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Virulence Factors of Erwinia amylovora: A Review.

Piqué N, Miñana-Galbis D, Merino S, Tomás JM - Int J Mol Sci (2015)

Bottom Line: To successfully establish an infection, E. amylovora uses a complex regulatory network to sense the relevant environmental signals and coordinate the expression of early and late stage virulence factors involving two component signal transduction systems, bis-(3'-5')-cyclic di-GMP (c-di-GMP) and quorum sensing.Other differential factors, such as the presence and composition of an integrative conjugative element associated with the Hrp T3SS (hrp genes encoding the T3SS apparatus), have been recently described.In the present review, we present the recent findings on virulence factors research, focusing on their role in bacterial pathogenesis and indicating other virulence factors that deserve future research to characterize them.

View Article: PubMed Central - PubMed

Affiliation: Departament de Microbiologia i Parasiologia Sanitàries, Facultat de Farmàcia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain. npique@ub.edu.

ABSTRACT
Erwinia amylovora, a Gram negative bacteria of the Enterobacteriaceae family, is the causal agent of fire blight, a devastating plant disease affecting a wide range of host species within Rosaceae and a major global threat to commercial apple and pear production. Among the limited number of control options currently available, prophylactic application of antibiotics during the bloom period appears the most effective. Pathogen cells enter plants through the nectarthodes of flowers and other natural openings, such as wounds, and are capable of rapid movement within plants and the establishment of systemic infections. Many virulence determinants of E. amylovora have been characterized, including the Type III secretion system (T3SS), the exopolysaccharide (EPS) amylovoran, biofilm formation, and motility. To successfully establish an infection, E. amylovora uses a complex regulatory network to sense the relevant environmental signals and coordinate the expression of early and late stage virulence factors involving two component signal transduction systems, bis-(3'-5')-cyclic di-GMP (c-di-GMP) and quorum sensing. The LPS biosynthetic gene cluster is one of the relatively few genetic differences observed between Rubus- and Spiraeoideae-infecting genotypes of E. amylovora. Other differential factors, such as the presence and composition of an integrative conjugative element associated with the Hrp T3SS (hrp genes encoding the T3SS apparatus), have been recently described. In the present review, we present the recent findings on virulence factors research, focusing on their role in bacterial pathogenesis and indicating other virulence factors that deserve future research to characterize them.

No MeSH data available.


Related in: MedlinePlus

Images of putative attachment structures of E. amylovora [19] (adapted from [19], with permission from American Society for Microbiology). (A) TEM imaging of a planktonic E. amylovora cell grown in broth culture and negatively stained. Peritrichous flagella are indicated by arrows (scale: 1 µm); (B) TEM image of E. amylovora in planta. Putative attachment structures connect bacterial cells to host cells (scale: 1 µm); (C) SEM image of E. amylovora cells found within a biofilm, with multiple appendages that protrude from the bacterial cell and attach to the host surface, as indicated by the arrows (scale: 2 µm).
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ijms-16-12836-f002: Images of putative attachment structures of E. amylovora [19] (adapted from [19], with permission from American Society for Microbiology). (A) TEM imaging of a planktonic E. amylovora cell grown in broth culture and negatively stained. Peritrichous flagella are indicated by arrows (scale: 1 µm); (B) TEM image of E. amylovora in planta. Putative attachment structures connect bacterial cells to host cells (scale: 1 µm); (C) SEM image of E. amylovora cells found within a biofilm, with multiple appendages that protrude from the bacterial cell and attach to the host surface, as indicated by the arrows (scale: 2 µm).

Mentions: In a study using a bioinformatic approach and the recently sequenced genome of E. amylovora [19,42,43], genes encoding putative cell surface attachment structures were identified [19]. A time course assay indicated that type I fimbriae function earlier in attachment, while type IV pilus structures appeared to function later in attachment. Deficiencies in type I fimbriae lead to an overall reduction in E. amylovora virulence. By deletion of individual genes and gene clusters and using a combination of in vitro attachment assays and plant virulence assays it was demonstrated that multiple attachment structures are present in E. amylovora and play a role in mature biofilm formation, which is critical to pathogenesis and systemic movement in the host (Figure 2). In contrast, a fully functional biofilm was not necessary to survival and growth in planta [19].


