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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 284: 121757, 2023 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-36029743

RESUMEN

Here, an aptamer-based SERS method for the detection of Staphylococcus aureus (S. aureus) without immobilization using Au@Ag NPs/slide as enhanced substrate was constructed. ROX-aptamer of S. aureus was modified on the surface of Au@Ag NPs/slide through electrostatic interaction. Based on the specific binding effect of the aptamer to S. aureus, the ROX-aptamer fell off from the surface of the substrate, resulting in a decrease of the SERS signal intensity of the substrate. Under the optimal experimental conditions, a good linear relationship was found between SERS intensity at 1500 cm-1 and the logarithm of concentration of S. aureus in the range of 102 cfu/mL-107 cfu/mL (y = 6623-796lgx, R2 = 0.994) with a detection limit of 6 cfu/mL. The selectivity analysis revealed that the method had higher selectivity toward the corresponding target. The results for milk sample using the developed SERS method for the detection of S. aureus were similar to those of the plate counting method. The recovery ratio was from 90.60% to 107.26%, indicating the accuracy and reliability of the developed method. This method eliminates the need for bacterial immobilization and improves the convenience and efficiency of detection.


Asunto(s)
Nanopartículas del Metal , Staphylococcus aureus , Oro , Oligonucleótidos , Reproducibilidad de los Resultados , Espectrometría Raman/métodos
2.
Food Chem ; 398: 133923, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-35987005

RESUMEN

This study aimed to characterize a novel antimicrobial peptide (AMP) obtained from Moringa oleifera seed protein hydrolysates. Cell membrane chromatography and live bacteria adsorption were combined into a single step to efficiently isolate the active fraction of the AMP. Five peptides were identified by LC-MS/MS, among which the MCNDCGA peptide (termed MOp3) showed the greatest inhibitory effect against Staphylococcus aureus [minimum inhibitory concentration (MIC): 2 mg/mL]. MOp3 was identified as a hydrophobic anionic AMP rich in ß-sheet structures with negligible hemolytic activity at 2.0 × MIC. MOp3 had good tolerance to salt solutions at 5 % and pH range 6.0-8.0, but was sensitive to high temperatures (>100 °C) and acid protease. Microscopic observation further revealed that MOp3 induced irreversible damage onto the cell membrane of S. aureus and interacted with dihydrofolate reductase and DNA gyrase by hydrogen bonding and hydrophobic interaction. These findings highlight the potential application of a new antimicrobial agent against S. aureus in the food industry.


Asunto(s)
Moringa oleifera , Adenosina Monofosfato/análisis , Adsorción , Péptidos Antimicrobianos , Cromatografía Liquida , Moringa oleifera/química , Extractos Vegetales/química , Semillas/química , Staphylococcus aureus , Espectrometría de Masas en Tándem
3.
J Ethnopharmacol ; 300: 115677, 2023 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-36064148

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Bioactive substance identification is always the focal point and the main challenge in Chinese herbal medicine (CHM). Most CHM present multiple efficacies and multiple tropisms, which has improved the application accuracy of CHM, and is worthy of further study. In this article, the concept of "multi-tropism efficacy of CHM" has been proposed for the first time. In addition, it is hypothesized that the different components in CHM can be classified based on their efficacy status. AIM OF THE STUDY: The spectrum-effect relationship between the fingerprint and efficacy was established to identify the efficacy status of components. This provided a practical, efficient and accurate way to identify the bioactive substances from a complex CHM system. MATERIALS AND METHODS: The network pharmacology approach was applied to preliminarily analyze the potential antibacterial compounds and mechanisms of HQ. Furthermore, its chemical fingerprint was established and the characteristic peaks were identified by LC-MS/MS. The antibacterial and anti-inflammatory bioactivities of HQ were determined to evaluate its pharmacological effect of heat-clearing and detoxification, and its anticoagulation activity was determined to evaluate its heat-clearing and tocolysis effects. The spectrum-effect relationships were assessed by gray correlation analysis to discriminate the status of active components in HQ with different efficacies. RESULTS: Network pharmacology analysis revealed apigenin, wogonin, baicalein, acacetin, ß-sitosterol, baicalin, eugenol, moslosooflavone, palmitic acid, oroxylin-A 7-O-glucuronide, and scutevulin as the potential active compounds responsible for the efficacy of HQ against both E. coli and S. aureus. The spectrum-effect relationship was utilized to reveal the orientation activities, with the results as follows: 1) The main basic-efficacy components in HQ with antibacterial, anti-inflammatory, and anticoagulant effects were P5, P8, P9, P15, P18, P19, P20; while the general basic-efficacy components were P2, P3, P6, P7, P11, P14, P21, P22, P28. 2) The main efficacy-oriented components in HQ with antibacterial effects on E. coli were P1, P12, P17, while the general efficacy-oriented compound was P10, P24, P25, P26, P27; the main efficacy-oriented in HQ with antibacterial effects on S. aureus were P14 and the general efficacy-oriented components were P1, P12, P26, P29, P30, respectively. 3) The main efficacy-oriented components with anti-inflammatory activity were P14, P24, P25, P27, and P30, while the general efficacy-oriented components were P13, P23, P26. 4) The main efficacy-oriented compounds in HQ with effects on anticoagulation were P6 and P22; these acted by prolonging APTT through the intrinsic coagulation pathway and PT through the extrinsic coagulation pathway, respectively. 5) The pharmacodynamic status classification of Scutellaria baicalensis ingredients were confirmed by nine reference compounds exemplarily. CONCLUSION: This work established a novel strategy for active compound efficacy status identification in multi-tropism Chinese herbal medicine (Scutellaria baicalensis Georgi) based on multi-indexes spectrum-effect gray correlation analysis, the method is scientific feasible and can be applied to the effective substances identification and quality control of other CHM.


