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1.
Biotechnol Rep (Amst) ; 7: 64-71, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28626716

RESUMO

A highly sensitive and convenient method for detecting influenza virus was developed using modified end-point melt curve analysis of a RT-qPCR SYBR Green method and influenza virus-binding sugar chain-immobilized gold-nanoparticles (SGNP). Because SGNPs capture influenza viruses, the virus-SGNP complex was separated easily by centrifugation. Viral RNA was detected at very low concentrations, suggesting that SGNP increased sensitivity compared with standard methods. This method was applied to clinical studies. Influenza viruses were detected in saliva of patients or inpatients who had been considered influenza-free by a rapid diagnostic assay of nasal swabs. Furthermore, the method was applied to a human trial of prophylactic anti-influenza properties of yogurt containing Lactobacillus acidophilus L-92. The incidence of influenza viruses in saliva of the L-92 group was found to be significantly lower compared to the control group. Thus, this method was useful for monitoring the course of anti-influenza treatment or preventive measures against nosocomial infection.

2.
Extremophiles ; 14(4): 403-7, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20556446

RESUMO

Pyrobaculum islandicum is a hyperthermophilic archaeon. P. islandicum cells have been suggested to multiply by constriction, budding and branching, as no septa were observed in cells by phase-contrast light microscopy. In this study, we observed the cells using transmission electron microscopy, scanning electron microscopy, and light microscopy with dark-field image analyses, and we report binary fission via septum formation to be the main mode of P. islandicum's proliferation. "Long cells" reported previously were found to comprise several cylindrical cells that align in tandem.


Assuntos
Pyrobaculum/crescimento & desenvolvimento , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Pyrobaculum/citologia , Pyrobaculum/ultraestrutura
3.
Biomed Res ; 29(1): 9-18, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18344593

RESUMO

H. pylori is a gram-negative bacterium associated with gastric inflammation and peptic ulcer and considered a risk factor for gastric cancer in its natural habitat. However, the energy metabolism of H. pylori in the stomach remains to be clarified. H. pylori shows rather high respiratory activity with L-proline and significantly large amounts of L-proline are present in the gastric juice from H. pylori infected patients. We constructed a disrupted mutant of the put A gene, which encodes the proline utilization A (Put A) flavin-linked enzyme, in order to examine the role of put A in the gastric colonization of H. pylori. The put A disrupted mutant, DeltaputA, was constructed by inserting a chloramphenicol resistant gene into put A. DeltaputA did not show respiratory activity using L-proline and could not incorporate L-proline into cells. DeltaputA also did not show motility in response to amino acids and did not display the swarming activity observed with the wild-type. DeltaputA had lost its ability to colonize the stomach of nude mice, an ability possessed by the wild-type. These findings indicate that put A may play an important role in H. pylori colonization on the gastric mucus layer.


Assuntos
Proteínas de Bactérias/metabolismo , Proliferação de Células , Helicobacter pylori/enzimologia , Helicobacter pylori/patogenicidade , Proteínas de Membrana/metabolismo , Movimento , Animais , Fenômenos Fisiológicos Bacterianos , Proteínas de Bactérias/genética , Transporte Biológico , Células Cultivadas , Resistência ao Cloranfenicol , Contagem de Colônia Microbiana , Feminino , Infecções por Helicobacter/enzimologia , Helicobacter pylori/genética , Helicobacter pylori/crescimento & desenvolvimento , Processos Heterotróficos , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos BALB C , Mutagênese Insercional , Proteínas Mutantes , Prolina/metabolismo , Prolina Oxidase/deficiência , Estômago/microbiologia , Estômago/fisiopatologia , Transformação Bacteriana
4.
Infect Immun ; 75(4): 1926-32, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17283098

RESUMO

Lipoteichoic acid (LTA) is a cell surface glycoconjugate of gram-positive bacteria and is reported to activate the innate immune system. We previously reported that purified LTA obtained from Enterococcus hirae has no immunostimulating activity, but a subfraction (Eh-AF) in an LTA fraction possesses activity. In this study, we established a mouse monoclonal antibody neutralizing the activity of Eh-AF and investigated its inhibitory effects. Monoclonal antibody (MAbEh1) was established by the immunization of BALB/c mice with Eh-AF, followed by hybridoma screening based on its inhibitory effect for the production of interleukin-6 (IL-6) induced by Eh-AF. MAbEh1 neutralized the production of IL-6 by LTA fraction from not only E. hirae but also Staphylococcus aureus, while it failed to block that of lipopolysaccharide, suggesting that the antibody recognized a common active structure(s) in LTA fractions. Synthetic glycolipids in these LTAs did not induce cytokine production, at least in our system. Interestingly, the antibody was found to inhibit the activity of immunostimulating synthetic lipopeptides, Pam(3)CSK(4) and FSL-1. These results suggest that MAbEh1 neutralizes the activity of lipoprotein-like compounds which is responsible for the activity of the LTA fraction of E. hirae and S. aureus.


Assuntos
Anticorpos Antibacterianos/imunologia , Anticorpos Monoclonais/imunologia , Enterococcus/imunologia , Lipopolissacarídeos/imunologia , Lipoproteínas/imunologia , Ácidos Teicoicos/imunologia , Animais , Linhagem Celular Tumoral , Interleucina-6/metabolismo , Lipopolissacarídeos/isolamento & purificação , Lipoproteínas/isolamento & purificação , Camundongos , Camundongos Endogâmicos BALB C , Modelos Animais , Testes de Neutralização , Staphylococcus aureus/imunologia , Ácidos Teicoicos/isolamento & purificação
5.
Int Immunol ; 18(2): 355-62, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16373361

RESUMO

Lipoteichoic acid (LTA) derived from Staphylococcus aureus is reported to be a ligand of Toll-like receptor 2 (TLR2). In this study, we demonstrated that lipoproteins obtained from S. aureus are potent activators of TLR2. A fraction obtained by Triton X-114 phase partitioning activated cells through TLR2. The fraction contained proteins and LTA. The activity was detected in compounds in a mass range of 12-40 kDa. Proteinase K digested the active compounds into lower molecular weight active materials <10 kDa. In contrast, hydrofluoric acid treatment, which decomposes LTA, did not alter the molecular mass of the active compounds. Further, most of the activity was abrogated by lipoprotein lipase digestion. These results suggested that lipoproteins are predominant TLR2 ligands in S. aureus cell wall components.


Assuntos
Proteínas de Bactérias/metabolismo , Lipoproteínas/metabolismo , Staphylococcus aureus/metabolismo , Receptor 2 Toll-Like/metabolismo , Animais , Proteínas de Bactérias/imunologia , Parede Celular/metabolismo , Citocinas/biossíntese , Sistema Imunitário/citologia , Sistema Imunitário/imunologia , Ligantes , Lipoproteínas/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Octoxinol , Polietilenoglicóis , Staphylococcus aureus/imunologia
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