Abstract:
:Rhodococcus equi is a facultative intracellular opportunistic pathogen of immunocompromised people and a major cause of pneumonia in young horses. An effective live attenuated vaccine would be extremely useful in the prevention of R. equi disease in horses. Toward that end, we have developed an efficient transposon mutagenesis system that makes use of a Himar1 minitransposon delivered by a conditionally replicating plasmid for construction of R. equi mutants. We show that Himar1 transposition in R. equi is random and needs no apparent consensus sequence beyond the required TA dinucleotide. The diversity of the transposon library was demonstrated by the ease with which we were able to screen for auxotrophs and mutants with pigmentation and capsular phenotypes. One of the pigmentation mutants contained an insertion in a gene encoding phytoene desaturase, an enzyme of carotenoid biosynthesis, the pathway necessary for production of the characteristic salmon color of R. equi. We identified an auxotrophic mutant with a transposon insertion in the gene encoding a putative dual-functioning GTP cyclohydrolase II-3,4-dihydroxy-2-butanone-4-phosphate synthase, an enzyme essential for riboflavin biosynthesis. This mutant cannot grow in minimal medium in the absence of riboflavin supplementation. Experimental murine infection studies showed that, in contrast to wild-type R. equi, the riboflavin-requiring mutant is attenuated because it is unable to replicate in vivo. The mutagenesis methodology we have developed will allow the characterization of R. equi virulence mechanisms and the creation of other attenuated strains with vaccine potential.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Ashour J,Hondalus MKdoi
10.1128/jb.185.8.2644-2652.2003keywords:
subject
Has Abstractpub_date
2003-04-01 00:00:00pages
2644-52issue
8eissn
0021-9193issn
1098-5530journal_volume
185pub_type
杂志文章abstract::Tn5 insertion mutations in the recN gene, and in what appears to be a new RecF pathway gene designated recO and mapping at approximately 55.4 min on the standard genetic map, were isolated by screening Tn5 insertion mutations that cotransduced with tyrA. The recO1504::Tn5 mutation decreased the frequency of recombinat...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.163.3.1060-1066.1985
更新日期:1985-09-01 00:00:00
abstract::Escherichia coli K-12, polAl(-) is a mutant strain whose extracts are deficient in Kornberg deoxyribonucleic acid (DNA) polymerase activity. We have compared the mutant and parental strains on the basis of a number of responses to ultraviolet (UV) and X-irradiation. For both types of radiation, the mutant is more sens...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.107.1.61-67.1971
更新日期:1971-07-01 00:00:00
abstract::A macrorestriction map representing the complete physical map of the Rhodobacter sphaeroides 2.4.1 chromosomes has been constructed by ordering the chromosomal DNA fragments from total genomic DNA digested with the restriction endonucleases AseI, SpeI, DraI, and SnaBI. Junction fragments and multiple restriction endon...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.171.11.5850-5859.1989
更新日期:1989-11-01 00:00:00
abstract::Hg2+-resistant mutants were isolated from Saccharomyces cerevisiae. Although they were very much like the parental strains in terms of colony-forming ability, they grew faster than the parental strains in the presence of sublethal doses of Hg2+. The Hg2+-resistant mutations were dominant. They were centromere linked a...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.170.12.5877-5882.1988
更新日期:1988-12-01 00:00:00
abstract::A number of catalase-deficient mutants of Escherichia coli which exhibit no assayable catalase activity were isolated. The only physiological difference between the catalase mutants and their parents was a 50- to 60-fold greater sensitivity to killing by hydrogen peroxide. For comparison, mutations in the xthA and rec...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.157.2.622-626.1984
更新日期:1984-02-01 00:00:00
abstract::Buck, C. A. (Kansas State University, Manhattan), R. L. Anacker, F. S. Newman, and A. Eisenstark. Phage isolated from lysogenic Bacillus anthracis. J. Bacteriol. 85:1423-1430. 1963.-Bacillus anthracis cultures (a total of 311) were obtained from several laboratories throughout the world; 139 of these were screened for...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.85.6.1423-1430.1963
更新日期:1963-06-01 00:00:00
abstract::In the microbial conversion of added hypoxanthine to 5'-inosinic acid, Mn(2+) concentration in the growth medium is known to have a profound effect both on the yield of 5'-inosinic acid and the morphology of cells of Brevibacterium ammoniagenes. To elucidate the mechanism in which Mn(2+) was concerned with cell morpho...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.96.5.1760-1767.1968
