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1.
Background
Mycoplasma pneumoniae has previously been characterized as a micro-organism that is genetically highly stable. In spite of this genetic stability, homologous DNA recombination has been hypothesized to lie at the basis of antigenic variation of the major surface protein, P1, of M. pneumoniae. In order to identify the proteins that may be involved in homologous DNA recombination in M. pneumoniae, we set out to characterize the MPN229 open reading frame (ORF), which bears sequence similarity to the gene encoding the single-stranded DNA-binding (SSB) protein of other micro-organisms. 相似文献2.
Hélène Nuyttens Camille Cyncynatus Hélène Renaudin Sabine Pereyre Cécile Bébéar 《BMC microbiology》2010,10(1):216
Background
Mycoplasma pneumoniae is responsible for acute respiratory tract infections (RTIs) common in children and young adults. As M. pneumoniae is innately resistant to β-lactams antibiotics usually given as the first-line treatment for RTIs, specific and early diagnosis is important in order to select the right treatment. Serology is the most used diagnostic method for M. pneumoniae infections. 相似文献3.
Background
Phospholipid biosynthesis commences with the acylation of glycerol-3-phosphate (G3P) to form 1-acyl-G3P. This step is catalyzed by the PlsB protein in Escherichia coli. The gene encoding this protein has not been identified, however, in the majority of bacterial genome sequences, including that of Bacillus subtilis. Recently, a new two-step pathway catalyzed by PlsX and PlsY proteins for the initiation of phospholipid formation in Streptococcus pneumoniae has been reported. 相似文献4.
Olfa Frikha-Gargouri Radhouane Gdoura Abir Znazen Boutheina Gargouri Jalel Gargouri Ahmed Rebai Adnene Hammami 《BMC microbiology》2008,8(1):217
Background
The OmcB protein is one of the most immunogenic proteins in C. trachomatis and C. pneumoniae infections. This protein is highly conserved leading to serum cross reactivity between the various chlamydial species. Since previous studies based on recombinant proteins failed to identify a species specific immune response against the OmcB protein, this study evaluated an in silico predicted specific and immunogenic antigen from the OmcB protein for the serodiagnosis of C. trachomatis infections. 相似文献5.
Nan Li Fei Wang Siqiang Niu Ju Cao Kaifeng Wu Youqiang Li Nanlin Yin Xuemei Zhang Weiliang Zhu Yibing Yin 《BMC microbiology》2009,9(1):129
Background
Due to the widespread abusage of antibiotics, antibiotic-resistance in Streptococcus pneumoniae (S. pneumoniae) has been increasing quickly in recent years, and it is obviously urgent to develop new types of antibiotics. Two-component systems (TCSs) are the major signal transduction pathways in bacteria and have emerged as potential targets for antibacterial drugs. Among the 13 pairs of TCSs proteins presenting in S. pneumoniae, VicR/K is the unique one essential for bacterium growth, and block agents to which, if can be found, may be developed as effective antibiotics against S. pneumoniae infection. 相似文献6.
Al-Anoud Jaber Suhail Ahmad Eiman Mokaddas 《Annals of clinical microbiology and antimicrobials》2009,8(1):1-9
Background
Mycoplasma pneumoniae and Chlamydophila pneumoniae are major causes of lower and upper respiratory infections that are difficult to diagnose using conventional methods such as culture. The ProPneumo-1 (Prodesse, Waukesha, WI) assay is a commercial multiplex real-time PCR assay for the simultaneous detection of M. pneumoniae and/or C. pneumoniae DNA in clinical respiratory samples.Objective
The aim of this study was to evaluate the sensitivity and specificity of the ProPneumo-1, a newly developed commercial multiplex real-time PCR assay.Methods
A total of 146 clinical respiratory specimens, collected from 1997 to 2007, suspected of C. pneumoniae or M. pneumoniae infections were tested retrospectively. Nucleic acid was extracted using an automated NucliSense easyMag (bioMerieux, Netherlands). We used a "Home-brew" monoplex real-time assay as the reference method for the analysis of C. pneumoniae and culture as the reference method for the analysis of M. pneumoniae. For discordant analysis specimens were re-tested using another commercial multiplex PCR, the PneumoBacter-1 assay (Seegene, Korea).Results
Following discordant analysis, the sensitivity of the ProPneumo-1 assay for pathogens, C. pneumoniae or M. pneumoniae, was 100%. The specificity of the ProPneumo-1 assay, however, was 100% for C. pneumoniae and 98% for M. pneumoniae. The limits of detection were 1 genome equivalent (Geq) per reaction for pathogens, M. pneumoniae and C. pneumoniae. Due to the multipex format of the ProPneumo-1 assay, we identified 5 additional positive specimens, 2 C. pneumoniae in the M. pneumoniae-negative pool and 3 M. pneumoniae in the C. pneumoniae-negative pool.Conclusion
The ProPneumo-1 assay is a rapid, sensitive and effective method for the simultaneous detection of M. pneumoniae and C. pneumoniae directly in respiratory specimens. 相似文献7.