Asunto(s)
Medicamentos Herbarios Chinos , Scutellaria baicalensis , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Anticoagulantes , Apigenina , Cromatografía Liquida , Medicamentos Herbarios Chinos/química , Medicamentos Herbarios Chinos/farmacología , Medicamentos Herbarios Chinos/uso terapéutico , Escherichia coli , Eugenol , Glucurónidos , Ácido Palmítico , Piridinolcarbamato , Scutellaria baicalensis/química , Staphylococcus aureus , Espectrometría de Masas en Tándem , Tropismo
4.
Food Chem ; 399: 133970, 2023 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-35998499

RESUMEN

Lateral flow immunoassays (LFIAs) are routine methods for rapid foodborne pollutants screening, with detection limits that are closely associated with the label probes used. The exploitation of high performance and robust probe is highly desirable, and remains a great challenge. Herein, we reported an emerging fluorescent nanobeads i.e. carbon-dots (CD) covalently incorporated mesoporous silicon nanoparticles (CD-MSNs) for LFIAs. CD-MSNs revealed brighter fluorescence, larger particle size and more modification sites in comparison with those of single CD. After bio-functionalisation, CD-MSNs probes were introduced to construct LFIA test strips, and designed for ultrasensitive detection of aflatoxin B1 (AFB1) and Staphylococcus aureus (S. aureus), two representative foodborne pollutants, based on the competitive and sandwich models, respectively. Very competitive quantitative detection limits i.e. 0.05 ng/mL and 102 cfu/mL were correspondingly obtained. Additionally, the test strips were successfully applied to rapidly and accurately screen AFB1 and S. aureus in food samples, highlighting their practicality.


Asunto(s)
Contaminantes Ambientales , Nanopartículas , Aflatoxina B1/análisis , Carbono , Colorantes Fluorescentes , Inmunoensayo/métodos , Límite de Detección , Silicio , Staphylococcus aureus
5.
Braz. j. biol ; 83: e243332, 2023. tab, graf
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1345537

RESUMEN

Abstract The present study was aimed to manifest the antibacterial and antifungal activity of methanolic extracts of Salix alba L. against seven Gram-positive and Gram-negative bacterial pathogens e.g. Streptococcus pyogenes, Staphylococcus aureus (1), S. aureus (2), Shigella sonnei, Escherichia coli (1), E. coli (2) and Neisseria gonorrhoeae and three fungal isolates from the air such as Aspergillus terreus, A. ornatus, and Rhizopus stolonifer. Two different serotypes of S. aureus and E. coli were used. The agar well-diffusion method results showed the dose-dependent response of plant extracts against bacterial and fungal strains while some organisms were found resistant e.g. E. coli (1), S. sonnei, A. terreus and R. stolonifer. The highest antibacterial activity was recorded at 17.000±1.732 mm from 100 mg/mL of leaves methanolic extracts against S. pyogenes while the activity of most of the pathogens decreased after 24 h of incubation. The highest antifungal activity was reported at 11.833±1.0 mm against A. ornatus at 50 mg/mL after 48 h of the incubation period. These experimental findings endorse the use of S. alba in ethnopharmacological formulations and suggest the use of methanolic extracts of the said plant to develop drugs to control the proliferation of resistant disease causing pathogenic microbes.


Resumo O presente estudo teve como objetivo manifestar a atividade antibacteriana e antifúngica de extratos metanólicos de Salix alba L. contra sete patógenos bacterianos Gram-positivos e Gram-negativos. Streptococcus pyogenes, Staphylococcus aureus (1), S. aureus (2), Shigella sonnei, Escherichia coli (1), E. coli (2) e Neisseria gonorrhoeae e três isolados de fungos do ar, como Aspergillus terreus, A. ornatus, e Rhizopus stolonifer. Dois sorotipos diferentes de S. aureus e E. coli foram usados. Os resultados do método de difusão em ágar mostraram a resposta dependente da dose de extratos de plantas contra cepas de bactérias e fungos, enquanto alguns organismos foram considerados resistentes, e.g. E. coli (1), S. sonnei, A. terreus e R. stolonifer. A maior atividade antibacteriana foi registrada em 17.000 ± 1.732 de 100 mg/mL de extratos metanólicos de folhas contra S. pyogenes, enquanto a atividade da maioria dos patógenos diminuiu após 24 h de incubação. A maior atividade antifúngica foi relatada em 11,833 ± 1,0 contra A. ornatus a 50 mg/mL após 48 h do período de incubação. Esses achados experimentais endossam o uso de S. alba em formulações etnofarmacológicas e sugerem o uso de extratos metanólicos da referida planta para o desenvolvimento de fármacos que controlem a proliferação de doenças resistentes que causam micróbios patogênicos.


