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1.
Int J Food Microbiol ; 338: 108952, 2021 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-33229046

RESUMO

This study tested the hypothesis that growth of Listeria monocytogenes in processed cheese with added nisin can be predicted from residual nisin A concentrations in the final product after processing. A LC-MS/MS method and a bioassay were studied to quantify residual nisin A concentrations and a growth and growth boundary model was developed to predict the antilisterial effect in processed cheese. 278 growth rates were determined in broth for 11 L. monocytogenes isolates and used to determine 13 minimum inhibitory concentration (MIC) values for nisin between pH 5.5 and 6.5. To supplement these data, 67 MIC-values at different pH-values were collected from the scientific literature. A MIC-term was developed to describe the effect of pH on nisin MIC-values. An available growth and growth boundary model (doi: https://doi.org/10.1016/j.fm.2019.103255) was expanded with the new MIC-term for nisin to predict growth in processed cheese. To generate data for model evaluation and further model development, challenge tests with a total of 45 growth curves, were performed using processed cheese. Cheeses were formulated with 11.2 or 12.0 ppm of nisin A and heat treated to obtain residual nisin A concentrations ranging from 0.56 to 5.28 ppm. Below 15 °C, nisin resulted in extended lag times. A global regression approach was used to fit all growth curves determined in challenge tests. This was obtained by combining the secondary growth and growth boundary model including the new term for the inhibiting effect of nisin on µmax with the primary logistic growth model with delay. This model appropriately described the growth inhibiting effect of residual nisin A and showed that relative lag times depended on storage temperatures. With residual nisin A concentrations, other product characteristics and storage temperature as input the new model correctly predicted all observed growth and no-growth responses for L. monocytogenes. This model can support development of nisin A containing recipes for processed cheese that prevent growth of L. monocytogenes. Residual nisin A concentrations in processed cheese were accurately quantified by the developed LC-MS/MS method with recoveries of 83 to 110% and limits of detection and quantification being 0.04 and 0.13 ppm, respectively. The tested bioassay was less precise and nisin A recoveries varied for 53% to 94%.


Assuntos
Queijo , Microbiologia de Alimentos , Listeria monocytogenes/efeitos dos fármacos , Modelos Biológicos , Nisina/análise , Nisina/farmacologia , Anti-Infecciosos/análise , Anti-Infecciosos/farmacologia , Queijo/análise , Queijo/microbiologia , Cromatografia Líquida , Espectrometria de Massas em Tandem , Temperatura
2.
Food Chem ; 339: 127882, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32889131

RESUMO

Unconventional parts of vegetables represent a rich source of health-promoting phytochemicals. The phenolic profile of cabbage-stalk flour (CSF), pineapple-crown flour (PCF), and their essential oils were characterized via UPLC-ESI-QTOF-MSE and GC-FID/MS. Antimicrobial activity was tested against five strains, and antioxidant activities were determined in free and bound extracts. Globally, 177 phenolics were tentatively identified in PCF (major p-coumaric acid, ferulic acid, and 4-hydroxybenzaldehyde) and 56 in CSF (major chlorogenicacid, quercetin 3-O-glucuronide, and p-coumaric acid). PCF exhibited a distinguished profile (lignans, stilbenes) and antioxidant capacity, especially in bound extracts (1.3 g GAE.100 g-1; 0.6 g catechin eq.100 g-1; DPPH: 244.7; ABTS: 467.8; FRAP: 762.6 µg TE.g-1, ORAC: 40.9 mg TE.g-1). The main classes of volatile compounds were fatty acids, their esters, and terpenes in CSF (30) and PCF (41). A comprehensive metabolomic approach revealed CSF and PCF as a promising source of PC, showing great antioxidant and discrete antimicrobial activities.


Assuntos
Ananas/química , Anti-Infecciosos/análise , Antioxidantes/química , Brassica/química , Farinha/análise , Fenóis/química , Compostos Orgânicos Voláteis/química , Ananas/metabolismo , Anti-Infecciosos/farmacologia , Brassica/metabolismo , Cromatografia Líquida de Alta Pressão , Análise Discriminante , Cromatografia Gasosa-Espectrometria de Massas , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Óleos Voláteis/análise , Óleos Voláteis/química , Fenóis/análise , Fenóis/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Análise de Componente Principal , Espectrometria de Massas por Ionização por Electrospray , Compostos Orgânicos Voláteis/análise
3.
Food Chem ; 334: 127603, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32712492

