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1.
Shokuhin Eiseigaku Zasshi ; 60(4): 88-95, 2019.
Artigo em Japonês | MEDLINE | ID: mdl-31474656

RESUMO

Microbial colony counts of concern of food products are one of the most important items in microbiological examinations. The distributions of colony counts per agar plate of food samples are considered to be reflected with microbial cell distributions in food homogenates. However, (i) the probabilistic distributions of the colony counts per agar plate at the dilution of counting and (ii) the relationship between the colony counts per plate and the number of agar plates for food samples have not been intensively studied so far. In this study, therefore, these two points were studied with raw food samples of raw minced beef and chicken and raw milk and microbial culture samples of Escherichia coli, Staphylococcus aureus, and Saccharomyces cerevisiae. Among four major probabilistic distributions, it was found that aerobic plate counts per plate of the foods were well described with negative binomial, Poisson, and normal distributions and that the colony counts per plate of microbial cultures were described well with binomial, Poisson, and normal distributions. The effect of the number of agar plates on the estimation of the mean of colony counts per plate of a sample was then studied with the data randomly resampled from the experimental data. The resampled data showed that with more number of plates the mean of counts fluctuated less and the coefficients of variation of colony counts per plate decreased further, which were coincident to the estimated by the central limit theory. Our study would provide useful information on the characteristics of colony counts per plate of food samples which are routinely examined.


Assuntos
Contagem de Colônia Microbiana , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Ágar , Animais , Bovinos , Escherichia coli/isolamento & purificação , Carne/microbiologia , Leite/microbiologia , Saccharomyces cerevisiae/isolamento & purificação , Staphylococcus aureus/isolamento & purificação
2.
Klin Lab Diagn ; 64(8): 503-506, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31479608

RESUMO

The results of the bacteriological catheter investigation on the analyzer with the technology of laser light scattering and using D. Maki culture technique coincided in 91.8% of cases. Catheter-associated infections are proven in 8 cases. The following obtained from blood and intravascular catheter in 5 patients: Staphylococcus epidermidis (n=1), Staphylococcus haemolyticus (n=1), Escherichia coli (n=1), Staphylococcus aureus (n=2); Staphylococcus epidermidis (n=1) was detected in 1 child from ventricular shunt and cerebrospinal fluid and Escherichia coli lactose-negative + Staphylococcus haemolyticus were detected in 1 child from ventricular shunt, whily only Escherichia coli lactose-negative was detected from cerebrospinal fluid; Pseudomonas aeruginosa (n=1) was foud out in 1 patient from the urinary catheter and urine. Clinical significance of the isolated microorganisms from the catheter must be assessed in each particular case taking into account its quantity and type of the isolated microorganism.


Assuntos
Infecções Bacterianas/diagnóstico , Infecções Relacionadas a Cateter/diagnóstico , Lasers , Criança , Escherichia coli , Humanos , Pseudomonas aeruginosa , Staphylococcus aureus , Staphylococcus epidermidis , Staphylococcus haemolyticus
3.
Vet Immunol Immunopathol ; 214: 109890, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31378218

RESUMO

Bovine mastitis is a significant cause of economic losses in the dairy industry. Staphylococcus aureus is one of the most common contagious mastitis pathogens, whereas Staphylococcus chromogenes increasingly became a significant cause of subclinical mastitis in dairy cows. Current mastitis control measures are not effective on all mastitis pathogens. There is no effective vaccine to control Staphylococcal mastitis in dairy cows. The objective of this study was to evaluate the immune responses and protection in dairy cows vaccinated with S. aureus surface proteins (SASP) or S. chromogenes surface proteins (SCSP). We divided eighteen Holstein dairy cows randomly into three groups of 6 animals each. We vaccinated group 1 and 2 animals with SASP and SCSP with Emulsigen-D adjuvant, respectively. We injected control (group 3) animals with PBS (pH 7.2) in Emulsigen®-D. We vaccinated animals three times at 28 and 14 days before drying off, and at dry off. Two weeks after the third vaccination, we challenged each animal by dipping all teats in S. aureus culture suspension once daily for 14 consecutive days. We evaluated milk or mammary secretion and serum antibody titers during vaccination and challenge periods. We evaluated milk samples for the number of bacteria shedding and somatic cell counts (SCC). Out of six cows vaccinated with SASP, one cow was removed from the study due to injury, two were infected clinically, another two were infected subclinically, and the remaining cow was not infected. No SCSP vaccinated cows developed clinical or subclinical mastitis. Out of six control cows, two developed clinical mastitis whereas four were infected subclinically. The SCSP vaccine cross-protected against S. aureus mastitis and reduced number of S. aureus shedding in milk. We concluded that the SCSP is a promising vaccine to control Staphylococcal mastitis in dairy cows.


