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'Pasteuria ramosa'

Pasteuria ramosa is a gram-positive, endospore-forming bacterium in the Bacillus/Clostridia clade within Firmicutes. It is an obligate pathogen with cladoceran crustaceans from the Daphnia genus serving as its hosts ^[1]. An established and widely used coevolutionary model of host-pathogen interactions exists with P. ramosa and D. magna^[2].

Pasteuria ramosa
Scientific classification
Domain:	Bacteria
Phylum:	Firmicutes
Class:	Bacilli
Order:	Bacillales
Family:	Pasteuriaceae
Genus:	Pasteuria
Species:	P.ramosa

Characteristics

Growth and sporulation

Pasteuria ramosa is an obligate pathogen and it can only grow inside its host. Transmission between hosts takes place through the endospore stage, ad it is strictly horizontalCite error: A <ref> tag is missing the closing </ref> (see the help page).. These endospores are highly resistant to different environmental stresses and they can remain in the environment for decades without any deleterious effects.

The infection starts when a Daphnia has ingested a spore of P. ramosa during its filter feeding. The spore activates and attaches to the host esophagus. The pathogen then enters the body cavity of the host by penetrating the esophagus wall. Once inside the body cavity, the bacterium begins to propagate in cauliflower like colonies. After the infection has spread throughout the host, the bacterium begins to sporulate in preparation for transmission to a new host. The spores are shed into the environment from the dead host and can remain in the sediment for dacades while maintaining their virulence ^[3].

Pathogenicity

The infection success of P. ramosa depends on its ability to attach to the host esophagus and to spread into its body cavity where the propagation of the pathogen takes place. The attachment step of the infection depends on the genotypes of the host and the bacterium, meaning that only certain host genotypes can be infected by certain strains of the bacterium ^[4]. During an infection, P. ramosa castrates its host early on and causes gigantism. The fecundity of the host is reduced due to the early induction of castration. In addition, the lifespan of the host is significantly reduced ^[5]. Infections of P.ramosa are common in natural environments. In laboratory conditions, infection takes approximately 8 weeks to run its course.

Host range

P. ramosa has been found in D. magna, D. pulex and D. longispina ^[6].

Coevolutionary model with Daphnia magna

^[7]

References

^ Ebert et al., 1996; Preston et al., 2003
^ Carius et al., 2001; Ebert et al., 2008
^ Duneau et al., 2011
^ Luijckx et al, 2010; Duneau et al, 2011
^ Ebert et al., 1996
^ Ebert et al., 1996
^ http://www.sciencedirect.com/science/article/pii/S1369527408000696

[1] Ebert et al., 1996; Preston et al., 2003

[2] Carius et al., 2001; Ebert et al., 2008

[3] Duneau et al., 2011

[4] Luijckx et al, 2010; Duneau et al, 2011

[5] Ebert et al., 1996

[6] Ebert et al., 1996

[7] ttp://www.sciencedirect.com/science/article/pii/S1369527408000696

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[2]

[3]

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[5]

[6]

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@@ Line 1: / Line 1: @@
 == ''''Pasteuria ramosa'''' ==
-''Pasteuria ramosa'' is a gram-positive, endospore-forming bacterium in the Bacillus/Clostridia clade within Firmicutes. It is an obligate pathogen with cladoceran crustaceans from the ''[[Daphnia]]'' genus serving as its hosts. An established and widely used [[Coevolution|coevolutionary]] model of host-pathogen interactions exists with ''P. ramosa'' and ''[[Daphnia magna|D. magna]].''
+''Pasteuria ramosa'' is a gram-positive, endospore-forming bacterium in the Bacillus/Clostridia clade within Firmicutes. It is an obligate pathogen with cladoceran crustaceans from the ''[[Daphnia]]'' genus serving as its hosts <ref>Ebert et al., 1996; Preston et al., 2003</ref>. An established and widely used [[Coevolution|coevolutionary]] model of host-pathogen interactions exists with ''P. ramosa'' and ''[[Daphnia magna|D. magna]]<ref>Carius et al., 2001; Ebert et al., 2008</ref>.''
 {| class="wikitable"
 | colspan="2" |'''''Pasteuria ramosa'''''
@@ Line 31: / Line 31: @@
 === Characteristics ===
 ==== Growth and sporulation ====
-''Pasteuria ramosa'' is an [[obligate]] pathogen and it can only grow inside its host. Transmission between hosts takes place through the [[Endospores|endospore]] stage, ad it is strictly [[Horizontal transmission|horizontal]]<ref>Ebert et a., 1996</ref>. These endospores are highly resistant to different environmental stresses and they can remain in the environment for decades without any deleterious effects.
+''Pasteuria ramosa'' is an [[obligate]] pathogen and it can only grow inside its host. Transmission between hosts takes place through the [[Endospores|endospore]] stage, ad it is strictly [[Horizontal transmission|horizontal]]<ref>Ebert et a., 1996<ref name="undefined" /></ref>. These endospores are highly resistant to different environmental stresses and they can remain in the environment for decades without any deleterious effects.
  The infection starts when a ''Daphnia'' has ingested a spore of ''P. ramosa'' during its filter feeding. The spore activates and attaches to the host esophagus. The pathogen then enters the body cavity of the host by penetrating the esophagus wall. Once inside the body cavity, the bacterium begins to propagate in cauliflower like colonies. After the infection has spread throughout the host, the bacterium begins to sporulate in preparation for transmission to a new host. The spores are shed into the environment from the dead host and can remain in the sediment for dacades while maintaining their virulence <ref>Duneau et al., 2011</ref>.
@@ Line 43: / Line 43: @@
 ==== Coevolutionary model with ''Daphnia magna'' ====
+<ref>http://www.sciencedirect.com/science/article/pii/S1369527408000696</ref>
 === References ===