RESUMO

Present work comprises the use of different solid-state Nuclear Magnetic Resonance strategies for characterizing structural and motional aspects of the peptide matrix that compose a set of four lyophilized Mexican cheese aqueous soluble extracts, each with a controlled ripening. Heteronuclear dipolar coupling modulation schemes allowed to characterize local mobility and structural homogeneity of cheeses' peptide segments in the solid-state as a function of ripening. Results suggest that ripened samples with certain local flexibility but important structural homogeneity present efficient microbial inhibition against tested bacterial strains, whilst high local rigidity of peptides within ripened cheese soluble fractions could partially explain the observed lack of antimicrobial activity. The present study attempts to propose novel observables for lyophilized cheese water soluble extracts that could be partially associated to their ripening-dependent antimicrobial activities, whereas said observables shall contribute to the better targeting, design and optimization of solid-state natural food bio-preservatives.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Queijo , Espectroscopia de Ressonância Magnética/métodos , Anti-Infecciosos/análise , Isótopos de Carbono , Queijo/análise , Liofilização , Testes de Sensibilidade Microbiana , Peptídeos/análise , Peptídeos/química , Peptídeos/farmacologia , Solubilidade , Água
4.
Food Chem ; 334: 127562, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32707368

RESUMO

Brown seaweeds are traditionally used as food in Asian countries, and they are a valuable source of bioactive compounds. Herein, a novel high-throughput methodological approach was developed for the tracing of compounds with radical scavenging and antimicrobial activities in Saccharina japonica and Undaria pinnatifida methanol extracts. The seaweed metabolites were separated by a novel high-performance thin-layer chromatography method, the bioactive bands were identified by bioautography assays. The bioactive compounds were characterized with ultra-high-performance liquid chromatography coupled with linear trap quadrupole tandem mass spectrometry. Stearidonic, eicosapentaenoic, and arachidonic acids were identified as major components having radical scavenging and antimicrobial activities. The suggested method provides a fast identification and quantification of bioactive compounds in multicomponent biological samples.


Assuntos
Anti-Infecciosos/análise , Cromatografia em Camada Delgada/métodos , Alga Marinha/química , Espectrometria de Massas em Tandem/métodos , Anti-Infecciosos/química , Ácidos Araquidônicos/análise , Ácidos Araquidônicos/farmacologia , Ácido Eicosapentaenoico/análise , Ácido Eicosapentaenoico/farmacologia , Ácidos Graxos Ômega-3/análise , Ácidos Graxos Ômega-3/farmacologia , Depuradores de Radicais Livres/química , Depuradores de Radicais Livres/farmacologia , Cromatografia Gasosa-Espectrometria de Massas , Ensaios de Triagem em Larga Escala/métodos , Laminaria/química , Laminaria/metabolismo , Alga Marinha/metabolismo , Undaria/química , Undaria/metabolismo
5.
Arch Environ Contam Toxicol ; 79(4): 488-499, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33215293

RESUMO

Personal care product (PCP) chemicals have a greater chance of accumulation in the aquatic environments because of their volume of use. PCPs are biologically active substances that can exert an adverse effect on the ecology and food safety. Information on the status of these substances in Indian open water ecosystems is scarce. In this paper, we report the incidence of two synthetic antimicrobials, triclosan (TCS), including its metabolite methyl-triclosan (Me-TCS) and triclocarban (TCC) in Torsa, a transboundary river flowing through India. In water TCS and TCC were detected at levels exceeding their respective PNEC (Predictive No Effect Concentration). Both the compounds were found to be bioaccumulative in fish. TCS concentration (91.1-589 µg/kg) in fish was higher than that of TCC (29.1-285.5 µg/kg). The accumulation of residues of the biocides varied widely among fishes of different species, ecological niche, and feeding habits. Me-TCS could be detected in fishes and not in water. The environmental hazard quotient of both TCS and TCC in water indicated a moderate risk. However, the health risk analysis revealed that fishes of the river would not pose any direct hazard to human when consumed. This is the first report of the occurrence of these PCP chemicals in a torrential river system of the eastern Himalayan region.