Asunto(s)
Salix , Antifúngicos/farmacología , Aspergillus , Rhizopus , Staphylococcus aureus , Extractos Vegetales/farmacología , Pruebas de Sensibilidad Microbiana , Metanol , Escherichia coli , Antibacterianos/farmacología
6.
Braz. j. biol ; 83: e247016, 2023. tab, graf
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1339416

RESUMEN

Abstract Pheretima posthuma (Vaillant, 1868), a native earthworm of Pakistan and Southeast Asia, has wide utilization in vermicomposting and bioremediation process. In this study, P. posthuma coelomic fluid (PCF) and body paste (PBP) was evaluated as antibacterial agent against ampicillin (AMP) resistant five Gram positive and four Gram negative clinical isolates. The antibacterial effect of different doses (i.e. 25-100 µg/ml) of PCF and PBP along with AMP and azithromycin (AZM) (negative and positive controls, respectively) were observed through disc diffusion and micro-dilution methods. All nine clinical isolates were noticed as AMP resistant and AZM sensitive. Antibacterial effects of PCF and PBP were dose dependent and zone of inhibitions (ZI) against all clinical isolates were between 23.4 ± 0.92 to 0 ± 00 mm. The sensitivity profile of PCF and PBP against clinical isolates was noticed as 44.44 and 55.56%, respectively. Both PCF and PBP showed bacteriostatic (BTS) action against S. aureus, S. pyogenes, K. pneumonia, N. gonorrhoeae. Moreover, the cumulative BTS potential of PCF and PBP against all isolates was 66.67 and 55.56%, respectively. The MICs of PCF and PBP were ranged from 50-200 µg/ml against selected isolates. The bacterial growth curves indicated that PCF and PBP inhibited the growth of all isolates at their specific MIC concentrations. However, PBP has better antibacterial potential compared to PCF against selected isolates. Therefore, it is concluded that both PCF and PBP of P. posthuma possess antibacterial and BTS potential against ampicillin resistant clinical isolates. This organism might be considered as a second choice of antibacterial agents and can further be utilized in pharmaceutical industries for novel drug manufacturing by prospecting bioactive potential agents.


Resumo Pheretima posthuma (Vaillant, 1868), uma minhoca nativa do Paquistão e sudeste da Ásia, tem ampla utilização em processos de vermicompostagem e biorremediação. Neste estudo, o fluido celômico de P. posthuma (PCF) e a pasta corporal (PBP) foram avaliados como agente antibacteriano contra cinco isolados clínicos Gram-positivos e quatro Gram-negativos resistentes à ampicilina (AMP). O efeito antibacteriano de diferentes doses (ou seja, 25-100 µg / ml) de PCF e PBP juntamente com AMP e azitromicina (AZM) (controles negativo e positivo, respectivamente) foi observado por meio de métodos de difusão em disco e microdiluição. Todos os nove isolados clínicos foram notados como resistentes a AMP e sensíveis a AZM. Os efeitos antibacterianos de PCF e PBP foram dependentes da dose e a zona de inibição (ZI) contra todos os isolados clínicos foi entre 23,4 ± 0,92 a 0 ± 00 mm. O perfil de sensibilidade do PCF e PBP contra isolados clínicos foi observado como 44,44% e 55,56%, respectivamente. Tanto o PCF quanto o PBP mostraram ação bacteriostática (BTS) contra S. aureus, S. pyogenes, K. pneumonia, N. gonorrhoeae. Além disso, o potencial BTS cumulativo de PCF e PBP contra todos os isolados foi de 66,67% e 55,56%, respectivamente. Os MICs de PCF e PBP variaram de 50-200 µg / ml contra isolados selecionados. As curvas de crescimento bacteriano indicaram que o PCF e o PBP inibiram o crescimento de todos os isolados em suas concentrações específicas de MIC. No entanto, PBP tem melhor potencial antibacteriano em comparação com PCF contra isolados selecionados. Portanto, conclui-se que tanto o PCF quanto o PBP de P. posthuma possuem potencial antibacteriano e BTS contra isolados clínicos resistentes à ampicilina. Esse organismo pode ser considerado como uma segunda escolha de agentes antibacterianos e pode ainda ser utilizado nas indústrias farmacêuticas para a fabricação de novos medicamentos por meio da prospecção de agentes com potencial bioativo.


Asunto(s)
Animales , Oligoquetos , Staphylococcus aureus , Pruebas de Sensibilidad Microbiana , Ampicilina/farmacología , Antibacterianos/farmacología
7.
Braz. j. biol ; 83: e245585, 2023. tab, graf
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1339413

RESUMEN

Abstract 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.


