| identification of amino acid residues at the active site of endosialidase that dissociate the polysialic acid binding and cleaving activities in escherichia coli k1 bacteriophages. | endosialidase (endo-n-acetylneuraminidase) is a tailspike enzyme of bacteriophages specific for human pathogenic escherichia coli k1, which specifically recognizes and degrades polysia (polysialic acid). polysia is also a polysaccharide of the capsules of other meningitis- and sepsis-causing bacteria, and a post-translational modification of the ncam (neural cell-adhesion molecule). we have cloned and sequenced three spontaneously mutated endosialidases of the pk1a bacteriophage and one of the p ... | 2007 | 17394421 |
| Capsular polysaccharide vaccine for Group B Neisseria meningitidis, Escherichia coli K1, and Pasteurella haemolytica A2. | We reviewed the literature that is the basis for our proposal that (2?8)-a-Neu5Ac conjugates will be safe and effective vaccines for Group B meningococci (GBMs), Escherichia coli K1, and Pasteurella haemolytica A2. Although (2?8)-a-Neu5Ac is a virulence factor and a protective antigen of these three pathogens, it is also a component of normal tissues (neural cell adhesion molecule). Natural, anti-(2?8)-a-Neu5Ac present in most adults, vaccine-induced antibodies, and even high levels of spontaneo ... | 2011 | 22025709 |
| separate pathways for o acetylation of polymeric and monomeric sialic acids and identification of sialyl o-acetyl esterase in escherichia coli k1. | o acetylation at carbon positions 7 or 9 of the sialic acid residues in the polysialic acid capsule of escherichia coli k1 is catalyzed by a phase-variable contingency locus, neuo, carried by the k1-specific prophage, cus-3. here we describe a novel method for analyzing polymeric sialic acid o acetylation that involves the release of surface sialic acids by endo-n-acetylneuraminidase digestion, followed by fluorescent labeling and detection of quinoxalinone derivatives by chromatography. the res ... | 2006 | 16923886 |
| the microbiome of the middle meatus in healthy adults. | rhinitis and rhinosinusitis are multifactorial disease processes in which bacteria may play a role either in infection or stimulation of the inflammatory process. rhinosinusitis has been historically studied with culture-based techniques, which have implicated several common pathogens in disease states. more recently, the nih human microbiome project has examined the microbiome at a number of accessible body sites, and demonstrated differences among healthy and diseased patients. recent dna-base ... | 2013 | 24386477 |
| analysis of the sds-page patterns of outer membrane proteins from escherichia coli strains that have lost the ability to form k1 antigen and varied in the susceptibility to normal human serum. | we used sds-polyacrylamide gel electrophoresis to investigate the outer membrane proteins (omps) band composition of 19 escherichia coli k1 strains that have spontaneously lost the ability to form k1 polysaccharide capsule (e. coli k1-) and demonstrated different degrees of susceptibility to the bactericidal action of normal human serum. presented results showed that there were differences between e. coli k1- strains in omps expressing capacity. the analysis performed on omps has not revealed a ... | 2013 | 23794053 |
| analysis of the sds-page patterns of outer membrane proteins from escherichia coli strains that have lost the ability to form k1 antigen and varied in the susceptibility to normal human serum. | we used sds-polyacrylamide gel electrophoresis to investigate the outer membrane proteins (omps) band composition of 19 escherichia coli k1 strains that have spontaneously lost the ability to form k1 polysaccharide capsule (e. coli k1-) and demonstrated different degrees of susceptibility to the bactericidal action of normal human serum. presented results showed that there were differences between e. coli k1- strains in omps expressing capacity. the analysis performed on omps has not revealed a ... | 2013 | 23794053 |
| performance comparison of illumina and ion torrent next-generation sequencing platforms for 16s rrna-based bacterial community profiling. | high-throughput sequencing of the taxonomically informative 16s rrna gene provides a powerful approach for exploring microbial diversity. here we compare the performances of two common "benchtop" sequencing platforms, illumina miseq and ion torrent personal genome machine (pgm), for bacterial community profiling by 16s rrna (v1-v2) amplicon sequencing. we benchmarked performance by using a 20-organism mock bacterial community and a collection of primary human specimens. we observed comparatively ... | 2014 | 25261520 |
| profiling bacterial community in upper respiratory tracts. | infection by pathogenic viruses results in rapid epithelial damage and significantly impacts on the condition of the upper respiratory tract, thus the effects of viral infection may induce changes in microbiota. thus, we aimed to define the healthy microbiota and the viral pathogen-affected microbiota in the upper respiratory tract. in addition, any association between the type of viral agent and the resultant microbiota profile was assessed. | 2014 | 25391813 |