Assuntos
Mastite Bovina/prevenção & controle , Proteínas de Membrana/imunologia , Infecções Estafilocócicas/veterinária , Vacinas Antiestafilocócicas/imunologia , Staphylococcus aureus/imunologia , Animais , Derrame de Bactérias , Bovinos , Contagem de Células , Indústria de Laticínios , Feminino , Proteínas de Membrana/administração & dosagem , Leite/microbiologia , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/prevenção & controle , Vacinação
5.
Pestic Biochem Physiol ; 158: 185-200, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31378356

RESUMO

The present work describes the antimicrobial action of 25 monoterpenes (six hydrocarbons, five ketones, two aldehydes, six alcohols and six acetate analogues) against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus and antifungal activity against Aspergillus flavus. The antibacterial activity was evaluated by broth microdilution technique as a minimum inhibitory concentration (MIC) and the antifungal activity was performed by mycelia radial growth technique as the effective concentration causing 50% inhibition of the mycelial growth (EC50). The results showed that thymol and α-terpineol were the most potent against E. coli (MIC = 45 and 55 mg/L, respectively) and S. aureus (MIC = 135 and 225 mg/L, respectively). The results also showed that thymol displayed the maximum antifungal action against A. flavus with EC50 20 mg/L. Furthermore, the antioxidant activity was determined using N,N-dimethyl-1,4-phenylenediamine (DMPD) and the results showed that geraniol were the most potent compound (IC50 = 19 mg/L). Molecular docking studies indicated that the compounds displayed different binding interactions with the amino acid residues at the catalytic sites of N5-carboxyaminoimidazole synthetase and oxysterol binding protein Osh4 enzymes. Non-covalent interactions including van der Waals, hydrogen bonding as well as hydrophobic were observed between the compounds and the enzymes. A significant relationship was found between the docking score and the biological activity of the tested monoterpenes compared to the ceftriaxone and carbendazim as standard bactericide and fungicide, respectively. In silico ADMET properties were also performed and displayed potential for the development of promising antimicrobial agents. For these reasons, these compounds may be considered as potential ecofriendly alternatives in food preservation to delay or prevent the microbial infection and prolong the shelf life of food products.


Assuntos
Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Monoterpenos/metabolismo , Antibacterianos/química , Antibacterianos/farmacologia , Anti-Infecciosos/química , Cicloexenos/química , Cicloexenos/farmacologia , Escherichia coli/efeitos dos fármacos , Hidrocarbonetos/química , Hidrocarbonetos/farmacologia , Testes de Sensibilidade Microbiana , Monoterpenos/química , Monoterpenos/farmacologia , Staphylococcus aureus/efeitos dos fármacos
6.
Pharm Res ; 36(10): 147, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31414240

RESUMO

PURPOSE: The aim was to design and thoroughly characterize monodisperse Fe3O4@SiO2-Ag nanoparticles with strong antibacterial properties, which makes them a candidate for targeting bacterial infections. METHODS: The monodisperse Fe3O4 nanoparticles were prepared by oleic acid-stabilized thermal decomposition of Fe(III) oleate; the particles were coated with silica shell using a water-in-oil reverse microemulsion, involving hydrolysis and condensation of tetramethyl orthosilicate. Resulting Fe3O4@SiO2 particles were modified by (3-mercaptopropyl)trimethoxysilane to introduce 1.1 mmol SH/g. Finally, the Fe3O4@SiO2-SH nanoparticles were decorated with silver nanoclusters formed by reduction of silver nitrate with NaBH4. The particles were analyzed by FTIR, X-ray photoelectron and atomic absorption spectroscopy, dynamic light scattering and vibrating sample magnetometry. The antibacterial activity of the Fe3O4@SiO2 and Fe3O4@SiO2-Ag nanoparticles was tested against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria cultivated on Luria agar plates or in Luria broth. RESULTS: The superparamagnetic Fe3O4@SiO2-Ag nanoparticles (21 nm in diameter; saturation magnetization 26 A∙m2/kg) were successfully obtained and characterized. Inhibitory and toxic effects against bacteria were documented by incubation of the Fe3O4@SiO2-Ag nanoparticles with Staphylococcus aureus and Escherichia coli. CONCLUSIONS: The combination of magnetic properties together with bactericidal effects is suitable for the disinfection of medical instruments, water purification, food packaging, etc.


