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1.
J Prosthet Dent ; 122(5): 493.e1-493.e8, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31648793

RESUMO

STATEMENT OF PROBLEM: The single-species biofilm method cannot represent the interaction and complex functions of microorganisms associated with oral biofilms. PURPOSE: The purpose of this in vitro study was to investigate microbial changes in biofilms on composite resins of varying surface roughness by using a multispecies biofilm model with early-colonizing streptococci, middle colonizer, and late-colonizing gram-negative anaerobes. MATERIAL AND METHODS: Composite resin disks were prepared with different roughness: SR180, SR400, SR1500, and SRGlass roughened with 180-, 400-, and 1500-grit silicon carbide paper and glass (control surface without surface roughening). Surface roughness was analyzed by confocal laser scanning and scanning electron microscopy. After multispecies biofilms had been grown on the composite resin surfaces, the adhesion of Streptococcus mutans, Streptococcus sobrinus, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and of total bacteria was determined after 1 (T1) and 4 (T2) days. Differences in surface roughness among the 4 groups were tested with 1-way ANOVA. Multifactorial analysis of variance was used to determine the time-related differences in the bacterial composition with respect to surface roughness (α=.05). RESULTS: The order of SR, from highest to lowest, was SR180 (1.45 ±0.11 µm), SR400 (0.62 ±0.05 µm), SR1500 (0.35 ±0.02 µm), and SRGlass (0.15 ±0.01 µm) (SR180>SR400>SR1500>SRGlass, P<.001). Increased surface roughness was not proportional to bacterial adhesion. Significant differences in the adhesion of total bacteria was only found between SRGlass and SR180 (SR180>SRGlass, P=.029). The adhesion of S. mutans and S. sobrinus to SR180 and SR400 was higher than that to SRGlass (SR180=SR400>SRGlass; S. mutans, P=.003; S. sobrinus, P=.002). However, the adhesion of A. actinomycetemcomitans and P. gingivalis to composite resin was not significantly influenced by surface roughness. Adhesion of total bacteria, S. mutans, and S. sobrinus increased from T1 to T2 (T1T2; A. actinomycetemcomitans, P<.001; P. gingivalis, P=.013). CONCLUSIONS: Decreased adhesion of cariogenic streptococci and total bacteria was observed at surface roughness values of around 0.15 µm. Periodic finishing of surface roughness should be considered to minimize the adhesion of cariogenic streptococci to composite resin surfaces.


Assuntos
Resinas Compostas , Streptococcus mutans , Aderência Bacteriana , Biofilmes , Propriedades de Superfície
2.
World J Microbiol Biotechnol ; 35(10): 156, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31576430

RESUMO

Adhesion ability is a primary criterion for the selection of probiotic microorganisms. Lactic acid bacteria contribute the majority of microorganisms with probiotic properties. They have several important mechanisms for intestinal epithelial cell adhesion. In order to adhere to the intestinal cells, they generally use various structures such as flagella, pili, S layer proteins, lipoteichoic acid, exopolysaccharides and mucus binding proteins. Various in vitro experiments were designed or study models were developed to reveal the mechanisms they utilize for binding to the intestinal cells, yet, the mechanisms for their adhesion are not fully explained. The major disadvantage of conventional models is the lack of layers forming the intestinal mucosa. Besides, these models omit the presence of natural microbiota, digestive conditions and the presence of a food matrix. Because of the disadvantages of existing models, natural tissues or novel applications like 3D organ cultures, which are better able to mimic in vivo conditions, are preferred.


Assuntos
Aderência Bacteriana , Mucosa Intestinal/microbiologia , Lactobacillales/fisiologia , Animais , Células Epiteliais/microbiologia , Humanos , Lactobacillales/genética , Modelos Biológicos
3.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 36(5): 862-869, 2019 Oct 25.
Artigo em Chinês | MEDLINE | ID: mdl-31631637

