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Like Bacteria (like + bacteria)
Selected AbstractsIdentification and characterization of the genes for N -acetylglucosamine kinase and N -acetylglucosamine-phosphate deacetylase in the pathogenic fungus Candida albicansFEBS JOURNAL, Issue 8 2001Toshiko Yamada-Okabe Like bacteria and many fungi, the pathogenic fungus Candida albicans can utilize GlcNAc as a carbon source for growth. A cluster of six genes was identified in the C. albicans genome. One of the genes in the cluster was CaNAG1, which is responsible for GlcN6P deaminase and is therefore essential for GlcNAc-dependent growth. The other five genes were designated CaNAG2, CaNAG3, CaNAG4, CaNAG5 and CaNAG6. The mRNA levels of CaNAG1, CaNAG2 and CaNAG5 were significantly induced by GlcNAc, whereas those of CaNAG3, CaNAG4 and CaNAG6 were not. Neither CaNAG2 nor CaNAG5 was essential for growth, but disruption of CaNAG2 or CaNAG5 greatly retarded the growth of cells using GlcNAc as the sole carbon source. Although no homolog of CaNAG2 or CaNAG5 was found in the Saccharomyces cerevisiae genome, CaNag2p displayed sequence similarities to Escherichia coli nagA, and CaNag5p is homologous to a wide variety of hexose kinases. When expressed as a fusion protein with glutathione S -transferase (GST), CaNag5p produced GlcNAc-P from GlcNAc in the presence of ATP, whereas GST alone did not. Furthermore, the recombinant GST,CaNag2p fusion protein converted GlcNAcP, which was produced by CaNag5p, into GlcNP. These results clearly demonstrate that CaNAG2 and CaNAG5 encode GlcNAcP deacetylase and GlcNAc kinase, respectively. CaNag5p recognized glucose and mannose as substrates, whereas the recently identified human GlcNAc kinase was specific to GlcNAc. Deletion of CaNAG2 or CaNAG5 markedly, and that of CaNAG1 moderately, attenuated the virulence of C. albicans in a mouse systemic infection model. Thus, it appears that GlcNAc metabolism of C. albicans is closely associated with its virulence. [source] Contribution of Chloroflexus respiration to oxygen cycling in a hypersaline microbial mat from Lake Chiprana, SpainENVIRONMENTAL MICROBIOLOGY, Issue 8 2007Lubos Polerecky Summary In dense stratified systems such as microbial mats, photosynthesis and respiration are coupled due to a tight spatial overlap between oxygen-producing and -consuming microorganisms. We combined microsensors and a membrane inlet mass spectrometer with two independent light sources emitting in the visible (VIS) and near infrared (NIR) regions to study this coupling in more detail. Using this novel approach, we separately quantified the activity of the major players in the oxygen cycle in a hypersaline microbial mat: gross photosynthesis of cyanobacteria, NIR light-dependent respiration of Chloroflexus -like bacteria (CLB) and respiration of aerobic heterotrophs. Illumination by VIS light induced oxygen production in the top ,1 mm of the mat. In this zone CLB were found responsible for all respiration, while the contribution of the aerobic heterotrophs was negligible. Additional illumination of the mat with saturating NIR light completely switched off CLB respiration, resulting in zero respiration in the photosynthetically active zone. We demonstrate that microsensor-based quantification of gross and net photosyntheses in dense stratified systems should carefully consider the NIR light-dependent behaviour of CLB and other anoxygenic phototrophic groups. [source] Burkholderia anthina sp. nov. and Burkholderia pyrrocinia, two additional Burkholderia cepacia complex bacteria, may confound results of new molecular diagnostic toolsFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 2 2002Peter Vandamme Abstract Nineteen Burkholderia cepacia -like isolates of human and environmental origin could not be assigned to one of the seven currently established genomovars using recently developed molecular diagnostic tools for B. cepacia complex bacteria. Various genotypic and phenotypic characteristics were examined. The results of this polyphasic study allowed classification of the 19 isolates as an eighth B. cepacia complex genomovar (Burkholderia anthina sp. nov.) and to design tools for its identification in the diagnostic laboratory. In addition, new and published data for Burkholderia pyrrocinia indicated that this soil bacterium is also a member of the B. cepacia