Assuntos
Antibacterianos/química , Nanopartículas de Magnetita/química , Prata/química , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Ácido Oleico/química , Tamanho da Partícula , Silanos/química , Dióxido de Silício/química , Prata/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície
7.
Onderstepoort J Vet Res ; 86(1): e1-e9, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31291733

RESUMO

South Africa is a large country of approximately 1.22 million km2, made up of nine provinces with three climatic zones. Farming in the country is mostly defined by regional differences. Of the different organisms isolated from milk samples of dairy cows, Staphylococcus aureus poses a challenge to maintain udder health and wholesome dairy products for human consumption. Antibiotic resistant bacteria are therefore a potential health hazard. The objective of this study was to investigate the seasonal and regional relationships of antibiotic resistance of S. aureus, of which little is known. This study was undertaken to evaluate a data set of 3410 S. aureus isolates, taken from milk samples with a somatic cell count of > 400 000 cells/mL from commercial dairy herds. These isolates were tested for antimicrobial susceptibility using the Kirby Bauer method for ampicillin, cloxacillin, penicillin G, clindamycin, oxy-tetracycline, cephalexin, cefuroxime and tylosin. The samples were from 830 dairy herds, out of the estimated 2000 commercial dairy herds in South Africa. All the antibiotics tested, except for cephalosporins, showed a predicted prevalence of resistance of above 50% in most provinces, which is a concern. The lowest prevalence of resistance to the majority of the categories of antibiotics tested was present in KwaZulu-Natal during spring. The cephalosporins had the lowest levels of prevalence of bacterial resistance in Gauteng during winter. Resistance patterns of S. aureus to the eight antibiotics varied in the different seasons and provinces, possibly because of different weather conditions, and the action and spectrum of antibiotics.


Assuntos
Antibacterianos/farmacologia , Indústria de Laticínios , Mastite Bovina/epidemiologia , Leite/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/efeitos dos fármacos , Animais , Bovinos , Clima , Demografia , Farmacorresistência Bacteriana , Feminino , Mastite Bovina/microbiologia , Testes de Sensibilidade Microbiana/veterinária , Prevalência , África do Sul/epidemiologia , Infecções Estafilocócicas/epidemiologia
8.
J Insect Sci ; 19(4)2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31343690

RESUMO

Bombyx mori (Lepidoptera: Bombycidae) is an important economic insect and a classic Lepidopteran model system. Although immune-related genes have been identified at a genome-wide scale in the silkworm, proteins involved in immune defense of the silkworm have not been comprehensively characterized. In this study, two types of bacteria were injected into the silkworm larvae, Gram-negative Escherichia coli (Enterobacteriales: Enterobacteriaceae), or Gram-positive Staphylococcus aureus (Bacillales: Staphylococcaceae). After injection, proteomic analyses of hemolymph were performed by liquid chromatography-tandem mass spectrometry. In total, 514 proteins were identified in the uninduced control group, 540 were identified in the E. coli-induced group, and 537 were identified in the S. aureus-induced group. Based on Uniprot annotations, 32 immunological recognition proteins, 28 immunological signaling proteins, and 21 immunological effector proteins were identified. We found that 127 proteins showed significant upregulation, including 10 immunological recognition proteins, 4 immunological signaling proteins, 11 immunological effector proteins, and 102 other proteins. Using real-time quantitative polymerase chain reaction in the fat body, we verified that immunological recognition proteins, signaling proteins, and effector proteins also showed significant increases at the transcriptional level after infection with E. coli and S. aureus. Five newly identified proteins showed upregulation at both protein and transcription levels after infection, including 30K protein, yellow-d protein, chemosensory protein, and two uncharacterized proteins. This study identified many new immune-related proteins, deepening our understanding of the immune defense system in B. mori. The data have been deposited to the iProX with identifier IPX0001337000.


