Measurement of the Decay of Microbial Pathogens in South ... · 10/16/2009  · Measurement of the Decay of Microbial Pathogens in South East Queensland Reservoirs. Simon Toze, Leonie

Measurement of the Decay of Microbial Pathogens in South East Queensland

Reservoirs

Simon Toze, Leonie Hodgers, Andrew Palmer, Darren Morrow

Purified Recycled Water Project

18 August 2009

Urban Water Security Research Alliance

PRW Project

• Project aimed to research safety and sustainability of PRW

• Project is divided into three research components– Source– Reservoirs– Advanced Monitoring

Techniques

Introduction to Pathogens in SE QLD Freshwater

Multiple sources of pathogens– Purified Recycled Water– Wastewater treatment plants– Farm animals and activities– Wild animals

Experiment Research Aims

• To determine pathogen survival in SE QLD freshwater sources– Persistence, what drives decay, major potential

sources

• To assist predictive modelling and management of pathogen risks in SEQ freshwater

• Research is being undertaken in partnership with Seqwater

Norovirus

Target Pathogens and Indicators of Interest

• Indicator Microorganisms– E. coli, enterococci, bacteriophage

• Enteric microbial pathogens– Bacteria

• E. coli O157:H7, Campylobacter, Salmonella

– Protozoa• Cryptosporidium, (Giardia)

– Viruses• Rotavirus, adenovirus, (norovirus)

Cryptosporidium

Campylobacter

Measuring Pathogen Decay

• Decay is measured In-Situ• Diffusion chambers used to retain

pathogens• Conditions within chambers can

be modified or controlled– Presence/absence of native

microbiota– Sediment– Depth

O-rings

Main chamberSize exclusion membranes

End plate

Screws

End plate

Injection ports

Methodology

Day 7 Day 14 Day 21 Day 35

Initial Results of Microbial Attenuation Bacteria

0 5 10 15 20 25 30 350

1

2

3

4

5

6

Log

cfu

mL-1

Time (days)

T90 = 7 days

0 5 10 15 20 25 300

1

2

3

4

Log

cfu

mL-1

Time (days)

T90 = 8 days

0 5 10 15 20 25 300

1

2

3

4

5

6

Log

cfu

mL-1

Time (days)

T901 = 2 daysT902 = 86 days

0 5 10 15 20 25 30 350

1

2

3

4

5

6

7

Log

cfu

mL-1

Time (days)

T90 = 2.5 days

Campylobacter

Salmonella E. coli O157:H7

Enterococcus

Initial Results of Microbial Attenuation Viruses and Cryptosporidium

0 10 20 30 40 50 60100

101

102

103

104

105

106

Ooc

ysts

mL-1

Time (days)

T90 = 45 days

0 5 10 15 20 25 30 350

1

2

3

4

5

6

7

Log

pfu

mL-1

Time (days)

T90 = 5 days

Cryptosporidium oocysts MS2

CoxsackievirusAdenovirus

0 10 20 30 40 500

1

2

3

4

Log

PDU

mL-1

Time (days)

T90 = 12 days

0 10 20 30 400

1

2

3

4

Log

PD

U m

L-1

Time (days)

T90= 4 days

Microorganisms T90 (days)In-Situ Laboratory

Enterococcus 2.5E. coli O157:H7 2; 86Campylobacter 8Salmonella 7Cryptosporidium 45MS2 5Adenovirus 12Coxsackievirus 4

Microorganisms T90 (days)In-Situ Laboratory

Enterococcus 2.5 3E. coli O157:H7 2; 86 6Campylobacter 8 NDSalmonella 7 NDCryptosporidium 45 84 (Giardia)MS2 5 8Adenovirus 12 8Coxsackievirus 4 ND

Decay Rates From First Experiment

Next Stages of Research

• Re-examine decay of bacterial indicators and pathogens

• Determine influence of native microbiota• Impact of sunlight• Influence of sediment• Start to incorporate findings into Seqwater

hydrologic models

Thank you

www.urbanwateralliance.org.au