Biomaterial Database

Filamentation promotes F'lac loss in Escherichia coli K12. 1992

E A Debbia

Institute of Microbiology, University of Genoa, Italy.

The stability of plasmid F'lac in Escherichia coli strain SP45 (a temperature conditional mutant which grows as spherical cells at 42 degrees C and as a rod at 30 degrees C) was studied. F'lac elimination was demonstrated when bacteria exposed to subinhibitory concentrations of various chemicals were induced to form filaments. No plasmid loss was found when spherical cells were subjected to the same treatments. Plasmid loss was also observed in dnaA46 and lexA41 mutants when cell filamentation was induced at 42 degrees C, but not when they were cultured at 30 degrees C. Nalidixic acid promoted F'lac elimination at 0.25 micrograms ml-1 in a recA13 mutant and at 1.5 micrograms ml-1 in the recA+ counterpart. A marked difference was found in the rate of F'lac elimination from thermosensitive DNA gyrase mutants [gyrA43(Ts) and gyrB41(Ts)] between rods and their spherical (rodA51) derivatives growing at semipermissive temperature (36.5 degrees C). Plasmids carrying the ccd segment of F in DNA gyrase mutants were lost after 2.5 generations from rods and after 6 generation from spherical cells. Plasmid segregation into non-viable minicell-like elements was found after induction of filaments. These data suggest that plasmid stability is correlated with cell shape and that curing is more easily achieved when bacteria can elongate normally.

UI	MeSH Term	Description	Entries
D007785	Lactose	A disaccharide of GLUCOSE and GALACTOSE in human and cow milk. It is used in pharmacy for tablets, in medicine as a nutrient, and in industry.	Anhydrous Lactose,Lactose, Anhydrous
D009024	Morphogenesis	The development of anatomical structures to create the form of a single- or multi-cell organism. Morphogenesis provides form changes of a part, parts, or the whole organism.
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
D009268	Nalidixic Acid	A synthetic 1,8-naphthyridine antimicrobial agent with a limited bacteriocidal spectrum. It is an inhibitor of the A subunit of bacterial DNA GYRASE.	Nalidixin,Nalidixate Sodium,Nalidixate Sodium Anhydrous,Nevigramon,Sodium Nalidixic Acid, Anhydrous,Sodium Nalidixic Acid, Monohydrate,Acid, Nalidixic,Anhydrous, Nalidixate Sodium,Sodium Anhydrous, Nalidixate,Sodium, Nalidixate
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D004250	DNA Topoisomerases, Type II	DNA TOPOISOMERASES that catalyze ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. These enzymes bring about relaxation of the supercoiled DNA and resolution of a knotted circular DNA duplex.	DNA Topoisomerase (ATP-Hydrolysing),DNA Topoisomerase II,DNA Topoisomerase II alpha,DNA Topoisomerase II beta,DNA Type 2 Topoisomerase,TOP2A Protein,TOP2B Protein,Topoisomerase II,Topoisomerase II alpha,Topoisomerase II beta,Type II DNA Topoisomerase,alpha, Topoisomerase II,beta, Topoisomerase II
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
D005144	F Factor	A plasmid whose presence in the cell, either extrachromosomal or integrated into the BACTERIAL CHROMOSOME, determines the "sex" of the bacterium, host chromosome mobilization, transfer via conjugation (CONJUGATION, GENETIC) of genetic material, and the formation of SEX PILI.	Resistance Transfer Factor,Sex Factor F,Sex Factor, Bacterial,Bacterial Sex Factor,Bacterial Sex Factors,F Plasmid,F Plasmids,Factor, Bacterial Sex,Factors, Bacterial Sex,Fertility Factor, Bacterial,Sex Factors, Bacterial,Bacterial Fertility Factor,Bacterial Fertility Factors,F Factors,Factor F, Sex,Factor Fs, Sex,Factor, Bacterial Fertility,Factor, F,Factor, Resistance Transfer,Factors, Bacterial Fertility,Factors, F,Factors, Resistance Transfer,Fertility Factors, Bacterial,Fs, Sex Factor,Plasmid, F,Plasmids, F,Resistance Transfer Factors,Sex Factor Fs,Transfer Factor, Resistance,Transfer Factors, Resistance
D006358	Hot Temperature	Presence of warmth or heat or a temperature notably higher than an accustomed norm.	Heat,Hot Temperatures,Temperature, Hot,Temperatures, Hot
D048429	Cell Size	The quantity of volume or surface area of CELLS.	Cell Volume,Cell Sizes,Cell Volumes,Size, Cell,Sizes, Cell,Volume, Cell,Volumes, Cell