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Marie Agnes Jacques – One of the best experts on this subject based on the ideXlab platform.
Adhesion Mechanisms of Plant-Pathogenic Xanthomonadaceae, 2011Co-Authors: Nadia Mhedbi-hajri, Marie Agnes Jacques, Ralf KoebnikAbstract:
The family Xanthomonadaceae is a wide-spread family of bacteria belonging to the gamma subdivision of the Gram-negative proteobacteria, including the two plant-pathogenic genera Xanthomonas and Xylella, and the related genus Stenotrophomonas. Adhesion is a widely conserved virulence mechanism among Gram-negative bacteria, no matter whether they are human, animal or plant pathogens, since attachment to the host tissue is one of the key early steps of the bacterial infection process. Bacterial attachment to surfaces is mediated by surface structures that are anchored in the bacterial outer membrane and cover a broad group of fimbrial and non-fimbrial structures, commonly known as Adhesins. In this chapter, we discuss recent findings on candidate Adhesins of plant-pathogenic Xanthomonadaceae, including polysaccharidic (lipopolysaccharides, exopolysaccharides) and proteineous structures (chaperone/usher pili, type IV pili, autotransporters, two-partner-secreted and other outer membrane Adhesins), their involvement in the formation of biofilms and their mode of regulation via quorum sensing. We then compare the arsenals of Adhesins among different Xanthomonas strains and evaluate their mode of selection. Finally, we summarize the sparse knowledge on specific Adhesin receptors in plants and the possible role of RGD motifs in binding to integrin-like plant molecules.
Sensing and adhesion are adaptive functions in the plant pathogenic xanthomonadsBMC Evolutionary Biology, 2011Co-Authors: Nadia Mhedbi-hajri, Armelle Darrasse, Karine Durand, Charles Manceau, Sandrine Pigné, Stéphanie Fouteau, Valérie Barbe, Christophe Lemaire, Marie Agnes JacquesAbstract:
Background: Bacterial plant pathogens belonging to the Xanthomonas genus are tightly adapted to their host plants and are not known to colonise other environments. The host range of each strain is usually restricted to a few host plant species. Bacterial strains responsible for the same type of symptoms on the same host range cluster in a pathovar. The phyllosphere is a highly stressful environment, but it provides a selective habitat and a source of substrates for these bacteria. Xanthomonads colonise host phylloplane before entering leaf tissues and engaging in an invasive pathogenic phase. Hence, these bacteria are likely to have evolved strategies to adapt to life in this environment. We hypothesised that determinants responsible for bacterial host adaptation are expressed starting from the establishment of chemotactic attraction and adhesion on host tissue. Results: We established the distribution of 70 genes coding sensors and Adhesins in a large collection of xanthomonad strains. These 173 strains belong to different pathovars of Xanthomonas spp and display different host ranges. Candidate genes are involved in chemotactic attraction (25 genes), chemical environment sensing (35 genes), and adhesion (10 genes). Our study revealed that candidate gene repertoires comprised core and variable gene suites that likely have distinct roles in host adaptation. Most pathovars were characterized by unique repertoires of candidate genes, highlighting a correspondence between pathovar clustering and repertoires of sensors and Adhesins. To further challenge our hypothesis, we tested for molecular signatures of selection on candidate genes extracted from sequenced genomes of strains belonging to different pathovars. We found strong evidence of adaptive divergence acting on most candidate genes. Conclusions: These data provide insight into the potential role played by sensors and Adhesins in the adaptation of xanthomonads to their host plants. The correspondence between repertoires of sensor and Adhesin genes and pathovars and the rapid evolution of sensors and Adhesins shows that, for plant pathogenic xanthomonads, events leading to host specificity may occur as early as chemotactic attraction by host and adhesion to tissues.
