Abstract:
:Enterohemorrhagic Escherichia coli O157:H7 (EHEC) causes bloody diarrhea and hemolytic-uremic syndrome. EHEC encodes the sRNA chaperone Hfq, which is important in posttranscriptional regulation. In EHEC strain EDL933, Hfq acts as a negative regulator of the locus of enterocyte effacement (LEE), which encodes most of the proteins involved in type III secretion and attaching and effacing (AE) lesions. Here, we deleted hfq in the EHEC strain 86-24 and compared global transcription profiles of the hfq mutant and wild-type (WT) strains in exponential growth phase. Deletion of hfq affected transcription of genes common to nonpathogenic and pathogenic strains of E. coli as well as pathogen-specific genes. Downregulated genes in the hfq mutant included ler, the transcriptional activator of all the LEE genes, as well as genes encoded in the LEE2 to -5 operons. Decreased expression of the LEE genes in the hfq mutant occurred at middle, late, and stationary growth phases. We also confirmed decreased regulation of the LEE genes by examining the proteins secreted and AE lesion formation by the hfq mutant and WT strains. Deletion of hfq also caused decreased expression of the two-component system qseBC, which is involved in interkingdom signaling and virulence gene regulation in EHEC, as well as an increase in expression of stx(2AB), which encodes the deadly Shiga toxin. Altogether, these data indicate that Hfq plays a regulatory role in EHEC 86-24 that is different from what has been reported for EHEC strain EDL933 and that the role of Hfq in EHEC virulence regulation extends beyond the LEE.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Kendall MM,Gruber CC,Rasko DA,Hughes DT,Sperandio Vdoi
10.1128/JB.06141-11subject
Has Abstractpub_date
2011-12-01 00:00:00pages
6843-51issue
24eissn
0021-9193issn
1098-5530pii
JB.06141-11journal_volume
193pub_type
杂志文章abstract::Howard, Dexter H. (University of California, Los Angeles). Intracellular behavior of Histoplasma capsulatum. J. Bacteriol. 87:33-38. 1964.-The tinctorial characteristics and intracellular generation time of Histoplasma capsulatum within mouse histiocytes maintained in tissue culture were studied. The appearance of via...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.87.1.33-38.1964
更新日期:1964-01-01 00:00:00
abstract::Three gene libraries of Bordetella avium 197 DNA were prepared in Escherichia coli LE392 by using the cosmid vectors pCP13 and pYA2329, a derivative of pCP13 specifying spectinomycin resistance. The cosmid libraries were screened with convalescent-phase anti-B. avium turkey sera and polyclonal rabbit antisera against ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.174.23.7729-7742.1992
更新日期:1992-12-01 00:00:00
abstract::A thermosensitive episome bearing the transposon Tn10, F(Ts)::Tn10 Lac+, has been successfully transferred from Escherichia coli to several wild strains of the enterobacteria Erwinia carotovora subsp. chrysanthemi, which are pathogenic on Saintpaulia ionantha. In one of these strains, all of the characters controlled ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.150.1.122-131.1982
更新日期:1982-04-01 00:00:00
abstract::The tprK gene of Treponema pallidum subsp. pallidum, the causative agent of venereal syphilis, belongs to a 12-member gene family and encodes a protein with a predicted cleavable signal sequence and predicted transmembrane domains. Except for the Nichols type strain, all rabbit-propagated isolates of T. pallidum exami...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.185.21.6262-6268.2003
更新日期:2003-11-01 00:00:00
abstract::Heterocysts isolated from Anabaena sp. strain 7120 with lysozyme plus sonication were permeabilized with the cationic detergent cetyltrimethylammonium bromide, and they then exhibited comparable acetylene reduction activity in the light and dark with an ATP-regenerating system plus dithionite. The detergent diminished...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.155.2.940-942.1983
更新日期:1983-08-01 00:00:00
abstract::Shapira, Jacob (Consolidated Veterans Administration Hospital, Little Rock, Ark.), Lois Lowden, and Ralph Hale. Inhibition of a thymine-deficient mutant of Escherichia coli by 5-substituted uracils. J. Bacteriol. 83:919-923. 1962.-Small inocula of well-washed cells of a thymine-requiring mutant of Escherichia coli wer...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.83.4.919-923.1962
更新日期:1962-04-01 00:00:00
abstract::Hottle, G. A. (Naval Biological Laboratory, University of California, Berkeley), and D. N. Wright. Growth and survival of Mycoplasma neurolyticum in liquid media. J. Bacteriol. 91:1834-1839. 1966.-Maximal growth of Mycoplasma neurolyticum (between 10(8) and 10(9) colony-forming units per ml) was obtained after 3 days ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.91.5.1834-1839.1966
更新日期:1966-05-01 00:00:00
