Abstract:
:Whether or not bacteria form coherent evolutionary groups via means of genetic exchange and, hence, elicit distinct species boundaries remains an unsettled issue. A recent report implied that not only may the former be true but also, in fact, the clearly distinct Campylobacter jejuni and Campylobacter coli species may be converging as a consequence of increased interspecies gene flow fostered, presumably, by the recent invasion of an overlapping ecological niche (S. K. Sheppard, N. D. McCarthy, D. Falush, and M. C. Maiden, Science 320:237-239, 2008). We have reanalyzed the Campylobacter multilocus sequence typing database used in the previous study and found that the number of interspecies gene transfer events may actually be too infrequent to account, unequivocally, for species convergence. For instance, only 1 to 2% of the 4,507 Campylobacter isolates examined appeared to have imported gene alleles from another Campylobacter species. Furthermore, by analyzing the available Campylobacter genomic sequences, we show that although there seems to be a slightly higher number of exchanged genes between C. jejuni and C. coli relative to other comparable species ( approximately 10% versus 2 to 3% of the total genes in the genome, respectively), the function and spatial distribution in the genome of the exchanged genes are far from random, and hence, inconsistent with the species convergence hypothesis. In fact, the exchanged genes appear to be limited to a few environmentally selected cellular functions. Accordingly, these genes may represent important pathogenic determinants of pathogenic Campylobacter, and convergence of (any) two bacterial species remains to be seen.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Caro-Quintero A,Rodriguez-Castaño GP,Konstantinidis KTdoi
10.1128/JB.00519-09subject
Has Abstractpub_date
2009-09-01 00:00:00pages
5824-31issue
18eissn
0021-9193issn
1098-5530pii
JB.00519-09journal_volume
191pub_type
杂志文章abstract::Bacillus subtilis strains containing deletions in the genes coding for one or two of the major small, acid-soluble spore proteins (SASP; termed SASP-alpha and SASP-beta) were constructed. These mutants sporulated normally, but the spores lacked either SASP-alpha, SASP-beta, or both proteins. The level of minor SASP di...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.167.1.174-178.1986
更新日期:1986-07-01 00:00:00
abstract::Lysates of Escherichia coli Ymel obtained from cultures grown in the absence of tryptophan in minimal medium supplemented with 0.1% casein hydrolysate show an approximate fivefold increase in steady-state specific activity of both anthranilate synthetase and tryptophan synthetase A protein relative to cultures grown i...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.108.3.1181-1191.1971
更新日期:1971-12-01 00:00:00
abstract::The formation of bacteriolytic enzymes of Staphylococcus aureus, with special reference to strain M18, was investigated under a variety of conditions. The bacteriolytic activity was tested by using whole cells of Micrococcus lysodeikticus as a substrate. Complex media were required for production, and a Casein Hydroly...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.104.1.227-233.1970
更新日期:1970-10-01 00:00:00
abstract::Site-specific mutagenesis has identified amino acids involved in bR proton transport. Biophysical studies of the mutants have elucidated the roles of two membrane-embedded residues: Asp-85 serves as the acceptor for the proton from the isomerized retinylidene Schiff base, and Asp-96 participates in reprotonation of th...