Resumo Muitos microrganismos do solo, ou seja, bactérias e fungos produzem metabólitos secundários chamados antibióticos. Eles são usados ​​para tratamento de algumas doenças bacterianas, fúngicas e protozoárias em humanos. Há necessidade de isolamento de um amplo espectro de antibióticos de microrganismos devido ao surgimento de resistência aos antibióticos. No presente estudo, duas bactérias produtoras de antibióticos, Klebsiella pneumoniae e Bacillus cereus, foram isoladas da indústria farmacêutica e de ração avícola de Hattar, Haripur, Paquistão. Um total de 10 amostras de resíduos foi coletado de diferentes indústrias (mármore, ghee, sabão, mineral, aço, ração para aves, farmacêutica, Qarshi, cosmética e vidro). Trinta e três cepas bacterianas foram isoladas de resíduos industriais dessas dez diferentes indústrias. Quatorze das 33 cepas bacterianas exibiram atividades antimicrobianas contra pelo menos um dos micróbios de teste considerados neste estudo, incluindo Escherchia coli, Staphylococcus aureus e Salmonella typhi. As bactérias foram isoladas pela técnica de placa de diluição em série padrão. A caracterização morfológica dos isolados foi feita por coloração de gram. Nove isolados bacterianos de 14 foram inicialmente identificados como B. cereus e cinco como K. pneumoniae por meio de caracterização bioquímica. As atividades antibacterianas foram testadas pelo método de difusão em poço. O número máximo de bactérias produtoras de antibióticos foi isolado da indústria farmacêutica e de ração avícola com base nos resultados da triagem primária, os isolados mais potenciais S9, S19, S20, S22 e S23 foram selecionados para a triagem secundária. A atividade máxima contra E. coli e S. aureus foi registrada pelo isolado bacteriano S19, ou seja, zonas de inibição de 6,5 mm e 9 mm, enquanto S20 mostrou zonas de 7,5 mm e 6 mm, respectivamente. A identificação molecular foi realizada com base na análise da sequência 16S rRNA. Finalmente, os isolados foram identificados como B. cereus número de acesso LC538271 e K. pneumoniae número de acesso MT078679. A análise do extrato bacteriano S20 por meio de GC-MS indicou a presença de oito compostos de natureza e estrutura diversas. O presente estudo sugere que resíduos da indústria farmacêutica e de ração para aves podem conter bactérias produtoras de antibióticos. Essas bactérias podem ser utilizadas para a produção de antibióticos B. cereus e K. pneumoniae isolados de resíduos de rações de aves e indústrias farmacêuticas têm potencial para produzir antibióticos e podem ser usados ​​para controlar o crescimento microbiano.


Asunto(s)
Humanos , Staphylococcus aureus , Residuos Industriales , ARN Ribosómico 16S , Extractos Vegetales , Pruebas de Sensibilidad Microbiana , Escherichia coli , Cromatografía de Gases y Espectrometría de Masas , Antibacterianos/farmacología
8.
Braz. j. biol ; 83: e244435, 2023. tab, graf
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1285619

RESUMEN

Abstract Increasing trend in antimicrobial resistance and failure of chemically synthesized antibiotics lead to discover alternative methods for the treatment of bacterial infections. Various medicinal plants are in use traditionally and their active compounds can be further applied for treatment of bacterial diseases. This study was designed to determine the antibacterial activity of Punica granatum (P. granatum L.) (pomegranate) peel extract against Enterobacteriaceae [Escherichia coli (E. coli), Salmonella Typhimurium (S. Typhimurium) and Shigella Dysenteriae (S. Dysenteriae)] and gram-positive bacterium [Staphylococcus aureus (Staph aureus)]. Methanolic extract of P. granatum L. peel was prepared by Soxhlet apparatus method. Total flavonoid and phenolic contents from the extract were determined by High Performance Liquid Chromatography (HPLC). The antibacterial activity of P. granatum L. peel extract was evaluated through agar well diffusion method. HPLC showed the range of phenolics (gallic acid, caffeic acid, benzoic acid, cinnamic acid) and flavonoid compounds. The chemical structures of flavonoid and phenolics found in the methanolic extract of P. granatum L. peel have been reported for the first time. The methanolic peel extract (50 ul) of yellow P. granatum L. showed 26, 10, 10 and 9mm zones of inhibition (ZOI) against S. aureus, S. Typhimurium, S. Dysenteriae and E. coli, respectively. The methanolic extract of red P. granatum L. (100 ul) showed 27, 8, 12 and 15 mm ZOI against Staph. aureus, S. Typhimurium, S. Dysenteriae and E. coli, respectively. Highest ZOI was observed against Staph. aureus. Many of the bacteria studied in the present work may cause serious gastrointestinal infections, which can lead to hemorrhagic diarrhea in children. These infections can be life-threatening to young children and the elderly. There is an incentive to find alternative control measures, such as plant and herbal extracts, especially in lesser-developed countries where traditional antibiotics may not be readily available.


