Abstract:
UNLABELLED:Resistance to methicillin and other β-lactam antibiotics in staphylococci is due to mecA, which is carried on a genomic island, staphylococcal cassette chromosome mec (SCCmec). The chromosomal excision and integration of SCCmec are mediated by the site-specific recombinase CcrAB or CcrC, encoded within this element. A plasmid-borne system was constructed to assess the activities of CcrA and CcrB in the excision and integration of SCCmec in Escherichia coli and Staphylococcus aureus. The excision frequency in E. coli mediated by CcrAB from methicillin-resistant S. aureus (MRSA) strain N315 was only 9.2%, while the integration frequency was 31.4%. In S. aureus the excision and integration frequencies were 11.0% and 18.7%, respectively. Truncated mutants identified the N-terminal domain of either CcrB or CcrA to be necessary for both integration and excision, while the C-terminal domain was important for recombination efficiency. Site-directed mutagenesis of the N-terminal domain identified S11 and R79 of CcrA and S16, R89, T149, and R151 of CcrB to be residues essential for catalytic activities, and the critical location of these residues was consistent with a model of the tertiary structure of the N terminus of CcrA and CcrB. Furthermore, CcrAB and CcrC, cloned from a panel of 6 methicillin-resistant S. aureus strains and 2 methicillin-resistant Staphylococcus epidermidis strains carrying SCCmec types II, IV, and V, also catalyzed integration at rates 1.3 to 10 times higher than the rates at which they catalyzed excision, similar to the results from N315. The tendency of SCCmec integration to be favored over excision may explain the low spontaneous excision frequency seen among MRSA strains. IMPORTANCE:Spontaneous excision of the genomic island (SCCmec) that encodes resistance to beta-lactam antibiotics (methicillin resistance) in staphylococci would convert a methicillin-resistant strain to a methicillin-susceptible strain, improving therapy of difficult-to-treat infections. This study characterizes a model system by which the relative frequencies of excision and integration can be compared. Using a plasmid-based model for excision and integration mediated by the recombinases CcrA and CcrB, integration occurred at a higher frequency than excision, consistent with the low baseline excision frequency seen in most strains. This model system can now be used to study conditions and drugs that may raise the SCCmec excision frequency and generate strains that are beta-lactam susceptible.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Wang L,Ahmed MH,Safo MK,Archer GLdoi
10.1128/JB.00078-15subject
Has Abstractpub_date
2015-09-01 00:00:00pages
2754-61issue
17eissn
0021-9193issn
1098-5530pii
JB.00078-15journal_volume
197pub_type
杂志文章abstract::No catalase activity was detected in four strains of glucose-grown Mycoplasma pneumoniae at any time during the replication of the organism. Exogenous catalase dramatically increased the O(2) uptake with glycerol, presumably by releasing inhibition caused by hydrogen peroxide. The effect of added catalase on the O(2) ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.95.4.1425-1430.1968
更新日期:1968-04-01 00:00:00
abstract::We previously showed that dprA is required for efficient processing of linear DNA during cellular transformation in Haemophilus influenzae. In this study the transcriptional regulation of dprA and two downstream genes, dprB and dprC, is examined. We demonstrate by Northern blot analysis that the dprABC genes are trans...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.179.15.4815-4820.1997
更新日期:1997-08-01 00:00:00
abstract::Using a quantitative assay for measuring chemotaxis, we tested a variety of sugars and sugar derivatives for their ability to attract Escherichia coli bacteria. The most effective attractants, i.e., those that have thresholds near 10(-5) M or below, are N-acetyl-d-glucosamine, 6-deoxy-d-glucose, d-fructose, d-fucose, ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.115.3.824-847.1973
更新日期:1973-09-01 00:00:00
abstract::Staphylococcus aureus responds to changing extracellular environments in part by adjusting its proteome through alterations of transcriptional priorities and selective degradation of the preexisting pool of proteins. In Bacillus subtilis, the proteolytic adaptor protein MecA has been shown to play a role in assisting ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.02222-14
更新日期:2014-12-01 00:00:00
abstract:UNLABELLED:The Mycobacterium tuberculosis exported repetitive protein (RvErp) is a crucial virulence-associated factor as determined by its role in the survival and multiplication of mycobacteria in cultured macrophages and in vivo Although attempts have been made to understand the function of Erp protein, its exact ro...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00120-16
更新日期:2016-09-22 00:00:00
