental data showed that the mechanism of the heat-induced structural alteration, and the enzyme-substrate complex formation, changed upon mutation. These natural versions of the connecting helix can be used as an efficient linker in protein engineering studies as well as those investigations involving the use of biological linkers.


Assuntos
Condroitina ABC Liase , Proteus vulgaris , Catálise , Condroitina ABC Liase/química , Cinética , Engenharia de Proteínas , Proteus vulgaris/genética
6.
Lett Appl Microbiol ; 74(5): 695-706, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35034356

RESUMO

Antibacterial activities of as-synthesized nanoparticles have gained attention in past few years due to rapid phylogenesis of pathogens developing multi-drug resistance (MDR). Antibacterial activity of copper nanoparticles (CuNPs) on surrogate pathogenic Gram-negative bacteria Escherichia coli (MTCC no. 739) and Proteus vulgaris (MTCC no. 426) was evaluated under culture conditions. Three sets of colloidal CuNPs were synthesized by chemical reduction method with per batch yield of 0·2, 0·3 and 0·4 g. As-synthesized CuNPs possess identical plasmonic properties and have similar hydrodynamic particle sizes (11-14 nm). Antibacterial activities of CuNPs were evaluated by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests, cytoplasmic leakage and reactive oxygen species (ROS) assays. MIC and MBC tests revealed dose dependence bactericidal action. Growth curves of E. coli show faster growth inhibition along with higher cytoplasmic leakage than that of P. vulgaris. This might be because of increased membrane permeability of E. coli. CuNP-microorganism interaction induces oxidative stress generated by ROS. Leakage of cytoplasmic components, loss of membrane permeability and ROS generation are the primary causes of CuNP-induced bacterial cell death. As-synthesized CuNPs exhibiting promising antibacterial activities and could be a promising candidate for novel antibacterial agents.


Assuntos
Infecções por Escherichia coli , Nanopartículas Metálicas , Antibacterianos/química , Antibacterianos/farmacologia , Bactérias , Cobre/química , Cobre/farmacologia , Escherichia coli , Bactérias Gram-Negativas , Humanos , Nanopartículas Metálicas/química , Testes de Sensibilidade Microbiana , Proteus vulgaris , Espécies Reativas de Oxigênio
7.
Genomics ; 114(1): 38-44, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34839020

RESUMO

Proteus phage vB_PvuS_Pm34 (Pm34) isolated from the sewage, is a novel virus specific to Proteus vulgaris. Pm34 belonged to the family Siphovirodae with an icosahedron capsid head and a non-contractile tail. Its genome was 39,558 bp in length with a G + C content of 41.4%. Similarity analysis showed that Pm34 shared low identities of 27.6%-38.4% with any other Proteus phages, but had the 96% high identity with Proteus mirabilis AOUC-001. In the genome of Pm34, 70 open reading frames was deduced and 32 had putative functions including integrase and host lysis proteins. No tRNAs, antibiotic resistance and virulence genes were detected. Pm 34 presented a broad pH (4-8) and good temperature tolerance (<40 °C). This is the first report of the bacteriophage specific to P. vulgaris, which can enrich the knowledge of bacteriophages of Prouteus bacteria and provide the possibility for the alternative treatment of P. vulgaris infection.


Assuntos
Bacteriófagos , Siphoviridae , Bacteriófagos/genética , Genoma Viral , Genômica , Fases de Leitura Aberta , Proteus mirabilis/genética , Proteus vulgaris/genética , Siphoviridae/genética
8.
BMC Microbiol ; 21(1): 322, 2021 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-34798838