Assuntos
Anti-Infecciosos/análise , Carbanilidas/análise , Monitoramento Ambiental , Triclosan/análogos & derivados , Poluentes Químicos da Água/análise , Animais , Desinfetantes , Ecossistema , Peixes , Humanos , Índia , Rios/química , Segurança , Triclosan/análise , Água/análise
6.
Ecotoxicol Environ Saf ; 206: 111371, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32979719

RESUMO

Antibiotics, antimicrobial resistance determinants and human pathogens are new types of environmental pollutants that pose a great threat to human health. Wastewater treatment plants (WWTPs) are important sources of novel pollutants; however, few studies have investigated their impact on surrounding natural water. Therefore, this study used a WWTP as the entry point to explore WWTP removal efficiency of antibiotics, antimicrobial resistance determinants and human pathogens and further analyze the impact of WWTP effluent on receiving waters. The investigated WWTP had a good removal effect on fluoroquinolones, macrolides, lincomycin, sulfanilamide, tetracycline and chloramphenicol antibiotics in wastewater, and the concentration of antibiotics in the WWTP's effluent was reduced by >80% relative to the influent. In addition to cmlA, the effect of the WWTP on antimicrobial resistance determinants removal was poor, although the effluent from the WWTP had no effect on the abundance of antimicrobial resistance determinants in the receiving water. However, with the dilution of receiving water, the abundance of antimicrobial resistance determinants gradually decreased. The WWTP could reduce the abundance of bacteria by 1000 times from influent water to effluent water. The major bacteria in the influent and effluent were Bacteroidetes and Proteobacteria. After effluent is discharged into receiving water, Cyanobacteria proliferate in large quantities, which can affect the microbial structure in the environment.The abundance of Acinetobacter, which was the predominant potential human pathogen in local wastewater, decreased dramatically after wastewater treatment. We also conducted an ecological risk assessment of the antibiotics identified and found that the ecological risk AZM and CLR posed to aquatic organisms was high. Overall, we identified the efficiency of WWTP control of antibiotics, antimicrobial resistance determinants and potential human pathogens and the impact of WWTP effluent on receiving water and provided data to support the control of the investigated pollutants.


Assuntos
Bactérias/isolamento & purificação , Farmacorresistência Bacteriana , Águas Residuárias/microbiologia , Microbiologia da Água , Purificação da Água , Anti-Infecciosos/análise , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/farmacologia , Bactérias/classificação , Bactérias/efeitos dos fármacos , China , Humanos , Medição de Risco , Águas Residuárias/química , Poluentes Químicos da Água/análise , Purificação da Água/estatística & dados numéricos
7.
PLoS One ; 15(8): e0231685, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760069

RESUMO

Mycobacterium ulcerans, a non-tuberculous mycobacterium responsible for Buruli ulcer, resides in poorly defined environmental niches in the vicinity of stagnant water. Very few isolates have been confirmed. With a view to culturing M. ulcerans from such contaminated environmental specimens, we tested the in vitro susceptibility of the M. ulcerans CU001 strain co-cultivated with XTC cells to anti-infectious molecules registered in the French pharmacopoeia. We used a standardised concentration to identify molecules that were inactive against M. ulcerans and which could be incorporated into a decontaminating solution. Of 116 tested molecules, 64 (55.1%) molecules were ineffective against M. ulcerans CU001. These included 34 (29.3%) antibiotics, 14 (12%) antivirals, eight (6.8%) antiparasitics, and eight (6.8%) antifungals. This left 52 molecules which were active against M. ulcerans CU001. Three of the inactive antimicrobial molecules (oxytetracycline, polymyxin E and voriconazole) were then selected to prepare a decontamination solution which was shown to respect M. ulcerans CU001 viability. These three antimicrobials could be incorporated into a decontamination solution to potentially isolate and culture M. ulcerans from environmental samples.


Assuntos
Anti-Infecciosos/análise , Mycobacterium ulcerans/crescimento & desenvolvimento , Mycobacterium ulcerans/isolamento & purificação , Úlcera de Buruli/microbiologia , Colistina , Humanos , Programas de Rastreamento , Testes de Sensibilidade Microbiana/métodos , Mycobacterium , Mycobacterium ulcerans/patogenicidade , Oxitetraciclina , Voriconazol
8.
Cell Mol Biol (Noisy-le-grand) ; 66(1): 20-26, 2020 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-32359378

RESUMO

Moringa oleifera is a tree native to tropical and subtropical regions of South India and used in traditional medicine. The aim of this study was characterize the phytochemicals present in M. oleifera leaf extracts and study their antimicrobial activities. Solvent extractions with Soxhlet apparatus of leaves were obtained using hexane, benzene, isopropanol, methanol, and water. The crude extracts were concentrated and screened for qualitative phytochemical analysis, and the antibacterial, antifungal and antiviral activities of crude extracts were measured by in vitro methods. Alkaloids, carbohydrates, tannins, phenolic compounds, terpenoids, cardiac glycosides, amino acids, oils and fats were found in the different crude extracts analyzed. Water and methanol extracts showed antibacterial activity against all selected bacteria, hexane and benzene extracts showed antifungal activity against all fungi tested, and hexane, benzene and isopropanol extracts showed activity against Hepatitis B virus. In conclusion, the leaves of M. oleifera have antimicrobial phytochemicals.