abstract::Strains monosomic for chromosome I of Saccharomyces cerevisiae contain 25 to 35% fewer rRNA genes than do normal diploid strains. When these strains are repeatedly subcultured, colonies are isolated that have magnified their number of rRNA genes to the diploid amount while remaining monosomic for chromosome I. We have...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.134.1.237-245.1978
更新日期:1978-04-01 00:00:00
abstract::Whole-genome sequence analysis of Mycobacterium leprae has revealed a limited number of protein-coding genes, with half of the genome composed of pseudogenes and noncoding regions. We previously showed that some M. leprae pseudogenes are transcribed at high levels and that their expression levels change following infe...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00120-09
更新日期:2009-05-01 00:00:00
abstract::A temperate phage, phi CTX, is a cytotoxin-converting phage of Pseudomonas aeruginosa. In this study, we characterized the lipopolysaccharide (LPS) structures of phi CTX-resistant mutants derived from phi CTX-sensitive strains. phi CTX infectivity was neutralized by LPS preparations derived from sensitive strains but ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.176.17.5262-5269.1994
更新日期:1994-09-01 00:00:00
abstract::Tetragenococcus halophila D10 catalyzes the decarboxylation of L-aspartate with nearly stoichiometric release of L-alanine and CO(2). This trait is encoded on a 25-kb plasmid, pD1. We found in this plasmid a putative asp operon consisting of two genes, which we designated aspD and aspT, encoding an L-aspartate-beta-de...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.184.11.2906-2913.2002
更新日期:2002-06-01 00:00:00
abstract::Cells of the gliding bacterium Flavobacterium johnsoniae move rapidly over surfaces. Mutations in gldN cause a partial defect in gliding. A novel bacteriophage selection strategy was used to aid construction of a strain with a deletion spanning gldN and the closely related gene gldO in an otherwise wild-type F. johnso...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01495-09
更新日期:2010-03-01 00:00:00
abstract::The reactivation of membranes from Gaffkya homari for the synthesis of sodium dodecyl sulfate-insoluble peptidoglycan (SDS-insoluble PG) was achieved by successive cycles of freeze-thawing (- 196 versus 25 degrees C). The presence of G. homari walls during this process affected the synthesis of both SDS-soluble (nasce...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.150.2.535-544.1982
更新日期:1982-05-01 00:00:00
abstract::The alpha-aminoadipate pathway for the biosynthesis of lysine is present only in fungi and euglena. Until now, this unique metabolic pathway has never been investigated in the opportunistic fungal pathogens Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus. Five of the eight enzymes (homocitrate syn...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.174.22.7379-7384.1992
更新日期:1992-11-01 00:00:00
abstract::A chemotaxis system for Pseudomonas aeruginosa was defined by using the method of Adler. Cells were attracted to compounds in the order ammonium chloride greater than amino acids greater than organic acids. Two sugars were assayed and elicited no response. Comparisons with other model systems are discussed. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.133.1.427-429.1978
更新日期:1978-01-01 00:00:00
abstract::The Bacillus subtilis skin element confers resistance to arsenate and arsenite. The ars operon in the skin element contains four genes in the order arsR, ORF2, arsB, and arsC. Three of these genes are homologous to the arsR, arsB, and arsC genes from the staphylococcal plasmid pI258, while no homologs of ORF2 have bee...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.180.7.1655-1661.1998
更新日期:1998-04-01 00:00:00
abstract:UNLABELLED:Helicobacter pylori must be able to rapidly respond to fluctuating conditions within the stomach. Despite this need for constant adaptation, H. pylori encodes few regulatory proteins. Of the identified regulators, the ferric uptake regulator (Fur), the nickel response regulator (NikR), and the two-component ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00324-16
更新日期:2016-08-25 00:00:00
abstract::Bacterial Gre factors associate with RNA polymerase (RNAP) and stimulate intrinsic cleavage of the nascent transcript at the active site of RNAP. Biochemical and genetic studies to date have shown that Escherichia coli Gre factors prevent transcriptional arrest during elongation and enhance transcription fidelity. Fur...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00086-11
更新日期:2011-06-01 00:00:00
abstract::Comamonas testosteroni T-2 uses a standard, if seldom examined, attack on an aromatic compound and oxygenates the side chain of p-toluenesulfonate (TS) (or p-toluenecarboxylate) to p-sulfobenzoate (or terephthalate) prior to complete oxidation. The expression of the first three catabolic enzymes in the pathway, the TS...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.179.3.919-927.1997
更新日期:1997-02-01 00:00:00