Role of type III secretion system and Adhesins in the fitness of Xanthomonas fuscans subsp. fuscans in bean phyllosphere and in transmission to seeds, 2009Co-Authors: Arnaud Darsonval, Armelle Darrasse, Karine Durand, Christine Bureau, Charles Manceau, Marie Agnes JacquesAbstract:
Deciphering the mechanisms enabling plant pathogenic bacteria to disperse, colonize and survive on their hosts provides the necessary basis to set up new control methods. We evaluated the role of the type III secretion system (T3SS) and Adhesins in two steps of the asymptomatic host colonization process: phyllospheric colonization and transmission to seeds. Xanthomonas fuscans subsp. fuscans is responsible for the common bacterial blight of bean, a seedborne disease. Unlike the wild-type X. fuscans subsp. fuscans, strains with mutations in T3SS regulatory genes were impaired in their phyllospheric growth as was Escherichia coli on bean. Strains with mutations in the hrp structural genes maintained the same constant epiphytic population densities as did X. campestris pv. campestris on bean in a non-host interaction. Among the five Adhesins identified in X. fuscans subsp. fuscans, only the non-polar Adhesin YapH was required for adhesion on leaves. Transmission to seeds by the vascular pathway was abolished for mutants in T3SS regulatory and structural genes, and remained possible but altered, for mutants in Adhesin genes, except for mutant in yapH which behaved as the wild-type strain. Transmission to seeds by floral structures did not require any of the known Adhesins and remained possible but with a low efficiency for hrp mutants and was repeatedly recorded for a non-host pathogen (X. campestris pv. campestris). E. coli did no transmit to bean seed. In conclusion, we showed that T3SS and bacterial Adhesins are implicated in the various processes leading to host phyllosphere colonization and systemic transmission to seeds in the absence of symptoms in compatible interactions.
Alain L Servin – One of the best experts on this subject based on the ideXlab platform.
a subfamily of dr Adhesins of escherichia coli bind independently to decay accelerating factor and the n domain of carcinoembryonic antigenJournal of Biological Chemistry, 2006Co-Authors: Natalia Korotkova, Ernesto Cota, Yuri Lebedin, Severine Monpouet, Julie Guignot, Alain L Servin, Steve Matthews, Steve L MoseleyAbstract:
Abstract Escherichia coli expressing the Dr family of Adhesins adheres to epithelial cells by binding to decay-accelerating factor (DAF) and carcinoembryonic antigen (CEA)-related cell surface proteins. The attachment of bacteria expressing Dr Adhesins to DAF induces clustering of DAF around bacterial cells and also recruitment of CEA-related cell adhesion molecules. CEA, CEACAM1, and CEACAM6 have been shown to serve as receptors for some Dr Adhesins (AfaE-I, AfaE-III, DraE, and DaaE). We demonstrate that AfaE-I, AfaE-V, DraE, and DaaE Adhesins bind to the N-domain of CEA. To identify the residues involved in the N-CEA/DraE interaction, we performed SPR binding analyses of naturally occurring variants and a number of randomly generated mutants in DraE and N-CEA. Additionally, we used chemical shift mapping by NMR to determine the surface of DraE involved in N-CEA binding. These results show a distinct CEA binding site located primarily in the A, B, E, and D strands of the Dr Adhesin. Interestingly, this site is located opposite to the β-sheet encompassing the previously determined binding site for DAF, which implies that the Adhesin can bind simultaneously to both receptors on the epithelial cell surface. The recognition of CEACAMs from a highly diverse DrCEA subfamily of Dr Adhesins indicates that interaction with these receptors plays an important role in niche adaptation of E. coli strains expressing Dr Adhesins.