Assuntos
Bombyx/genética , Bombyx/imunologia , Escherichia coli/fisiologia , Proteínas de Insetos/imunologia , Proteoma/imunologia , Staphylococcus aureus/fisiologia , Animais , Bombyx/crescimento & desenvolvimento , Bombyx/microbiologia , Proteínas de Insetos/análise , Larva/crescimento & desenvolvimento , Larva/imunologia , Larva/microbiologia , Proteoma/análise , Proteômica
9.
J Agric Food Chem ; 67(29): 8191-8196, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31282662

RESUMO

Conversion of free fatty acids into monoacylglycerol gives rise to new structural properties, particularly amphipathic property. Therefore, monoacylglycerols are widely used in pharmaceutical and food industries and are also reported to facilitate better absorption into the human body. A functional fatty acid when transformed into a monoacylglycerol will possibly conserve both the original functionality and amphipathic property. The compound 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) was generated from oleic acid by Pseudomonas aeruginosa PR3 and was known to contain antimicrobial activities against a broad range of food-borne and plant pathogenic bacteria. Here, we attempted to convert DOD into its monoacylglycerol form using lipase for producing an amphipathic antibacterial agent. Consequently, the monoacylglycerol of DOD (DOD-MAG) was successfully produced by coincubating DOD, glycerol, and lipase at 30 °C. The maximum conversion yield reached 70% after 12 h of incubation. Antibacterial activity of DOD-MAG was enhanced by 8 times from the original activity of DOD against food-borne bacteria.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Monoglicerídeos/química , Ácidos Oleicos/química , Ácidos Oleicos/farmacologia , Pseudomonas aeruginosa/química , Antibacterianos/metabolismo , Microbiologia de Alimentos , Ácidos Oleicos/metabolismo , Pseudomonas aeruginosa/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento
10.
Zhongguo Zhong Yao Za Zhi ; 44(9): 1946-1952, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31342725

RESUMO

In this study,in order to detect the antimicrobial activity of artemisinin and its derivatives artesunate and dihydroartemisinin,two methods including broth dilution and plate punching method were used to detect the antibacterial activity against gram-negative bacteria(Escherichia coli)and gram-positive bacteria(Staphylococcus aureus)of artemisinin,dihydroartemisinin and artesunate at various concentrations within 5 mmol·L~(-1)and at four time points(8,16,24,32 h).Two antibacterial positive drugs,streptomycin against E.coli and penicillin against S.aureus,were used as positive controls.Plate punching method showed that,unlike the results of 5 mmol·L~(-1)dihydroartemisinin or artesunate,no inhibition zone was detected at the same concentration of artemisinin after 24 h-treatment against E.coli.Broth dilution method showed that,the antibacterial activity of dihydroartemisinin against E.coli.was stronger than those of both artesunate and artemisinin;IC_(50)at24 h-treatment was 155.9µmol·L~(-1)for dihydroartemisinin,370.0µmol·L~(-1)for artesunate and none for artemisinin.Interestingly,dihydroartemisinin and artesunate showed the strongest antibacterial activity between 16-24 h,while artemisinin showed relatively stronger antibacterial activity between 8-16 h.Dihydroartermisinin showed no antibacterial activity against S.aureus.Above all,the antibacterial activity of artemisinins against E.coli is dihydroartemisinin>artesunate>artemisinin.Artemisinin and its derivatives have showed different antibacterial kinetics,and no antibacterial activity against S.aureus.has been detected with dihydroartemisinin.


Assuntos
Antibacterianos/farmacologia , Artemisininas/farmacologia , Escherichia coli/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Artesunato/farmacologia , Testes de Sensibilidade Microbiana
11.
Rev Soc Bras Med Trop ; 52: e20190095, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31340369

RESUMO

INTRODUCTION: Staphylococcus aureus is a major nosocomial pathogen that is associated with high virulence and the rapid development of drug resistance. METHODS: We analyzed and compared the antimicrobial resistance, virulence profiles, and molecular epidemiology of 67 S. aureus strains, including 36 methicillin-sensitive (MSSA) and 31 methicillin-resistant (MRSA) strains recovered from a public hospital located in south-eastern Brazil. RESULTS: The clones circulating in this hospital presented a great diversity, and the majority of the strains were related to clones responsible for causing worldwide epidemics: these included USA100 (New York/Japan clone), USA300, and USA600. The 31 MRSA (22 SCCmecII and 9 SCCmecIV) and 36 MSSA strains exhibited low resistance against gentamicin and trimethoprim/sulfamethoxazole. No MRSA strain showed resistance to tetracycline. Virulence gene carriage was more diverse and abundant in MSSA than in MRSA. Of the evaluated adhesion-related genes, ebpS was the most prevalent in both MSSA and MRSA strains. The genes bbp and cna showed a strong association with MSSA strains. CONCLUSIONS: Our findings reinforce the idea that MSSA and MRSA strains should be carefully monitored, owing to their high pathogenic potential.