Resumo A tendência crescente na resistência antimicrobiana e na falha dos antibióticos sintetizados quimicamente leva à descoberta de métodos alternativos para o tratamento de infecções bacterianas. Várias plantas medicinais estão em uso tradicionalmente e seus compostos ativos podem ser posteriormente aplicados para o tratamento de doenças bacterianas. Este estudo foi desenhado para determinar a atividade antibacteriana do extrato de casca de Punica granatum (P. granatum L.) (romã) contra Enterobacteriaceae [Escherichia coli (E. coli), Salmonella Typhimurium (S. Typhimurium) e Shigella Dysenteriae (S. Dysenteriae) ] e bactéria gram-positiva [Staphylococcus aureus (Staph aureus)]. O extrato metanólico da casca de P. granatum L. foi preparado pelo método do aparelho de Soxhlet. O conteúdo total de flavonoides e fenólicos do extrato foi determinado por cromatografia líquida de alta eficiência (HPLC). A atividade antibacteriana do extrato da casca de P. granatum L. foi avaliada através do método de difusão em ágar. HPLC mostrou a gama de compostos fenólicos (ácido gálico, ácido cafeico, ácido benzoico, ácido cinâmico) e flavonoides. As estruturas químicas de flavonoides e fenólicos encontradas no extrato metanólico da casca de P. granatum L. foram relatadas pela primeira vez. O extrato metanólico da casca (50 ul) de P. granatum L. amarelo apresentou zonas de inibição (ZOI) de 26, 10, 10 e 9mm contra S. aureus, S. Typhimurium, S. Dysenteriae e E. coli, respectivamente. O extrato metanólico de P. granatum L. vermelho (100 ul) apresentou 27, 8, 12 e 15 mm IOI contra Staph. aureus, S. Typhimurium, S. Dysenteriae e E. coli, respectivamente. O ZOI mais alto foi observado contra Staph. aureus. Muitas das bactérias estudadas no presente trabalho podem causar infecções gastrointestinais graves, que podem levar à diarreia hemorrágica em crianças. Essas infecções podem ser fatais para crianças pequenas e idosos. Há um incentivo para encontrar medidas de controle alternativas, como extratos de plantas e ervas, especialmente em países menos desenvolvidos, onde os antibióticos tradicionais podem não estar prontamente disponíveis.


Asunto(s)
Humanos , Preescolar , Niño , Anciano , Granada (Fruta) , Staphylococcus aureus , Extractos Vegetales/farmacología , Cromatografía Líquida de Alta Presión , Escherichia coli , Antiinfecciosos
9.
Braz. j. biol ; 83: e245807, 2023. tab, graf
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1285613

RESUMEN

Abstract Linum usitatissimum L is a widely used traditionally for multiple ailments. The present research was carried out to explore the antimicrobial, and anti-biofilm activity of crude extract of Linum usitatissimum L (Lu. Cr). Phytochemical and proximate analyses were performed. The bandages of diabetic foot patients were collected from the various hospitals. The bandages were cultured to isolate the bacterial strains present on it. The disc diffusion method was used to identify the antimicrobial potential whereas the minimum inhibitory concentration of the Lu.Cr were also determined. Proximate analysis confirms moisture content 8.33%, ash content 4.33%, crude protein 21.20%, crude fat 49.2% and crude fiber 5.63%. It was revealed that Gram-positive bacteria are most prevalent among all study groups. Lu.Cr possess significant bactericidal potential against S. aureus among all other microbes. Owing to this potential, linseed coated bandages can be used alternatively for the treatment of diabetic foot.


Resumo Linum usitatissimum L é amplamente utilizado tradicionalmente para doenças múltiplas. O presente trabalho foi realizado para explorar a atividade antimicrobiana e antibiofilme do extrato bruto de Linum usitatissimum L (Lu.Cr). Foram realizadas análises fitoquímicas e aproximadas. As ataduras de pacientes diabéticos com pé foram recolhidas nos vários hospitais. As bandagens foram cultivadas para isolar as cepas bacterianas presentes nas mesmas. O método de difusão em disco foi utilizado para identificar o potencial antimicrobiano e a concentração inibitória mínima do Lu.Cr também foi determinada. A análise aproximada confirma o teor de umidade 8,33%, teor de cinzas 4,33%, proteína bruta 21,20%, gordura bruta 49,2% e fibra bruta 5,63%. Foi revelado que as bactérias Gram-positivas são mais prevalentes entre todos os grupos de estudo. Lu.Cr possui potencial bactericida significativo contra S. aureus entre todos os outros micróbios. Devido a esse potencial, as ligaduras revestidas com linhaça podem ser utilizadas alternativamente para o tratamento do pé diabético.


Asunto(s)
Humanos , Pie Diabético/tratamiento farmacológico , Lino , Diabetes Mellitus , Staphylococcus aureus , Extractos Vegetales/farmacología , Pruebas de Sensibilidad Microbiana , Biopelículas , Metanol
10.
Food Microbiol ; 109: 104119, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36309431

RESUMEN

Photocatalysts, including titanium dioxide (TiO2), have attracted much attention in food safety for controlling foodborne pathogens. However, the study of the photocatalytic activity on various food-surrounding media and the factors that affect the efficacy of photocatalytic inactivation is incomplete. In this study, to inactivate foodborne pathogens in food-surrounding environments, TiO2-based photocatalysts with ultraviolet A (UVA, 365 nm) and visible light (VIS, 405 nm) were employed. Three TiO2-based photocatalysts, namely, Degussa P25 TiO2, carbon-modified KRONOClean 7000® (C-TiO2), and Pt-doped Ishihara-Sangyo MPT-623 (Pt-TiO2) inactivated Staphylococcus aureus and Escherichia coli O157:H7 exposed to UVA and VIS light in both water and air samples. Among them, Degussa P25 under UVA showed the highest bactericidal effects in both water and air treatments, which induced 5.19 log reductions in S. aureus when treated for 11.68 J/cm2, and E. coli O157:H7 was reduced by more than 6.21 log for 1.32 J/cm2 in the water sample. For air treatment, the combination of Degussa P25 and UVA achieved 3.45 and 3.28 log reductions for Staphylococcus aureus and E. coli O157:H7, respectively, in a developed laboratory-scale chamber for 1 h and 20.02 J/cm2. Scavenger assays showed that regardless of the photocatalyst and wavelength used, reactive oxygen species (ROS) generation causes cell membrane disruption of foodborne pathogens. However, the types of ROS that are generated vary among the photocatalysts and are related to different bactericidal efficacies. These results indicated that TiO2-based photocatalytic activity can be used to control microbiological hazards in various environments in the food industry.