RESUMO

PROBLEM BACKGROUND: Penicillin was the first and most famous fungal secondary metabolite used as broad spectrum antibiotic that revolutionarised pharmaceutical research and also saved millions of lives. The over optimistic belief in 1967 that sufficient antibiotics had been discovered to defeat infectious diseases was quickly crashed with the appearance of multidrug resistant (MDR) bacteria in 1990s. This has posed a serious threat to mankind. Although scientists are making efforts to synthesize and discover new antibiotics there are not enough new drugs in pharmaceutical pipeline to beat the pace at which MDR bacteria are emerging. In view of this there is an urgent and serious medical need for new bioactive compounds to be discovered to treat infections caused by MDR pathogens. The present study is aimed to investigate the antibacterial potential of Aspergillus flavus originated compounds that may act as drug leads to treat future infections. METHODOLOGY: Among the 6 isolated fungal strains from the rhizosphere of Mentha piperetta, one was processed for isolation of secondary metabolites on the basis of preliminary antibacterial testing. Observation of morphological and microscopic features helped in identification of the fungal strain as Aspergillus flavus. Potato Dextrose Agar (PDA) medium was used for fungal growth while Czapec Yeast Broth (CYB) medium was used for production of fungal metabolites. Column chromatography technique was utilized for purification of compound from crude fungal extract and the mass of the compound was determined using Liquid Chromatography Mass Spectrometry (LCMS) method. Structure elucidation of the pure compound was performed using 500 Varian Nuclear Magnetic Resonance (NMR) machine. Docking was performed using Glide SP algorithm. Agar well diffusion method was used to determine the invitro antibacterial potential of the compound against two MDR bacterial strains i.e. Staphylococcus aureus and Proteus vulgaris. For this a total of 4 dose concentrations i.e. (100, 250, 500, 1000 µg mL- 1) of the compound were prepared and applied to bacterial strains on Mueller Hinton agar using tetracycline as control. RESULTS: The chemical name of the purified compound from A. flavus was determined as (2E)-3-[(3S, 4R)-8-hydroxy-3, 4-dimethyl-1-oxo-3, 4-dihydro-1H-2- benzopyran-7-yl] prop-2-enoic acid with the formula C14H14O5 and exact mass of 262.08. The in-Silico analysis showed that this compound has the potential to inhibit the binding pocket of S. aureus TyrRS (1JII) with docking score of - 8.67 Kcal mole- 1. The results obtained from invitro experiments were encouraging as at 1000 µg mL- 1 the compound showed 58.8% inhibition against S. aureus and 28% inhibition against P. vulgaris. CONCLUSIONS: The pure compound with formula C14H14O5 and exact mass of 262 exhibited antibacterial potential both insilico and invitro against both Gram negative and Gram positive bacteria. The compound was more active against S. aureus in comparison to P. vulgaris. From the obtained results it is concluded that this compound can be used as potent antibacterial candidate but further studies will be needed prior to its use as antibiotic.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Aspergillus flavus/química , Aspergillus flavus/metabolismo , Antibacterianos/metabolismo , Aspergillus flavus/genética , Aspergillus flavus/isolamento & purificação , Farmacorresistência Bacteriana , Mentha piperita/microbiologia , Testes de Sensibilidade Microbiana , Proteus vulgaris/efeitos dos fármacos , Proteus vulgaris/crescimento & desenvolvimento , Metabolismo Secundário , Microbiologia do Solo , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento
9.
J Biosci ; 462021.
Artigo em Inglês | MEDLINE | ID: mdl-34845992

RESUMO

Proteus vulgaris is a rod-shaped Gram-negative bacterium known to be the member of Enterobacteriaceae that is able to cause disease in human being. Generally, non-protein-coding RNAs (npcRNAs) do not code for proteins, but they play a vital role in gene regulation at the RNA level including pathogenicity. The present study aims at elucidating homologous npcRNAs from other bacteria in Proteus vulgaris. A comparative genomic analysis was carried out to identify npcRNA homolog of other Enterobacteriaceae pathogens in Proteus vulgaris. A total of 231 npcRNAs previously reported in Salmonella typhi, Salmonella typhimurium and Escherichia coli were screened using BLASTn tool against Proteus vulgaris genome. Interestingly, 33 npcRNAs are homologs to Proteus vulgaris. Northern blot analysis of 6 out of 33 npcRNA candidates confirmed their expression and showed that most of them are differentially expressed during lag, exponential and stationary growth phases. This study is the first approach of identification and characterization of npcRNAs in P. vulgaris. Hence, this could be a pioneer study to further validate the regulatory functions of these npcRNAs to fill the gaps in understanding of the pathogenicity of P. vulgaris.