RESUMO

Despite the continuous improvement in perioperative use of antibiotics and aseptic techniques, the incidence of infection continues to rise as the need for surgery increasing and brings great challenges to orthopedic surgery. The rough or porous structure of the prosthesis provides an excellent place for bacterial adhesion, proliferation and biofilm formation, which is the main cause of infection. Traditional antibiotic therapy and surgical debridement are difficult to determine whether the infected focus have been removed completely and whether the infection will recur. In recent years, nanotechnology has shown obvious advantages in biomaterials and drug delivery. Nano drug carriers can effectively achieve local antimicrobial therapy, prevent surgical infection by local sustained drug release or intelligent controlled drug release under specific stimuli, and reduce the toxic side effects of drugs. The unique advantages of nanotechnology provide new ideas and options for the prevention and treatment of periprosthetic infection. At present, the application of nano-technology in the prevention and treatment of infection can be divided into the addition of nano-drug-loaded materials to prosthesis materials, the construction of drug-loaded nano-coatings on the surface of prosthesis, the perfusable nano-antimicrobial drug carriers, and the stimulation-responsive drug controlled release system. This article reviews the methods of infection prevention and treatment in orthopaedic surgery, especially the research status of nanotechnology in the prevention and treatment of periprosthetic infection.


Assuntos
Anti-Infecciosos/administração & dosagem , Portadores de Fármacos , Nanotecnologia , Ortopedia , Infecções Relacionadas à Prótese/prevenção & controle , Aderência Bacteriana , Humanos
4.
J Agric Food Chem ; 67(38): 10774-10781, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31479258

RESUMO

The released milk N-glycome has been found to possess antipathogenic activity. Natively, they are covalently linked onto proteins. Whether the conjugated N-glycans still have antipathogenic properties and how the glycosylation influences the antipathogenic activity of proteins remain unclear. Herein, we compared the quantitative differences of milk protein N-glycosylation and the antilisterial differences of native milk proteins, released N-glycan pools, and deglycosylated proteins between human and bovine milk. N-glycosylation exhibited to be quantitatively species-specific. The entire growth inhibitory activity and the majority of the antiadhesive activity against Listeria monocytogenes of milk whey proteins, although not as high as the released N-glycans, are attributed to N-glycosylation. Moreover, all N-glycan-bearing samples from human milk showed better growth inhibitory activities than those from bovine milk. Generally, N-glycosylation significantly contributes to the antilisterial function of milk proteins and to the functional differences between species. This gives novel insights into the role of these glycoconjugates in nature.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Listeria monocytogenes/efeitos dos fármacos , Proteínas do Leite/química , Proteínas do Leite/farmacologia , Leite Humano/química , Animais , Aderência Bacteriana/efeitos dos fármacos , Células CACO-2 , Bovinos , Glicosilação , Humanos , Listeria monocytogenes/crescimento & desenvolvimento , Listeria monocytogenes/fisiologia , Polissacarídeos/química , Especificidade da Espécie
5.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 37(4): 366-371, 2019 Aug 01.
Artigo em Chinês | MEDLINE | ID: mdl-31512827

RESUMO

OBJECTIVE: To evaluate the process characterization of graphene oxide loaded on pure titanium surface and effect on the biological properties of Staphylococcus aureus and osteoblasts. METHODS: Graphene oxide at four concentrations (20, 50, 80, and 100 µg·mL⁻¹) was loaded on the pure titanium surface via electroplating, and the morphology, properties, and hydrophilic properties were measured with a field emission scanning electron microscope, micro Raman spectrometer, and contact angle tester, respectively. In addition, Staphylococcus aureus and osteoblasts were used as models and cultured with pure titanium-graphene oxide. Then, field-emission scanning electron microscopy and laser confocal microscopy were utilized to observe the changes in the amount of bacteria and osteoblast morphology and structure, respectively. RESULTS: Graphene oxide at the four concentrations was successfully loaded on pure titanium surface via electroplating. It improved the hydrophilic properties of pure titanium surface, which benefitted the adhesion and growth of Staphylococcus aureus and changed the morphology and structure of the osteoblasts. CONCLUSIONS: The pure titanium-graphene oxide composite has no antibacterial properties and has good biocompatibility.


Assuntos
Grafite , Titânio , Aderência Bacteriana , Adesão Celular , Microscopia Eletrônica de Varredura , Osteoblastos , Óxidos , Propriedades de Superfície
6.
J Appl Oral Sci ; 27: e20180262, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31508789

