共查询到20条相似文献,搜索用时 31 毫秒
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Christian Theilacker Irina Sava Patricia Sanchez-Carballo Yinyin Bao Andrea Kropec Elisabeth Grohmann Otto Holst Johannes Huebner 《BMC microbiology》2011,11(1):67
Background
Deletion of the glycosyltransferase bgsA in Enterococcus faecalis leads to loss of diglucosyldiacylglycerol from the cell membrane and accumulation of its precursor monoglucosyldiacylglycerol, associated with impaired biofilm formation and reduced virulence in vivo. Here we analyzed the function of a putative glucosyltransferase EF2890 designated biofilm-associated glycolipid synthesis B (bgsB) immediately downstream of bgsA. 相似文献3.
Aim
This study aimed to develop a simplified chemically defined medium that could sustain the growth and bacteriocin (enterolysin A) production by Enterococcus faecalis B9510.Methods and Results
The nutritional requirements of E. faecalis B9510 in a chemically defined medium were determined by single omission experiments. It was observed that eight amino acids (arginine, glycine, histidine, isoleucine, leucine, methionine, tryptophan and valine), three B vitamins (nicotinic acid, Ca‐pantothenic acid and pyridoxal) and magnesium sulphate were essential for growth. Based on this information, a Simplified Defined Medium (SDM) was formed consisting of 26 components. Comparison of SDM with M‐17 showed that growth and bacteriocin production in SDM was similar to that in M‐17. The bacteriocin from SDM was then purified by ultrafiltration. The retentate of ultrafiltration step was analysed by SDS‐PAGE and the results showed a single active band in the gel, which was excised and analysed by mass spectrometry, which indicated that the active band was enterolysin A, a cell wall degrading bacteriocin.Conclusions
A simplified defined medium can be formulated for the growth and bacteriocin production by Enterococcus faecalis, whose efficiency is comparable with that of a complex commercial medium.Significance and Impact of the Study
The development of such a medium can be useful for bacteriocin production and subsequent purification in a simplified manner and, therefore, helpful in the identification of novel bacteriocins. 相似文献4.
Chan Yean Yean Lee Su Yin Pattabhiraman Lalitha Manickam Ravichandran 《BMC microbiology》2007,7(1):112
Background
Enterococci have emerged as a significant cause of nosocomial infections in many parts of the world over the last decade. The most common enterococci strains present in clinical isolates are E. faecalis and E. faecium which have acquired resistant to either gentamicin or vancomycin. The conventional culture test takes 2–5 days to yield complete information of the organism and its antibiotic sensitivity pattern. Hence our present study was focused on developing a nanoplex PCR assay for the rapid detection of vancomycin and bifunctional aminoglycoside resistant enterococci (V-BiA-RE). This assay simultaneously detects 8 genes namely 16S rRNA of Enterococcus genus, ddl of E. faecalis and E. faecium, aacA-aphD that encodes high level gentamicin resistance (HLGR), multilevel vancomycin resistant genotypes such as vanA, vanB, vanC and vanD and one internal control gene. 相似文献5.
Margrete Solheim Mari C Brekke Lars G Snipen Rob JL Willems Ingolf F Nes Dag A Brede 《BMC microbiology》2011,11(1):3
Background
Enterococci rank among the leading causes of nosocomial infections. The failure to identify pathogen-specific genes in Enterococcus faecalis has led to a hypothesis where the virulence of different strains may be linked to strain-specific genes, and where the combined endeavor of the different gene-sets result in the ability to cause infection. Population structure studies by multilocus sequence typing have defined distinct clonal complexes (CC) of E. faecalis enriched in hospitalized patients (CC2, CC9, CC28 and CC40). 相似文献6.
Renato S. Gonçalves Patrícia V. Abdelnur Vanessa G. Santos Rosineide C. Simas Marcos N. Eberlin Alviclér Magalhães Eduardo R. Pérez González 《Amino acids》2011,40(1):197-204
Abstract
Potentially bioactive N-(aminoalkyl)lactamic amino acids and esters were synthesized in satisfactory to good yields by SNAr reactions of aromatic acids with N-(3-aminopropyl)lactams followed by esterification with tertiary amino alcohols. The addition–elimination SNAr mechanism was confirmed by NMR and MS measurements. 相似文献7.
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Carolyn T Hsu Amanda L Ganong Barbara Reinap Zafiria Mourelatos Johannes Huebner Julia Y Wang 《BMC microbiology》2006,6(1):62-9
Background
Enterococci have become major nosocomial pathogens due to their intrinsic and acquired resistance to a broad spectrum of antibiotics. Their increasing drug resistance prompts us to search for prominent antigens to develop vaccines against enterococci. Given the success of polysaccharide-based vaccines against various bacterial pathogens, we isolated and characterized the immunochemical properties of polysaccharide antigens from five strains of Enterococcus faecalis and one strain of vancomycin-resistant E. faecium. 相似文献10.
Dirk Kraus Silvia Herbert Sascha A Kristian Arya Khosravi Victor Nizet Friedrich Götz Andreas Peschel 《BMC microbiology》2008,8(1):85
Background
Modification of teichoic acids with D-alanine by the products of the dlt operon protects Gram-positive bacteria against major antimicrobial host defense molecules such as defensins, cathelicidins, myeloperoxidase or phospholipase. The graRS regulatory genes have recently been implicated in the control of D-alanylation in Staphylococcus aureus. 相似文献11.