complex. This highlights another potential source for diagnostic problems with B. cepacia -like bacteria. [source] Isolation of a Carnobacterium maltaromaticum- like bacterium from systemically infected lake whitefish (Coregonus clupeaformis)FEMS MICROBIOLOGY LETTERS, Issue 1 2008Thomas P. Loch Abstract Herein we report on the first isolation of a Carnobacterium maltaromaticum -like bacterium from kidneys and swim bladders of lake whitefish (Coregonus clupeaformis) caught from Lakes Michigan and Huron, Michigan. Isolates were Gram-positive, nonmotile, facultatively anaerobic, asporogenous rods that did not produce catalase, cytochrome oxidase, or H2S, and did not grow on acetate agar. Except for carbohydrate fermentation, many phenotypic characteristics of lake whitefish isolates coincided with those of C. maltaromaticum, the causative agent of pseudokidney disease. Partial sequencing of 16S and 23S rRNA genes, as well as the piscicolin 126 precursor gene, yielded 97% and 98% nucleotide matches with C. maltaromaticum, respectively (accession numbers EU546836 and EU546837; EU643471). Phylogenetic analyses showed that lake whitefish isolates of this study are highly related, yet not fully identical to C. maltaromaticum. The presence of the C. maltaromaticum -like bacterium was associated with splenomegaly, renal and splenic congestion, and thickening of the swim bladder wall with accumulation of a mucoid exudate. Examination of stained tissue sections revealed renal and splenic congestion, vacuolation and bile stasis within the liver, and hyperplasia within the epithelial lining of the swim bladder. The concurrent presence of pathological changes and the C. maltaromaticum -like bacteria suggests that this bacterium is pathogenic to lake whitefish. [source] Ultrastructural and molecular identification of a Wolbachia endosymbiont in a spider, Nephila clavataINSECT MOLECULAR BIOLOGY, Issue 5 2000Hyun Woo Oh Abstract Wolbachia -like bacteria were observed in the egg cells of golden orb-weaving spider, Nephila clavata, by means of transmission electron microscopy. The bacteria exhibited the typical morphology of Wolbachia, including three enveloping membranes. Based on the amplification and sequencing of partial 16S rDNA and ftsZ gene, the bacteria were identified as Wolbachia, intracellular, transovarially inherited ,-proteobacteria in invertebrates. Phylogenetic analysis based on 16S rDNA and ftsZ gene sequences invariably indicated that the intracellular bacteria from N. clavata belonged to group A Wolbachia, which were found only from insects. Clustering of Wolbachia from N. clavata with group A Wolbachia indicates that the bacteria were probably transferred horizontally between insects and the spider. [source] Detection and identification of rumen bacteria constituting a fibrolytic consortium dominated by Fibrobacter succinogenesANIMAL SCIENCE JOURNAL, Issue 1 2010Takumi SHINKAI ABSTRACT A fibrolytic consortium, dominated by the rumen cellulolytic bacterium Fibrobacter succinogenes, was artificially constructed on hay stems to detect and identify rumen bacteria that can potentially interact with F. succinogenes. Consortium-bacterial members were determined by DGGE and sequencing analysis targeted bacterial 16S rDNA. An artificial consortium was formed in a 2-step incubation of hay stems; the first step with group 1, 2 or 3 F. succinogenes strains, the second step with rumen fluid. After consortium formation, morphologically different bacteria were observed in association with F. succinogenes. DGGE exhibited more than 30 bands, the pattern of which depended on the F. succinogenes group. Sequencing suggested that Butyrivibrio fibrisolvens, Pseudobutyrivibrio ruminis, Clostridium sp., F. succinogenes group 2, Prevotella ruminicola and unclassified Bacteroides were prominent in the group 1 consortium and that Treponema bryantii, B. fibrisolvens, Acinetobacter sp, and Wolinella succinogenes were prominent in the group 2 consortium. However, in the group 3 consortium, F. succinogenes -like bacteria were microscopically undetectable, whereas cellulolytic Ruminococcus albus and F. succinogenes group 1 were prominent, suggesting that the group 3 cannot be a core member of this consortium. This study is the first attempt to identify bacterial members of a fibrolytic consortium dominated by a specific bacterium. [source] | ||||||||||