Assuntos
Antibacterianos/farmacologia , Resistência a Meticilina , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Fatores de Virulência/genética , Brasil/epidemiologia , Hospitais Públicos , Humanos , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/classificação , Staphylococcus aureus/isolamento & purificação , Centros de Atenção Terciária , Virulência/genética
12.
J Photochem Photobiol B ; 197: 111539, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31301638

RESUMO

Treatment of burn injury is clinically challenging one, therefore several steps and noteworthy approaches have been taken to improve wound mechanisms. Citrus pectin plays a stabilizing agent to synthesis of ZnO nanoparticles (ZnO NPs). The present study is focused on ZnO loaded collagen/chitosan nanofibrous were synthesized by electrospinning method using ZnO NPs. The chemical structure, phase purity and morphological observation were investigated under spectroscopic and mircoscopic techniques and demonstrated their suitable properties as a wound healing material. In addition, that prepared nanoparticles loaded biopolymeric fibrous nanomaterial showed suitable antibacterial activity against S. aureus and E. coli bacterial pathogens and also in vitro studies was confirmed the enhanced proliferation, cell viability and biocompatibility. In vitro evaluations have been exhibited acceptable cell proliferation is observed throughout the ZnO loaded Coll/CS nanofibrous within 3 days, which was comparable to the control material. In vivo wound healing ability was monitored on the rat wound experimental model. From the in vivo observations, revealed that the loaded of ZnO NPs with Coll/CS nanofibrous can effectively quicken wound healing mechanism, expressed in the initial stage healing process. These results suggest that ZnO loaded collagen/chitosan nanofibrous is a potential candidate for wound healing applications with enhanced biological properties.


Assuntos
Queimaduras/patologia , Quitosana/química , Colágeno/química , Nanopartículas Metálicas/química , Nanofibras/química , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bacteriemia/prevenção & controle , Queimaduras/veterinária , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Humanos , Nanofibras/uso terapêutico , Nanofibras/toxicidade , Ratos , Pele/efeitos dos fármacos , Pele/patologia , Staphylococcus aureus/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Óxido de Zinco/química
13.
Arch Insect Biochem Physiol ; 102(1): e21592, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31276235

RESUMO

Ferritin, which is ubiquitous among all living organisms, plays a crucial role in maintaining iron homeostasis, immune response, and detoxification. In the present research, we identified an iron-binding protein, ferritin heavy chain subunit, from Papilio xuthus and named PxFerHCH. The complete complementary DNA of PxFerHCH was 1,252 bp encoding a sequence of 211 amino acids, which includes an iron-responsive element. Phylogenetic analysis showed that PxFerHCH is clustered with Manduca sexta and Galleria mellonella ferritin heavy chain subunits. Expression levels of PxFerHCH in various tissues were analyzed by reverse transcription quantitative polymerase chain reaction, and the results exhibited that PxFerHCH was expressed in all tissues with the highest expression in the fat body. The relative expression level of PxFerHCH in response to bacterial (Escherichia coli and Staphylococcus aureus) challenges sharply increased by about 12 hr postinfection (hpi) and then decreased at 24 hpi. In addition, the iron-binding capacity and antioxidation activity of recombinant PxFerHCH protein were also investigated. These results reveal that PxFerHCH might play an important role in defense against bacterial infection.


Assuntos
Apoferritinas/metabolismo , Borboletas/metabolismo , Ferro/metabolismo , Sequência de Aminoácidos , Animais , Apoferritinas/genética , Apoferritinas/isolamento & purificação , Sequência de Bases , Borboletas/genética , Borboletas/imunologia , Escherichia coli , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Staphylococcus aureus
14.
J Agric Food Chem ; 67(30): 8382-8392, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31271032