Assuntos
Anti-Infecciosos/análise , Anti-Infecciosos/farmacologia , Avaliação Pré-Clínica de Medicamentos , Moringa oleifera/química , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Folhas de Planta/química , Antifúngicos/farmacologia , Antivirais/farmacologia , Bactérias/efeitos dos fármacos , Misturas Complexas , Fungos/efeitos dos fármacos , Células Hep G2 , Vírus da Hepatite B/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Solventes
9.
Proc Natl Acad Sci U S A ; 117(22): 12444-12451, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32393619

RESUMO

Antibiotic resistance and viral diseases are rising around the world and are becoming major threats to global health, food security, and development. One measure that has been suggested to mitigate this crisis is the development of new antibiotics. Here, we provide a comprehensive evaluation of the phylogenetic and biogeographic patterns of antiinfective compounds from seed plants in one of the most species-rich regions on Earth and identify clades with naturally occurring substances potentially suitable for the development of new pharmaceutical compounds. Specifically, we combine taxonomic and phylogenetic data for >7,500 seed plant species from the flora of Java with >16,500 secondary metabolites and 6,255 georeferenced occurrence records to 1) identify clades in the phylogeny that are characterized by either an overrepresentation ("hot clades") or an underrepresentation ("cold clades") of antiinfective compounds and 2) assess the spatial patterns of plants with antiinfective compounds relative to total plant diversity across the region. Across the flora of Java, we identify 26 "hot clades" with plant species providing a high probability of finding antibiotic constituents. In addition, 24 "cold clades" constitute lineages with low numbers of reported activities but which have the potential to yield novel compounds. Spatial patterns of plant species and metabolite diversity are strongly correlated across Java, indicating that regions of highest species diversity afford the highest potential to discover novel natural products. Our results indicate that the combination of phylogenetic, spatial, and phytochemical information is a useful tool to guide the selection of taxa for efforts aimed at lead compound discovery.


Assuntos
Anti-Infecciosos/análise , Chumbo/análise , Filogenia , Plantas/química , Plantas/genética , Anti-Infecciosos/metabolismo , Biodiversidade , Chumbo/metabolismo , Plantas/classificação , Plantas/metabolismo
10.
Int J Food Microbiol ; 325: 108645, 2020 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-32353648

RESUMO

In this study, we focus on the antimicrobial properties of tempeh, a soybean fermented food, against oral bacteria. Tempeh showed antimicrobial activity against dental caries pathogenic bacterium Streptococcus mutans at a final concentration of 1 mg/mL. An antimicrobial substance contained in tempeh was present in the 100 kDa or greater fraction generated by ultrafiltration, but it was found not to be proteinaceous by native-PAGE, SDS-PAGE and protein degradation tests. Next, when the fraction was purified with an ODS column, the 80% and 100% methanol eluates showed antimicrobial activity against S. mutans. The 100% methanol eluate was further subjected to a 2nd column purification, and isolation of the target was confirmed by HPLC. When the isolated material was analyzed by ESI-MS, the m/z was 279.234. Further analysis by Raman spectroscopy revealed a peak similar to linoleic acid. This substance also possessed antimicrobial properties equivalent to linoleic acid.