Antibacterial aryl‐crowned polyketide from Bacillus subtilis associated with seaweed Anthophycus longifolius
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Aims
Microbiological, biotechnological and chemical characterization of a previously undescribed aryl‐crowned polyketide from Bacillus subtilis MTCC 10403 isolated from brown seaweed Anthophycus longifolius with activity against opportunistic Gram‐negative food‐borne pathogenic bacterial strains.Methods and Results
A culture‐dependent method was used to isolate heterotrophic B. subtilis associated with A. longifolius and assessed for its antimicrobial properties. Minimum inhibitory concentration (MIC) of the title compound against the test pathogens was analysed by microtube dilution coupled with the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide‐based colorimetric endpoint detection. Bacillus subtilis MTCC 10403 was found to be antagonistic against Gram‐negative food‐borne pathogenic Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Salmonella enterica serotype Typhi, Aeromonas hydrophila and Vibrio sp. (diameter of zone of growth inhibition 13–22 mm). Bacillus subtilis was assessed for the presence of secondary metabolite coding polyketide synthase (pks) gene ( KC589397 , 700‐bp gene product) and carboxylate siderophore framework in the aryl‐crowned polyketide designated as 7‐O‐6′‐(2″‐acetylphenyl)‐5′‐hydroxyhexanoate‐macrolactin by exhaustive spectroscopic techniques. The MIC assay showed that the reference antibiotics tetracycline and ampicillin were active at 25 μg ml?1 against the test pathogens, whereas the newly isolated polyketide displayed anti‐infective properties against E. coli, A. hydrophilla, P. aeruginosa and Vibrio sp. at a lower concentration (MIC <13 μg ml?1). The MIC of the aryl macrolactin against K. pneumoniae was comparable with that of the referral antibiotics (~25 μg ml?1). The mode of antimicrobial action of acryl‐crowned macrolactin was found to be iron chelating similar to siderophores. Putative biosynthetic pathway of the pks gene product further validated its molecular attributions.Conclusions
This study recognized new variant of antimicrobial aryl‐crowned polyketide bearing methyl 6′‐(2″‐acetylphenyl)‐5′‐hydroxyhexanoate moiety at the C‐7 position of the macrolactin system from A. longifolius‐associated bacterium B. subtilis.Significance and Impact of the Study
This study revealed seaweed‐associated micro‐organisms as promising biological strata to produce new‐generation anti‐infective agents. 相似文献8.
Dustin L Johnson Chris B Stone David C Bulir Brian K Coombes James B Mahony 《BMC microbiology》2009,9(1):218
Background
We have shown previously that Chlamydophila pneumoniae contains a dual-specific Ser/Thr protein kinase that phosphorylates CdsD, a structural component of the type III secretion apparatus. To further study the role of PknD in growth and development we sought to identify a PknD inhibitor to determine whether PknD activity is required for replication. 相似文献9.