Assuntos
Proteus vulgaris , RNA não Traduzido , Genômica , Humanos , Proteus vulgaris/genética , Proteus vulgaris/metabolismo , RNA não Traduzido/genética
10.
Int J Mol Sci ; 22(19)2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34638966

RESUMO

Bacterial non-coding RNAs (ncRNAs) play important regulatory roles in various physiological metabolic pathways. In this study, a novel ncRNA CsiR (ciprofloxacin stress-induced ncRNA) involved in the regulation of ciprofloxacin resistance in the foodborne multidrug-resistant Proteus vulgaris (P. vulgaris) strain P3M was identified. The survival rate of the CsiR-deficient strain was higher than that of the wild-type strain P3M under the ciprofloxacin treatment condition, indicating that CsiR played a negative regulatory role, and its target gene emrB was identified through further target prediction, quantitative real-time PCR (qRT-PCR), and microscale thermophoresis (MST). Further studies showed that the interaction between CsiR and emrB mRNA affected the stability of the latter at the post-transcriptional level to a large degree, and ultimately affected the ciprofloxacin resistance of P3M. Notably, the base-pairing sites between CsiR and emrB mRNAs were highly conserved in other sequenced P. vulgaris strains, suggesting that this regulatory mechanism may be ubiquitous in this species. To the best of our knowledge, this is the first identification of a novel ncRNA involved in the regulation of ciprofloxacin resistance in P. vulgaris species, which lays a solid foundation for comprehensively expounding the antibiotic resistance mechanism of P. vulgaris.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Ciprofloxacina/farmacologia , Farmacorresistência Bacteriana/genética , Proteínas de Membrana/metabolismo , Proteus vulgaris/efeitos dos fármacos , Proteus vulgaris/metabolismo , RNA não Traduzido/metabolismo , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana/efeitos dos fármacos , Deleção de Genes , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Proteínas de Membrana/genética , Organismos Geneticamente Modificados , Proteus vulgaris/genética , RNA Mensageiro/metabolismo , RNA não Traduzido/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética
11.
Pak J Pharm Sci ; 34(3): 995-1001, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34602424

RESUMO

A novel method, for the synthesis of silver nanoparticles that are eco-friendly by means of mixed reductants method, has been developed. The combined extract of Mentha viridis plant and Prunus domestica gum were used as reducing agents for the synthesis of silver nanoparticles of the size less than 40 nm in diameter. The effect of time and concentration on the formation of silver nanoparticles were also monitored. The silver nanoparticles formed were verified by surface Plasmon spectra using single and double beam UV-Vis spectrophotometer. The XRD technique and scanning electron microscopy were performed to analyze the crystalline structure, crystallite size and morphology. The synthesized silver nanoparticles were tested against different bacterial and fungus strains. The silver nanoparticles showed good inhibition in antimicrobial study and low MIC for bacterial strains. The antioxidant assay was performed to check the scavenging activity. In DPPH, the silver nanoparticles showed good scavenging activity and were found close to that of ascorbic acid.


