Biomaterial Database

Tetracycline-dependent appearance of plasmidlike forms in Bacteroides uniformis 0061 mediated by conjugal Bacteroides tetracycline resistance elements. 1988

N B Shoemaker, and A A Salyers

Department of Microbiology, University of Illinois, Urbana 61801.

Some human colonic Bacteroides strains carry conjugal tetracycline resistance (Tcr) elements, which are thought to be chromosomal. We have found that some of these Tcr elements can mediate the appearance of plasmidlike forms in Bacteroides uniformis 0061. When B. uniformis 0061, containing a conjugal Tcr element designated Tcr ERL, was grown in medium containing tetracycline (1 microgram/ml), two circular DNA forms were found in the alkaline plasmid preparations: NBU1 (10.3 +/- 0.5 kilobases) and NBU2 (11.5 +/- 0.5 kilobases). Restriction analysis of NBU1 and NBU2 showed that they were not identical, although Southern blot analysis indicated that they did contain some region(s) of homology. Results of Southern blot analysis also demonstrated that both NBU1 and NBU2 were normally integrated in the chromosome of B. uniformis or in some undetected large plasmid. Although we were unable to determine the exact structure and location of the integrated forms of NBU1 and NBU2 in B. uniformis, they appear to be in close proximity to each other. Neither NBU1 or NBU2 could be detected as a plasmidlike form in cells exposed to UV light, thymidine starvation, mitomycin C, or autoclaved chlortetracycline (50 micrograms/ml). Four conjugal Tcr elements other than the Tcr ERL element were able to mediate the appearance of NBU1 alone, and two Tcr elements did not mediate the excision of either NBU1 or NBU2. Three strains from different Bacteroides species contained some DNA sequences which had homology to NBU1 and NBU2.

UI	MeSH Term	Description	Entries
D009693	Nucleic Acid Hybridization	Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)	Genomic Hybridization,Acid Hybridization, Nucleic,Acid Hybridizations, Nucleic,Genomic Hybridizations,Hybridization, Genomic,Hybridization, Nucleic Acid,Hybridizations, Genomic,Hybridizations, Nucleic Acid,Nucleic Acid Hybridizations
D011815	R Factors	A class of plasmids that transfer antibiotic resistance from one bacterium to another by conjugation.	R Factor,R Plasmid,R Plasmids,Resistance Factor,Resistance Factors,Factor, R,Factor, Resistance,Factors, R,Factors, Resistance,Plasmid, R,Plasmids, R
D002751	Chlortetracycline	A TETRACYCLINE with a 7-chloro substitution.	Aureocyclin,Aureomycin,Aureomycine,Biomycin,Chlorotetracycline,Chlortetracycline Bisulfate,Chlortetracycline Hydrochloride,Chlortetracycline Monohydrochloride,Chlortetracycline Sulfate (1:1),Chlortetracycline Sulfate (2:1),Chlortetracycline, 4-Epimer,Chlortetracycline, Calcium Salt,4-Epimer Chlortetracycline,Bisulfate, Chlortetracycline,Calcium Salt Chlortetracycline,Chlortetracycline, 4 Epimer,Hydrochloride, Chlortetracycline,Monohydrochloride, Chlortetracycline,Salt Chlortetracycline, Calcium
D003106	Colon	The segment of LARGE INTESTINE between the CECUM and the RECTUM. It includes the ASCENDING COLON; the TRANSVERSE COLON; the DESCENDING COLON; and the SIGMOID COLON.	Appendix Epiploica,Taenia Coli,Omental Appendices,Omental Appendix,Appendices, Omental,Appendix, Omental
D003227	Conjugation, Genetic	A parasexual process in BACTERIA; ALGAE; FUNGI; and ciliate EUKARYOTA for achieving exchange of chromosome material during fusion of two cells. In bacteria, this is a uni-directional transfer of genetic material; in protozoa it is a bi-directional exchange. In algae and fungi, it is a form of sexual reproduction, with the union of male and female gametes.	Bacterial Conjugation,Conjugation, Bacterial,Genetic Conjugation
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
D004269	DNA, Bacterial	Deoxyribonucleic acid that makes up the genetic material of bacteria.	Bacterial DNA
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D001439	Bacteroides	A genus of gram-negative, anaerobic, rod-shaped bacteria. Its organisms are normal inhabitants of the oral, respiratory, intestinal, and urogenital cavities of humans, animals, and insects. Some species may be pathogenic.
D012689	Sequence Homology, Nucleic Acid	The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.	Base Sequence Homology,Homologous Sequences, Nucleic Acid,Homologs, Nucleic Acid Sequence,Homology, Base Sequence,Homology, Nucleic Acid Sequence,Nucleic Acid Sequence Homologs,Nucleic Acid Sequence Homology,Sequence Homology, Base,Base Sequence Homologies,Homologies, Base Sequence,Sequence Homologies, Base