Occurrence of Vibrio cholerae in water reservoirs of Burkina Faso.

Africa is currently an important region in which cholera epidemics occur. Little is known about the presence of Vibrio cholerae in freshwater bodies in Africa. There are ca.

Exposure to pairs of Aeromonas strains enhances virulence in the Caenorhabditis elegans infection model.

Aeromonad virulence remains poorly understood, and is difficult to predict from strain characteristics. In addition, infections are often polymicrobial (i.e.

Rapid proliferation of Vibrio parahaemolyticus, Vibrio vulnificus, and Vibrio cholerae during freshwater flash floods in French Mediterranean coastal lagoons.

Vibrio parahaemolyticus, Vibrio vulnificus, and Vibrio cholerae of the non-O1/non-O139 serotype are present in coastal lagoons of southern France. In these Mediterranean regions, the rivers have long low-flow periods followed by short-duration or flash floods during and after heavy intense rainstorms, particularly at the end of the summer and in autumn. These floods bring large volumes of freshwater into the lagoons, reducing their salinity.

Highly diverse recombining populations of Vibrio cholerae and Vibrio parahaemolyticus in French Mediterranean coastal lagoons.

Vibrio parahaemolyticus and Vibrio cholerae are ubiquitous to estuarine and marine environments. These two species found in Mediterranean coastal systems can induce infections in humans. Environmental isolates of V.

Pathogen-induced Caenorhabditis elegans developmental plasticity has a hormetic effect on the resistance to biotic and abiotic stresses.

Background: Phenotypic plasticity, i.e. the capacity to change the phenotype in response to changes in the environment without alteration of the genotype, is important for coping with unstable environments.

Bacterium-induced internal egg hatching frequency is predictive of life span in Caenorhabditis elegans populations.

Internal egg hatching in Caenorhabditis elegans, "worm bagging," is induced by exposure to bacteria. This study demonstrates that the determination of worm bagging frequency allows for advanced insight into the degree of bacterial pathogenicity and is highly predictive of the survival of worm populations. Therefore, worm bagging frequency can be regarded as a reliable population-wide stress reporter.

Pathogenicity-associated islands in extraintestinal pathogenic Escherichia coli are fitness elements involved in intestinal colonization.

The virulence of many human pathogens does not seem to be an evolutionarily selected trait, but an accidental by-product of the selection that operates in another ecological context. We investigated the possibility that virulence of the extraintestinal pathogenic Escherichia coli (ExPEC) strains, which frequently cause disease in the host in which they asymptomatically colonize the intestine, is the consequence of commensalism. Most of the ExPEC virulence factors are clustered on genomic islands called pathogenicity-associated islands (PAIs).

Modulation of aging profiles in isogenic populations of Caenorhabditis elegans by bacteria causing different extrinsic mortality rates.

It has been postulated that the presence of parasites causing high extrinsic mortality may trigger an inducible acceleration of the host aging. We tested this hypothesis using isogenic populations of Caenorhabditis elegans nematodes and different Escherichia coli strains. When exposed to pathogenic bacteria, nematodes showed up to fourfold higher mortality rates, reproduced earlier, produced more H(2)O(2), and accumulated more autofluorescence, than when exposed to an innocuous strain.

CDR3 loop flexibility contributes to the degeneracy of TCR recognition.

T cell receptor (TCR) binding degeneracy lies at the heart of several physiological and pathological phenomena, yet its structural basis is poorly understood. We determined the crystal structure of a complex involving the BM3.3 TCR and an octapeptide (VSV8) bound to the H-2K(b) major histocompatibility complex molecule at a 2.

A T cell receptor CDR3beta loop undergoes conformational changes of unprecedented magnitude upon binding to a peptide/MHC class I complex.

The elongated complementary-determining region (CDR) 3beta found in the unliganded KB5-C20 TCR protrudes from the antigen binding site and prevents its docking onto the peptide/MHC (pMHC) surface according to a canonical diagonal orientation. We now present the crystal structure of a complex involving the KB5-C20 TCR and an octapeptide bound to the allogeneic H-2K(b) MHC class I molecule. This structure reveals how a tremendously large CDR3beta conformational change allows the KB5-C20 TCR to adapt to the rather constrained pMHC surface and achieve a diagonal docking mode.