RESUMO

The incorporation of antimicrobials in the composites as an attempt to reduce bacterial adhesion without jeopardizing mechanical properties is a challenge for Dentistry. OBJECTIVE To evaluate the bacterial adhesion and physical properties of a composite containing the methacrylate triclosan- derivative monomer (TM). METHODOLOGY TM was synthesized and added to an experimental composite. Samples were divided into two groups: Control and TM (13.4 wt%). Antibacterial Activity: Three specimens of each material were prepared and placed on bacterial suspensions of Streptococcus mutans for 1, 5 and 10 days. After these periods the counting of the colonies (log10) was performed. Assays was performed in triplicate. Physical Properties: Three-body Abrasion (TBA): Ten specimens of each material were prepared and stored at 37°C/24 h. The surface roughness (Ra) and hardness (KHN) were analyzed. Next, the specimens were submitted to abrasive wear (30,000 cycles) and re-evaluated for Ra and KHN; Sorption/solubility (SS): cylindrical specimens (n=10) were prepared and weighted. The specimens were immersed in deionized water for 7 days at 37°C and then their weight was verified again. SS were calculated using accepted formulas; Diametral tensile strength (DTS): specimens (n=10) underwent test performed in an Instron universal testing machine at a crosshead speed of 1 mm/min. Data were submitted to appropriate statistical tests according to data distribution and assay (p<0.05). RESULTS Bacterial Adhesion: TM showed a significant reduction on biofilm accumulation in the evaluated periods: 1 day (1.537±0.146); 5 days (2.183±0.138) and 10 days (4.469±0.155) when compared with Control: 1 day (4.954±0.249); 5 days (5.498±0.257) and 10 days (6.306±0.287). Physical Properties: For TBA, SS and DTS no significant difference was found between groups Control and TM. The incorporation of methacrylate triclosan-based monomer in the experimental composite reduce bacterial adhesion of S. mutans and did not affect important polymer properties.


Assuntos
Antibacterianos/química , Resinas Compostas/química , Metacrilatos/química , Triclosan/química , Antibacterianos/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Contagem de Colônia Microbiana , Resinas Compostas/farmacologia , Testes de Dureza , Teste de Materiais , Metacrilatos/farmacologia , Valores de Referência , Reprodutibilidade dos Testes , Solubilidade , Streptococcus mutans/efeitos dos fármacos , Propriedades de Superfície , Resistência à Tração , Fatores de Tempo , Escovação Dentária , Triclosan/farmacologia
7.
Autops. Case Rep ; 9(3): e2019093, July-Sept. 2019. ilus
Artigo em Inglês | LILACS | ID: biblio-1016685
8.
Nature ; 574(7776): 57-62, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31534221

RESUMO

The causative agent of plague, Yersinia pestis, uses a type III secretion system to selectively destroy immune cells in humans, thus enabling Y. pestis to reproduce in the bloodstream and be transmitted to new hosts through fleabites. The host factors that are responsible for the selective destruction of immune cells by plague bacteria are unknown. Here we show that LcrV, the needle cap protein of the Y. pestis type III secretion system, binds to the N-formylpeptide receptor (FPR1) on human immune cells to promote the translocation of bacterial effectors. Plague infection in mice is characterized by high mortality; however, Fpr1-deficient mice have increased survival and antibody responses that are protective against plague. We identified FPR1R190W as a candidate resistance allele in humans that protects neutrophils from destruction by the Y. pestis type III secretion system. Thus, FPR1 is a plague receptor on immune cells in both humans and mice, and its absence or mutation provides protection against Y. pestis. Furthermore, plague selection of FPR1 alleles appears to have shaped human immune responses towards other infectious diseases and malignant neoplasms.


Assuntos
Macrófagos/metabolismo , Neutrófilos/metabolismo , Peste/microbiologia , Receptores de Formil Peptídeo/metabolismo , Yersinia pestis/metabolismo , Alelos , Animais , Antígenos de Bactérias/metabolismo , Aderência Bacteriana , Sistemas CRISPR-Cas , Quimiotaxia/imunologia , Modelos Animais de Doenças , Feminino , Células HEK293 , Humanos , Macrófagos/citologia , Macrófagos/imunologia , Macrófagos/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neutrófilos/citologia , Neutrófilos/imunologia , Neutrófilos/microbiologia , Peste/imunologia , Peste/prevenção & controle , Polimorfismo de Nucleotídeo Único/genética , Proteínas Citotóxicas Formadoras de Poros/metabolismo , Receptores de Formil Peptídeo/antagonistas & inibidores , Receptores de Formil Peptídeo/deficiência , Receptores de Formil Peptídeo/genética , Sistemas de Secreção Tipo III/efeitos dos fármacos , Células U937 , Yersinia pestis/química , Yersinia pestis/imunologia , Yersinia pestis/patogenicidade
9.
J Med Microbiol ; 68(9): 1359-1366, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31364964

