Type I fimbriation in fimE mutants of Escherichia coli K-12

We reexamined the influence of fimE, also referred to as hyp, on type 1 fimbriation in Escherichia coli K-12. We found that one strain used previously and extensively in the analysis of type 1 fimbriation, strain CSH50, is in fact a fimE mutant; the fimE gene of CSH50 contains a copy of the insertion sequence IS1. Using a recently described allelic exchange procedure, we transferred the fimE::IS1 allele from CSH50 to our present wild-type strain, MG1655. Characterization of this IS1-containing strain (AAEC137), together with another fimE mutant of MG1655 (AAEC143), led to two conclusions about the role of fimE. First, the formation of phase variant colony types, reported widely in strains of E. coli, depends on mutation of fimE, at least in K-12 strain MG1655. Here we showed that this phenomenon reflects the ability of fimE to stimulate the rapid inversion of the fim invertible element from on to off when the bacteria are grown on agar. Second, our analysis of fimE mutants, which is limited to chromosomal constructs, provided no evidence that they are hyperfimbriate. We believe that these results, which are at odds with a previous study using fim-containing multicopy plasmids, reflect differences in gene copy number

Identifikace mnozstvi a puvodu balastnich vod ve stokovem systemu Hradce Kralove.

A distribution of total inflow/infiltration among major parts of sewer system has been studied. The assesment has been done with help of volumetric method, which compares amount of water delivered to basin to amount of water drained. The qualitative method has been also used. It arises from water quality changes during night decrease of flow in sewersAvailable from STL Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi

The antitumor Effect of Magnetic Nanodiscs and Aptamer Conjugates

Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала.Here we descrabe a method of forming large arrays of free magnetic Ni-nanodiscs 50 nm thick coated on both sides with layers of 5 nm thick Au. The antitumor effect of the magnetic nickel gold-cjated nanodiscs and DNA aptamer conjugates was evaluated in vivo and in vitro. Under the influence of rotating magnetic fields tht studied nanodisks can cause the death of Erlich carcinoma cells

The antitumor Effect of Magnetic Nanodiscs and Aptamer Conjugates

Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала.Here we descrabe a method of forming large arrays of free magnetic Ni-nanodiscs 50 nm thick coated on both sides with layers of 5 nm thick Au. The antitumor effect of the magnetic nickel gold-cjated nanodiscs and DNA aptamer conjugates was evaluated in vivo and in vitro. Under the influence of rotating magnetic fields tht studied nanodisks can cause the death of Erlich carcinoma cells