更新日期:1968-11-01 00:00:00
abstract::Mutants of the fhuA gene of Escherichia coli K-12, which encodes a receptor protein in the outer membrane, took up ferrichrome after exposure to pronase, whereas fhuB mutants remained transport negative. The latter finding supports our previous proposal that fhuB mutants are defective in a function that residues in th...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.146.3.1158-1161.1981
更新日期:1981-06-01 00:00:00
abstract::Plasmid ColIb-P9 of the I alpha incompatibility group is known to encode a DNA primase that acts in the conjugal transfer of the plasmid and can substitute for mutant dnaG gene product in vegetative replication of the Escherichia coli chromosome. The relevant genetic determinant (sog) has previously been cloned into a...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.151.1.1-7.1982
更新日期:1982-07-01 00:00:00
abstract::MurG is a peripheral membrane protein that is one of the key enzymes in peptidoglycan biosynthesis. The crystal structure of Escherichia coli MurG (S. Ha, D. Walker, Y. Shi, and S. Walker, Protein Sci. 9:1045-1052, 2000) contains a hydrophobic patch surrounded by basic residues that may represent a membrane associatio...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.185.13.3773-3779.2003
更新日期:2003-07-01 00:00:00
abstract::The products of phospholipid turnover in Bacillus stearothermophilus were determined in cultures labeled to equilibrium and with short pulses of [32P]phosphate and [2-3H]glycerol. Label lost from the cellular lipid pool was recovered in three fractions: low-molecular-weight extracellular products, extracellular lipid,...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.154.1.294-303.1983
更新日期:1983-04-01 00:00:00
abstract::Youmans, Anne S. (Northwestern University Medical School, Chicago, Ill.) and Guy P. Youmans. Effect of mycosuppressin on the respiration and growth of Mycobacterium tuberculosis. J. Bacteriol. 84:708-715. 1962.-A substance, called mycosuppressin, was found in the lungs of guinea pigs and rabbits vaccinated with BCG or...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.84.4.708-715.1962
更新日期:1962-10-01 00:00:00
abstract::Plasmid R1 is a low-copy-number plasmid that is present at a level of about four or five copies per average cell. The copy number is controlled posttranscriptionally at the level of synthesis of the rate-limiting initiator protein RepA. In addition to this, R1 has an auxiliary system that derepresses a second promoter...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.186.1.207-211.2004
更新日期:2004-01-01 00:00:00
abstract::Two-component signal transduction systems are utilized by prokaryotic and eukaryotic cells to sense and respond to environmental stimuli, both to maintain homeostasis and to rapidly adapt to changing conditions. Studies have begun to emerge that utilize a large-scale mutagenesis approach to analyzing these systems in ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00242-07
更新日期:2007-08-01 00:00:00
abstract::Yersinia enterocolitica transports YscM1 and YscM2 via the type III pathway, a mechanism that is required for the establishment of bacterial infections. Prior to host cell contact, YscM1 and YscM2 exert posttranscriptional regulation to inhibit expression of effector yop genes, which encode virulence factors that trav...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.186.3.829-841.2004
更新日期:2004-02-01 00:00:00
abstract::Direct evidence for the involvement of ubiquinone in H2 oxidation by Rhizobium japonicum was demonstrated; H2 reduced ca. 80% of the extractable ubiquinone. The inhibitor 2-n-heptyl-4-hydroxyquinoline-N-oxide blocked electron transport at a site between ubiquinone and the cytochromes. The results showed that no cytoch...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.161.2.775-777.1985
更新日期:1985-02-01 00:00:00
abstract::The bacterium Myxococcus xanthus undergoes multicellular development during times of nutritional stress and uses extracellular signals to coordinate cell behavior. C-signal affects gene expression late in development, including that of Omega4499, an operon identified by insertion of Tn5 lac into the M. xanthus chromos...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.186.12.3766-3776.2004
更新日期:2004-06-01 00:00:00
abstract::A DNA fragment from Xanthomonas campestris pv. campestris that partially restored the carbohydrate fermentation pattern of a cya crp Escherichia coli strain was cloned and expressed in E. coli. The nucleotide sequence of this fragment revealed the presence of a 700-base-pair open reading frame that coded for a protein...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.172.10.5877-5883.1990