RESUMO

Methodology. Biochemical and molecular methods were used to identify 100 lactobacilli isolated from rectal swabs. Among these, L. paracasei ssp. paracasei LP5 and L. brevis LP9 showed significant antibacterial activity against S. agalactiae and L. monocytogenes. Accordingly, characterization of their bacteriocins, BacLP5 and BacLP9, was conducted to obtain information on their kinetic production, sensitivity to chemico-physical parameters and molecular weight. To investigate the possible use of the two Lactobacillus strains as probiotics, their gastrointestinal resistance, cellular adhesiveness and sensitivity to antibiotics were also studied.Results. The obtained data show that BacLP5 and BacLP9 most likely belong to class II bacteriocins and both have a molecular weight of approximately 3 kDa. The production of BacLP5 and BacLP9 started after 4 h (40 and 80 AU ml-1), respectively. Both of the Lactobacillus strains survived gastric and intestinal juices well and showed adhesive capability on HEp-2 cells.Conclusion. Due to their peculiar antimicrobial characteristics, L. paracasei ssp. paracasei LP5 and L. brevis LP9 are suitable for use in the treatment of vaginal disorders, through both oral and transvaginal administration.


Assuntos
Antibacterianos/metabolismo , Bacteriocinas/metabolismo , Lactobacillus brevis/metabolismo , Lactobacillus paracasei/metabolismo , Antibacterianos/química , Antibacterianos/isolamento & purificação , Aderência Bacteriana , Bacteriocinas/química , Bacteriocinas/isolamento & purificação , Ácidos e Sais Biliares/farmacologia , Linhagem Celular , Fenômenos Químicos , Suco Gástrico/metabolismo , Humanos , Lactobacillus brevis/classificação , Lactobacillus brevis/isolamento & purificação , Lactobacillus paracasei/classificação , Lactobacillus paracasei/isolamento & purificação , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Peso Molecular , Probióticos , Reto/microbiologia , Streptococcus agalactiae/efeitos dos fármacos , Streptococcus agalactiae/crescimento & desenvolvimento
10.
Chem Commun (Camb) ; 55(68): 10158-10161, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31389420

RESUMO

We developed a chemical method to covalently functionalize cellulose nanofibers and cellulose paper with mannoside ligands displaying a strong affinity for the FimH adhesin from pathogenic E. coli strains. Mannose-grafted cellulose proved efficient to selectively bind FimH lectin and discriminate pathogenic E. coli strains from non-pathogenic ones. These modified papers are valuable tools for diagnosing infections promoted by E. coli, such as cystitis or inflammatory bowel diseases, and the concept may be applicable to other life-threatening pathogens.


Assuntos
Celulose/química , Escherichia coli K12/isolamento & purificação , Mananas/química , Nanofibras/química , Adesinas de Escherichia coli/metabolismo , Aderência Bacteriana/efeitos dos fármacos , Técnicas de Tipagem Bacteriana/instrumentação , Técnicas de Tipagem Bacteriana/métodos , Linhagem Celular Tumoral , Celulose/metabolismo , Escherichia coli K12/química , Fezes/microbiologia , Proteínas de Fímbrias/metabolismo , Microbioma Gastrointestinal/efeitos dos fármacos , Humanos , Mananas/metabolismo , Papel , Ligação Proteica
11.
J Sci Food Agric ; 99(15): 6680-6688, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31328278

RESUMO

BACKGROUND: Traditional fermented products are a rich source of microorganisms which may have remarkable probiotic properties even more significant than probiotic strains of human origin. In this study three Lactobacillus plantarum and one Lactobacillus fermentum strains, isolated from either Iranian traditionally fermented products or children's feces, identified with molecular methods and selected based on high acid resistance, were investigated for their probiotic properties in vitro and compared with standard probiotic strains of the species; L. plantarum ATCC 14917, L. fermentum PTCC 1744 and L. acidophilus ATCC 4356. RESULTS: Most of the isolates showed a high survival rate under gastrointestinal tract conditions and L. plantarum strains displayed a moderate ability to adhere to human colon adenocarcinoma cell line, HT-29. Neutralized cell free culture supernatants of L. plantarum strains were capable of inhibiting pathogens. Almost all of the strains were resistant to vancomycin and streptomycin and susceptible to other clinically relevant antibiotics. Isolated strains exhibited low to moderate autoaggregation (Auto-A), co-aggregation (Co-A) and hydrophobicity, following a strain specific manner. None of the strains invaded into HT-29 cells while strain PF11 could significantly decrease the number of adhering pathogenic bacteria. Most of the strains increased apoptosis of HT-29 cells, though they had no effect on human umbilical vein endothelial cells (HUVECs). CONCLUSION: Favorable probiotic properties of strains PL4 and PF11 along with their anticancer activity imply their potential for clinical or technological applications. However, further in vitro/in vivo investigations are recommended. © 2019 Society of Chemical Industry.