abstract::The endophytic diazotroph Azoarcus sp. strain BH72 is capable of infecting rice roots and of expressing the nitrogenase (nif) genes there. In order to study the genetic background for nitrogen fixation in strain BH72, the structural genes of nitrogenase (nifHDK) were cloned and sequenced. The sequence analysis reveale...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.183.12.3752-3760.2001
更新日期:2001-06-01 00:00:00
abstract::Agrobacterium tumefaciens wild-type strains have a unique quorum-sensing (QS)-dependent Ti plasmid conjugative transfer phenotype in which QS signaling is activated by corresponding conjugative opine inducers. Strain K588, with a nopaline-type chromosomal background harboring an octopine-type Ti plasmid, however, is a...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.188.7.2435-2445.2006
更新日期:2006-04-01 00:00:00
abstract::We show that both flanking IS256 elements carried by transposon Tn4001 are capable of generating head-to-tail tandem copies and free circular forms, implying that both are active. Our results suggest that the tandem structures arise from dimeric copies of the donor or vector plasmid present in the population by a mech...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.184.2.433-443.2002
更新日期:2002-01-01 00:00:00
abstract::We have utilized transposon mutagenesis to obtain insertional mutations in Providencia stuartii that activate the chromosomal aac(2')-la gene. Two closely linked mini-Tn5Cm insertions were obtained in a locus designated aarA, and a single insertion was obtained in a separate locus, aarC. Nucleotide sequence analysis, ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.176.16.5140-5144.1994
更新日期:1994-08-01 00:00:00
abstract::Analysis of two virulence mutants of Pseudomonas syringae B728a revealed that the Tn 5 sites of insertion were within the gidA open reading frame (ORF). These mutations were pleiotropic, affecting diverse phenotypic traits, such as lipodepsipeptide (syringomycin and syringopeptin) antibiotic production, swarming, pres...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.184.8.2281-2286.2002
更新日期:2002-04-01 00:00:00
abstract::The mecA-27r gene from Staphylococcus aureus 27r encodes penicillin-binding protein 2a (PBP2a-27r), which causes this strain to be methicillin resistant. Removal or replacement of the N-terminal transmembrane domain had no effect on binding of penicillin, but removal of portions of the putative transglycosylase domain...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.176.2.443-449.1994
更新日期:1994-01-01 00:00:00
abstract::In Escherichia coli, pyrimidine-mediated regulation of upp expression occurs by UTP-sensitive selection of alternative transcriptional start sites, which produces transcripts that differ in the ability to be elongated. The upp initially transcribed region contains the sequence GATTTTTTTTG (nontemplate strand). Initiat...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.183.1.221-228.2001
更新日期:2001-01-01 00:00:00
abstract::Wild-type strains of Escherichia coli K-12 are resistant to acriflavine. Gene acrA(+) which determines resistance to acriflavine is located near the lac region of the chromosome. This gene determines not only resistance to basic dyes but also resistance to phenethyl alcohol. Acriflavine resistance was transmitted, tog...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.96.4.987-996.1968
更新日期:1968-10-01 00:00:00
abstract::Converse, John L. (U.S. Army Biological Laboratories, Fort Detrick, Frederick, Md.), Merida W. Castleberry, and Ernest M. Snyder. Experimental viable vaccine against pulmonary coccidioidomycosis in monkeys. J. Bacteriol. 86:1041-1051. 1963.-Monkeys (Macaca mulatta) vaccinated by subcutaneous injection in the forearm w...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.86.5.1041-1051.1963
更新日期:1963-11-01 00:00:00
abstract::Mycoplasma showing at least two colony types were isolated from the nares and oropharynx of New Zealand white rabbits. Two strains were purified by single-colony passages and characterized. Morphology by phase-contrast and electron microscopy was typical of Mycoplasmataceae. Both grew anaerobically as well as aerobica...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.93.4.1416-1424.1967
更新日期:1967-04-01 00:00:00
abstract::Auxotrophic mutants of the filamentous cyanobacterium Anabaena variabilis were isolated by a method in which, after mutagenesis and before penicllin enrichment, mutant and wild-type cells were separated by cavitation. Auxotrophs were identified by their inability to grow on minimal medium, and they were partially char...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.129.3.1556-1562.1977
更新日期:1977-03-01 00:00:00
abstract::In order to assess the roles of specific amino acid residues in the delta 5-3-ketosteroid isomerase from Pseudomonas putida biotype B during catalysis, we replaced aspartic acid 40 with asparagine (D40N) and tyrosine 16 with phenylalanine (Y16F) in the enzyme by site-directed mutagenesis. Both purified mutant enzymes ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.177.9.2602-2605.1995
