Upload
lucas
View
46
Download
0
Embed Size (px)
DESCRIPTION
MU ORRC Ohio River Research Center. Are Current Bacteriological Assessment Practices Sufficient for Water Resource Management in the Ohio River Basin?. Chuck Somerville Marshall University Huntington, WV. MU ORRC Ohio River Research Center. In other words. - PowerPoint PPT Presentation
Citation preview
Chuck SomervilleMarshall UniversityHuntington, WV
In other words . . .In other words . . .Are fecal indicators (coliforms, fecal
coliforms, E. coli) sufficient for determining the safety of water resources?
Specifically, do they predict the numbers and distribution of antibiotic resistant bacteria in surface waters?
Why Study Antibiotic Resistance?Why Study Antibiotic Resistance?
http://www.fda.gov/oc/opacom/hottopics/antiresist_facts.html
Why Study Antibiotic Resistance?Why Study Antibiotic Resistance?NARMS - the National Antimicrobial Resistance
Monitoring System
USFDA, USDA & CDC collaboration formed in 1996
Monitors resistance of isolates from humans, animals, raw food products & retail meats
Does notnot monitor water supplies
http://www.fda.gov/cvm/narms_pg.html
Why Study the Ohio River?Why Study the Ohio River?
Experimental Questions . . .Experimental Questions . . .
Are antibiotic resistant bacteria present in detectable numbers in the Ohio River?
If so, how are they distributed?
Testing a common assumption . . .Testing a common assumption . . .The use of antibiotics in medicine and
agriculture selects for resistant strains in the animal gut.
Failing or absent septic systems causes the distribution of resistant bacteria to the environment.
Antibiotic resistant bacteria should be a subset of fecal-derived bacteria in environmental samples.
Total cultivable bacteria
Total Coliforms
Fecal Coliforms
Escherichia coli
Antibiotic resistant bacteria
MethodsMethods
Mid-channel, sub-surface water samples
5 mile intervals in mainstem
All major tributaries
MethodsMethodsR2A agar + antibiotic for cultivable resistant
cellsFungizone (375 ng/ml; used in all plates)Ampicillin (50 g/ml)Ciprofloxacin (4 g/ml)Erythromycin (8 g/ml)Streptomycin (25 g/ml)Sulfamethizole (128 g/ml)Tetracycline (12.5 g/ml)Virginiamycin (16 g/ml)
http://www.nsri.upd.edu.ph/mrsl/img/services1.jpg
MethodsMethodsm-FC at 44.5˚C for fecal
coliforms (2001 – 2003)
IDEXX Colilert QuantiTray/2000 for total coliforms and Escherichia coli (2004 – present)
QT/2K + antibiotic for resistant coliforms and E. coli (2005 – present)
http://ceeserver3.mit.edu/~Nepal/Mic_mFC.jpg
MethodsMethodsConcurrent determination of:
pH, DO, turbidity, conductivityChlorophyll (UC)Total N & P (UC)Particulate N & P (UC)Phytoplankton (NKU)Zebra mussel veligers (TMC)Land use patterns
Results - 2006Results - 2006
Two, 100-mile reaches of OR with complete cultivable counts (CFU/ml) and coliform data (MPN/ml)
Compared numbers of resistant cultivable cells to numbers of E. coli and resistant coliforms
198
0.26 0.00 0.00
0
50
100
150
200
250
300
Me
an
CF
U o
r M
PN
pe
r m
l
1
RM 200 to 305.2
R2A-cip E. coli cipR total coliforms cipR E. coli
* **
CiprofloxacinCiprofloxacin
75
0.26 0.01 0.00
0
50
100
150
200
250
300
Av
era
ge
CF
U o
r M
PN
pe
r m
l
1
RM 200 to 305.2
R2A-tet E. coli tetR coliforms tetR E. coli
* * *
TetracyclineTetracycline
199
0.26 0.34 0.02
0
50
100
150
200
250
300
Av
era
ge
CF
U o
r M
PN
pe
r m
l
1
RM 200 to 305.2
R2A-vir E. coli virR coliforms virR E. coli
***
VirginiamycinVirginiamycin
VirginiamycinVirginiamycin
103
0.49 0.03 0.00
0
50
100
150
200
250
300
Av
era
ge
CF
U o
r M
PN
pe
r m
l
1
RM 410 to 498.8
R2A-cip E. coli cipR coliforms cipR E. coli
***
CiprofloxacinCiprofloxacin
VirginiamycinVirginiamycinCiprofloxacinCiprofloxacin
76
0.49 1.04 0.02
0
50
100
150
200
250
300
Av
era
ge
CF
U o
r M
PN
pe
r m
l
RM 410 to 498.8
R2A-tet E. coli tetR coliforms tetR E. coli
***
TetracyclineTetracycline
289
0.49 10.29 0.29
0
50
100
150
200
250
300
Av
era
ge
CF
U o
r M
PN
pe
r m
l
RM 410 to 498.8
R2A-vir E. coli virR coliforms virR E. coli
***
VirginiamycinVirginiamycin
Results - 2006
Two, 100-mile reaches of OR with complete cultivable counts (CFU/ml) and coliform data (MPN/ml)
Compared distribution of resistant cultivable cells to distribution of E. coli and resistant coliforms
0
200
400
600
800
1000
200 225 250 275 300
CF
U p
er m
lR2A-cip R2A-tet R2A-vir
0.0
2.0
4.0
6.0
8.0
10.0
200 225 250 275 300
MP
N p
er m
l
River Mile- - - coliforms E. coli
- - - coliforms E. coli
Total cultivable bacteria
Total Coliforms
Fecal Coliforms
Escherichia coli
Antibiotic resistant bacteria
Conclusions
The Ohio River and major tributaries are significant reservoirs for antibiotic resistant bacteria.
Antibiotic resistant bacteria are present in much greater numbers than fecal indicator bacteria.
Conclusions
The distribution of antibiotic resistant bacteria is distinct from that of fecal indicator bacteria.
Antibiotic resistant bacteria are not a subset of fecal indicator bacteria
ConclusionsAntibiotic resistant bacteria in surface waters
may represent a significant public health issue.
Their concentration and distribution can not be predicted by monitoring fecal-indicator organisms.
Additional work is needed to determine how resistant cells are distributed and their impacts on health.
Implications & new questionsTracking known sources of fecal bacteria
does not reliably track ARB. So what?
Can resistance genes be transmitted on sand bed filters?
What types of genetic elements are involved in resistance?
CF
U/m
l
Flow Volume (liters)
Total bacteria
Amp-R bacteria
Thanks . . .Thanks . . .MU Students/StaffMU Students/Staff
Lisa SmithLisa Smith
Andy JohnsonAndy Johnson
Tim DotsonTim Dotson
Robert NagyRobert Nagy
FundingFundingNSF-EPSCoRNSF-EPSCoR
MU Graduate CollegeMU Graduate College
Ms. Shelba PewMs. Shelba Pew
CollaboratorsCollaboratorsMiriam Kannan (NKU)Miriam Kannan (NKU)
Rebecca Evans-Kelly Rebecca Evans-Kelly (NKU)(NKU)
Michael Miller (UC)Michael Miller (UC)
John Hageman (TMC)John Hageman (TMC)