更新日期:1990-10-01 00:00:00
abstract::Studies on the crisp-1 (cr-1), cyclic adenosine 3',5'-monophosphate (cAMP)-deficient mutants of Neurospora crassa were undertaken to characterize the response of these mutants to exogenous cyclic nucleotides and cyclic nucleotide analogs. A growth tube bioassay and a radioimmune assay for cyclic nucleotides yielded th...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.137.3.1140-1144.1979
更新日期:1979-03-01 00:00:00
abstract::The cheW gene from Escherichia coli has been cloned an inducible promoter, and the effects of the overproduction of the CheW protein on chemotactic behavior and receptor covalent modification have been examined. Plasmids that contain the cheW gene behind a regulatable promoter complement a cheW mutation when the CheW ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.171.11.6271-6278.1989
更新日期:1989-11-01 00:00:00
abstract::The genome sequences of several pseudomonads have revealed a gene cluster containing genes for a two-component heavy metal histidine sensor kinase and response regulator upstream of cinA and cinQ, which we show herein to encode a copper-containing azurin-like protein and a pre-Q(0) reductase, respectively. In the pres...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00377-07
更新日期:2007-07-01 00:00:00
abstract::Six uvr mutants of Saccharomyces cerevisiae with hypersensitivity to ultraviolet (UV) light were isolated after mutagen treatment with ethylmethanesulfonate. UV sensitivity ranges from moderate to extreme, and four of the mutants are also sensitive to nitrous acid. Ranking in terms of UV sensitivity does not parallel ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.94.3.571-575.1967
更新日期:1967-09-01 00:00:00
abstract::Deletions in the tet genes derived from Tn10 were formed from different tet::Tn5 insertion mutations by removing DNA sequences located between a HindIII site in Tn5 and a HindIII site adjacent to the tet genes. Tetracycline-sensitive point mutations were mapped in recombination tests with the deletions and were thus a...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.153.2.921-929.1983
更新日期:1983-02-01 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::FtsK is essential for Escherichia coli cell division. We report that cells lacking the C terminus of FtsK are defective in chromosome segregation as well as septation, often exhibiting asymmetrically positioned nucleoids and large anucleate regions. Combining the corresponding truncated ftsK gene with a mukB null muta...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:
更新日期:1998-12-01 00:00:00
abstract::Defective phage lambdadg, when present in certain Salmonella typhosa hybrids, could be eliminated with acridine orange or ethidium bromide treatment. The lambdadg deoxyribonucleic acid could be separated from the S. typhosa host deoxyribonucleic acid as a distinctly covalently closed molecule. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.102.1.288-290.1970
更新日期:1970-04-01 00:00:00
abstract::Three genes were shown to provide functions specific for ferric enterobactin transport in Escherichia coli: fepA encoded the outer membrane receptor, fepB produced a periplasmic protein, and the fepC product was presumably a component of a cytoplasmic membrane permease system for this siderophore. A 10.6-kilobase-pair...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.169.8.3638-3646.1987
更新日期:1987-08-01 00:00:00
abstract::The Escherichia coli gene cluster encoding enzymatic activities responsible for the synthesis and activation of 2,3-dihydroxybenzoic acid in the formation of the catechol siderophore enterobactin was localized to a 4.2-kilobase chromosomal DNA fragment. Analysis of various subclones and transposon insertion mutations ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.169.9.4163-4170.1987
更新日期:1987-09-01 00:00:00
abstract::The inducible temperate bacteriophage phi75 and a clear-plaque-forming variant, phi75C1, mediated transduction of a 4.4 X 10(6)-dalton multicopy Bacillus pumilus plasmid, pPL10, at frequencies of 10(-5) to 10(-6) transductants per plaque-forming unit. phi75- and phi75C1-mediated transduction of several chromosome mark...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.131.3.1029-1032.1977
更新日期:1977-09-01 00:00:00
abstract::This study examined the catabolism of xanthone by an Arthrobacter sp. (strain GFB100) capable of growth on xanthone as its main source of carbon and energy. An early catabolic intermediate was 3,4-dihydroxyxanthone. This compound was isolated from the growth medium of a mutant strain of the Arthrobacter sp. which lack...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.167.3.818-827.1986
更新日期:1986-09-01 00:00:00