Assuntos
Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Mentha , Nanopartículas Metálicas , Prunus domestica , Prata/farmacologia , Anti-Infecciosos/química , Antioxidantes/química , Aspergillus/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Técnicas de Química Sintética , Química Farmacêutica , Fusarium/efeitos dos fármacos , Hypocreales/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Microscopia Eletrônica de Varredura , Penicillium chrysogenum/efeitos dos fármacos , Espectroscopia Fotoeletrônica , Extratos Vegetais , Gomas Vegetais , Proteus vulgaris/efeitos dos fármacos , Pseudomonas/efeitos dos fármacos , Substâncias Redutoras , Prata/química , Nitrato de Prata , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacos , Ressonância de Plasmônio de Superfície
12.
J Contemp Dent Pract ; 22(6): 674-679, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34393126

RESUMO

AIM: The purpose of this in vitro study was to evaluate the intraorifice sealing ability of light-cured glass-ionomer cement (LC-GIC), Tetric N-Flow, and ProRoot mineral trioxide aggregate (MTA) against Enterococcus faecalis and Proteus vulgaris. MATERIALS AND METHODS: Crowns of the eighty human mandibular teeth were decapitated. Working length determination was performed, after which cleaning and shaping were carried out. A uniform orifice diameter of 1.3 mm, at its widest point, was made. Once instrumentation was completed, the canals were irrigated and then obturated. A heat carrier was used to remove gutta-percha to the depth of 3.5 mm. Samples were then divided into a control group (Group 1) with no barrier, and three groups, namely, Group 2, Group 3, and Group 4, were restored with the LC-GIC, Tetric N-Flow, and ProRoot MTA, respectively. The groups were further subdivided into Subgroup A for checking bacterial leakage against E. faecalis and Subgroup B, against P. vulgaris. All samples were subjected to the bacterial leakage test and observed daily for the appearance of turbidity after which statistical analysis was performed. RESULTS: Group 1 showed leakage in, as early as, 3 days. The longest time for the turbidity to appear was shown by Group 4 with an average of 31 days. The mean number of days for turbidity to appear in Group 2 and Group 3 was 23 and 24 days, respectively. Group 4 showed the best intraorifice sealing ability with a significant difference. CONCLUSION: The teeth with an intraorifice coronal seal had better protection against microbial leakage. Among all materials used, the ProRoot MTA showed the best intraorifice sealing ability. CLINICAL SIGNIFICANCE: Use of the ProRoot MTA promises long-term results in the endodontically treated teeth as compared with other materials.


Assuntos
Infiltração Dentária , Materiais Restauradores do Canal Radicular , Compostos de Alumínio , Compostos de Cálcio , Infiltração Dentária/prevenção & controle , Combinação de Medicamentos , Enterococcus faecalis , Guta-Percha , Humanos , Óxidos , Proteus vulgaris , Silicatos
13.
Bioorg Chem ; 114: 105078, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34161878

RESUMO

This study was focused on the synthesis of new pyrimidines 4a,b, 5a,b and pyrazoles 6a, b as ATP mimicking tyrosine kinase inhibitors of the epidermal growth factor receptor (EGFR). The new compounds were assessed as cytotoxic candidates against human breast cancer cells (MCF-7) and hepatocellular carcinoma cells (HepG-2). All the new compounds appeared as more potent cytotoxic agents than erlotinib, while only compound 4a exhibited more potency than 5-flourouracil and 4b analogue was equipotent to it. Accordingly, the kinase suppression effect of 4a and 4b was further evaluated against EGFRWT, EGFRL858R and EGFRT790M. Both pyrimidine analogues 4a and 4b displayed outstanding inhibitory activity against EGFRWT and its two mutated isoforms EGFRL858R and EGFRT790M in comparing to erlotinib and osimertinib as reference drugs. Additionally, all the new analogues were subjected to antimicrobial assay. Interestingly, both 4a and 4b represented the most promising activity of wide spectrum antimicrobial effect against the examined microbes in comparison to gentamycin and ketoconazole as standard drugs. Moreover, docking results proved the good binding interactions of the compounds 4a and 4b with EGFRWT and EGFRT790M which were in accordance with the results of the in vitro enzyme assay. Additional in silico ADMET studies were performed for the new derivatives which represented their good oral absorption, good drug-likeness properties and low toxicity risks in human.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Antineoplásicos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Pirazóis/farmacologia , Pirimidinas/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Antifúngicos/síntese química , Antifúngicos/química , Antineoplásicos/síntese química , Antineoplásicos/química , Aspergillus fumigatus/efeitos dos fármacos , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/metabolismo , Humanos , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura Molecular , Mucorales/efeitos dos fármacos , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Proteus vulgaris/efeitos dos fármacos , Pirazóis/síntese química , Pirazóis/química , Pirimidinas/síntese química , Pirimidinas/química , Streptococcus/efeitos dos fármacos , Relação Estrutura-Atividade
14.
Microb Drug Resist ; 27(10): 1360-1370, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33877915

