Download Virus-like particles

Virus-like particles
a new rapid method for virus removal!
Henrik Rydberg
Gothenburg Water, Sweden
The John Snow Society Scandinavia
Copenhagen 2010
Drinking water pathogens and risk
-what have we learnt the last 150 years!?
Past (John Snow 1813-1858):
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Very hard to gain acceptance
regarding waterborne pathogens.
Very limited technical resources to
work with drinking water and
microbiology.
Present (WHO guidelines 2004):
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”The most common and widespread
health risk associated with drinking
water is microbial contamination”
Methods and techniques exist, but…
will we use them!?
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To produce healthy drinking water
…which questions do we need to answer?
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Is our raw water currently more fecally
contaminated than usual?
Is pathogen removal reduced today?
Is pathogen disinfection impaired right now?
Process changes, do they influence biostability?
Depending on individual conditions of each WTW,
…so you need to do your HACCP-analyses!
Depending on pathogen parasite-bacteria-virus!
Relevance: accidents, optimization, choice of
treatment!
To find and apply relevant methods
-exemplified by virus-like particles
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Year 2000, Gothenburg Water begins investigating ultrafiltration.
Today 2010, final decision concerning Lackarebäcksverket.
Membrane integrity will be high priority quality control!
Need: ”Is ultrafilter integrity good enough to grant virus removal”
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smallest viruses, size down to approx 20nm
generally, the smaller the particles/microorganisms, the higher their
natural density, and hence the highest range of removal can be
montitored
ultrafiltration is based on size-exclusion, to verify ”particle removal”
down to 20nm is enough!
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What do we find at the end of
conventional treatment…
with a size of ~20-100nm?
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with high enough counts to allow
quantification of removal?
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that can be easily analysed?
Viruses infecting bacteria = phages!
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Most common entities in the biosphere!
More than 95% dsDNA phages.
Public health: alternative to antibiotcs!
Important pieces in the hunt for a method…
-what keeps deep sea plankton ecologists busy all day!?
National Food Administration
(…thanks Torbjörn!)
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SLVFS 2001:30: ”microbiolocical barriers”
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Guidance 2006: barrier efficiency, staining of biological particles
Our Scandinavian neighbours
(…thanks Finland!)
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Rinta-Kanto et al. Water Research (2004) ”Rapid enumeration of viruslike particles in drinking water samples using SYBR green I-staining”
Plankton ecologists
(…thanks Jed Fuhrman!)
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Worked with virus influence on deep sea plankton communities, using
fluorescence microscopy for virus quantification since the late 1990s.
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Simple method and results within an hour!
Nature Protocols | Vol.2 No.2 | 2007
- filter 100ml sample
- aluminiumoxide filter, 20nm
Note. Filter with well defined pore size
and minimal autofluorescence required!
- stain with SYBR Green I
- count in fluorescence
Virus-like particles in drinking water
Finished drinking water
Salmonella phage 28B, control
Lackarebäck WTW ~1.5 million
VLPs/ml after coagulation,
sedimentation and GAC filtration!
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Virus-like particles and ultrafiltration
Surface water pre ultrafiltration…
…and post ultrafiltration!
Removal: from 1.3E6 to <1.0E2/ml, that is
more than 4 log virus removal!
A revolution in membrane integrity control!
Hurray, we have a new application for
virus removal quantification…or do we?
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2009-10-01, worldwide notification regarding cancellation of
aluminiumoxide filter prduction 2009-12-20.
Plankton researchers plead, without notice: ”help save viral ecology”
2009-12-11, mobilization of drinking water community!
2009-12-20, filter production cancelled!
2010-01-04, cancellation re-evaluated. Filter improvements and
working on new production line!
…so, apparently we may continue to run the analyses of virus-like
particles, thanks to great support from a lot of persons:
CTH/Göteborg Vatten, Svenskt Vatten, AWWA, US EPA, IWA, GE ...
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Now we focus on viruses in water!
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Today we know that virus-like particles will be a ”key-analyses”
concerning membrane integrity in Gothenburg!
VISK-project: ”Reduce society´s vulnerability to waterborne
pathogens despite a changing climate”
n 18 partners from Sweden, Norway and Denmark lead by
Kretsloppskontoret, Göteborgs Stad (contact Lena Blom).
n work packages epidemiology, mapping, virus reduction…
n virus-like particles is a revolutionary application to increase our
knowledge regarding microbiological barriers!
Right know we are very inspired…since we have noticed we do not
understand virus removal in drinking water treatment!
Challanges today and in the future…
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John Snow couldn´t use
modern technique, but we
can if we want!
Keep focus on the needs
”what to do and why?”
Simple tasks are often hard
enough, ”keep it simple”!
We want to improve
drinking water quality
control methods, do you!?
Personnel at Lackarebäck
lab, my most important
resource…without
experienced staff, no new
methods. Thank you all!
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