更新日期:1995-05-01 00:00:00
abstract::Tn4551, a clindamycin resistance (Ccr) transposon from the R plasmid pBI136, was cloned onto an Escherichia coli-Bacteroides shuttle vector which could replicate normally in E. coli but was maintained unstably in Bacteroides fragilis. To aid in cloning and to ensure maintenance of Tn4551 in E. coli, a kanamycin resist...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.169.8.3450-3457.1987
更新日期:1987-08-01 00:00:00
abstract::In Escherichia coli, synthesis of sialic acid is not regulated by allosteric inhibition mediated by cytidine 5'-monophospho-N-acetylneuraminic acid (CMP-NeuNAc). Evidence for the lack of metabolic control by feedback inhibition was demonstrated by measuring the intracellular level of sialic acid and CMP-NeuNAc in muta...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.164.2.854-860.1985
更新日期:1985-11-01 00:00:00
abstract::Streptococcus mutans transports glucose via the phosphoenolpyruvate (PEP)-dependent sugar phosphotransferase system (PTS). Earlier studies indicated that an alternate glucose transport system functions in this organism under conditions of high growth rates, low pH, or excess glucose. To identify this system, S. mutans...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.177.9.2251-2258.1995
更新日期:1995-05-01 00:00:00
abstract::The spx gene encodes an RNA polymerase-binding protein that exerts negative and positive transcriptional control in response to oxidative stress in Bacillus subtilis. It resides in the yjbC-spx operon and is transcribed from at least five promoters located in the yjbC regulatory region or in the yjbC-spx intergenic re...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01520-06
更新日期:2007-03-01 00:00:00
abstract::We have identified and characterized enzymes of phospholipid synthesis in two plasmalogen-rich anaerobes. Megasphaera elsdenii and Veillonella parvula, and one anaerobe lacking plasmalogens. Desulfovibrio vulgaris. All three species contained phosphatidate cytidylyltransferase and phosphatidylserine synthase. Phosphat...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.147.1.57-61.1981
更新日期:1981-07-01 00:00:00
abstract::Myxobacterial hemagglutinin (MBHA) is a major developmentally induced protein that accumulates during the period of cellular aggregation in the bacterium Myxococcus xanthus. It has been shown that this lectin is targeted to the cell surface and periplasmic space of developmental cells, suggesting that it may play a ro...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.169.8.3801-3808.1987
更新日期:1987-08-01 00:00:00
abstract::Radiorespirometric and enzymatic analyses reveal that glucose-grown cells of Rhizobium japonicum isolates I-110 and L1-110, both derivatives of R. japonicum strain 3I1b110, possess an active tricarboxylic acid cycle and metabolize glucose by simultaneous operation of the Embden-Meyerhof-Parnas and Entner-Doudoroff pat...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.131.1.179-187.1977
更新日期:1977-07-01 00:00:00
abstract::Achromobacter xylosoxidans strain A8 was isolated from soil contaminated with polychlorinated biphenyls. It can use 2-chlorobenzoate and 2,5-dichlorobenzoate as sole sources of carbon and energy. This property makes it a good starting microorganism for further development toward a bioremediation tool. The genome of A....
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01299-10
更新日期:2011-02-01 00:00:00
abstract::Among 30 conjugative plasmids of enteric bacteria from 23 incompatibility (Inc) groups, we found 19 (from 12 Inc groups) which can complement defects caused by a defective single-stranded DNA-binding protein of Escherichia coli K-12. The genes which are responsible for the complementation from three of these plasmids ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.162.1.235-241.1985
更新日期:1985-04-01 00:00:00
abstract::Injection of mice with a sublethal dose of endotoxin 2 hr after administration of 0.1 ml of carbon tetrachloride (CCl(4)) killed 75% of the animals. CCl(4) alone killed no controls. Significant protection against this effect was afforded by 5 mg of cortisone and by 5 mg of nicotinamide adenine dinucleotide (NAD). With...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.94.6.1817-1823.1967
更新日期:1967-12-01 00:00:00
abstract::The entry of oligogalacturonates into Dickeya dadantii occurs through the specific channel KdgM. The genome of the bacterium encodes a second member of this family of outer membrane proteins, KdgN. We showed that this protein is also involved in the uptake of oligogalacturonates. When KdgN was reconstituted in proteol...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00218-07
更新日期:2007-08-01 00:00:00