Pasteuria

Animals that are susceptible to Pasteuria become infected when they are exposed to endospores in soil or water. Therefore, Pasteuria are transmitted horizontally between hosts and when an infected host dies, it releases spores to the soil or sediment. The likelihood of infections is related to the endospore density in the environment{{Cite journal |last=Davies |first=K. G. |last2=Kerry |first2=B. R. |last3=Flynn |first3=C. A. |date=1988 |title=Observations on the pathogenicity of Pasteuria penetrans, a parasite of root-knot nematodes |journal=Annals of Applied Biology |volume=112 |pages=491-501}} and can be affected by temperature.{{Cite journal|last1=Hatz|first1=B.|last2=Dickson|first2=D. W.|date=1992|title=Effect of Temperature on Attachment, Development, and Interactions of Pasteuria penetrans on Meloidogyne incognita|journal=Journal of Nematology|volume=24|issue=4|pages=512–521|issn=0022-300X|pmc=2619314|pmid=19283029}} However, the ability of an endospore to attach to and infect a host is highly specific and following contact with a compatible host, the Pasteuria endospores are activated, penetrate the host's cuticle, proliferate within the host thereby restricting it from reproducing and ultimately the host dies.{{Cite journal|last1=Duneau|first1=David|last2=Luijckx|first2=Pepijn|last3=Ben-Ami|first3=Frida|last4=Laforsch|first4=Christian|last5=Ebert|first5=Dieter|date=2011|title=Resolving the infection process reveals striking differences in the contribution of environment, genetics and phylogeny to host-parasite interactions|journal=BMC Biology|language=En|volume=9|issue=1|doi=10.1186/1741-7007-9-11|pmc=3052238|pmid=21342515|page=11 |doi-access=free }} In water fleas, the ability of the endospore to successfully attach during the infection process is related to the genotype of the host and the parasite.{{Cite journal|last1=Luijckx|first1=Pepijn|last2=Duneau|first2=David|last3=Andras|first3=Jason P.|last4=Ebert|first4=Dieter|date=2014|title=Cross-Species Infection Trials Reveal Cryptic Parasite Varieties and a Putative Polymorphism Shared Among Host Species|journal=Evolution|language=en|volume=68|issue=2|pages=577–586|doi=10.1111/evo.12289|issn=1558-5646|pmid=24116675|s2cid=6083589|doi-access=free}} However, in phytonematodes there was no direct relationship between cuticle heterogeneity as exhibited by endospore attachment and the phylogeny of the nematode.{{Cite journal |last=Davies |first=K.G. |last2=Fargette |first2=M. |last3=Balla |first3=G. |last4=Daudi |first4=A. |last5=Duponnois |first5=R. |last6=Gowen |first6=S.R. |last7=Mateille |first7=T. |last8=Phillips |first8=M.S. |last9=Sawadogo |first9=A. |last10=Trivino |first10=C. |last11=Vouyoukalou |first11=E. |last12=Trudgill |first12=D.L. |date=2001 |title=Cuticle heterogeneity as exhibited by Pasteuria spore attachment is not linked to the phylogeny of parthenogenetic root-knot nematodes (Meloidogyne spp.) |journal=Parasitology |volume=122 |pages=111-120 |doi=10.1017/s0031182000006958}} Furthermore, in phytonematodes the cues which initiate germination differ between different endospore isolates. For example, in Pasteuria penetrans that infects root-knot nematodes (Meloidogyne spp.) endospore germination usually occurs sometime between the nematode entering the root, setting up the feeding site and the first molt as currently there are no reports of second-stage juveniles (J2) of Meloidogyne spp. containing either developmental stages or endospores of P. penetrans. However, developmental stages and endospores of a field population of Pasteuria have been observed in J2s of Heterodera avenae{{Cite journal |last=Davies |first=K G |last2=Flynn |first2=C A |last3=Laird |first3=V |last4=Kerry |first4=B R |title=The life-cycle, population dynamics and host specificity of a parasite of Heterodera avenae, similar to Pasteuria penetrans. |journal=Revue de Nématologie |volume=13 |pages=303 - 309}}. An infected root-knot female can contain up to two million endpsores, while an infected J2 of H. avenae will contain less than a thousand endospores. Interestingly, endopores that do not infect water fleas and pass through a resistant host can still remain viable and infectious.{{Cite journal |last1=King |first1=Kayla C |last2=Auld |first2=Stuart K J R |last3=Wilson |first3=Philip J |last4=James |first4=Janna |last5=Little |first5=Tom J |date=2013 |title=The bacterial parasite Pasteuria ramosa is not killed if it fails to infect: implications for coevolution |journal=Ecology and Evolution |volume=3 |issue=2 |pages=197–203 |doi=10.1002/ece3.438 |issn=2045-7758 |pmc=3586630 |pmid=23467806}} This suggests that different species or strains of the bacterium have evolved different life-cycle strategies.