Assuntos
Fezes/microbiologia , Alimentos Fermentados/microbiologia , Lactobacillus/isolamento & purificação , Probióticos/análise , Antibacterianos/farmacologia , Aderência Bacteriana , Células HT29 , Humanos , Irã (Geográfico) , Lactobacillus/efeitos dos fármacos , Lactobacillus/genética , Lactobacillus/fisiologia , Probióticos/classificação , Probióticos/isolamento & purificação
12.
Can J Vet Res ; 83(3): 231-234, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31308596

RESUMO

Assays were done to assess the ability of 5 methicillin-resistant Staphylococcus pseudintermedius (MRSP) isolates from difference sources to adhere to canine and human corneocytes. Cell wall-associated (CWA) protein gene profiles were examined to look for associations with adherence. Five MRSP strains were studied: 3 with the same CWA protein gene profile (14 genes) and belonging to sequence type (ST) 45 were isolated from a dog, a human, and the environment. The other 2 were an environmental isolate belonging to ST433 that had the lowest number of CWA protein genes (12) and a canine clinical isolate belonging to ST733 that had the greatest number of CWA protein genes (18). The 3 isolates of MRSP ST45, a major clone in Thailand, had the greatest ability to adhere to canine and human corneocytes. Nevertheless, MRSP adherence ability could not be predicted from the profile of genes encoding CWA proteins.


Assuntos
Aderência Bacteriana , Pele/citologia , Staphylococcus/efeitos dos fármacos , Animais , Células Cultivadas , Cães , Humanos , Meticilina/farmacologia , Resistência a Meticilina , Staphylococcus/classificação
13.
Lett Appl Microbiol ; 69(4): 246-251, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31357240

RESUMO

Staphylococcus epidermidis and Staphylococcus aureus, two bacterial strains commonly associated with biofilm-related medical infections and food poisoning, can rapidly colonize biotic and abiotic surfaces. The present study investigates the ability of anodic alumina surfaces with nanoporous surface topography to minimize the attachment and biofilm formation mediated by these pathogenic bacterial strains. Early attachment and subsequent biofilm development were retarded on surfaces with nanopores of 15-25 nm in diameter compared to surfaces with 50-100 nm pore diameter and nanosmooth surfaces. After 30 min of incubation in nutritive media, the biomass accumulation per unit surface area was 2·93 ± 1·72 µm3  µm-2 for the 15 nm, 3·49 ± 1·97 µm3  µm-2 for the 25 nm, as compared to 14·04 ± 6·39 µm3  µm-2 for the nanosmooth, 11·88 ± 9·72 µm3  µm-2 for the 50 nm and 12·09 ± 11·84 µm3  µm-2 for the 100 nm surfaces respectively. These findings suggest that anodic alumina with small size nanoscale pores could reduce the incidence of staphylococcal biofilms and infections, and shows promise as a material for a variety of medical applications and food contact surfaces. SIGNIFICANCE AND IMPACT OF THE STUDY: This paper reports on a simple, robust and scientifically sound method to reduce attachment and biofilm formation by Staphylococcus aureus and Staphylococcus epidermidis to abiotic surfaces using a carefully designed nanoscale topography. This approach can help to reduce the incidence of staphylococcal biofilms and infections without imposing selective stresses on bacteria, thus preventing the creation of resistant strains.


Assuntos
Óxido de Alumínio/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus epidermidis/crescimento & desenvolvimento , Nanoporos , Infecções Estafilocócicas/microbiologia
14.
BMC Vet Res ; 15(1): 234, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31286936