Virulence Factors of Erwinia amylovora: A Review.

Piqué N, Miñana-Galbis D, Merino S, Tomás JM - Int J Mol Sci (2015)

Images of putative attachment structures of E. amylovora [19] (adapted from [19], with permission from American Society for Microbiology). (A) TEM imaging of a planktonic E. amylovora cell grown in broth culture and negatively stained. Peritrichous flagella are indicated by arrows (scale: 1 µm); (B) TEM image of E. amylovora in planta. Putative attachment structures connect bacterial cells to host cells (scale: 1 µm); (C) SEM image of E. amylovora cells found within a biofilm, with multiple appendages that protrude from the bacterial cell and attach to the host surface, as indicated by the arrows (scale: 2 µm).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4490474&req=5

ijms-16-12836-f002: Images of putative attachment structures of E. amylovora [19] (adapted from [19], with permission from American Society for Microbiology). (A) TEM imaging of a planktonic E. amylovora cell grown in broth culture and negatively stained. Peritrichous flagella are indicated by arrows (scale: 1 µm); (B) TEM image of E. amylovora in planta. Putative attachment structures connect bacterial cells to host cells (scale: 1 µm); (C) SEM image of E. amylovora cells found within a biofilm, with multiple appendages that protrude from the bacterial cell and attach to the host surface, as indicated by the arrows (scale: 2 µm).
Mentions: In a study using a bioinformatic approach and the recently sequenced genome of E. amylovora [19,42,43], genes encoding putative cell surface attachment structures were identified [19]. A time course assay indicated that type I fimbriae function earlier in attachment, while type IV pilus structures appeared to function later in attachment. Deficiencies in type I fimbriae lead to an overall reduction in E. amylovora virulence. By deletion of individual genes and gene clusters and using a combination of in vitro attachment assays and plant virulence assays it was demonstrated that multiple attachment structures are present in E. amylovora and play a role in mature biofilm formation, which is critical to pathogenesis and systemic movement in the host (Figure 2). In contrast, a fully functional biofilm was not necessary to survival and growth in planta [19].

Bottom Line: To successfully establish an infection, E. amylovora uses a complex regulatory network to sense the relevant environmental signals and coordinate the expression of early and late stage virulence factors involving two component signal transduction systems, bis-(3'-5')-cyclic di-GMP (c-di-GMP) and quorum sensing.Other differential factors, such as the presence and composition of an integrative conjugative element associated with the Hrp T3SS (hrp genes encoding the T3SS apparatus), have been recently described.In the present review, we present the recent findings on virulence factors research, focusing on their role in bacterial pathogenesis and indicating other virulence factors that deserve future research to characterize them.

View Article: PubMed Central - PubMed

Affiliation: Departament de Microbiologia i Parasiologia Sanitàries, Facultat de Farmàcia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain. npique@ub.edu.

ABSTRACT
Erwinia amylovora, a Gram negative bacteria of the Enterobacteriaceae family, is the causal agent of fire blight, a devastating plant disease affecting a wide range of host species within Rosaceae and a major global threat to commercial apple and pear production. Among the limited number of control options currently available, prophylactic application of antibiotics during the bloom period appears the most effective. Pathogen cells enter plants through the nectarthodes of flowers and other natural openings, such as wounds, and are capable of rapid movement within plants and the establishment of systemic infections. Many virulence determinants of E. amylovora have been characterized, including the Type III secretion system (T3SS), the exopolysaccharide (EPS) amylovoran, biofilm formation, and motility. To successfully establish an infection, E. amylovora uses a complex regulatory network to sense the relevant environmental signals and coordinate the expression of early and late stage virulence factors involving two component signal transduction systems, bis-(3'-5')-cyclic di-GMP (c-di-GMP) and quorum sensing. The LPS biosynthetic gene cluster is one of the relatively few genetic differences observed between Rubus- and Spiraeoideae-infecting genotypes of E. amylovora. Other differential factors, such as the presence and composition of an integrative conjugative element associated with the Hrp T3SS (hrp genes encoding the T3SS apparatus), have been recently described. In the present review, we present the recent findings on virulence factors research, focusing on their role in bacterial pathogenesis and indicating other virulence factors that deserve future research to characterize them.

No MeSH data available.


Related in: MedlinePlus