Joseph Marino Isabelle Stoeckli Michael Walch Sonja Latinovic-Golic Hanna Sundstroem Peter Groscurth Urs Ziegler Claudia Dumrese 《BMC microbiology》2008,8(1):32
Background
Atherosclerosis is still the leading cause of death in the western world. Besides known risk factors studies demonstrating Chlamydophila pneumoniae (C. pneumoniae) to be implicated in the progression of the disease, little is known about C. pneumoniae infection dynamics. We investigated whether C. pneumoniae induce cell death of human aortic endothelial cells, a cell type involved in the initiation of atherosclerosis, and whether chlamydial spots derive from inclusions. 相似文献10.
Aims
To test the hypothesis that Mycobacterium bovis can persist in the environment within protozoa.Methods and Results
In this study, we used a novel approach to detect internalized mycobacteria in environmental protozoa from badger latrines. Acid‐fast micro‐organisms were visualized in isolated amoebae, although we were unable to identify them to species level as no mycobacteria were grown from these samples nor was M. bovis detected by IS6110 PCR. Co‐incubation of Acanthamoeba castellanii with virulent M. bovis substantially reduced levels of bacilli, indicating that the amoebae have a negative effect on the persistence of M. bovis.Conclusions
The internalization of mycobacteria in protozoa might be a rare event under environmental conditions. The results suggest that amoebae might contribute to the inactivation of M. bovis rather than representing a potential environmental reservoir.Significance and Impact of the Study
Protozoa have been suggested to act as an environmental reservoir for M. bovis. The current study suggests that environmental amoebae play at most a minor role as potential reservoirs of M. bovis and that protozoa might inhibit persistence of M. bovis in the environment. 相似文献11.
Background
Klebsiella pneumoniae is an important gram-negative opportunistic pathogen causing primarily urinary tract infections, respiratory infections, and bacteraemia. The ability of bacteria to form biofilms on medical devices, e.g. catheters, has a major role in development of many nosocomial infections. Most clinical K. pneumoniae isolates express two types of fimbrial adhesins, type 1 fimbriae and type 3 fimbriae. In this study, we characterized the role of type 1 and type 3 fimbriae in K. pneumoniae biofilm formation. 相似文献12.
13.
E Ramos-Sevillano C Rodríguez-Sosa F Cafini MJ Giménez A Navarro D Sevillano L Alou E García L Aguilar J Yuste 《PloS one》2012,7(9):e44135
Background
Specific antibodies mediate humoral and cellular protection against invading pathogens such as Streptococcus pneumoniae by activating complement mediated immunity, promoting phagocytosis and stimulating bacterial clearance. The emergence of pneumococcal strains with high levels of antibiotic resistance is of great concern worldwide and a serious threat for public health.Methodology/Principal Findings
Flow cytometry was used to determine whether complement-mediated immunity against three antibiotic-resistant S. pneumoniae clinical isolates is enhanced in the presence of sub-inhibitory concentrations of cefditoren and ceftriaxone. The binding of acute phase proteins such as C-reactive protein and serum amyloid P component, and of complement component C1q, to pneumococci was enhanced in the presence of serum plus either of these antibiotics. Both antibiotics therefore trigger the activation of the classical complement pathway against S. pneumoniae. C3b deposition was also increased in the presence of specific anti-pneumococcal antibodies and sub-inhibitory concentrations of cefditoren and ceftriaxone confirming that the presence of these antibiotics enhances complement-mediated immunity to S. pneumoniae.Conclusions/Significance
Using cefditoren and ceftriaxone to promote the binding of acute phase proteins and C1q to pneumococci, and to increase C3b deposition, when anti-pneumococcal antibodies are present, might help reduce the impact of antibiotic resistance in S. pneumoniae infections. 相似文献14.
15.