RESUMO

BACKGROUND: Enterotoxigenic Escherichia coli K88 (E. coli K88) are considered as a major cause of diarrhea and death in newly weaned piglets. Oral passive immunization with chicken egg yolk immunoglobulins (IgY) have attracted considerable attention for treatment of gastrointestinal infection due to its high specificity. In this study it was estimated the protective effect of anti-K88 fimbriae IgY against E. coli K88 adhesion to piglet intestinal mucus in vitro and to investigate the potential use of IgY for controlling E. coli-induced diarrhea in weaned piglets in vivo. RESULTS: E. coli K88 was incubated with IgY for 24 h, and the bacterial growth profiles showed that specific IgY with a concentration higher than 5 mg/mL was observed to significantly inhibit the growth of E. coli K88 compared to nonspecific yolk powder in a liquid medium. Moreover, pretreatment with 50 mg/mL of IgY was found to significantly decrease the adhesion ability of E. coli K88 to porcine jejunal and ileal mucus, further supported by the observations from our immunofluorescence microscopic analysis. In vivo, administration of IgY successfully protected piglets from diarrhea caused by E. coli K88 challenge. Additionally, IgY treatment efficiently alleviated E. coli-induced intestinal inflammation in piglets as the gene expression levels of inflammatory cytokines TNF-α, IL-22, IL-6 and IL-1ß in IgY-treated piglets remained unchanged after E. coli K88 infection. Furthermore, IgY significantly prevented E. coli K88 adhering to the jejunal and ileal mucosa of piglets with E. coli infection and significantly decreased E. coli and enterotoxin expression in colonic contents. CONCLUSION: Outcome of the study demonstrated that IgY against the fimbrial antigen K88 was able to significantly inhibit the growth of E. coli K88, block the binding of E. coli to small intestinal mucus, and protect piglets from E. coli-induced diarrhea. These results indicate that passive immunization with IgY may be useful to prevent bacterial colonization and to control enteric diseases due to E. coli infection. The study has great clinical implication to provide alternative therapy to antibiotics in E coli induced diarrhea.


Assuntos
Aderência Bacteriana/efeitos dos fármacos , Diarreia/etiologia , Diarreia/prevenção & controle , Escherichia coli Enterotoxigênica/efeitos dos fármacos , Infecções por Escherichia coli/complicações , Imunoglobulinas/farmacologia , Animais , Antígenos de Bactérias/imunologia , Citocinas/genética , Diarreia/microbiologia , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/patologia , Infecções por Escherichia coli/prevenção & controle , Proteínas de Escherichia coli/imunologia , Proteínas de Fímbrias/imunologia , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/imunologia , Imunização Passiva , Imunoglobulinas/uso terapêutico , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Ligação Proteica/efeitos dos fármacos , Suínos
15.
J Agric Food Chem ; 67(28): 8029-8034, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31246026

RESUMO

A special levan-type exopolysaccharide (EPS) from Bacillus amyloliquefaciens JN4 with antiadhesive activity against enterotoxigenic Escherichia coli (ETEC) was purified and identified. Chemical analysis indicated that EPS-JN4 with a low molecular weight of 8 kDa is composed of fructose and glucose with a molar ratio of 46.1:1. Structural analysis clarified that EPS-JN4 contains a main chain of ß-(2,6)-linked Fruf residues and intensive branches of a single 2-linked Fruf at every six residues. Furthermore, the superior antiadhesive activity of EPS-JN4 against ETEC showed its potential usage as an antiadhesive agent for diarrhea prevention. EPS-JN4 is a specific type of levan family, for its small molecular size and intensive branches. The results expand the knowledge on structural types of levan and illustrate its potential as an antiadhesive agent for diarrhea prevention, which will be conducive to elucidate the relation between structure and function.


Assuntos
Antibacterianos/farmacologia , Bacillus amyloliquefaciens/química , Aderência Bacteriana/efeitos dos fármacos , Escherichia coli Enterotoxigênica/efeitos dos fármacos , Frutanos/farmacologia , Polissacarídeos Bacterianos/farmacologia , Antibacterianos/química , Antibacterianos/metabolismo , Bacillus amyloliquefaciens/metabolismo , Escherichia coli Enterotoxigênica/fisiologia , Frutanos/química , Frutanos/metabolismo , Espectroscopia de Ressonância Magnética , Peso Molecular , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/metabolismo
16.
J Dairy Sci ; 102(8): 6738-6749, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31178178

RESUMO

Microbiome modulators such as probiotics are known to modulate oral diseases. Very few probiotics are commercially available for use in the oral cavity. In this context, we selected human-origin Lactobacillus salivarius AR809 as a promising oropharyngeal probiotic and characterized its functional and immunomodulatory properties. Results demonstrated that AR809 could efficiently adhere to pharyngeal epithelial FaDu cells, antagonize Staphylococcus aureus, adapt to the oral environment, and modulate host innate immunity by inducing potentially protective effects. Particularly, AR809 diminished proinflammatory activity by enhancing the production of IL10 and inhibiting the expression of tumor necrosis factor-α, IL1B, inducible nitric oxide synthase, and RELA. Finally, we observed that AR809 grew efficiently when cultured in milk, suggesting that the preparation of a fermented milk product containing AR809 could be a practical way to administer this probiotic to humans. In conclusion, AR809 has high potential to adhere to the pharyngeal mucosa and could be applied in novel milk-based probiotic fermented food products.