Asunto(s)
Escherichia coli O157 , Infecciones Estafilocócicas , Humanos , Staphylococcus aureus , Especies Reactivas de Oxígeno , Antibacterianos/farmacología , Agua/farmacología , Membrana Celular , Recuento de Colonia Microbiana
11.
J Hazard Mater ; 442: 130112, 2023 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-36303348

RESUMEN

Rifampicin (RIF) resistance imposes a challenge on the antimicrobial treatment of pathogen infections. Figuring out the development mechanism of RIF resistance is critical to improving antimicrobial therapy strategy in clinics and biological treatment strategy of RIF polluted sewage in environmental engineering. The RIF resistance development of Staphylococcus aureus (S. aureus) with exposure to RIF at sub-inhibitory concentrations was comprehensively investigated via genomic and transcriptomic approaches in this study. RIF minimal inhibitory concentration (MIC) for S. aureus rapidly increased from 0.032 to 256 mg/L. Membrane permeability decrease, biofilm formation enhancement, and ROS production increase associated with RIF resistance were observed in RIF-induced strains. Through comparative genomic analysis, mutations in rpoB and rpoC were considered to be associated with RIF resistance in S. aureus mutants. Pan-genome-wide single-nucleotide variant analysis indicated that mutations at rpoB-1412, rpoB-1451, and rpoB-1457 were prevalent in 13849 public genomes of S. aureus, while mutations at rpoB-2256, and rpoC-3092 were first discovered in this study. The panorama of adaptative alteration of cellular physiological processes was observed via transcriptomic analysis. The oxidation pressure responses, metabolism, transporters, virulence factors, and multiple steps of DNA and RNA machinery were found to be perturbed by RIF in S. aureus.


Asunto(s)
Rifampin , Staphylococcus aureus , Rifampin/farmacología , Staphylococcus aureus/genética , Farmacorresistencia Bacteriana/genética , Transcriptoma , ARN Polimerasas Dirigidas por ADN/genética , ARN Polimerasas Dirigidas por ADN/farmacología , Pruebas de Sensibilidad Microbiana , Antibacterianos/farmacología , Mutación , Genómica , Proteínas Bacterianas/genética
12.
Methods Mol Biol ; 2575: 261-268, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36301479

RESUMEN

Genome alteration results in several diseases for which therapeutics are limited. Gene editing provides a strong and potential alternative for the treatment of rare and genetic diseases. CRISPR-Cas9-based system is now being envisaged as a potential tool for the cure of genetic diseases. The RNA-guided nuclease, SaCas9 enzyme, along with its HF versions is widely employed for in vivo gene editing because of its small size and high efficiency. The current work summarizes the widely used and improved methods for in vivo manipulation of genes. The potential of CRISPR-Cas9-based systems can be harnessed to treat genetic diseases and holds great promise for therapeutic interventions in gene therapy. The in vivo gene editing poses a caveat in the form of delivery systems, the tissue in question, and several other factors. This work describes the methods which have been optimized to offer high efficiency, delivery, and gene editing in vivo.


Asunto(s)
Sistemas CRISPR-Cas , Staphylococcus aureus , Sistemas CRISPR-Cas/genética , Staphylococcus aureus/metabolismo , Edición Génica/métodos , Terapia Genética , Endonucleasas/genética
13.
Int J Food Microbiol ; 384: 109963, 2023 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-36274385

RESUMEN

A mixed solid matrix of the depolymerized pectin (DP) and rice protein (RP) were investigated to improve the antibacterial activity of star anise essential oil (SAEO) through microencapsulation. The encapsulation was undertaken via electrostatic complexation method followed by spray drying. Under the optimized conditions, SAEO microcapsules with 92.2 % encapsulation efficiency was acquired at 3:2 of DP-to-RP, 1:3 of DP-to-SAEO and pH 4.0. DP-RP/SAEO microcapsules exhibited a spherical-shaped particle with smaller particle size, and sustained release. FTIR and morphology analysis confirmed that SAEO was successfully encapsulated in the solid matrix of microcapsules. DP-RP/SAEO microcapsules caused the destruction of cytomembranes and reduction of membrane proteins, which led to the alteration of cell membrane fluidity and integrity. Meanwhile, DP-RP/SAEO microcapsules repressed the key enzyme in tricarboxylic acid (TCA) and Hexose monophosphate pathway (HMP) cycle pathway of E. coli, S. aureus. The application experiments indicated DP-RP/SAEO microcapsules can effectively control the growth of E. coli and S. aureus in crab meatballs.