Bergman P Linde C Pütsep K Pohanka A Normark S Henriques-Normark B Andersson J Björkhem-Bergman L 《PloS one》2011,6(8):e24394
Background
Statin treatment has been associated with a beneficial outcome on respiratory tract infections. In addition, previous in vitro and in vivo experiments have indicated favorable effects of statins in bacterial infections.Aim
The aim of the present study was to elucidate possible antibacterial effects of statins against primary pathogens of the respiratory tract.Methods
MIC-values for simvastatin, fluvastatin and pravastatin against S. pneumoniae, M. catarrhalis and H. influenzae were determined by traditional antibacterial assays. A BioScreen instrument was used to monitor effects of statins on bacterial growth and to assess possible synergistic effects with penicillin. Bacterial growth in whole blood and serum from healthy volunteers before and after a single dose of simvastatin, fluvastatin and penicillin (positive control) was determined using a blood culture system (BactAlert).Findings
The MIC-value for simvastatin against S pneumoniae and M catarrhalis was 15 µg/mL (36 mmol/L). Fluvastatin and Pravastatin showed no antibacterial effect in concentrations up to 100 µg/mL (230 µmol/L). Statins did not affect growth or viability of H influenzae. Single doses of statins given to healthy volunteers did not affect growth of pneumococci, whereas penicillin efficiently killed all bacteria.Conclusions
Simvastatin at high concentrations 15 µg/mL (36 µmol/L) rapidly kills S pneumoniae and M catarrhalis. However, these concentrations by far exceed the concentrations detected in human blood during simvastatin therapy (1–15 nmol/L) and single doses of statins given to healthy volunteers did not improve antibacterial effects of whole blood. Thus, a direct bactericidal effect of statins in vivo is probably not the mechanism behind the observed beneficial effect of statins against various infections. 相似文献16.
Katie L Propst-Graham Laurel C Preheim Elizabeth A Vander Top Mary U Snitily Martha J Gentry-Nielsen 《BMC microbiology》2007,7(1):94
Background
The risk of mortality from pneumonia caused by Streptococcus pneumoniae is increased in patients with cirrhosis. However, the specific pneumococcal virulence factors and host immune defects responsible for this finding have not been clearly established. This study used a cirrhotic rat model of pneumococcal pneumonia to identify defect(s) in innate pulmonary defenses in the cirrhotic host and to determine the impact of the pneumococcal toxin pneumolysin on these defenses in the setting of severe cirrhosis. 相似文献17.
Claudia?Dumrese Christine?F?Maurus Daniel?Gygi M?rten?KJ?Schneider Michael?Walch Peter?Groscurth Urs?Ziegler
Background
The intracellular bacterium Chlamydia pneumoniae is suspected to play a role in formation and progression of atherosclerosis. Many studies investigated cell death initiation versus inhibition by Chlamydia pneumoniae in established cell lines but nothing is known in primary human aortic smooth muscle cells, a cell type among others known to be involved in the formation of the atherosclerotic plaque. Type of cell death was analyzed by various methods in primary aortic smooth muscle cells after infection with Chlamydia pneumoniae to investigate a possible pathogenic link in atherosclerosis. 相似文献18.
Kathrin M Felder Katharina Hoelzle Karl Heinritzi Mathias Ritzmann Ludwig E Hoelzle 《BMC veterinary research》2010,6(1):18
Background
In autoimmune haemolytic anaemia (AIHA), autoreactive antibodies directed against red blood cells are up-regulated, leading to erythrocyte death. Mycoplasma suis infections in pigs induce AIHA of both the warm and cold types. The aim of this study was to identify the target autoantigens of warm autoreactive IgG antibodies. Sera from experimentally M. suis-infected pigs were screened for autoreactivity. 相似文献19.
Mark T Albrecht Wei Wang Olga Shamova Robert I Lehrer Neal L Schiller 《Respiratory research》2002,3(1):18
Background
Pseudomonas aeruginosa and Burkholderia cepacia infections of cystic fibrosis patients' lungs are often resistant to conventional antibiotic therapy. Protegrins are antimicrobial peptides with potent activity against many bacteria, including P. aeruginosa. The present study evaluates the correlation between protegrin-1 (PG-1) sensitivity/resistance and protegrin binding in P. aeruginosa and B. cepacia. 相似文献20.
Guma MK Abdeldaim Kristoffer Strålin Jens Korsgaard Jonas Blomberg Christina Welinder-Olsson Björn Herrmann 《BMC microbiology》2010,10(1):310