journal_title:Journal of bacteriology
pub_type: 杂志文章,评审
doi:10.1128/jb.175.6.1555-1560.1993
更新日期:1993-03-01 00:00:00
abstract::Haemophilus influenzae is a common gram-negative pathogen that initiates infection by colonizing the upper respiratory tract epithelium. In previous work, we reported the isolation of a locus involved in expression of short, thin surface fibrils by H. influenzae type b and presented evidence that surface fibrils promo...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.178.21.6281-6287.1996
更新日期:1996-11-01 00:00:00
abstract::Nitrogenase activities were determined from maximum acetylene reduction rates for mutant strains of Azotobacter vinelandii which are unable to fix N2 in the presence of molybdenum (Nif-) but undergo phenotypic reversal to Nif+ under conditions of Mo deficiency. The system responsible for N2 fixation under these condit...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.150.3.1244-1251.1982
更新日期:1982-06-01 00:00:00
abstract::Heterokaryons of Mucor racemosus were produced by fusion of spheroplasts from two auxotrophic strains of the fungus. Germinated sporangiospores were converted to spheroplasts by using commercial chitinase and Myxobacter AL-1 chitosanase. Spheroplasts from the auxotrophic strains were mixed in a buffered Ca(NO3)2 solut...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.134.1.349-352.1978
更新日期:1978-04-01 00:00:00
abstract::A gene coding for thermophilic beta-amylase of Clostridium thermosulfurogenes was cloned into Bacillus subtilis, and its nucleotide sequence was determined. The nucleotide sequence suggested that the thermophilic beta-amylase is translated from monocistronic mRNA as a secretory precursor with a signal peptide of 32 am...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.170.12.5848-5854.1988
更新日期:1988-12-01 00:00:00
abstract::The autolytic capacity of Streptococcus faecium (S. faecalis ATCC 9790) varied during synchronous cell division. This phenomenon was initially observed in rapidly dividing populations (TD=30 to 33 min) synchronized by a combination of induction and size selection techniques. To minimize the problems inherent in studie...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.133.2.822-829.1978
更新日期:1978-02-01 00:00:00
abstract::CRISPR-Cas systems are prokaryotic adaptive immune systems that facilitate protection of bacteria and archaea against infection by external mobile genetic elements. The model pathogen Francisella novicida encodes a CRISPR-Cas12a (FnoCas12a) system and a CRISPR-Cas9 (FnoCas9) system, the latter of which has an addition...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00670-19
更新日期:2020-05-27 00:00:00
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 mu...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.185.8.2644-2652.2003
更新日期:2003-04-01 00:00:00
abstract::The expression of the positively charged human protein secretory leukocyte protease inhibitor (SLPI) in Escherichia coli causes severe cellular toxicity. After induction of SLPI synthesis in a high-level-expression strain, SGE61, the growth of the strain is arrested and total protein and RNA synthesis rates decline by...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.171.4.2166-2172.1989
更新日期:1989-04-01 00:00:00
abstract::The model of pneumonia produced by intranasal inoculation of Mycoplasma pulmonis in gnotobiotic mice provided the opportunity to study the localization and identification of the infecting organisms in the tissues by immunofluorescence techniques. Frozen sections of pneumonic mouse lung were fixed in acetone, layered w...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.96.1.250-258.1968
更新日期:1968-07-01 00:00:00
abstract::A plasmid, R773, which confers resistance to arsenic compounds, is transmissible between strains of Escherichia coli. It is a member of compatibility group F(1). ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.115.1.459-460.1973
更新日期:1973-07-01 00:00:00
abstract::Sphingobium japonicum UT26 utilizes gamma-hexachlorocyclohexane (gamma-HCH) as its sole source of carbon and energy. In our previous studies, we cloned and characterized genes encoding enzymes for the conversion of gamma-HCH to beta-ketoadipate in UT26. In this study, we analyzed a mutant obtained by transposon mutage...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01883-06
更新日期:2007-05-01 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::Overexpression of vsr in Escherichia coli stimulates transition and frameshift mutations. The pattern of mutations suggests that mutagenesis is due to saturation or inactivation of dam-directed mismatch repair. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.178.14.4294-4296.1996
更新日期:1996-07-01 00:00:00
abstract::Comparative genome analysis of Enterococcus faecium recently revealed that a genomic island containing the esp gene, referred to as the esp-containing pathogenicity island (esp PAI), can be transferred by conjugation and contains a partial Tn916-like element and an integrase gene, intA. Here, we characterize the role ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00952-10