The life-cycles of the bacteria that infect cladoceran parasites and phytonematodes have been shown to be similar in that during infection they both exhibit morphological stages that are in common with the original description by Metchinkoff.{{Cite journal |last=Sayre |first=R M |last2=Gherna |first2=R L |last3=Wergin |first3=W P |date=1983 |title=Morphological and taxonomic reevaluation of Pasteuria ramosa Metchnikoff 1888 and "Bacillus penetrans" Mankau 1975. |url=https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/00207713-33-3-636 |journal=International Journal of Systematic Bacteriology |issue=33 |pages=636 - 649}} Following infection with Pasteuria, the parasite interferes with the reproduction of their female hosts. Hosts can live with the parasite for a prolonged period of time after infection.{{Cite book|title=Ecology, epidemiology and evolution of parasitism in Daphnia|last=Ebert|first=D.|publisher=National Library of Medicine (US), National Center for Biotechnology Information, Bethesda (MD)|year=2005|isbn=978-1-932811-06-3}} In Daphnia, P. ramosa induces gigantism.{{Cite journal|last1=Cressler|first1=Clayton E.|last2=Nelson|first2=William A.|last3=Day|first3=Troy|last4=McCauley|first4=Edward|date=2014|title=Starvation reveals the cause of infection-induced castration and gigantism|journal=Proceedings of the Royal Society of London B: Biological Sciences|language=en|volume=281|issue=1792|pages=20141087|doi=10.1098/rspb.2014.1087|issn=0962-8452|pmc=4150321|pmid=25143034}} P. penetrans parasitized females of the nematode Meloidogyne javanica, on the other hand, were smaller than healthy individuals, although there is a direct relationship between the numbers of endospores produced by an individual female and its volume.

Due to the effect of Pasteuria on reproduction, especially on nematode pests of important crops, there is an interest to develop Pasteuria as a biological control agent.{{Cite journal|last1=Davies|first1=K. G.|last2=Rowe|first2=J. A.|last3=Williamson|first3=V. M.|date=2008|title=Inter- and intra-specific cuticle variation between amphimictic and parthenogenetic species of root-knot nematode (Meloidogyne spp.) as revealed by a bacterial parasite (Pasteuria penetrans)|journal=International Journal for Parasitology|volume=38|issue=7|pages=851–859|doi=10.1016/j.ijpara.2007.11.007|pmid=18171577}} In 2012, Syngenta acquired a company named Pasteuria Bioscience to commercialize Pasteuria as a biological control.{{Cite web|url=https://www.syngenta.com/global/corporate/en/news-center/news-releases/Pages/120919.aspx|title=Syngenta to acquire Pasteuria Bioscience|website=www.syngenta.com|access-date=2016-04-08|archive-url=https://web.archive.org/web/20160424161450/https://www.syngenta.com/global/corporate/en/news-center/news-releases/Pages/120919.aspx|archive-date=2016-04-24|url-status=dead}} In 2013, Syngenta launched CLARIVA™ pn, which has the active ingredient of Pasteuria nishizawae to combat the soybean cyst nematode.{{Cite web|url=http://www.syngenta.com/GLOBAL/CORPORATE/EN/PRODUCTS-AND-INNOVATION/PRODUCT-BRANDS/SEED-CARE/Pages/clariva.aspx|title=CLARIVA|website=www.syngenta.com|access-date=2016-04-08|url-status=dead|archive-url=https://web.archive.org/web/20160424171200/http://www.syngenta.com/GLOBAL/CORPORATE/EN/PRODUCTS-AND-INNOVATION/PRODUCT-BRANDS/SEED-CARE/Pages/clariva.aspx|archive-date=2016-04-24}} The effectiveness of Pasteuria as a biocontrol may depend on the biotypes of the nematode host that are present since they can vary in their susceptibility to Pasteuria.{{Cite journal|last1=Tzortzakakis|first1=E. A.|last2=De. R. Channer|first2=A. G.|last3=Gowen|first3=S. R.|last4=Ahmed|first4=R.|date=1997|title=Studies on the potential use of Pasteuria penetrans as a biocontrol agent of root-knot nematodes (Meloidogyne spp.)|journal=Plant Pathology|language=en|volume=46|issue=1|pages=44–55|doi=10.1046/j.1365-3059.1997.d01-211.x|issn=1365-3059|doi-access=free}}