A subfamily of Dr Adhesins of Escherichia coli bind independently to decay-accelerating factor and the N-domain of carcinoembryonic antigen.Journal of Biological Chemistry, 2006Co-Authors: Natalia Korotkova, Ernesto Cota, Yuri Lebedin, Severine Monpouet, Julie Guignot, Alain L Servin, Steve Matthews, Steve MoseleyAbstract:
Escherichia coli expressing the Dr family of Adhesins adheres to epithelial cells by binding to decay-accelerating factor (DAF) and carcinoembryonic antigen (CEA)-related cell surface proteins. The attachment of bacteria expressing Dr Adhesins to DAF induces clustering of DAF around bacterial cells and also recruitment of CEA-related cell adhesion molecules. CEA, CEACAM1, and CEACAM6 have been shown to serve as receptors for some Dr Adhesins (AfaE-I, AfaE-III, DraE, and DaaE). We demonstrate that AfaE-I, AfaE-V, DraE, and DaaE Adhesins bind to the N-domain of CEA. To identify the residues involved in the N-CEA/DraE interaction, we performed SPR binding analyses of naturally occurring variants and a number of randomly generated mutants in DraE and N-CEA. Additionally, we used chemical shift mapping by NMR to determine the surface of DraE involved in N-CEA binding. These results show a distinct CEA binding site located primarily in the A, B, E, and D strands of the Dr Adhesin. Interestingly, this site is located opposite to the beta-sheet encompassing the previously determined binding site for DAF, which implies that the Adhesin can bind simultaneously to both receptors on the epithelial cell surface. The recognition of CEACAMs from a highly diverse DrCEA subfamily of Dr Adhesins indicates that interaction with these receptors plays an important role in niche adaptation of E. coli strains expressing Dr Adhesins.
afa dr diffusely adhering escherichia coli infection in t84 cell monolayers induces increased neutrophil transepithelial migration which in turn promotes cytokine dependent upregulation of decay accelerating factor cd55 the receptor for afa dr adhesiInfection and Immunity, 2003Co-Authors: Frederic Betis, Julie Guignot, Alain L Servin, Patrick Brest, Veronique Hofman, Imad Kansau, Bernard Rossi, Paul HofmanAbstract:
Ulcerative colitis and Crohn’s disease are inflammatory bowel diseases thought to involve strains of Escherichia coli. We report here that two wild-type Afa/Dr diffusely adhering E. coli (DAEC) strains, C1845 and IH11128, which harbor the fimbrial F1845 Adhesin and the Dr hemagglutinin, respectively, and the E. coli laboratory strain HB101, transformed with the pSSS1 plasmid to produce Afa/Dr F1845 Adhesin, all induced interleukin-8 (IL-8) production and transepithelial migration of polymorphonuclear leukocytes (PMNL) in polarized monolayers of the human intestinal cell line T84 grown on semipermeable filters. We observed that after PMNL migration, expression of decay-accelerating factor (DAF, or CD55), the brush border-associated receptor for Afa/Dr Adhesins, was strongly enhanced, increasing the adhesion of Afa/Dr DAEC bacteria. When examining the mechanism by which DAF expression was enhanced, we observed that the PMNL transepithelial migration induced epithelial synthesis of tumor necrosis factor alpha and IL-1β, which in turn promoted the upregulation of DAF.
Bogdan Nowicki – One of the best experts on this subject based on the ideXlab platform.
family of escherichia coli dr Adhesins decay accelerating factor receptor recognition and invasivenessThe Journal of Infectious Diseases, 2001Co-Authors: Bogdan Nowicki, Rangaraj Selvarangan, Stella NowickiAbstract:
In 1984, Viiisinen-Rhen  and Labigne-Roussel et al.  described a novel Escherichia coli Adhesin of unknown receptor specificity. Due to its association with uropathogenic strains of serotype 075 and because of the unknown receptor, the Adhesin was named 075X . Between 1984 and 1989, 3 groups independently cloned novel Adhesins that were later found to have very similar genetic organization: The clones were Dr (cloned by Nowicki et al. ), afimbrial Adhesins (Afa)-I and Afa-III (cloned by Labigne-Roussel and colleagues [2, 4]), and F1845 (cloned by Bilge et al. ). In 1990, Nowicki et al.  provided evidence that the novel Adhesins, including 075X, recognize a common receptor, Dr (a’) blood group antigen. Dr (a+) blood antigen was later localized to the key complement regulatory molecule, decay-accelerating factor ([DAF]; CD55), which protects tissues from damage by autologous complement attack. Most uropathogenic Adhesins traditionally were named after the receptor they recognized; hence, we proposed to rename 075X the “Dr Adhesin,” with the remaining Adhesins to be included in the Dr family of E. coli Adhesins. In the 1990s, various investigators described several Adhesins that were cloned from E. coli of human and animal origin and that display similar genetic organization and/or DAF receptor recognition. Of interest, most of the tested Adhesins appeared to have invasive capacity, with probably at least two genes contributing to the internalization process [7, 8]. We therefore propose that the prototypes and the new related Adhesins constitute members of the Dr family of Adhesins (table 1).