更新日期:2011-02-01 00:00:00
abstract::Lactococcus garvieae is the etiological agent of lactococcosis, one of the most important disease threats to the sustainability of the rainbow trout farming industry. Here, we present the draft genome sequence of Lactococcus garvieae strain 8831, isolated from diseased rainbow trout, which is composed of 2,087,276 bp ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.05326-11
更新日期:2011-08-01 00:00:00
abstract::Spiralin could not be solubilized in the absence of detergents, and it was shown by charge-shift crossed immunoelectrophoresis that this protein was capable of binding detergents under nondenaturing conditions. These properties indicate the amphiphilic nature of spiralin, which therefore should be regarded as an intri...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.140.2.738-741.1979
更新日期:1979-11-01 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::The homotrimeric enzyme Mt-Cam from Methanosarcina thermophila is the archetype of the gamma class of carbonic anhydrases. A search of databases queried with Mt-Cam revealed that a majority of the homologs comprise a putative subclass (CamH) in which there is major conservation of all of the residues essential for the...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01164-09
更新日期:2010-03-01 00:00:00
abstract::MntH, a bacterial homolog of mammalian natural resistance associated macrophage protein 1 (Nramp1), is a primary transporter for Mn(2+) influx in Salmonella enterica serovar Typhimurium and Escherichia coli. S. enterica serovar Typhimurium MntH contributes to H(2)O(2) resistance and is important for full virulence. Co...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.184.12.3151-3158.2002
更新日期:2002-06-01 00:00:00
abstract::Over most of the range of salt concentrations in which the moderately halophilic bacterium Vibrio costicola could grow, the sum of the cell-associated Na+ + K+ ions was at least as high as in the external medium. This is in contrast to other moderate halophiles, which have substantially lower internal than external sa...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.130.2.698-703.1977
更新日期:1977-05-01 00:00:00
abstract::Three evolutionarily distinct families of replicative DNA polymerases, designated polymerase B (Pol B), Pol C, and Pol D, have been identified. Members of the Pol B family are present in all three domains of life, whereas Pol C exists only in Bacteria and Pol D exists only in Archaea. Pol B enzymes replicate eukaryoti...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.02037-12
更新日期:2013-05-01 00:00:00
abstract::Flagellum formation by ubiquinone- and menaquinone-deficient mutant strains of Escherichia coli K-12 was studied under both aerobic and anaerobic growth conditions. Ubiquinone was found to be obligatory for aerobic flagellum formation but could be replaced by menaquinone for anaerobic flagellum formation. A mutant dev...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.132.3.1034-1035.1977
更新日期:1977-12-01 00:00:00
abstract::Pseudomonas MS can grow on methylamine and a number of other compounds containing C1 units as a sole source of carbon and energy. Assimilation of carbon into cell material occurs via the "serine pathway" since enzymes of this pathway are induced after growth on methylamine, but not malate or acetate. A mutant has been...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.122.3.905-910.1975
更新日期:1975-06-01 00:00:00
abstract::Tn2603 is a multiple-resistance transposon encoding resistance to ampicillin, streptomycin, sulfonamide, and mercury and having a molecular size of 20 kilobase pairs, with 200-base-pair inverted repeats at both ends. The essential sites and functions of Tn2603 which are required for its transposition were determined t...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.151.2.723-728.1982
更新日期:1982-08-01 00:00:00
abstract::Studies were made of the synthesis of Lac messenger ribonucleic acid (mRNA) by Escherichia coli in the absence of protein synthesis and of the coupling of transcription of lac operon to translation. Lac mRNA was not synthesized in the presence of chloramphenicol, and its synthesis steadily decreased during K(+) depriv...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.110.2.652-660.1972
更新日期:1972-05-01 00:00:00
abstract::Cores are large, rod-shaped structures that have been found almost exclusively in group D streptococci, measure 0.1 to 0.16 mum in diameter, and extend the width or length of cells. This study has shown that cores are produced in the cells at a reproducible point in early stationary growth after extensive mesosomal fo...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.129.1.445-456.1977
更新日期:1977-01-01 00:00:00