Assuntos
Anti-Infecciosos/isolamento & purificação , Extratos Vegetais/farmacologia , Rhizopus/metabolismo , Soja/metabolismo , Streptococcus mutans/efeitos dos fármacos , Anti-Infecciosos/análise , Cárie Dentária/microbiologia , Cárie Dentária/prevenção & controle , Fermentação , Alimentos e Bebidas Fermentados/análise , Alimentos de Soja/análise , Soja/microbiologia
11.
Food Chem ; 321: 126726, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32259735

RESUMO

2-Isopropylmalic acid (2-IPMA) and 3-isopropylmalic acid (3-IPMA), recently discovered in wines, were simultaneously quantified in forty wines by UHPLC-MS/MS triple quadrupole. Principal component analysis displayed that red wines were more correlated with high amounts of 2-IPMA (average content 31.60 mg/L); white wines were mostly characterized by low levels of both organic acids. No correlation of theirs levels to other wine features (wine ageing or alcoholic content) were found. 2-IPMA and 3-IPMA showed MICs values of 4096 mg/L and MBCs values of 8192 mg/L or higher against several food borne pathogens. In association, an interesting lower MIC and MBC values (2048 mg/L and 4096 mg/L respectively) were observed against Y. enterocolitica. Interestingly, 3-IPMA showed a mild antioxidant activity by DPPH assay (EC50 = 3940 mg/L), higher than that of 2-IPMA (EC50 > 4800 mg/L). No toxicity of these compounds against human colorectal and liver cells (TB assay) was observed.


Assuntos
Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Análise de Alimentos/métodos , Malatos/análise , Vinho/análise , Anti-Infecciosos/análise , Antioxidantes/análise , Células CACO-2 , Cromatografia Líquida de Alta Pressão , Células Hep G2 , Humanos , Itália , Malatos/farmacologia , Testes de Sensibilidade Microbiana , Espectrometria de Massas em Tandem , Testes de Toxicidade
12.
Molecules ; 25(5)2020 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-32138320

RESUMO

Antimicrobially active packaging has emerged as an effective technology to reduce microbial growth in food products increasing both their shelf-life and microbial safety for the consumer while maintaining their quality and sensorial properties. In the last years, a great effort has been made to develop more efficient, long-lasting and eco-friendly antimicrobial materials by improving the performance of the incorporated antimicrobial substances. With this purpose, more effective antimicrobial compounds of natural origin such as bacteriocins, bacteriophages and essential oils have been preferred over synthetic ones and new encapsulation strategies such as emulsions, core-shell nanofibres, cyclodextrins and liposomes among others, have been applied in order to protect these antimicrobials from degradation or volatilization while trying to enable a more controlled release and sustained antimicrobial action. On that account, this article provides an overview of the types of antimicrobials agents used and the most recent trends on the strategies used to encapsulate the antimicrobial agents for their stable inclusion in the packaging materials. Moreover, a thorough discussion regarding the benefits of each encapsulation technology as well as their application in food products is presented.


Assuntos
Embalagem de Alimentos/métodos , Anti-Infecciosos/análise , Emulsões , Nanopartículas Metálicas/análise , Óleos Voláteis/análise
13.
J Appl Microbiol ; 129(2): 296-310, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32145138

RESUMO

AIMS: A multidisciplinary approach was used to compare phenolic composition, radical scavenging and antimicrobial activity of propolis samples from different geographical localities, and plant resin against various microorganisms. METHODS AND RESULTS: Using UHPLC-qqqMS quantitative analysis, 28 phenolic compounds were determined. Caffeic and p-coumaric acids were identified as main phenolic acids in poplar propolis samples, except samples from Russia (P6) and China (P7). Radical scavenging activity (applying DPPH spectrophotometric assay) showed the highest activity of Serbian (40·51%) and Chinese (53·21%) propolis samples. Broth microdilution method was used for the oral cavity, fungal phytopathogenic and human vaginal isolates which have been identified at a molecular level. The most sensitive bacterial isolates were Lactobacillus acidophilus (MIC of 0·03-0·13 mg ml-1 ) and the oral streptococci isolates (MIC values of 0·19-0·13 mg ml-1 ). The most sensitive fungal phytopathogenic isolate was Fusarium oxysporum (MIC 0·003 mg ml-1 ). All samples, except propolis from Serbia (P4) and Turkey (P5), showed a strong antifungal activity against Fusarium sporotrichioides, Fusarium subglutinans and Fusarium proliferatum. CONCLUSION: The results of various tests indicate good radical scavenging and antimicrobial activity against important human and plant pathogens. SIGNIFICANCE AND IMPACT OF THE STUDY: A detailed propolis analysis is important when proposing a preparation of new biological antimicrobial products which have a positive impact on human health and reduce antibacterial resistance.


