Biomaterial Database

Chromosomal heterogeneity of Helicobacter pylori isolates by pulsed-field gel electrophoresis. 1993

S Takami, and T Hayashi, and Y Tonokatsu, and T Shimoyama, and T Tamura

Department of Bacteriology, Hyogo College of Medicine, Japan.

The genome of 24 Helicobacter pylori (H. pylori) isolates was analyzed by restriction endonuclease digestion and pulsed-field gel electrophoresis (PFGE). On PFGE profiles of NotI, 12 isolates among 24 yielded four to nine fragments which differed among them. The other 12 isolates could not be digested with NotI. The total genome size calculated from individual fragments ranged from 1.04 x 10(3) to 1.80 x 10(3) kb. This remarkable uneveness in the total genome size among isolates is unusual if H. pylori is considered a single species. Therefore, the extreme diversity in PFGE profiles and genome size among H. pylori strains, which had been considered as homogeneous according to conventional biochemical criteria, led us to reexamine the H. pylori species for their genomic homology. Furthermore, we used the genetic heterogeneity as a marker to identify specified strains among clinical isolates.

UI	MeSH Term	Description	Entries
D002876	Chromosomes, Bacterial	Structures within the nucleus of bacterial cells consisting of or containing DNA, which carry genetic information essential to the cell.	Bacterial Chromosome,Bacterial Chromosomes,Chromosome, Bacterial
D004262	DNA Restriction Enzymes	Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.	Restriction Endonucleases,DNA Restriction Enzyme,Restriction Endonuclease,Endonuclease, Restriction,Endonucleases, Restriction,Enzymes, DNA Restriction,Restriction Enzyme, DNA,Restriction Enzymes, DNA
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D001482	Base Composition	The relative amounts of the PURINES and PYRIMIDINES in a nucleic acid.	Base Ratio,G+C Composition,Guanine + Cytosine Composition,G+C Content,GC Composition,GC Content,Guanine + Cytosine Content,Base Compositions,Base Ratios,Composition, Base,Composition, G+C,Composition, GC,Compositions, Base,Compositions, G+C,Compositions, GC,Content, G+C,Content, GC,Contents, G+C,Contents, GC,G+C Compositions,G+C Contents,GC Compositions,GC Contents,Ratio, Base,Ratios, Base
D016480	Helicobacter pylori	A spiral bacterium active as a human gastric pathogen. It is a gram-negative, urease-positive, curved or slightly spiral organism initially isolated in 1982 from patients with lesions of gastritis or peptic ulcers in Western Australia. Helicobacter pylori was originally classified in the genus CAMPYLOBACTER, but RNA sequencing, cellular fatty acid profiles, growth patterns, and other taxonomic characteristics indicate that the micro-organism should be included in the genus HELICOBACTER. It has been officially transferred to Helicobacter gen. nov. (see Int J Syst Bacteriol 1989 Oct;39(4):297-405).	Campylobacter pylori,Campylobacter pylori subsp. pylori,Campylobacter pyloridis,Helicobacter nemestrinae
D016521	Electrophoresis, Gel, Pulsed-Field	Gel electrophoresis in which the direction of the electric field is changed periodically. This technique is similar to other electrophoretic methods normally used to separate double-stranded DNA molecules ranging in size up to tens of thousands of base-pairs. However, by alternating the electric field direction one is able to separate DNA molecules up to several million base-pairs in length.	Electrophoresis, Gel, Pulsed-Field Gradient,Gel Electrophoresis, Pulsed-Field,Contour-Clamped Homogeneous-Field Gel Electrophoresis,Electrophoresis, Gel, Pulsed Field,Electrophoresis, Pulsed Field Gel,Field Inversion Gel Electrophoresis,Orthogonal Field Alternation Gel Electrophoresis,Orthogonal-Field Alternation-Gel Electrophoresis,Pulsed Field Gradient Gel Electrophoresis,Pulsed-Field Gel Electrophoresis,Pulsed-Field Gradient Gel Electrophoresis,Alternation-Gel Electrophoresis, Orthogonal-Field,Contour Clamped Homogeneous Field Gel Electrophoresis,Electrophoresis, Orthogonal-Field Alternation-Gel,Electrophoresis, Pulsed-Field Gel,Gel Electrophoresis, Pulsed Field,Pulsed Field Gel Electrophoresis
D016680	Genome, Bacterial	The genetic complement of a BACTERIA as represented in its DNA.	Bacterial Genome,Bacterial Genomes,Genomes, Bacterial