Biomaterial Database

Stimulation of genetic instability and associated large genomic rearrangements in Streptomyces ambofaciens by three fluoroquinolones. 1994

J N Volff, and D Vandewiele, and B Decaris

Laboratoire de Génétique et Microbiologie, Unité associée INRA, Faculté des Sciences, Université de Nancy I, Vandoeuvre-lès-Nancy, France.

In Streptomyces ambofaciens NSA2002, pigmented wild-type colonies spontaneously give rise to pigment-negative (Pig-) mutants at a frequency of about 0.5%. This genetic instability is related to large deletions which can be associated with amplifications of DNA sequences. The influence of three fluoroquinolones (ciprofloxacin, enoxacin, and norfloxacin) on this property was investigated. At a survival rate higher than 60%, most colonies showed a patchwork phenotype consisting of phenotypically heterogeneous colonies harboring numerous mutant sectors. Moreover, the frequency of Pig- mutants rose to more than 90% at survival rates equal to or higher than 10%. Induced Pig- mutants showed the same phenotypical features as did spontaneous mutants. Most of them also harbored deletions, associated in some cases with DNA amplifications, in two loci of the large unstable region, AUD6 and AUD90 (derived from amplifiable unit of DNA). The size of deletions in induced mutants could rise to 1.5 Mb. These results show that ciprofloxacin, enoxacin, and norfloxacin greatly stimulate genetic instability and the occurrence of DNA rearrangements in S. ambofaciens. Moreover, these three fluoroquinolones had the same rank order for both toxic (i.e., antibacterial) and genotoxic activities. If the antibacterial effect of fluoroquinolones in S. ambofaciens is due to their interference with DNA gyrase, as shown for some other organisms, the genotoxic effect observed could be due to their interaction with this type II topoisomerase. This suggests that DNA gyrase is involved in the process of genetic instability in S. ambofaciens.

UI	MeSH Term	Description	Entries
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
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
D009643	Norfloxacin	A synthetic fluoroquinolone (FLUOROQUINOLONES) with broad-spectrum antibacterial activity against most gram-negative and gram-positive bacteria. Norfloxacin inhibits bacterial DNA GYRASE.	AM-0715,AM-715,MK-0366,MK-366,MK0366,MK366,Noroxin,AM 0715,AM 715,AM0715,MK 0366,MK 366
D010858	Pigmentation	Coloration or discoloration of a part by a pigment.	Pigmentations
D002939	Ciprofloxacin	A broad-spectrum antimicrobial carboxyfluoroquinoline.	Bay-09867,Ciprinol,Cipro,Ciprofloxacin Hydrochloride,Ciprofloxacin Hydrochloride Anhydrous,Ciprofloxacin Monohydrochloride Monohydrate,Anhydrous, Ciprofloxacin Hydrochloride,Bay 09867,Bay09867,Hydrochloride Anhydrous, Ciprofloxacin,Hydrochloride, Ciprofloxacin,Monohydrate, Ciprofloxacin Monohydrochloride,Monohydrochloride Monohydrate, Ciprofloxacin
D004269	DNA, Bacterial	Deoxyribonucleic acid that makes up the genetic material of bacteria.	Bacterial DNA
D005784	Gene Amplification	A selective increase in the number of copies of a gene coding for a specific protein without a proportional increase in other genes. It occurs naturally via the excision of a copy of the repeating sequence from the chromosome and its extrachromosomal replication in a plasmid, or via the production of an RNA transcript of the entire repeating sequence of ribosomal RNA followed by the reverse transcription of the molecule to produce an additional copy of the original DNA sequence. Laboratory techniques have been introduced for inducing disproportional replication by unequal crossing over, uptake of DNA from lysed cells, or generation of extrachromosomal sequences from rolling circle replication.	Amplification, Gene
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000890	Anti-Infective Agents	Substances that prevent infectious agents or organisms from spreading or kill infectious agents in order to prevent the spread of infection.	Anti-Infective Agent,Anti-Microbial Agent,Antimicrobial Agent,Microbicide,Microbicides,Anti-Microbial Agents,Antiinfective Agents,Antimicrobial Agents,Agent, Anti-Infective,Agent, Anti-Microbial,Agent, Antimicrobial,Agents, Anti-Infective,Agents, Anti-Microbial,Agents, Antiinfective,Agents, Antimicrobial,Anti Infective Agent,Anti Infective Agents,Anti Microbial Agent,Anti Microbial Agents
D013268	Stimulation, Chemical	The increase in a measurable parameter of a PHYSIOLOGICAL PROCESS, including cellular, microbial, and plant; immunological, cardiovascular, respiratory, reproductive, urinary, digestive, neural, musculoskeletal, ocular, and skin physiological processes; or METABOLIC PROCESS, including enzymatic and other pharmacological processes, by a drug or other chemical.	Chemical Stimulation,Chemical Stimulations,Stimulations, Chemical