Assuntos
Aderência Bacteriana/fisiologia , Imunidade/fisiologia , Lactobacillus salivarius/isolamento & purificação , Lactobacillus salivarius/fisiologia , Boca/microbiologia , Faringe/microbiologia , Animais , Produtos Fermentados do Leite , Epitélio/microbiologia , Humanos , Inflamação/prevenção & controle , Probióticos , Fator de Necrose Tumoral alfa/antagonistas & inibidores
17.
Microbes Environ ; 34(3): 244-251, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31189768

RESUMO

The thermophilic hydrogenotrophic methanogen, Methanothermobacter sp. CaT2, which possesses an extracellular sugar layer, commonly aggregates by itself or with other microorganisms. To elucidate the molecular mechanisms responsible for this aggregation, the aggregation-defective mutant, CLA160, was isolated. Optical and electron microscopy observations revealed that the mutant exhibited a significant reduction in aggregation. Genomic sequencing showed that CLA160 has a single point mutation, causing a nonsense mutation in MTCT_1020, which encodes a hypothetical protein. Motif and domain analyses indicated that the hypothetical protein bears two membrane-spanning segments at the N- and C-terminal regions and a large middle repeat-containing region. The results of a bioinformatic analysis suggested that the first middle region (RII) of the protein or the whole structure is responsible for the function of the product of MTCT_1020 in the aggregation of CaT2. A treatment with proteinase K suppressed sedimentation in CaT2, indicating a reduction in aggregation, with almost no effect on sedimentation in CLA160. The addition of Ca2+ or Mg2+ ions enhanced sedimentation in CaT2, whereas a DNase treatment had no effect on sedimentation in either strain. These results suggest that the hypothetical protein encoded by MTCT_1020 plays a key role as a membrane-bound adhesion protein in the aggregation of CaT2, which is enhanced by the addition of Ca2+ or Mg2+ ions.


Assuntos
Aderência Bacteriana/genética , Proteínas de Bactérias/genética , Methanobacteriaceae/genética , Aderência Bacteriana/efeitos dos fármacos , Proteínas de Bactérias/química , Cátions Bivalentes/farmacologia , Endopeptidase K/farmacologia , Genoma Bacteriano/genética , Temperatura Alta , Metano/metabolismo , Methanobacteriaceae/classificação , Methanobacteriaceae/ultraestrutura , Mutação , Filogenia , Domínios Proteicos , Análise de Sequência de DNA
18.
Int J Nanomedicine ; 14: 3245-3263, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31190792

RESUMO

Background: Bacterial resistance to antibiotics is one of the biggest challenges facing medicine today. Anti-adhesive therapy, using inhibitors of bacterial adhesion to epithelial cells, one of the first stages of infection, is a promising approximation in this area. The size, shape, number of sugar and their placement are variables that have to be taken into account in order to develop multivalent systems able to inhibit the bacterial adhesion based on sugar-lectin interaction. Materials and methods: In the present work we report a modular approach for the synthesis of water-soluble 1D-carbon nanotube-sugar nanoconstructs, with the necessary flexibility to allow an efficient sugar-lectin interaction. The method is based on the reaction of aryl diazonium salts generated in situ from aniline-substituted mannose and lactose derivatives with single wall carbon nanotubes (SWCNTs) sidewalls. Results: Two hybrid nanosystems, I-II, exposing mannose or lactose and having a tetraethylene glycol spacer between the sugar and the nanotube sidewall were rapidly assembled and adequately characterized. The sweet nano-objects were then tested for their ability to agglutinate and selectively inhibit the growth of uropathogenic Escherichia coli. These studies have shown that nanosystem I, exposing mannose on the nanotube surface is able to agglutinate and to inhibit the bacterial growth unlike nano-objects II exposing lactose. Conclusion: The results reported constitute a proof of principle in using mannose-coated 1D-carbon nanotubes as antiadhesive drugs that compete for FimH binding and prevent the uropathogenic bacteria from adhering to the urothelial surface.