Currently, four species of Pasteuria and two candidate species are described, all of which are obligate parasites with specific hosts. The described species and their hosts include:

• P. nishizawae Sayre et al. 1992: parasite of cyst-forming nematodes in the genera Heterodera and Globodera.{{Cite journal|last1=Sayre|first1=R. M|last2=Wergin|first2=W. P|last3=Schmidt|first3=J. M|last4=Starr|first4=M. P|date=1991|title=Pasteuria nishizawae sp. nov., a mycelial and endospore-forming bacterium parasitic on cyst nematodes of genera Heterodera and Globodera|journal=Research in Microbiology|volume=142|issue=5|pages=551–564|doi=10.1016/0923-2508(91)90188-G|pmid=1947427|url=https://zenodo.org/record/1258635}}
• P. penetrans Thorne 1940 ex Sayre & Starr 1986: parasite of root knot nematodes in the genus Meloidogyne spp.{{Cite journal|last1=Starr|first1=M. P.|last2=Sayre|first2=R. M.|date=1988|title=Pasteuria thornei sp. nov. and Pasteuria penetrans sensu stricto emend., mycelial and endospore-forming bacteria parasitic, respectively, on plant-parasitic nematodes of the genera Pratylenchus and Meloidogyne|journal=Annales de l'Institut Pasteur / Microbiologie|volume=139|issue=1|pages=11–31|doi=10.1016/0769-2609(88)90094-4|pmid=3382544|url=https://zenodo.org/record/1258561}}
• P. ramosa Metchnikoff 1888: parasite of Cladocerans, including Daphnia.{{Cite journal|last=Metchnikoff|first=M.E.|date=1888|title=Pasteuria ramosa un représentant des bactéries à division longitudinale|journal=Ann. Inst. Pasteur|pages=165–170}}
• P. thornei Starr & Sayre 1988: parasite of root-lesion nematodes in the genus Pratylenchus.

Candidate species and their hosts include:

• P. aldrichii Giblin-Davis et al. 2011: parasite of bacterivorous nematodes in the genus Bursilla spp.
• P. usage Giblin-Davis et al. 2003: parasite of the sting nematode, Belonolaimus longicaudatus{{Cite journal|last1=Giblin-Davis|first1=R. M.|last2=Nong|first2=G.|last3=Preston|first3=J. F.|last4=Williams|first4=D. S.|last5=Center|first5=B. J.|last6=Brito|first6=J. A.|last7=Dickson|first7=D. W.|date=2011|title='Candidatus Pasteuria aldrichii', an obligate endoparasite of the bacterivorous nematode Bursilla|journal=International Journal of Systematic and Evolutionary Microbiology|volume=61|issue=9|pages=2073–2080|doi=10.1099/ijs.0.021287-0|pmid=20870891|doi-access=free}}

Additional species of Pasteuria have been named but are yet to be formally described, including:

• "P. hartismeri" Atibalentja et al. 2002b
• "P. goettingianae" Bishop et al. 2007.{{Cite journal|last1=Bishop|first1=Alistair H.|last2=Gowen|first2=Simon R.|last3=Pembroke|first3=Barbara|last4=Trotter|first4=James R.|date=2007|title=Morphological and molecular characteristics of a new species of Pasteuria parasitic on Meloidogyne ardenensis|journal=Journal of Invertebrate Pathology|volume=96|issue=1|pages=28–33|doi=10.1016/j.jip.2007.02.008|pmid=17399736}}

• List of bacterial orders
• List of bacteria genera

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{{Bacteria classification}}

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Category:Gram-positive bacteria

Category:Bacteria genera