Assuntos
Anti-Infecciosos/farmacologia , Depuradores de Radicais Livres/farmacologia , Fenóis/análise , Populus/química , Própole/química , Anti-Infecciosos/análise , Feminino , Depuradores de Radicais Livres/análise , Fusarium/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Microbiota/efeitos dos fármacos , Boca/microbiologia , Fenóis/farmacologia , Própole/farmacologia , Vagina/microbiologia
14.
Food Addit Contam Part B Surveill ; 13(2): 121-129, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32200691

RESUMO

The treatment of animals with antimicrobial products may lead to the contamination of edible tissues by their residues, which may represent a risk to human health. Therefore, this study aimed to determine the level of antimicrobial residues in food-producing animals (chicken, beef, and milk) in Lebanon. A total of 310 samples were collected and analysed using an LC-MS/MS for the determination of 48 compounds belonging to different families in order to map their compliance according to the European Commission decision 2002/657/EC. Results show that 60% of the analysed samples were not contaminated by any residue, while 12% presented a concentration higher than the MRLs for tetracyclines, sulphonamides, quinolones, and macrolides. Results revealed that chicken were the most contaminated by antimicrobial residues, when compared to beef and milk. The obtained results demonstrate the uncontrolled use of antimicrobials in some Lebanese farms and claim for better management of livestock.


Assuntos
Anti-Infecciosos/análise , Resíduos de Drogas/análise , Contaminação de Alimentos/análise , Carne/análise , Leite/química , Animais , Bovinos , Galinhas , Líbano
15.
PLoS One ; 15(3): e0229589, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32155163

RESUMO

Securinega suffruticosa (Pall.) Rehd is an excellent natural secondary shrub in the Shell Islands of Yellow River Delta. The roots of S. suffruticosa have high medicinal value and are used to treat diseases, such as neurasthenia and infant malnutrition. Any organism that is isolated from this species is of immense interest due to its potential novel bioactive compounds. In this research, the distribution and diversity of culturable endophytic fungi in S. suffruticosa were studied, and the endophytic fungi with antimicrobial activity were screened. A total of 420 endophytic fungi isolates were obtained from the S. suffruticosa grown in Shell Islands, from which 20 genera and 35 species were identified through morphological and internal transcribed spacer (ITS) sequence analyses. Chaetomium, Fusarium, Cladosporium, and Ceratobasidium were the dominant genera. The high species richness S (42), Margalef index D' (5.6289), Shannon-Wiener index H' (3.1000), Simpson diversity index Ds (0.9459), PIE index (0.8670), and evenness Pielou index J (0.8719) and a low dominant index λ (0.0541) indicated the high diversity of endophytic fungi in S. suffruticosa, the various species of endophytic fungi with obvious tissue specificity. The inhibition percentages of the 12 species of such endophytic fungi against Colletotrichum siamense were 3.6%-26.3%. C. globosum, Fusarium sp.3, and C. ramotenellum had a high antibacterial activity against Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal Concentration (MBC) were between 0.5 mg/mL and 2 mg/mL. Alkaloid content detection indicated that endophytic fungi had a high alkaloid content, whereas the alkaloid contents of C. globosum and Fusarium sp.3 reached 0.231% and 0.170%, respectively. Members belonging to the endophytic fungal community in the S. suffruticosa of Shell Islands that may be used as antagonists and antibacterial agents for future biotechnology applications were identified for the first time.


Assuntos
Endófitos/genética , Endófitos/fisiologia , Fungos/genética , Fungos/fisiologia , Plantas Medicinais/microbiologia , Securinega/microbiologia , Alcaloides/análise , Anti-Infecciosos/análise , Biodiversidade , China , DNA Fúngico/genética , DNA Fúngico/isolamento & purificação , Endófitos/isolamento & purificação , Fungos/classificação , Testes de Sensibilidade Microbiana , Filogenia , Rios
16.
PLoS One ; 15(3): e0230021, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32160226