| meningitis due to moraxella nonliquefaciens in a paediatric patient: a case report and review of the literature. | introduction.moraxella nonliquefaciens is an unusual organism to be isolated from cerebral spinal fluid (csf) and there exists only one case report of m. nonliquefaciens meningitis from a neonate. moraxella species normally exist as part of the human upper respiratory tract flora and rarely cause invasive human disease. there are only a handful of case reports implicating the organism as a cause of endocarditis, bacteraemia, septic arthritis and endophthalmitis. identification to the species lev ... | 2017 | 28348808 |
| a fatal endocarditis case due to an emerging bacterium: moraxella nonliquefaciens. | moraxella nonliquefaciens is a gram-negative coccobacillus considered as a commensal organism from the upper respiratory tract, with low pathogenic potential. the phenotypical conventional identification is difficult and the matrix-assisted laser desorption/ionization time-of-flight technology has increased the resolution of identification of this bacterium. we report a fatal case of endocarditis due to m. nonliquefaciens whose identification was confirmed by 16s rrna, and we review the literatu ... | 2017 | 28271043 |
| the outer membrane secretin pilq from neisseria meningitidis binds dna. | neisseria meningitidis is naturally competent for transformation throughout its growth cycle. transformation in neisserial species is coupled to the expression of type iv pili, which are present on the cell surface as bundled filamentous appendages, and are assembled, extruded and retracted by the pilus biogenesis components. during the initial phase of the transformation process, binding and uptake of dna takes place with entry through a presumed outer-membrane channel into the periplasm. this ... | 2007 | 17464074 |
| infective endocarditis caused by moraxella nonliquefaciens in a percutaneous aortic valve replacement. | first case of infective endocarditis on a percutaneous aortic valve replacement due to moraxalla nonliquefaciens in 64 year old woman. it was successfully treated medically with antibiotics. she had not suitable for surgical aortic valve replacement due to 3 sternotomies for thymoma resection and subsequent radiotherapy with blocked major thoracic veins. due to her azathioprine immunosuppresion (myasthenia) she may have been at increased endocarditis risk. we suggest prophylactic antibiotics at ... | 2011 | 21640938 |
| masquerading microbial pathogens: capsular polysaccharides mimic host-tissue molecules. | the increasing prevalence of antibiotic-resistant bacteria portends an impending postantibiotic age, characterized by diminishing efficacy of common antibiotics and routine application of multifaceted, complementary therapeutic approaches to treat bacterial infections, particularly multidrug-resistant organisms. the first line of defense for most bacterial pathogens consists of a physical and immunologic barrier known as the capsule, commonly composed of a viscous layer of carbohydrates that are ... | 2014 | 24372337 |
| bacteriophages and phage-derived proteins--application approaches. | currently, the bacterial resistance, especially to most commonly used antibiotics has proved to be a severe therapeutic problem. nosocomial and community-acquired infections are usually caused by multidrug resistant strains. therefore, we are forced to develop an alternative or supportive treatment for successful cure of life-threatening infections. the idea of using natural bacterial pathogens such as bacteriophages is already well known. many papers have been published proving the high antibac ... | 2015 | 25666799 |
| characterization of the kingella kingae polysaccharide capsule and exopolysaccharide. | recent evidence indicates that kingella kingae produces a polysaccharide capsule. in an effort to determine the composition and structure of this polysaccharide capsule, in the current study we purified capsular material from the surface of k. kingae strain 269-492 variant kk01 using acidic conditions to release the capsule and a series of steps to remove dna, rna, and protein. analysis of the resulting material by gas chromatography and mass spectrometry revealed n-acetyl galactosamine (galnac) ... | 2013 | 24098695 |
| assessing genetic structure, diversity of bacterial aerosol from aeration system in an oxidation ditch wastewater treatment plant by culture methods and bio-molecular tools. | airborne bacteria emissions from oxidation ditch with rotating aeration brushes were investigated in a municipal wastewater treatment plant in beijing, china. microbial samples were collected at different distances from the rotating brushes, different heights above the water surface, and different operation state over a 3-month period (april, may, and june) in order to estimate the seasonal variation and site-related distribution characteristics of the microorganisms present. the concentration o ... | 2013 | 22402990 |