RESUMO

Proteus vulgaris is an important foodborne opportunistic pathogen, both environmentally and clinically. The use of appropriate antibiotics has significant therapeutic effects, but has led to the emergence and spread of drug-resistant strains. In this study, a P. vulgaris strain, designated "P3M," was isolated from Penaeus vannamei in Tianjin, China. The whole genome of P3M was sequenced, generating detailed information, including the key genes involved in important metabolic pathways and their physiological functions. A total of 218 antibiotic resistance genes (ARGs) were predicted in the genome. The determination of various minimum inhibitory concentrations indicated that P3M is a multidrug-resistant (MDR) bacterium, with significant resistance to 16 antibiotics in seven categories. Determination of fractional inhibitory concentration index showed that the combination of ciprofloxacin plus tetracycline exhibited synergistic antimicrobial activity. Bioinformatics and phylogenetic analyses detected the presence of two two-component systems that mediate multidrug resistance and several mobile genetic elements involved in the horizontal transfer of ARGs in P3M. P. vulgaris strains represent a serious challenge to clinicians and infection control teams for its ubiquity worldwide and close relevance with human life. To the best of our knowledge, we report the first isolation and characterization of an important foodborne MDR P. vulgaris strain, and this study will provide necessary theoretical basis for the selection and clinical use of the appropriate antibiotics.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Doenças Transmitidas por Alimentos/microbiologia , Penaeidae/microbiologia , Proteus vulgaris/efeitos dos fármacos , Proteus vulgaris/isolamento & purificação , Animais , China , Genes Bacterianos/genética , Testes de Sensibilidade Microbiana
16.
Molecules ; 26(8)2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33920893

RESUMO

Herein, we report the synthesis of eight new mononuclear and binuclear Co2+, Ni2+, Cu2+, and Zn2+ methoxy thiosemicarbazone (MTSC) complexes aiming at obtaining thiosemicarbazone complex with potent biological activity. The structure of the MTSC ligand and its metal complexes was fully characterized by elemental analysis, spectroscopic techniques (NMR, FTIR, UV-Vis), molar conductivity, thermogravimetric analysis (TG), and thermal differential analysis (DrTGA). The spectral and analytical data revealed that the obtained thiosemicarbazone-metal complexes have octahedral geometry around the metal center, except for the Zn2+-thiosemicarbazone complexes, which showed a tetrahedral geometry. The antibacterial and antifungal activities of the MTSC ligand and its (Co2+, Ni2+, Cu2+, and Zn2+) metal complexes were also investigated. Interestingly, the antibacterial activity of MTSC- metal complexes against examined bacteria was higher than that of the MTSC alone, which indicates that metal complexation improved the antibacterial activity of the parent ligand. Among different metal complexes, the MTSC- mono- and binuclear Cu2+ complexes showed significant antibacterial activity against Bacillus subtilis and Proteus vulgaris, better than that of the standard gentamycin drug. The in silico molecular docking study has revealed that the MTSC ligand could be a potential inhibitor for the oxidoreductase protein.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Cobalto/química , Cobre/química , Tiossemicarbazonas/química , Zinco/química , Bacillus subtilis/efeitos dos fármacos , Simulação de Acoplamento Molecular , Proteus vulgaris/efeitos dos fármacos , Termogravimetria
17.
Sci Rep ; 11(1): 3657, 2021 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-33574492