Asunto(s)
Braquiuros , Illicium , Aceites Volátiles , Oryza , Animales , Cápsulas , Pectinas/farmacología , Staphylococcus aureus , Electricidad Estática , Escherichia coli , Antibacterianos/farmacología , Aceites Volátiles/farmacología
14.
Food Chem ; 403: 134219, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36156402

RESUMEN

The antibacterial films prepared from high amylose corn starch-cinnamaldehyde (HACS-CIN) inclusion complex were reported in this work and the different structural, mechanical, physicochemical and antibacterial properties of the films were investigated. The FT-IR results supported that the CIN was encapsulated in the helical structure of HACS by self-assembly. The encapsulation efficiency was as high as 39.19%, and the releasing rate results showed HACS-CIN inclusion films could slow down the volatilization of CIN. The films showed excellent mechanical properties with tensile strength of 14.77 MPa and elongation at break of 44.95%; and good transparency with visible light transmittance of 70%. UV transmittance test showed good UV-blocking property with UV light transmittance of 30%. Antibacterial test indicated an inhibitory effect on S. aureus and E. coli. Strawberry preservation experiment showed the films delayed the shelf life of strawberries. This work provides the HACS-CIN inclusion films are potential candidates for biodegradable food packaging.


Asunto(s)
Amilosa , Almidón , Amilosa/química , Almidón/química , Embalaje de Alimentos/métodos , Zea mays/química , Staphylococcus aureus , Escherichia coli , Espectroscopía Infrarroja por Transformada de Fourier , Antibacterianos/farmacología , Antibacterianos/química
15.
Chemosphere ; 310: 136888, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36265706

RESUMEN

The bioaccumulation, non-biodegradability, and high toxicity of Cd(II) and U(VI) in water is a serious concerns. Manganese ferrite/graphene oxide (GMF) nanocomposites were synthesized, characterized, and used to efficiently remove Cd(II) and U(VI) from an aqueous solution in this study. X-ray diffraction (XRD) and X-ray photoemission spectroscopy (XPS) analyses, respectively, confirmed the formation of GMF and the adsorptive removal mechanism. The XRD results revealed an amorphous structure when MnFe2O4 was loaded onto the GO surface. XPS results suggest that C = C, C-OorOH, and metal oxides are responsible for the removal of Cd(II) and U(VI) via electrostatic and chemical interaction. According to the Brunauer Emmett and Teller (BET), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) characterization analysis, GMF has a high surface area (117.78 m2/g) and a spherical shape with even distribution. The kinetics data were successfully reproduced by a pseudo-second-order non-linear model indicating the complexity of the sorption mechanism was rate-limiting. The maximum Langmuir uptake ability of GMF for Cd(II) and U(VI) was calculated to be 232.56 mg/g and 201.65 mg/g, respectively. Using external magnetic power, the prepared GMF can easily separate from the aqueous solution and can keep both metal ions under Environmental protection agency standards in water for up to six cycles of re-use of GMF. Finally, the GMF nanocomposite demonstrated significant promise as an adsorbent for removing Cd(II) and U(VI) from actual contaminated water samples. The antibacterial test was expanded to include gram-negative E. coli and gram-positive S. aureus to better understand GMF's bacterial inhibition efficacy.


Asunto(s)
Cadmio , Contaminantes Químicos del Agua , Adsorción , Antibacterianos/farmacología , Antibacterianos/análisis , Cadmio/análisis , Escherichia coli , Cinética , Staphylococcus aureus , Agua/química , Contaminantes Químicos del Agua/análisis
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 285: 121838, 2023 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-36108407

RESUMEN

Chicken is at risk of contaminated foodborne pathogens in the production process. Timely and nondestructive detection of foodborne pathogens in chicken is essential for food security. The study aims to explore the feasibility of developing efficient classification models for qualitative detection of Staphylococcus aureus in chicken breast using the hyperspectral imaging technique. Principal component analysis was used to process the full spectral information and three wavelength selection methods (competitive adaptive reweighted sampling, genetic algorithm, and successive projections algorithm) were applied to extract effective wavelengths. These methods were combined with the support vector machine algorithm to develop conventional classification models, respectively. In addition, a convolutional neural network model based on deep learning was designed and trained for comparison. The performance of the convolutional neural network model was significantly better than that of conventional classification models. The overall accuracy for chicken sample classifications was improved from 83.88% to 91.38%. The results demonstrated that deep learning can effectively extract spectral features and promote the application of hyperspectral imaging in foodborne pathogens detection of chicken products.


Asunto(s)
Imágenes Hiperespectrales , Staphylococcus aureus , Animales , Pollos , Espectroscopía Infrarroja Corta/métodos , Máquina de Vectores de Soporte
17.
Spectrochim Acta A Mol Biomol Spectrosc ; 285: 121830, 2023 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-36179567

RESUMEN

Rapid, sensitive and simultaneous detection of multiple bacteria in foodborne is still a major challenge in public health field. Here, a fluorescence immunoassay that can achieve high-throughput detection of three Gram-positive foodborne pathogenic bacteria simultaneously was proposed. Vancomycin and bovine serum albumin conjugate (Van-BSA) was immobilized on a polycarbonate chip to capture three Gram-positive foodborne pathogenic bacteria, Staphylococcus aureus (S. aureus), Bacillus cereus (B. cereus) and Listeria monocytogenes (L. monocytogenes). CdSe/ZnS quantum dot modified antibodies (Ab-QD) were prepared by carbodiimide coupling chemistry. Due to the affinity reaction between antibodies and proteins on the bacterial surface, the simultaneous detection of multiple Gram-positive bacteria was achieved by monitoring the fluorescence signal of quantum dot by a portable microfluidic chip analyzer. Under optimal conditions, low detection limits was 18 CFU/well, 3 CFU/well and 36 CFU/well for S. aureus, B. cereus and L. monocytogenes, respectively. With satisfactory accuracy and precision, the proposed fluorescence immunoassay holds good prospects to detect pathogens in real food samples.