abstract::A new bacteriocin, termed lactococcin A (LCN-A), from Lactococcus lactis subsp. cremoris LMG 2130 was purified and sequenced. The polypeptide contained no unusual amino acids and showed no significant sequence similarity to other known proteins. Only lactococci were killed by the bacteriocin. Of more than 120 L. lacti...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.173.12.3879-3887.1991
更新日期:1991-06-01 00:00:00
abstract::TolB is a periplasmic protein of the cell envelope Tol complex. It is partially membrane associated through an interaction with the outer membrane lipoprotein PAL (peptidoglycan-associated lipoprotein), which also belongs to the Tol system. The interaction of TolB with outer membrane porins of Escherichia coli was inv...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.179.23.7274-7279.1997
更新日期:1997-12-01 00:00:00
abstract::The pst gene cluster encodes the phosphate-specific transport (Pst) system. Inactivation of the Pst system constitutively activates the two-component regulatory system PhoBR and attenuates the virulence of pathogenic bacteria. In uropathogenic Escherichia coli strain CFT073, attenuation by inactivation of pst is predo...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00168-17
更新日期:2017-11-14 00:00:00
abstract::Bacillus brevis HPD31 contains a surface (S)-layer protein, termed the HWP, which forms a hexagonal array in the cell wall. The 5' region of the HWP gene was isolated from a DNA library constructed in bacteriophage vector EMBL3 from a partial BamHI digest of the chromosomal DNA. The 3' region contained in a 2.7-kiloba...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.172.3.1312-1320.1990
更新日期:1990-03-01 00:00:00
abstract::Eklund, Curtis (The University of Texas, Austin) and Orville Wyss. Enzyme associated with bacteriophage infection. J. Bacteriol. 84:1209-1215. 1962.-A capsule-digesting enzyme was formed when azotobacter cells were infected with bacteriophage. The enzyme appeared in the medium when the phages lysed the cells. By disru...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.84.6.1209-1215.1962
更新日期:1962-12-01 00:00:00
abstract::Secretion vectors based on the genes from Bacillus amyloliquefaciens P for alkaline protease (aprBamP) and neutral protease (nprBamP) were constructed. With both aprBamP and nprBamP, a unique restriction site was introduced 3' of the predicted signal coding region by using the technique of oligonucleotide-directed mut...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.165.3.837-842.1986
更新日期:1986-03-01 00:00:00
abstract::Temperate bacteriophages play an important role in the pathogenicity of Staphylococcus aureus, for instance, by mediating the horizontal gene transfer of virulence factors. Here we established a classification scheme for staphylococcal prophages of the major Siphoviridae family based on integrase gene polymorphism. Se...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01804-08
更新日期:2009-06-01 00:00:00
abstract::The predominant mode of growth of bacteria in the environment is within sessile, matrix-enclosed communities known as biofilms. Biofilms often complicate chronic and difficult-to-treat infections by protecting bacteria from the immune system, decreasing antibiotic efficacy, and dispersing planktonic cells to distant b...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.184.1.290-301.2002
更新日期:2002-01-01 00:00:00
abstract::The function of serine protease EpiP in epidermin biosynthesis was investigated. Epidermin is synthesized as a 52-amino-acid precursor peptide, EpiA, which is posttranslationally modified and processed to the mature 22-amino-acid peptide antibiotic. epiP was expressed in Staphylococcus carnosus with xylose-regulated e...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.178.1.284-288.1996
更新日期:1996-01-01 00:00:00
abstract::The impact of arsenite [As(III)] on several levels of cellular metabolism and gene regulation was examined in Pseudomonas aeruginosa. P. aeruginosa isogenic mutants devoid of antioxidant enzymes or defective in various metabolic pathways, DNA repair systems, metal storage proteins, global regulators, or quorum sensing...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.187.14.4853-4864.2005
更新日期:2005-07-01 00:00:00
abstract::Borrelia burgdorferi, the Lyme disease agent, and other members of the spirochetal genus Borrelia have double-stranded linear plasmids in addition to supercoiled circular plasmids. The copy number relative to the chromosome was determined for 49- and 16-kb linear plasmids and a 27-kb circular plasmid of the type strai...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.174.16.5251-5257.1992
更新日期:1992-08-01 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::Thermococcus sp. strain 4557 is a hyperthermophilic anaerobic archaeon isolated from the deep-sea hydrothermal vent Guaymas Basin site in the Gulf of California at a depth of 2,000 m. Here, we present the complete genome sequence of Thermococcus sp. 4557, which consists of a single circular chromosome of 2,011,320 bp ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.05851-11
更新日期:2011-10-01 00:00:00