RESUMO

Staphylococcus aureus is a common pathogen that can cause life-threatening infections. Treatment of antibiotic-resistant S. aureus infection needs effective antibacterial agents. Thymol, a generally recognized safe natural compound, has potential as an alternative to treat S. aureus infections. However, the targets and mechanisms of action of thymol were not fully understood. Bioinformatics analysis showed that IolS, a predicted aldo-keto reductase (AKR) in S. aureus, could be a potential target of thymol. Isothermal titration calorimetry (ITC) analysis demonstrated that thymol directly binds IolS and amino acid residues (Y30 and L33) are essential for such binding. Deletion of IolS or mutation of Y30A and L33A reduced the bactericidal activity of thymol at the concentration of 200 µg/mL, suggesting that thymol mediates bactericidal activity via binding with IolS. Biochemical analysis showed that addition of thymol significantly increased AKR activity of IolS from 1.6 ± 0.1 to 2.4 ± 0.2 U (p < 0.05). The content of NADPH within S. aureus cells decreased significantly from 105 ± 5 to 72 ± 3 pmol/108 cells (p < 0.05) following thymol treatment at the concentration of 200 µg/mL. Importantly, addition of NADPH could alleviate the bactericidal effect of thymol on S. aureus, indicating that the depletion of NADPH is responsible for thymol-mediated bactericidal activity. Overall, these results demonstrated that thymol could directly bind IolS and increase its AKR activity, leading to the depletion of NADPH and bactericidal effect. AKR activity of IolS could be a promising target for the development of new antimicrobials.


Assuntos
Aldo-Ceto Redutases/antagonistas & inibidores , Antibacterianos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , NADP/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/enzimologia , Timol/farmacologia , Aldo-Ceto Redutases/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Humanos , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética
15.
Chem Biodivers ; 16(8): e1900317, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31264344

RESUMO

Four new diterpenoids named cuceolatins A-D, including three labdane-type (1-3) and one abietane-type (4) as well as three known labdane analogs (5-7), were reported from the leaves of Cunninghamia lanceolata. Structural assignments for these compounds were conducted by analyses of spectroscopic data, and their absolute configurations were determined by time-dependent density functional theory (TD-DFT) based electronic circular dichroism (ECD) calculations. Among them, the abietane-type diterpenoid (11-hydroxy-12-methoxyabieta-8,11,13-trien-3-one (4)) showed significant cytotoxicity against human MDA-MB-231, MCF-7, and HeLa tumor cell lines with IC50 measurements of 4.3, 2.8 and 4.5 µm, respectively, while the labdane-type diterpenoids with a 4α-carboxy group (1-3 and 5) exhibited moderate antibacterial activity towards Bacillus subtilis and Staphylococcus aureus with IC50 values all below 25 µm.


Assuntos
Cunninghamia/química , Diterpenos/química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Bacillus subtilis/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Dicroísmo Circular , Cunninghamia/metabolismo , Teoria da Densidade Funcional , Diterpenos/isolamento & purificação , Diterpenos/farmacologia , Diterpenos de Abietano/química , Diterpenos de Abietano/isolamento & purificação , Diterpenos de Abietano/farmacologia , Humanos , Conformação Molecular , Folhas de Planta/química , Folhas de Planta/metabolismo , Staphylococcus aureus/efeitos dos fármacos
16.
Bone Joint J ; 101-B(7): 848-851, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31256673

RESUMO

AIMS: The aims of this study were to compare the mean duration of antibiotic release and the mean zone of inhibition between vancomycin-loaded porous tantalum cylinders and antibiotic-loaded bone cement at intervals, and to evaluate potential intrinsic antimicrobial properties of tantalum in an in vitro medium environment against methicillin-sensitive Staphylococcus aureus (MSSA). MATERIALS AND METHODS: Ten porous tantalum cylinders and ten cylinders of cement were used. The tantalum cylinders were impregnated with vancomycin, which was also added during preparation of the cylinders of cement. The cylinders were then placed on agar plates inoculated with MSSA. The diameter of the inhibition zone was measured each day, and the cylinders were transferred to a new inoculated plate. Inhibition zones were measured with a Vernier caliper and using an automated computed evaluation, and the intra- and interobserver reproducibility were measured. The mean inhibition zones between the two groups were compared with Wilcoxon's test. RESULTS: MSSA was inhibited for 12 days by the tantalum cylinders and for nine days by the cement cylinders. At day one, the mean zone of inhibition was 28.6 mm for the tantalum and 19.8 mm for the cement group (p < 0.001). At day ten, the mean zone of inhibition was 3.8 mm for the tantalum and 0 mm for the cement group (p < 0.001). The porous tantalum cylinders soaked only with phosphate buffered solution showed no zone of inhibition. CONCLUSION: Compared with cement, tantalum could release antibiotics for longer. Further studies should assess the advantages of using antibiotic-loaded porous tantalum implants at revision arthroplasty. Cite this article: Bone Joint J 2019;101-B:848-851.