Kephir is a fermented carbonated refreshing milk, with a slightly acidic aromatic taste and creamy foam composition which contains lactobacilli, leuconostocci, acetic acid bacteria, lactostreptococci and yeasts. Recent studies have demonstrated its antibacterial, immunostimulating, antitumoral and cholesterol-lowering activities.
Purpose
The purpose of this study was to investigate the antimicrobial activity of kephir against Bacillus subtilis spp. spizizenii ATCC 6633, Staphylococcus aureus ATCC 6538, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 8739, Salmonella enteritidis ATCC 13076, Pseudomonas aeruginosa ATCC 9027 and Candida albicans ATCC 10231. The kephir fermented for 24 h and 48 h, as well and after 7 days preservation at 4–8 °C was tested by in vitro disk diffusion method. The intensity of the antimicrobial activity was interpreted by comparison with two antibiotics, i.e. ampicillin and neomycin.Results
The antimicrobial activity of 24 h as well as 48 fermented kephir, fresh or after 7 days preservation at 4–8 °C was similar and observed against B. subtilis, S. aureus, E. coli, E. faecalis and S. enteritidis. For E. coli, E. faecalis and S. enteritidis the antimicrobial activity was superior to both tested antibiotics and for B. subtilis and S. aureus to one antibiotic. The tested products exhibited no activity against P. aeruginosa and C. albicans.Conclusion
Kephir is exhibiting large spectrum and strong antibacterial activity probably due to the complex viable probiotic strains association producing antimicrobial substances. 相似文献12.
The house fly (Musca domestica L.) alimentary canal was evaluated for the potential of horizontal transfer of tetM on plasmid pCF10 among Enterococcus faecalis. Two sets of experiments were conducted: (1) house flies without surface sterilization and (2) surface-sterilized flies.
Both sets of flies were exposed to E. faecalis OG1RF:pCF10 as donor for 12 h and then E. faecalis OG1SSp as recipient for 1 h. Another group of flies received the recipient first for 12 h followed by exposure to the donor
strain for 1 h. House flies were screened daily to determine the donor, recipient, and transconjugant bacterial load for up
to 5 days. In addition, the sponge-like mouth parts used for food uptake (labellum) of surface-sterilized house flies were
removed and analyzed for donors, recipients, and transconjugants, separately. In both groups of flies (n = 90 flies/group), transfer occurred within 24 h after exposure with a transconjugant/donor rate from 8.6 × 10−5 to 4.5 × 101. Transconjugants were also isolated from the house fly labellum. Our data suggest that the house fly digestive tract provides
a suitable environment for horizontal transfer of conjugative plasmids and antibiotic resistance genes among enterococci.
Our results emphasize the importance of this insect as a potential vector of antibiotic-resistant bacterial strains. 相似文献
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Markus Klint Mikael Thollesson Erik Bongcam-Rudloff Svend Birkelund Anders Nilsson Björn Herrmann 《BMC microbiology》2010,10(1):81
Background
The histone-like protein Hc2 binds DNA in Chlamydia trachomatis and is known to vary in size between 165 and 237 amino acids, which is caused by different numbers of lysine-rich pentamers. A more complex structure was seen in this study when sequences from 378 specimens covering the hctB gene, which encodes Hc2, were compared. 相似文献14.
Objective
To investigate the effects of heat-killed Enterococcus faecalis ATCC 29212 and P25RC clinical strain (derived from an obturated root canal with apical periodontitis) on osteoclast differentiation within an osteoblast/osteoclast co-culture system.Results
Heat-killed E. faecalis significantly increased the proportion of multinucleated osteoclastic cells (MNCs) within the co-culture system. The IL-6 level was significantly increased upon exposure to heat-killed E. faecalis. Gene expression levels of NFATc1 and cathepsin K were significantly up-regulated compared to the untreated control. EphrinB2 and EphB4 expressions at both the mRNA and protein levels were also significantly upregulated compared to the untreated control.Conclusions
Heat-killed E. faecalis can induce osteoclast differentiation within the osteoblast/osteoclast co-culture system in vitro, possibly through ephrinB2-EphB4 bidirectional signaling.15.
Peter Sass Andrea Jansen Christiane Szekat Vera Sass Hans-Georg Sahl Gabriele Bierbaum 《BMC microbiology》2008,8(1):186
Background
The lantibiotic mersacidin is an antimicrobial peptide of 20 amino acids that is ribosomally produced by Bacillus sp. strain HIL Y-85,54728. Mersacidin acts by complexing the sugar phosphate head group of the peptidoglycan precursor lipid II, thereby inhibiting the transglycosylation reaction of peptidoglycan biosynthesis. 相似文献16.
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Background
The endoglycosidase EndoS and the cysteine proteinase SpeB from the human pathogen Streptococcus pyogenes are functionally related in that they both hydrolyze IgG leading to impairment of opsonizing antibodies and thus enhance bacterial survival in human blood. In this study, we further investigated the relationship between EndoS and SpeB by examining their in vitro temporal production and stability and activity of EndoS. Furthermore, theoretical structure modeling of EndoS combined with site-directed mutagenesis and chemical blocking of amino acids was used to identify amino acids required for the IgG glycan-hydrolyzing activity of EndoS. 相似文献18.
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Background
Lactococcus lactis is recognised as a safe (GRAS) microorganism and has hence gained interest in numerous biotechnological approaches. As it is fastidious for several amino acids, optimization of processes which involve this organism requires a thorough understanding of its metabolic regulations during multisubstrate growth. 相似文献20.
Cinzia Comino Sergio Lanteri Ezio Portis Alberto Acquadro Annalisa Romani Alain Hehn Romain Larbat Frédéric Bourgaud 《BMC plant biology》2007,7(1):14