J Hacker

..Here we discuss ways in which PAIs contribute to the pathogenic potency of bacteria, and the idea that genetic entities similar to genomic islands may also be present in the genomes of eukaryotes...

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..coli...

..The hypothesis that the HPI in STEC contributes to the fitness of the strains in certain ecological niches rather than to their pathogenic potential is discussed...

..In addition, assumptions can be made on the evolution of these important pathogens...

..aureus sequence solely transcribed by sigma(B). In contrast, a second clpC-homologous gene in S. aureus forming an operon with ctsR, yacH, and yacI was sigma(B) independently expressed...

..Southern analysis with a L. pneumophila Corby-specific flaR probe revealed homologous genes in various L. pneumophila strains, but not in the 12 nonpneumophila strains tested so far...

..coli isolate mediated a higher level of internalization. The finding that curli fibers promote bacterial internalization indicates a new role for curli fibers in pathogenesis...

..We have also observed two types of HPI deletions, suggesting genetic instability of this element. Notable exceptions are several strains isolated from septicemia in sheep that lacked both iron acquisition systems...

..Whereas two fragments were highly specific for uropathogenic E. coli (UPEC), the other fragments could also be detected among the other tested wild-type strains...

..Furthermore, the presence of two different subclasses of the chuA determinant and their distribution in E. coli pathogroups are described...

..coli strain 536, replaces a 40-kb DNA region which represents an E. coli K-12-specific genomic island...

..In recent years many different genomic islands have been discovered in a variety of pathogenic as well as non-pathogenic bacteria. Because they promote genetic variability, genomic islands play an important role in microbial evolution...

..Our finding expands our knowledge of the regulation of tRNA gene transcription and represents an additional mode of regulation of gene expression that can also affect bacterial virulence...

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..We conclude that the newly described island occurs exclusively in a subgroup of STEC strains that are eae negative and contain the variant stx(2d )gene...

..coli strain 536...

..This review summarises the current knowledge on bacterial genomic islands and their general features, and discusses their putative role in the evolution of microbes in the light of genomics of pathogenic bacteria...

..coli fliA mutant. This result suggests that the L. pneumophila sigma28 protein can bind to the E. coli core RNA polymerase to direct transcription initiation from the flaA-specific promoter...

..The evolutionary relationship of fimbrial adhesion determinants is discussed...

..Minor proteins of similar size were observed in purified S fimbriae. Remarkably, some mutations in the foc gene cluster result in an altered fimbrial morphology, i.e., rigid stubs or long, curly fimbriae...

..The mature Mip proteins exist in an oligomeric form. Site-directed mutagenesis demonstrated that a substitution of an Asp residue at position 142 by a Leu residue affects PPIase activity of Mip...

..pneumophila Legionella strains. Two L. pneumophila strains and isolates of Legionella bozemanii and Legionella feeleii (serogroup 1) carry flaA-specific sequences but were not able to produce flagella...

..pneumophila. The amino acid sequence of PplA exhibits a high degree of homology to the sequences of the Pal lipoproteins of E. coli K-12 and Haemophilus influenzae...

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..Like human cyclophilin, the L. p. Cyp18 exhibits nuclease activity, but this enzymatic activity does not appear to be linked with the native structure of the protein...

..In view of the activity of PPIases in protein-folding reactions, such prokaryotic FKBP analogues may represent a new class of bacterial pathogenicity factors...

..The data show that the Foc minor subunits are highly homologous to the corresponding Sfa proteins, whereas homology to the minor subunits of type 1 and P fimbriae is much lower...

..Immunological differences of SLT-IIvhc and SLT-II as well as their different toxicity to HeLa cells presumably resulted from the small deviations within the primary structure of the B subunit...

..Most high-pathogenicity island-positive isolates produced yersiniabactin under iron-limited conditions and were positive for the high-molecular-weight proteins HMWP1 and HMWP2...

..Substitution of arginine 118 by serine also had a negative effect on the amount of SfaS adhesin proteins isolated from the S fimbrial adhesin complex...

..coli O18ac strains could be divided into two serologically distinct subgroups called O18A and O18A1. E. coli strains belonging to the subgroup O18A are sensitive to phage omega 18A whereas bacteria of subgroup A1 are resistant...

..It was further shown that the amino-terminal protein sequence of the isolated SfaS protein was identical to the protein sequence calculated from the DNA sequence of the sfaS gene locus...

..The results demonstrate that cross-regulation of two unlinked virulence gene clusters together with the co-ordinate loss of large DNA regions significantly influences the virulence of an extraintestinal E. coli wild-type isolate...

..Taking these results together, we have demonstrated that the flagellum of L. pneumophila positively affects the establishment of infection by facilitating the encounter of the host cell as well as by enhancing the invasion capacity...

..Intracellular survival of L. pneumophila in U937 macrophage-like cells and in Acanthamoeba castellanii was not affected by mutagenization of the lly locus...

..aureus and the other protein was identified as the phosphocarrier protein Hpr of S. aureus. The identified immunodominant proteins may serve as potential targets for the development of antibody based therapy against MRSA...

..pneumophila...

..Finally, a 'sponge-microbe interaction model' is presented that summarizes our current understanding of the processes that might have shaped the community structure of the microbial assemblages within sponges...