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

• • • •

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

R3 R2 R1 Beaver Creek Sentinel fish studies Water samples

Polychaete Density Stained

Manayunkia speciosa

Field density = Av. # polychaetes x # squares 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

distribution temporal •

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