Asunto(s)
Listeria monocytogenes , Infecciones Estafilocócicas , Humanos , Animales , Leche , Microbiología de Alimentos , Staphylococcus aureus , Inmunoensayo
18.
Talanta ; 252: 123821, 2023 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-36027620

RESUMEN

As one of the major foodborne pathogens, Staphylococcus aureus (S. aureus) can cause infectious diseases. In the current study, a novel electrochemical biosensor based on saltatory rolling circle amplification (SRCA) combined with CRISPR/Cas12a system was developed for the accurate detection of S. aureus. The thio-modified reporter probes (SH-ssDNA-MB) was immobilized on the surface of gold nanoparticle-modified electrode through the Au-S bond. In the presence of S. aureus, the target DNA double strands obtained by SRCA can be specifically recognized with Cas12a/crRNA complex. The trans-cleavage activity of Cas12a induces SH-ssDNA-MB to be cleaved from the electrode surface, resulting in a decrease in the current signal. Subsequently, the ratio of the current can be calculated as the detection result. Under optimal conditions, the detection limits were 2.51 fg/µL for genomic DNA and 3 CFU/mL for S. aureus in pure cultures, respectively. Moreover, the method demonstrated satisfactory specificity, acceptable stability and reproducibility. In comparison with ISO methods, the sensitivity, specificity and accuracy of the developed method were 100%, 97.8% and 98%, respectively. In conclusion, the developed novel electrochemical biosensor provides a potential powerful platform for the accurate detection of S. aureus.


Asunto(s)
Técnicas Biosensibles , Nanopartículas del Metal , Infecciones Estafilocócicas , Humanos , Staphylococcus aureus/genética , Sistemas CRISPR-Cas , Oro/química , Límite de Detección , Reproducibilidad de los Resultados , Técnicas Biosensibles/métodos , Infecciones Estafilocócicas/diagnóstico , ADN/química , ADN de Cadena Simple
19.
Biochim Biophys Acta Gen Subj ; 1867(1): 130253, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36228877

RESUMEN

BACKGROUND: Cells exposed to stress factors experience time-dependent variations of metabolite concentration, acting as reliable sensors of the effective concentration of drugs in solution. NMR can detect and quantify changes in metabolite concentration, thus providing an indirect estimate of drug concentration. The quantification of bactericidal molecules released from antimicrobial-treated biomedical materials is crucial to determine their biocompatibility and the potential onset of drug resistance. METHODS: Real-time NMR measurements of extracellular metabolites produced by bacteria grown in the presence of known concentrations of an antibacterial molecule (irgasan) are employed to quantify the bactericidal molecule released from antimicrobial-treated biomedical devices. Viability tests assess their activity against E. coli and S. aureus planktonic and sessile cells. AFM and contact angle measurements assisted in the determination of the mechanism of antibacterial action. RESULTS: NMR-derived concentration kinetics of metabolites produced by bacteria grown in contact with functionalized materials allows for indirectly evaluating the effective concentration of toxic substances released from the device, lowering the detection limit to the nanomolar range. NMR, AFM and contact angle measurements support a surface-killing mechanism of action against bacteria. CONCLUSIONS: The NMR based approach provides a reliable tool to estimate bactericidal molecule release from antimicrobial materials. GENERAL SIGNIFICANCE: The novelty of the proposed NMR-based strategy is that it i) exploits bacteria as sensors of the presence of bactericidal molecules in solution; ii) is independent of the chemo-physical properties of the analyte; iii) establishes the detection limit to nanomolar concentrations.


Asunto(s)
Antiinfecciosos , Staphylococcus aureus , Escherichia coli , Antibacterianos/farmacología , Antibacterianos/química , Bacterias , Antiinfecciosos/farmacología
20.
Food Chem ; 404(Pt B): 134653, 2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-36327513

RESUMEN

Accurate and fast on-site detection of harmful microorganisms in food products is a key preventive step to avoid food-borne illness and product recall. In this study, screen-printed electrodes (SPEs) were functionalized via a facile strategy with surface imprinted polymers (SIPs). The SIP-coated SPEs were used in combination with the heat transfer method (HTM) for the real-time detection of Escherichia coli. The sensor was tested in buffer, with a reproducible and sensitive response that attained a limit of detection of 180 CFU/mL. Furthermore, selectivity was assessed by analyzing the sensor's response to C. sakazakii, K. pneumoniae and S. aureus as analogue strains. Finally, the device was successfully used for the detection of E. coli in spiked milk as proof-of-application, requiring no additional sample preparation. These results suggest the proposed thermal biosensor possesses the potential of becoming a tool for routine, on-site monitoring of E. coli in food safety applications.


Asunto(s)
Técnicas Biosensibles , Escherichia coli , Staphylococcus aureus , Electrodos , Técnicas Biosensibles/métodos , Productos Lácteos , Límite de Detección
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