| evidence that intraspecific trait variation among nasal bacteria shapes the distribution of staphylococcus aureus. | nasal carriage of staphylococcus aureus is a risk factor for infection, yet the bacterial determinants required for carriage are poorly defined. interactions between s. aureus and other members of the bacterial flora may determine colonization and have been inferred in previous studies by using correlated species distributions. however, traits mediating species interactions are often polymorphic, suggesting that understanding how interactions structure communities requires a trait-based approach ... | 2014 | 24980973 |
| detection of k1 antigen of escherichia coli rods isolated from pregnant women and neonates. | the k1 antigen is an important virulence determinant of escherichia coli strains and has been shown to be associated particularly with neonatal meningitis, bacteraemia and septicaemia. thus, its detection seems to be useful, especially in the case of e. coli strains isolated from pregnant women and newborns. in this study, the sensitivity and specificity of the latex agglutination test (pastorex meningitis) for identification of e. coli serogroup k1 were assessed, using pcr as the gold standard. ... | 2014 | 24737297 |
| effects of vaccination with 10-valent pneumococcal non-typeable haemophilus influenza protein d conjugate vaccine (phid-cv) on the nasopharyngeal microbiome of kenyan toddlers. | pneumococcal conjugate vaccines reduce the prevalence of vaccine serotypes carried in the nasopharynx. because this could alter carriage of other potential pathogens, we assessed the nasopharyngeal microbiome of children who had been vaccinated with 10-valent pneumococcal non-typeable haemophilus influenzae protein-d conjugate vaccine (phid-cv). | 2015 | 26083474 |
| antimicrobial susceptibility and mechanisms of high-level macrolide resistance in clinical isolates of moraxella nonliquefaciens. | we investigated antimicrobial susceptibility and the molecular mechanism involved in conferring high-level macrolide resistance in 47 clinical isolates of moraxella nonliquefaciens from japan. antimicrobial susceptibility was determined using etest and agar dilution methods. thirty-two erythromycin-non-susceptible strains were evaluated for the possibility of clonal spreading, using pfge. to analyse the mechanism related to macrolide resistance, mutations in the 23s rrna gene and the ribosomal p ... | 2014 | 24196134 |
| spectrum and sensitivity of bacterial keratitis isolates in auckland. | background. the bacteria isolated from severe cases of keratitis and their antibiotic sensitivity are recognised to vary geographically and over time. objectives. to identify the most commonly isolated bacteria in keratitis cases admitted over a 24-month period to a public hospital in auckland, new zealand, and to investigate in vitro sensitivity to antibiotics. methods. hospital admissions for culture-proven bacterial keratitis between january 2013 and december 2014 were identified. laboratory ... | 2016 | 27213052 |
| staphylococcus pseudintermedius and staphylococcus schleiferi subspecies coagulans from canine pyoderma cases in grenada, west indies, and their susceptibility to beta-lactam drugs. | over a 2-year period 66 cases of canine pyoderma in grenada, west indies, were examined by aerobic culture in order to ascertain the bacteria involved and their antimicrobial resistance patterns. of the 116 total bacterial isolates obtained, the majority belonged to gram-positive species, and the most common organism identified through biochemical and molecular methods was staphylococcus pseudintermedius. additionally, identification of a staphylococcus schleiferi subspecies coagulans isolate wa ... | 2014 | 24592351 |
| procalcitonin levels in gram-positive, gram-negative, and fungal bloodstream infections. | procalcitonin (pct) can discriminate bacterial from viral systemic infections and true bacteremia from contaminated blood cultures. the aim of this study was to evaluate pct diagnostic accuracy in discriminating gram-positive, gram-negative, and fungal bloodstream infections. a total of 1,949 samples from patients with suspected bloodstream infections were included in the study. median pct value in gram-negative (13.8 ng/ml, interquartile range (iqr) 3.4-44.1) bacteremias was significantly highe ... | 2015 | 25852221 |
| development of a rapid and simplified protocol for direct bacterial identification from positive blood cultures by using matrix assisted laser desorption ionization time-of- flight mass spectrometry. | bloodstream infections represent serious conditions carrying a high mortality and morbidity rate. rapid identification of microorganisms and prompt institution of adequate antimicrobial therapy is of utmost importance for a successful outcome. aiming at the development of a rapid, simplified and efficient protocol, we developed and compared two in-house preparatory methods for the direct identification of bacteria from positive blood culture flasks (bd bactec fx system) by using matrix-assisted ... | 2015 | 26546000 |