RESUMO

Supplementing chicken feed with antibiotics can improve survival and prevent disease outbreaks. However, overuse of antibiotics may promote the development of antibiotic-resistant bacteria. Recently, antimicrobial peptides have been proposed as alternatives to antibiotics in animal husbandry. Here, we evaluate the effects of antimicrobial peptide, Epinephelus lanceolatus piscidin (EP), in Gallus gallus domesticus. The gene encoding EP was isolated, sequenced, codon-optimized and cloned into a Pichia pastoris recombinant protein expression system. The expressed recombinant EP (rEP) was then used as a dietary supplement for G. g. domesticus; overall health, growth performance and immunity were assessed. Supernatant from rEP-expressing yeast showed in vitro antimicrobial activity against Gram-positive and Gram-negative bacteria, according to an inhibition-zone diameter (mm) assay. Moreover, the antimicrobial peptide function of rEP was temperature independent. The fermentation broth yielded a spray-dried powder formulation containing 262.9 µg EP/g powder, and LC-MS/MS (tandem MS) analysis confirmed that rEP had a molecular weight of 4279 Da, as expected for the 34-amino acid peptide; the DNA sequence of the expression vector was also validated. We then evaluated rEP as a feed additive for G. g. domesticus. Treatment groups included control, basal diet and rEP at different doses (0.75, 1.5, 3.0, 6.0 and 12%). Compared to control, rEP supplementation increased G. g. domesticus weight gain, feed efficiency, IL-10 and IFN-γ production. Our results suggest that crude rEP could provide an alternative to traditional antibiotic feed additives for G. g. domesticus, serving to enhance growth and health of the animals.


Assuntos
Peptídeos Catiônicos Antimicrobianos/metabolismo , Galinhas/imunologia , Sistema Imunitário/metabolismo , Perciformes/metabolismo , Sequência de Aminoácidos , Animais , Anti-Infecciosos/análise , Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/análise , Peptídeos Catiônicos Antimicrobianos/classificação , Peptídeos Catiônicos Antimicrobianos/genética , Galinhas/crescimento & desenvolvimento , Cromatografia Líquida de Alta Pressão , Clonagem Molecular , Suplementos Nutricionais , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Sistema Imunitário/efeitos dos fármacos , Interferon gama/metabolismo , Interleucina-10/metabolismo , Filogenia , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/farmacologia , Alinhamento de Sequência , Espectrometria de Massas em Tandem , Temperatura
17.
Artigo em Inglês | MEDLINE | ID: mdl-31911204

RESUMO

This study was conducted to develop a highly selective, sensitive, and validated method for quantifying metronidazole in human plasma and bile fluid. Metronidazole and metronidazole-d4 (internal standard) were extracted from 100 µL of plasma and bile fluid by liquid-liquid extraction. Liquid chromatography with a Hydrosphere C18 column (50 × 2.0 mm) was performed using 10 mM ammonium formate (pH 4.0) and acetonitrile (20:80, v/v) as the mobile phase. Triple quadrupole mass spectrometry was operated with an electrospray ionization interface in multiple reaction monitoring and positive ion modes. The calibration curves were linear for bile and plasma samples over the range of 50-20,000 ng/mL (r2 > 0.999). The intra- and inter-day coefficients of variation (CVs) for plasma ranged from 2.50% to 7.85% and 3.11% to 16.9%, respectively; for bile, the intra-and inter-run precision (CVs) ranged from 2.76% to 13.2% and 3.16% to 11.5%, respectively. The mean extraction recovery for metronidazole ranged from 76.5% to 82.1% in plasma and from 78.8% to 87.8% in bile, respectively. Our proposed analytical method was successfully applied to determine metronidazole concentrations in bile as well as in plasma at multiple time points in a patient with acute cholangitis.


Assuntos
Bile/química , Cromatografia Líquida de Alta Pressão/métodos , Metronidazol/análise , Espectrometria de Massas em Tandem/métodos , Anti-Infecciosos/análise , Anti-Infecciosos/sangue , Anti-Infecciosos/química , Anti-Infecciosos/farmacocinética , Humanos , Limite de Detecção , Modelos Lineares , Extração Líquido-Líquido , Metronidazol/sangue , Metronidazol/química , Metronidazol/farmacocinética , Reprodutibilidade dos Testes
18.
Biosens Bioelectron ; 152: 112012, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31941619

RESUMO

In this work, a versatile enzyme-catalyzed biosensor was developed by using the assembled nanohybrids of black phosphorus quantum dots (BPQDs)-doped metal-organic frameworks (MOF) and silver nanoclusters (AgNCs). The nanohybrids of AgNCs/BPQDs/MOF exhibit dual-emissive fluorescence (FL) centers at 630 nm (red) and 535 nm (blue) under excitation at 440 nm. Baicalin enhances the activity of catalase and catalytic decomposition of H2O2. With increase of baicalin contents in the mixture containing nanohybrids, catalase and H2O2, the catalase-caused decomposition of H2O2 was accelerated and the excessive H2O2 was consumed. Baicalin can restrain the oxidation capability of H2O2. The red-FL (response signal) of AgNCs adhering to MOF increases, while blue-FL (reference signal) of BPQDs doped into MOF has negligible changes. A new ratiometric FL biosensor was designed based on nanohybrids and enzyme-catalyzed reaction. This biosensor enables the detection of baicalin in the range of 0.01-500 µg mL-1, with a limit of detection of 3 ng mL-1. This biosensor has high sensitivity, selectivity and stability for baicalin detection in practical samples. Especially, it performed the solution, flexible substrate and latent fingerprint visual detection of baicalin through direct observation of FL color shades with naked eyes. This work explored a facile and efficient semi-quantitative method for versatile FL visual detection, which can promote the development of advanced chemo/bio-sensors and analysis methods.