RESUMO

Muscle is an important structural tissue in aquatic animals and it is susceptible to bacterial and fungal infection, which could affect flesh quality and health. In this study, Chinese soft-shelled turtles were artificially infected with two pathogens, Proteus vulgaris and Elizabethkingia meningoseptica and the effects on muscle nutritional characteristics, oxidative stress and autophagy were assayed. Upon infection, the muscle nutritional composition and muscle fiber structure were notably influenced. Meanwhile, the mRNA expression of Nrf2 was down-regulated and Keap1 up-regulated, thus resulting in a decrease in antioxidant capacity and oxidative stress. However, with N-acetylcysteine treatment, the level of oxidative stress was decreased, accompanied by significant increases in antioxidant enzyme activities and the mRNA levels of SOD, CAT, GSTCD, and GSTO1. Interestingly, there was a significant increase in autophagy in the muscle tissue after the pathogen infection, but this increase could be reduced by N-acetylcysteine treatment. Our findings suggest that muscle nutritional characteristics were dramatically changed after pathogen infection, and oxidative stress and autophagy were induced by pathogen infection. However, N-acetylcysteine treatment could compromise the process perhaps by decreasing the ROS level and regulating Nrf2-antioxidant signaling pathways.


Assuntos
Autofagia/efeitos dos fármacos , Músculos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Tartarugas/microbiologia , Acetilcisteína/farmacologia , Animais , Antioxidantes/farmacologia , China , Flavobacteriaceae/patogenicidade , Infecções por Flavobacteriaceae/genética , Infecções por Flavobacteriaceae/microbiologia , Infecções por Flavobacteriaceae/patologia , Músculos/microbiologia , Proteus vulgaris/patogenicidade , Transdução de Sinais/efeitos dos fármacos , Tartarugas/genética , Tartarugas/metabolismo
18.
Int J Biol Macromol ; 172: 350-359, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33453258

RESUMO

The improper management of wound exudates can expose the wound to bacterial invasion, skin maceration etc. thereby resulting in prolonged wound healing. Biopolymers are characterized by hydrophilic functional groups which when employed for the development of wound dressings promote the wound dressings capability to absorb a high amount of wound exudates. Alginate-gum acacia sponges were prepared from a combination of biopolymers such as sodium alginate and gum acacia in varying amounts with carbopol via crosslinking with 1 and 2% CaCl2. The prepared sponges were loaded with a combination of ampicillin and norfloxacin. In vitro antibacterial analysis revealed that the antibacterial activity of the loaded antibiotics was retained and the sponges were effective against gram-positive and gram-negative bacteria. The sponges displayed rapid and high absorption capability in the range of 1022-2419% at pH 5.5 simulating wound exudates, and 2268-5042% at pH 7.4 simulating blood within a period of 1-3 h. Furthermore, the whole blood clotting studies further revealed low absorbance values when compared to the control revealing the good clotting capability of the sponges. The unique features of the sponges revealed their potential application for the management of infected, high exuding and bleeding wounds.


Assuntos
Resinas Acrílicas/química , Alginatos/química , Antibacterianos/farmacologia , Bandagens , Cloreto de Cálcio/química , Goma Arábica/química , Ampicilina/química , Ampicilina/farmacologia , Antibacterianos/química , Coagulação Sanguínea/efeitos dos fármacos , Liofilização/métodos , Humanos , Testes de Sensibilidade Microbiana , Norfloxacino/química , Norfloxacino/farmacologia , Porosidade , Proteus vulgaris/efeitos dos fármacos , Proteus vulgaris/crescimento & desenvolvimento , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus epidermidis/efeitos dos fármacos , Staphylococcus epidermidis/crescimento & desenvolvimento
19.
Biotechnol J ; 16(5): e2000321, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33350041