Molecular cloning and characterization of Dr-II, a nonfimbrial Adhesin-I-like Adhesin isolated from gestational pyelonephritis-associated Escherichia coli that binds to decay-accelerating factor.Infection and immunity, 1997Co-Authors: Tuan Q. Pham, Pawel Goluszko, Vsevolod L. Popov, Stella Nowicki, Bogdan NowickiAbstract:
Bacterial Adhesins play an important role in the colonization of the human urogenital tract. Escherichia coli Dr family Adhesins have been found to be frequently expressed in strains associated with pyelonephritis in pregnant females. The tissue receptor for known Dr Adhesins has been localized to the short consensus repeat-3 (SCR-3) domain of decay accelerating factor (DAF), a complement regulatory protein. In this report, we identified and cloned draE2, a gene encoding a novel 17-kDa DAF-binding Adhesin, Dr-II, from a strain of E. coli associated with acute gestational pyelonephritis. Despite the significant sequence diversity between Dr-II and Dr family Adhesins, the receptor of Dr-II was found to be the SCR-3 domain of DAF. Sequence analysis of the 186-amino-acid Dr-II open reading frame revealed significant diversity from other members of the Dr Adhesin family, including Dr, AFA-I, AFA-III, and F1845, but only an 8-amino-acid difference in sequence from that of the 17-kDa nonfimbrial Adhesin NFA-I of unknown receptor specificity. N-terminal peptide sequencing of the purified Adhesin confirmed the identity of the open reading frame and indicated cleavage of a 28-amino-acid signal peptide. Antibodies raised against purified Dr-II Adhesin exhibited little or no cross-reactivity to Dr Adhesin. Characterization of the biological properties demonstrated that like the Dr Adhesins, Dr-II was associated with the ability of E. coli to bind to tubular basement membranes and Bowman’s capsule and to be internalized into HeLa cells.
Human cultured intestinal cells express attachment sites for uropathogenic Escherichia coli bearing Adhesins of the Dr Adhesin familyFEMS microbiology letters, 1994Co-Authors: Sophie Kernéis, Jean-marc Gabastou, Marie-françoise Bernet-camard, Marie-hélène Coconnier, Bogdan Nowicki, Alain L ServinAbstract:
We have recently demonstrated that cultured human intestinal HT-29 and Caco-2 cell lines express receptors for the F1845 fimbrial Adhesin harbored by the diarrheagenic C1845 Escherichia coli (Kerneis et al., Infect. Immun. 59 (1991) 4013–4018). This Adhesinn belongs to a family of Adhesins including the Dr hemagglutinin and the afimbrial Adhesin AFA-1 harbored by uropathogenic E. coli. Here we investigated the cell association of laboratory E. coli strains expressing the Dr hemagglutinin and the afimbrial Adhesin AFA-I with human cultured enterocyte-like or mucosecreting cells. We observed that the E. coli strains bearing these Adhesins adhere both to human intestinal undifferentiated and differentiated fluid-transporting cells, and to mucus-secreting cells. This result strongly suggests a high capacity of intestinal colonization for the uropathogenic E. coli harboring adhesive factors belonging to the Dr Adhesin family. These results further corroborate the intestinal colonization by uropathogenic E. coli of the Dr family related to the fecal-perineal-urethral hypothesis of urinary tract infection pathogenesis.