Biomaterial Database

Role of pyrimidine dimer excision in loss of potential streptomycin resistance mutations of ultraviolet-irradiated Escherichia coli on phosphate-buffered agar. 1975

A S Sideropoulos, and J Greenberg

The frequency of ultraviolet (UV)-induced mutations to streptomycin resistance dropped rapidly when starved Escherichia coli strains WP-2 B/r and B/r T- were incubated on phosphate-buffered agar (PBA), but was reduced only slightly in a WP-2 hcr- mutant. During postirradiation, incubation viability remained approximately constant. Cells given an optimal recovery treatment with photo-reactivating light showed no further recovery if subsequently incubated on PBA. At least 70% of the mutations induced to streptomycin resistance by UV could be repaired. The loss of potential streptomycin-resistant mutants was markedly reduced in strain B/r T- when 5 mug of acriflavin or 700 mug of caffeine per ml was added to PBA. The excision of UV-induced thymine-containing dimers from E. coli tb/r T- was investigated. Dimer excision progressed more slowly when the cells were incubated on PBA containing acriflavin or caffeine. There was no congruity between the kinetics of dimer excision and the kinetics of mutant loss. Our results indicate that removal of potential streptomycin-resistant mutants is considerably faster than the excision of pyrimidine dimers.

UI	MeSH Term	Description	Entries
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D011743	Pyrimidines	A family of 6-membered heterocyclic compounds occurring in nature in a wide variety of forms. They include several nucleic acid constituents (CYTOSINE; THYMINE; and URACIL) and form the basic structure of the barbiturates.
D011831	Radiation Genetics	A subdiscipline of genetics that studies RADIATION EFFECTS on the components and processes of biological inheritance.	Genetics, Radiation
D002110	Caffeine	A methylxanthine naturally occurring in some beverages and also used as a pharmacological agent. Caffeine's most notable pharmacological effect is as a central nervous system stimulant, increasing alertness and producing agitation. It also relaxes SMOOTH MUSCLE, stimulates CARDIAC MUSCLE, stimulates DIURESIS, and appears to be useful in the treatment of some types of headache. Several cellular actions of caffeine have been observed, but it is not entirely clear how each contributes to its pharmacological profile. Among the most important are inhibition of cyclic nucleotide PHOSPHODIESTERASES, antagonism of ADENOSINE RECEPTORS, and modulation of intracellular calcium handling.	1,3,7-Trimethylxanthine,Caffedrine,Coffeinum N,Coffeinum Purrum,Dexitac,Durvitan,No Doz,Percoffedrinol N,Percutaféine,Quick-Pep,Vivarin,Quick Pep,QuickPep
D004260	DNA Repair	The removal of DNA LESIONS and/or restoration of intact DNA strands without BASE PAIR MISMATCHES, intrastrand or interstrand crosslinks, or discontinuities in the DNA sugar-phosphate backbones.	DNA Damage Response
D004269	DNA, Bacterial	Deoxyribonucleic acid that makes up the genetic material of bacteria.	Bacterial DNA
D004352	Drug Resistance, Microbial	The ability of microorganisms, especially bacteria, to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).	Antibiotic Resistance,Antibiotic Resistance, Microbial,Antimicrobial Resistance, Drug,Antimicrobial Drug Resistance,Antimicrobial Drug Resistances,Antimicrobial Resistances, Drug,Drug Antimicrobial Resistance,Drug Antimicrobial Resistances,Drug Resistances, Microbial,Resistance, Antibiotic,Resistance, Drug Antimicrobial,Resistances, Drug Antimicrobial
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D005796	Genes	A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.	Cistron,Gene,Genetic Materials,Cistrons,Genetic Material,Material, Genetic,Materials, Genetic
D000167	Acriflavine	3,6-Diamino-10-methylacridinium chloride mixt. with 3,6-acridinediamine. Fluorescent dye used as a local antiseptic and also as a biological stain. It intercalates into nucleic acids thereby inhibiting bacterial and viral replication.	Xanthacridinum,2,8-Diamino-10-Methylacridinium Chloride Mixture With 2,8-Diaminoacridine