RESUMO

Chondroitinase ABC I (csABC I) has attracted intensive attention because of its great potential in heparin refining and the enzymatic preparation of low-molecular-weight chondroitin sulfate (LMW-CS). However, low thermal resistance (<30℃) restricts its applications. Herein, structure-guided and sequence-assisted combinatorial engineering approaches were applied to improve the thermal resistance of Proteus vulgaris csABC I. By integrating the deletion of the flexible fragment R166-L170 at the N-terminal domain and the mutation of E694P at the C-terminal domain, variant NΔ5/E694P exhibited 247-fold improvement of its half-life at 37℃ and a 2.3-fold increase in the specific activity. Through batch fermentation in a 3-L fermenter, the expression of variant NΔ5/E694P in an Escherichia coli host reached 1.7 g L-1 with the activity of 1.0 × 105 U L-1 . Finally, the enzymatic approach for the preparation of LMW-CS was established. By modulating enzyme concentration and controlling depolymerization time, specifically distributed LMW-CS (7000, 3400, and 1900 Da) with low polydispersity was produced, demonstrating the applicability of these processes for the industrial production of LMW-CS in a more environmentally friendly way.


Assuntos
Condroitina ABC Liase , Sulfatos de Condroitina , Condroitina ABC Liase/genética , Condroitinases e Condroitina Liases , Peso Molecular , Proteus vulgaris/genética
20.
Molecules ; 27(1)2021 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-35011355

RESUMO

Satureja nabateorum (Danin and Hedge) Bräuchler is a perennial herb in the Lamiaceae family that was discovered and classified in 1998. This green herb is restricted to the mountains overlooking the Dead Sea, specifically in Jordan's southwest, the Edom mountains, and the Tubas mountains in Palestine. Gas chromatography-mass spectrometry (GC-MS) analysis of essential oil (EO) of air-dried and fresh S. nabateorum resulted in the identification of 30 and 42 phytochemicals accounting for 99.56 and 98.64% of the EO, respectively. Thymol (46.07 ± 1.1 and 40.64 ± 1.21%) was the major compound, followed by its biosynthetic precursors γ-terpinene (21.15 ± 1.05% and 20.65 ± 1.12%), and p-cymene (15.02 ± 1.02% and 11.51 ± 0.97%), respectively. Microdilution assay was used to evaluate the antimicrobial property of EOs against Staphylococcus aureus (ATCC 25923), clinical isolate Methicillin-Resistant Staphylococcus aureus (MRSA), Enterococcus faecium (ATCC 700221) Klebsiella pneumoniae (ATCC 13883), Proteus vulgaris (ATCC 700221), Escherichia coli (ATCC 25922) and Pseudomonas aeruginosa (ATCC 27853) and Candida albicans (ATCC-90028). With a MIC of 0.135 µg/mL, the EOs has the most potent antibacterial action against K. pneumonia. Both EOs display good antifungal efficacy against C. albicans, with a MIC value of 0.75 µg/mL, which was better than that of Fluconazole's (positive control, MIC = 1.56 µg/mL). The antioxidant capacity of EOs extracted from air-dried and fresh S. nabateorum was determined using the DPPH assay, with IC50 values of 4.78 ± 0.41 and 5.37 ± 0.40 µg/mL, respectively. The tested EOs showed significant cytotoxicity against Hela, HepG2, and COLO-205 cells, with IC50 values ranging from 82 ± 0.98 to 256 ± 1.95 µg/mL. The current work shows there is a possibility to use the S. nabateorum EOs for various applications.


Assuntos
Anti-Infecciosos/química , Antioxidantes/química , Óleos Voláteis/química , Compostos Fitoquímicos/química , Extratos Vegetais/química , Satureja/química , Infecções Estafilocócicas/tratamento farmacológico , Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Candida albicans/efeitos dos fármacos , Monoterpenos Cicloexânicos/química , Cimenos/química , Enterococcus faecium/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Sequestradores de Radicais Livres/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Óleos Voláteis/farmacologia , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Proteus vulgaris/efeitos dos fármacos , Timol/química
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