The O-antigen moiety of the LPS is one of the most variable cell surface components of the Gram-negative bacterial outer membrane. Variation is due to the presence of different sugars and sugar linkages. Here, it is reported that a group of Escherichia coli O serogroups (O17, O44, O73, O77 and O106), and the Salmonella enterica serogroup O : 6,14 (H), share a common four-sugar backbone O-subuni...

Colonization of barley plants by the food-borne pathogens Salmonella enterica serovar typhimurium and three Listeria spp. (L. monocytogenes, L. ivanovii, L. innocua) was investigated in a monoxenic system. Herbaspirillum sp. N3 was used as a positive control and Escherichia coli HB101 as a negative control for endophytic root colonization. Colonization of the plants was tested 1-4 weeks after i...

The chromosomal iroBCDEN gene cluster first described for Salmonella enterica is involved in the uptake of catecholate-type siderophore compounds. An orthologous gene cluster has recently been detected in Escherichia coli strains which cause extraintestinal disease. This E. coli iroBCDEN gene cluster has an impact on virulence and has been reported to be located in a pathogenicity island on the...

BACKGROUND Our current understanding of biofilms indicates that these structures are typically composed of many different microbial species. However, the lack of reliable techniques for the discrimination of each population has meant that studies focusing on multi-species biofilms are scarce and typically generate qualitative rather than quantitative data. METHODOLOGY/PRINCIPAL FINDINGS We em...

Microbial systems have become the preferred testing grounds for experimental work on the evolution of traits that benefit other group members. This work, based on conceptual and theoretical models of frequency-dependent selection within populations, has proven fruitful in terms of understanding the dynamics of group beneficial or 'public goods' traits within species. Here, we expand the scope o...

Unlike the sigma(70)-controlled P2 promoter for the osmotically regulated proU operon of Escherichia coli and Salmonella enterica serovar Typhimurium, the sigma(s)-controlled P1 promoter situated further upstream appears not to contribute to expression of the proU structural genes under ordinary growth conditions. For S. enterica proU P1, there is evidence that promoter crypticity is the result...

conclusions: e. coli herb-resistance plasmid can replicate and be expressed in s. aureus. results: the identified 45 kb herb-resistance plasmid could be transferred from e. coli cp9 isolates to e. coli dh5α. as a consequence e. coli dh5α transconjugant mic increased from 0.0125 g/ml to 0.25 g/ml. the plasmid was easily transferred from e. coli cp9 strain to s. aureus rn450rf with a mean transfe...

Salmonella enterica serovar Typhi (S. Typhi), the causative agent of the typhoid fever, is a pathogen of great public health importance. Typhoid vaccines have the potential to be cost-effective measures towards combating this disease, yet the antigens triggering host protective immune responses are largely unknown. Given the key role of cellular-mediated immunity in S. Typhi protection, it is c...

viii The antibacterial activity of acetic acid is usually explained by weak acid theory, involving diffusion of the undissociated moiety followed by dissociation and cytoplasm acidification, and acetate anion accumulation and toxicity. These proposed mechanisms are ultimately mediated at the level of the cell envelope and, in particular, the cytoplasmic membrane. The most obvious changes due to...

Phenotypic differences among closely related bacteria have been largely ascribed to species-specific genes, such as those residing in pathogenicity islands. However, we now report that the differential regulation of homologous genes is the mechanism responsible for the divergence of the enteric bacteria Salmonella enterica and Escherichia coli in their ability to make LPS modifications mediatin...