Assuntos
Escherichia coli/citologia , Nanotubos de Carbono/química , Aglutinação , Aderência Bacteriana/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Escherichia coli/ultraestrutura , Manose/química , Nanotubos de Carbono/ultraestrutura , Polissacarídeos/síntese química , Polissacarídeos/química , Propriedades de Superfície
19.
Vet Res ; 50(1): 43, 2019 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-31164171

RESUMO

Riemerella anatipestifer is a major pathogenic agent of duck septicemic and exudative diseases. Genetic analyses suggest that this pathogen has a novel protein secretion system, known as the "type IX secretion system" (T9SS). We previously reported that deletion of the AS87_RS08465 gene significantly reduced the bacterial virulence of the R. anatipestifer strain Yb2, but the mechanism remained unclear. The AS87_RS08465 gene is predicted to encode the gliding motility protein GldM (GldM) protein, a key component of the T9SS complex. In this study, Western blotting analysis demonstrated that R. anatipestifer GldM was localized to the cytomembrane. Further study revealed that the adhesion and invasion capacities of the mutant strain RA2281 (designated Yb2ΔgldM) in Vero cells and the bacterial loads in the blood of infected ducks were significantly reduced. RNA-Seq and PCR analyses showed that six genes were upregulated and five genes were downregulated in the mutant strain Yb2ΔgldM and that these genes were mainly involved in the secretion of proteins. Yb2ΔgldM was also found to be defective in gliding motility and protein secretion. Liquid chromatography-tandem mass spectrometry analysis revealed that nine of the proteins had a conserved T9SS C-terminal domain and were differentially secreted by Yb2ΔgldM compared to Yb2. The complementation strain cYb2ΔgldM recovered the adhesion and invasion capacities in Vero cells and the bacterial loads in the blood of infected ducks as well as the bacterial gliding motility and most protein secretion in the mutant strain Yb2ΔgldM to the levels of the wild-type strain Yb2. Taken together, these results indicate that R. anatipestifer GldM is associated with T9SS and is important in bacterial virulence.


Assuntos
Aderência Bacteriana/genética , Expressão Gênica , Riemerella/genética , Riemerella/patogenicidade , Sistemas de Secreção Tipo IV/genética , Mutação , Peptídeo Hidrolases/biossíntese , Riemerella/enzimologia , Sistemas de Secreção Tipo IV/metabolismo , Virulência/genética , Fatores de Virulência/genética
20.
Mater Sci Eng C Mater Biol Appl ; 102: 623-633, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31147034

RESUMO

The current work deals with a time-dependent study to track the antibacterial action of electrodeposited Cu, Cu-SiC functionally graded coating (FGC) against Escherichia coli NCIM 2931 (Gram-negative) and Bacillus subtilis NCIM 2063 (Gram-positive). After 24 h of incubation, the Cu, Cu-SiC FGC causes 7 Escherichia coli NCIM 2931 and 10 Bacillus subtilis NCIM 2063 log reduction of planktonic cells. The outer membrane permeabilization experiment proves that the intake of excessive Cu ions leads to the damage of bacterial cell membrane followed by lipid degradation. The thiobarbituric acid reactive substances assay reveals that Cu ions released from the surface of Cu, Cu-SiC FGC triggers the oxidative degeneration of phospholipids (most abundant constituent of bacterial cell membrane). This was further cross-verified using atomic absorption spectroscopy. From 0 to 24 h, the bacterial morphology is characterized using transmission electron microscope and scanning electron microscope which shows the cytoplasmic leakage and cell death. The Cu, Cu-SiC FGC also exhibits hydrophobic surface (contact angle of 144°) which prevents the bacterial adherence to the surface and thus, inhibits them to penetrate into its bulk. The observed results of antibacterial and anti-adhesion properties of Cu, Cu-SiC FGC are compared with single-layered metallic Cu and Cu-SiC nanocomposite coatings. Hence, the electrodeposited Cu, Cu-SiC FGC has the potential to serve as an inexpensive touch surface alternative for the healthcare industries.


Assuntos
Membrana Celular/metabolismo , Materiais Revestidos Biocompatíveis/farmacologia , Galvanoplastia/métodos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Antibacterianos/farmacologia , Bacillus subtilis/efeitos dos fármacos , Bacillus subtilis/crescimento & desenvolvimento , Bacillus subtilis/ultraestrutura , Aderência Bacteriana/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Contagem de Colônia Microbiana , Cobre/metabolismo , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/ultraestrutura , Íons , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Fatores de Tempo
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