Assuntos
Antibacterianos/administração & dosagem , Cimentos para Ossos , Sistemas de Liberação de Medicamentos , Staphylococcus aureus/efeitos dos fármacos , Tantálio , Vancomicina/administração & dosagem , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Artroplastia de Substituição/instrumentação , Humanos , Prótese Articular , Testes de Sensibilidade Microbiana , Variações Dependentes do Observador , Infecções Relacionadas à Prótese/prevenção & controle , Fatores de Tempo , Vancomicina/farmacologia , Vancomicina/uso terapêutico
17.
Nat Commun ; 10(1): 2730, 2019 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-31227691

RESUMO

Recently our groups discovered lugdunin, a new cyclic peptide antibiotic that inhibits Staphylococcus aureus epithelial colonization in humans and rodents. In this work, we analyzed its immuno-modulatory and antimicrobial potential as a single agent or in combination with other microbiota- or host-derived factors. We show that pretreatment of primary human keratinocytes or mouse skin with lugdunin in combination with microbiota-derived factors results in a significant reduction of S. aureus colonization. Moreover, lugdunin increases expression and release of LL-37 and CXCL8/MIP-2 in human keratinocytes and mouse skin, and results in the recruitment of monocytes and neutrophils in vivo, both by a TLR/MyD88-dependent mechanism. Interestingly, S. aureus elimination by lugdunin is additionally achieved by synergistic antimicrobial activity with LL-37 and dermcidin-derived peptides. In summary, our results indicate that lugdunin provides multi-level protection against S. aureus and may thus become a promising treatment option for S. aureus skin infections in the future.


Assuntos
Antibacterianos/farmacologia , Imunidade Inata/efeitos dos fármacos , Peptídeos Cíclicos/farmacologia , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Tiazolidinas/farmacologia , Animais , Antibacterianos/uso terapêutico , Peptídeos Catiônicos Antimicrobianos/imunologia , Células Cultivadas , Modelos Animais de Doenças , Feminino , Humanos , Queratinócitos/efeitos dos fármacos , Queratinócitos/imunologia , Queratinócitos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microbiota/efeitos dos fármacos , Microbiota/imunologia , Peptídeos/imunologia , Peptídeos Cíclicos/uso terapêutico , Cultura Primária de Células , Pele/efeitos dos fármacos , Pele/imunologia , Pele/microbiologia , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/microbiologia , Tiazolidinas/uso terapêutico
18.
Talanta ; 202: 244-250, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31171177

RESUMO

We report here a sensitive method for immunoassay of Staphylococcus aureus (S. aureus) based on colorimetric and fluorescent responses of 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) to l-cysteine (Cys). S. aureus cells were separated from samples by immunomagnetic nanoparticles and labeled with Cys-encapsulated liposome (Cys@liposome) immuno-nanocapsules. After mangnetic separation, the Cys@liposome immuno-nanocapsules linked to bacterial cells were destructed by Tween-20, and then the released Cys molecules reacted with NBD-Cl to generate colorimetric and fluorescent signals. Due to the amplification effect of liposome nanocapsules, the high capture efficiency of immunomagnetic nanoparticles, and the high responses of NBD-Cl to Cys, the detection limits for colorimetric and fluorescent detection of S. aureus were as low as 10 and 1 CFU mL-1, respectively. The proposed method was successfully used to detect S. aureus in milk samples. This work has provided a novel NBD-Cl based colorimetric and fluorescent platform for immunoassay.


Assuntos
Colorimetria , Cisteína/química , Fluorescência , Imunoensaio , Nitrobenzenos/química , Oxidiazóis/química , Staphylococcus aureus/isolamento & purificação , Lipossomos/química , Estrutura Molecular , Nanopartículas/química
19.
Vet Immunol Immunopathol ; 212: 1-8, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31213246