Assuntos
Anti-Infecciosos/análise , Técnicas Biossensoriais/métodos , Flavonoides/análise , Estruturas Metalorgânicas/química , Fósforo/química , Pontos Quânticos/química , Catalase/química , Fluorescência , Limite de Detecção , Nanoestruturas/química , Prata/química , Espectrometria de Fluorescência/métodos , Comprimidos
19.
Nat Prod Res ; 34(4): 590-594, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30445846

RESUMO

The volatile constituents of the leaves and flowers of Brachychiton rupestris and Brachychiton discolor (Malvaceae) were characterized by GC-FID and GC-MS. A total of 92 compounds were identified. The major component of B. rupestris leaves was α-farnesene (34.57%) while in the flowers it was n-heptacosane (29.5%). (8Z, 11Z, 14Z)-heptadecatrienal (21.2%) in the leaves and palmitic acid (83.49%) in the flowers represent the abundant ingredients of B. discolor. Unsupervised pattern recognition techniques of multivariate data analysis exemplified by hierarchical cluster analysis (HCA) and principle component analysis (PCA) relying upon chromatographic results effectively discriminate the two related species. Also, both investigated species were assessed for their cytotoxic and antimicrobial efficacy. Results revealed that B. discolor flowers showed the highest cytotoxicity against human lung carcinoma (A-549) cell lines with IC50 equals 7.98 µg/mL, whereas B. discolor leaves exhibited the highest antimicrobial potency against all tested microorganisms namely Streptococcus pneumonia, Bacillus subtilis, Escherichia coli as well as Aspergillus fumigatus and Geotrichum candidum (MICs between 0.98 and 15.63 µg/mL) except for Salmonella typhi.


Assuntos
Anti-Infecciosos/isolamento & purificação , Citotoxinas/isolamento & purificação , Malvaceae/química , Óleos Voláteis/química , Células A549 , Anti-Infecciosos/análise , Anti-Infecciosos/farmacologia , Diferenciação Celular/efeitos dos fármacos , Citotoxinas/química , Citotoxinas/farmacologia , Análise de Dados , Ensaios de Seleção de Medicamentos Antitumorais , Flores/química , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Testes de Sensibilidade Microbiana , Óleos Voláteis/farmacologia , Folhas de Planta/química
20.
Nat Prod Res ; 34(1): 46-52, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30822145

RESUMO

This study was designed to establish the most effective solvent/technique for extracting antioxidant phytoconstituents from leaves and flower buds of Inula viscosa (L.) Aiton (Asteraceae) grown wild in Morocco. Maceration and hot extraction with methanol or water and Soxhlet ethanol extraction were utilized. The antioxidant potential was evaluated in vitro by DPPH, reducing power, and ferrous ions chelating activity assays. I. viscosa leaf and flower bud extracts displayed the strongest effect in the DPPH test, being the Soxhlet ethanol the most active ones (IC50 = 54.24 ± 0.21 µg/mL and 39.77 ± 0.23 µg/mL); thus, they were selected for further investigations. The antimicrobial efficacy of the Soxhlet ethanol extracts against ATCC and food isolates strains was assayed; the leaf extract showed the best activity, and Candida albicans was the most sensitive strain (MIC = 125 µg/mL). The extracts resulted non-toxic against Artemia salina. Among the phenolics characterised by HPLC-PDA-ESI-MS, hispidulin hexoside, patuletin and spinacetin were identified for the first time.


Assuntos
Anti-Infecciosos/isolamento & purificação , Antioxidantes/isolamento & purificação , Inula/química , Fenóis/análise , Extratos Vegetais/química , Animais , Anti-Infecciosos/análise , Anti-Infecciosos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Artemia/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Flores/química , Marrocos , Fenóis/química , Extratos Vegetais/normas , Folhas de Planta/química , Solventes/química
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