Download Abundance of the invertebrate polychaete host

Abundance of the polychaete
host of Ceratomyxa shasta and
prevalence of infection in the
Klamath River.
Sue-Jie Koo
Mentors: Jerri Bartholomew
Sascha Hallett
Department of Microbiology
Oregon State University
Ceratomyxa shasta : The parasite
• A myxozoan parasite
• Ceratomyxosis – epithelial lining
necrotises in salmonids.
~10 μm
• Enzootic to the Pacific NW of the United States.
– Particularly prevalent in the Klamath River
• One of the primary causes of juvenile salmonid death in
the Klamath River.
• 54% infected in 2008, compared to 10% in other rivers in
the West.
Life cycle of C. shasta
Manayunkia speciosa : The polychaete
• Freshwater
• Definitive host in the lifecycle of C. shasta
• Few studies on its ecology
• Spatial distribution
• Seasonality
• Density
• Few studies on its role in the infection dynamics of C.
shasta
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Prevalence of infection
Intensity of infection
Seasonality
Spatial distribution
Working hypothesis
• Polychaete densities and infection prevalence
with Ceratomyxa shasta directly correlate with
disease effects in salmonids.
+
=
Significance
• Assist in parasite management options to
reduce the impact of the parasite on salmonid
populations in the Klamath River.
• Reduction in returns affect fishermen and farmers
• Contribute data to the information known
about M. speciosa.
Methodology
• The samples were collected as part of a large
sampling study in the Klamath River in 2006.
R3
R2 R1
Sentinel fish studies
Water samples
R3
R2 R1
Beaver Creek
Polychaete Density
Stained Manayunkia speciosa
Av. # polychaetes x # squares
Field density =
Av. field sampling area
Results
R
3
R
2
R
1
Beaver
Creek
Prevalence of Infection
630 bp
Results – no parasite detection
Troubleshooting DNA recovery
• Parasite spike was inhibited
• Change DNA extraction buffers and dilution
• 2006 Polychaete DNA not replicated in PCR
• Change extraction buffers, dilution, primers,
PCR programs
• Diagnostics comparing 2006 and 2009 polychaetes
• Crude vs Qiagen purified
• Qiagen purified 2006 DNA inconsistent results
Conclusions
• Highest polychaete density in highly
infectious zone correlates to preliminary
studies.

Potential Future Work
• Manayunkia speciosa temporal
distribution
• M. speciosa prevalence of infection with
Ceratomyxa shasta
Acknowledgements
Sascha Hallett
Jerri Bartholomew
Gerri Buckles
Jill Pridgen
Dan Horner
Bartholomew Lab
Salmon Disease Lab
Oregon Department of
Fish and Wildlife
HHMI
Kevin Ahern