Antibiotic Resistant Escherichia Coli in Non-Tidal Wetlands of Maryland

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Antibiotic Resistant Escherichia Coli in
Non-Tidal Wetlands of Maryland

• Speakers Neil Agarwal Robert Vocke III
• University of Maryland, College Park

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Establishing a Baseline

• MDE
• Clean Water Act
• Antibiotics

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Site Overview

• Non-tidal, mitigation sites
• 3 plots per site

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Data Collection

• Vegetation
• Soils
• Land Use
• Water Quality
• Antibiotic Resistance

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Our focus today

• Water quality data
• Why Antibiotic Resistance?
• The Concept of Measuring Resistance
• Preliminary Results

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Water Quality Results
Nitrate (mg/L)
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Water Quality (continued)
Ammonia (mg/L)
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Water Quality (continued)
Total N (mg/L)
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Water Quality (continued)
Total P (mg/L)
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Why look at antibiotic resistance?

• The pharmaceutical problem
• Antibiotics and resistance
• Testing for antibiotic resistance is cost
  effective
• Questions to be asked
• Prevalence and temporal changes
• Correlation to other aspects of health
• Resistance sinks
• Nutrient Cycling

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Disk Diffusion The Concept
Image courtesy of http//biology.clc.uc.edu/fankha
user/Labs/Microbiology
Image courtesy of http//jyi.org/articleimages/555
/
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Disk Diffusion The Concept
Image courtesy of http//www.wings-china.com/showi
nfo.asp?typeid24xxid554LanguageEn
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Flemings Discovery
Image courtesy of http//www.accessexcellence.org/
AE/AEC/CC/s5.html
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Disk Diffusion The Procedure
Image courtesy of http//jyi.org/articleimages/555
/
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Disk Diffusion The Procedure
Image courtesy of http//jyi.org/articleimages/555
/
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Disk Diffusion The Procedure
Image courtesy of http//jyi.org/articleimages/555
/
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Disk Diffusion The Procedure
Image courtesy of http//jyi.org/articleimages/555
/
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Disk Diffusion The Procedure
Image courtesy of http//jyi.org/articleimages/555
/
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Disk Diffusion The Procedure
Image courtesy of http//jyi.org/articleimages/555
/
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Our specific procedure

• Collected surface samples
• Serial dilutions
• Culture on ColiBlue

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ColiBlue media
Red Coliforms
Blue E. Coli
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Our specific procedure

• Collected surface samples
• Serial dilutions
• Culture on ColiBlue
• Isolate a single E. coli colony
• Disk diffusion using 5 antibiotics
• Ampicillin
• Erythromycin
• Tetracycline
• Sulfisoxazole
• Ciprofloxacin
• Negative Control Vancomycin

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Converting Inhibition Zones

• CLSI standard
• Example
• Ampicillin with 7mm zone of inhibition

lt13 mm Resistant 14-16 mm Intermediate
gt17 mm Susceptible
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Converting Inhibition Zones

• CLSI standard
• Example
• Ampicillin with 7mm zone of inhibition

lt13 mm Resistant 14-16 mm Intermediate
gt17 mm Susceptible
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Results of Testing
Ampicillin Tetracycline Ciprofloxacin Sulfisoxazole
Susceptible 1 2 32 11
Intermediate 5 13 2 12
Resistant 27 18 0 11

Total 33 33 34 34

Resistant 82 55 0 32
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Whats next?

• Find correlations to health
• Test upstream downstream
• Effect on nutrient cycling

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Antibiotic Resistant Escherichia Coli in
Non-Tidal Wetlands of Maryland

• Speakers Neil Agarwal Robert Vocke III
• University of Maryland, College Park