RESUMO

Bovine mastitis caused by Staphylococcus aureus is a serious problem in dairy production and effective immunoprophylaxis is an unmet goal so far. The objective of this work was to assess the humoral immune response of heifer calves against two recombinant S. aureus antigens: Clumping factor A (ClfA) and Fibronectin Binding Protein A (FnBPA), formulated with a novel adjuvant based on cationic liposomes (Lip) and CpG oligodeoxynucleotides (CpG-ODN). Six groups of 6-8 months old heifer calves received three doses biweekly of antigens, formulated with Al(OH)3, liposomes, CpG-ODN or Lip + CpG-ODN. Animals also received a fourth dose after a year (day 410) and a booster before calving. The administration of Al(OH)3+FnBPA/ClfA and Lip + FnBPA/ClfA + CpG-ODN induced the highest specific IgG levels, after the first 3 doses and induced a fast increase of antibodies after the fourth dose. All the formulations stimulated the production of specific IgG1, after the third and fourth dose. Specific IgG2 for both proteins was only stimulated after the fourth dose by Lip + FnBPA/ClfA + CpG-ODN. Pre-calving immunisation with Lip + FnBPA/ClfA + CpG-ODN led to the highest IgG levels during the calving period and to the production of the IgG2 subclass. The formulation was also able to stimulate the highest antibody levels in milk, 30 and 45 days after pre-calving booster. The combination of liposomes and CpG-ODN as adjuvant for a subunit vaccine, together with the immunisation schedule described, induced a strong humoral immune response with production of specific IgG2. The formulation demonstrated to induce immune memory allowing the application of a single pre-calving booster to maintain high antibody levels throughout the period of increased susceptibility to intramammary infections.


Assuntos
Antígenos de Bactérias/imunologia , Imunidade Humoral , Mastite Bovina/prevenção & controle , Oligodesoxirribonucleotídeos/farmacologia , Adjuvantes Imunológicos/administração & dosagem , Fatores Etários , Animais , Anticorpos Antibacterianos/sangue , Bovinos , Imunoglobulina G/sangue , Memória Imunológica , Lipossomos/farmacologia , Mastite Bovina/imunologia , Mastite Bovina/microbiologia , Staphylococcus aureus , Vacinação , Soro do Leite/imunologia
20.
Int J Nanomedicine ; 14: 3861-3874, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31213806

RESUMO

Purpose: Infections associated with medical devices that are caused by biofilms remain a considerable challenge for health care systems owing to their multidrug resistance patterns. Biofilms of Pseudomonas aeruginosa and Staphylococcus aureus can result in life-threatening situations which are tough to eliminate by traditional methods. Antimicrobial photodynamic inactivation (aPDT) constitutes an alternative method of killing deadly pathogens and their biofilms using reactive oxygen species (ROS). This study investigated the efficacy of enhanced in vitro aPDT of P. aeruginosa and S. aureus using malachite green conjugated to carboxyl-functionalized multi-walled carbon nanotubes (MGCNT). Both the planktonic cells and biofilms of test bacteria were demonstrated to be susceptible to the MGCNT conjugate. These MGCNT conjugates may thus be employed as a facile strategy for designing antibacterial and anti-biofilm coatings to prevent the infections associated with medical devices. Methods: Conjugation of the cationic dye malachite green to carbon nanotube was studied by UV-visible spectroscopy, high-resolution transmission electron microscopy, and Fourier transform infrared spectrometry. P. aeruginosa and S. aureus photodestruction were studied using MGCNT conjugate irradiated for 3 mins with a red laser of wavelength 660 nm and radiant exposure of 58.49 J cm-2. Results: Upon MGCNT treatment, S. aureus and P. aeruginosa were reduced by 5.16 and 5.55 log10 , respectively. Compared to free dye, treatment with MGCNT afforded improved phototoxicity against test bacteria, concomitant with greater ROS production. The results revealed improved biofilm inhibition, exopolysaccharide inhibition, and reduced cell viability in test bacteria treated with MGCNT conjugate. P. aeruginosa and S. aureus biofilms were considerably reduced to 60.20±2.48% and 67.59±3.53%, respectively. Enhanced relative MGCNT phototoxicity in test bacteria was confirmed using confocal laser scanning microscopy. Conclusion: The findings indicated that MGCNT conjugate could be useful to eliminate the biofilms formed on medical devices by S. aureus and P. aeruginosa.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Nanotubos de Carbono/química , Fotoquimioterapia , Plâncton/citologia , Plâncton/efeitos dos fármacos , Pseudomonas aeruginosa/fisiologia , Corantes de Rosanilina/farmacologia , Staphylococcus aureus/fisiologia , Cinética , Peroxidação de Lipídeos/efeitos dos fármacos , Viabilidade Microbiana/efeitos dos fármacos , Nanotubos de Carbono/ultraestrutura , Pseudomonas aeruginosa/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Staphylococcus aureus/efeitos dos fármacos
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