Friday, November 13, 2015

Episode 290 (11-16-15): Antibiotic Resistance Research Follows Genetic Trails in Watersheds

CLICK HERE to listen to episode audio (4:59)

Transcript of audio, notes on the audio, images, and additional information follow below.

All Web addresses mentioned were functional as of 11-12-15.


From the Cumberland Gap to the Atlantic Ocean, this is Virginia Water Radio for the week of November 16, 2015.

This week, we feature another in a series of episodes on water research by Virginia students.  To start, have a listen for about 25 seconds to this mix of mystery sounds and see if you can guess the serious, worldwide disease issue that connects the sounds.  And here’s a hint: this microscopic phenomenon is NOT what the doctor MEANT to order.

SOUNDS - ~25 sec

If you guessed antibiotic resistance by bacteria, you’re right!  You heard bottles of medications, a toilet flush, livestock, a thunderstorm, and a stream filled with stormwater runoff.  All are connected to the occurrence or spread of certain bacteria that, over time, have become resistant to antibiotics to which the bacteria have been exposed.  Antibiotic resistance among bacteria that cause human disease is one of the world’s most serious current health threats, according to the World Health Organization; and the U.S. Centers for Disease Control and Prevention estimates that annually over two million Americans are affected by antibiotic-resistant bacteria.

Streams and watersheds
are connected to antibiotic resistance in two key ways. First, human sewage can contain resistant bacteria or residual antibiotics; if not completely removed during treatment, the bacteria and antibiotics can reach waterways and contribute to the spread or development of more resistant bacteria.  Second, resistant bacteria or residual antibiotics in agricultural animals may be excreted and then reach waterways through runoff of surface water, particularly during storms.

The role of stormwater runoff and other watershed processes in spreading antibiotic-resistant bacteria is the focus of research by Virginia Tech Civil and Environmental Engineering graduate student Emily Garner, one of four Virginia students who received research grants in 2014 from the Virginia Water Resources Research Center.   Working in Stroubles Creek in Blacksburg and in the Cache La Poudre River near Fort Collins, Colorado, Ms. Garner used DNA-sequencing technology to measure concentrations of antibiotic-resistant genetic material during and following storms.  By examining mechanisms that control the fate and transport of antibiotic-resistance genes through watersheds, Ms. Garner’s work may help identify ways to reduce the spread of resistant bacteria from wastewater and stormwater runoff.

While Ms. Garner’s research is helping clarify the role of water and watersheds in spreading antibiotic resistance, what’s already clear is that citizens’ awareness and practices are crucial to reducing the development of antibiotic resistance.  In fact, the First World Antibiotic Awareness Week is Nov. 16-22, 2015, and in Virginia, the state Department of Health has a campaign called “Get Smart Virginia: Know When Antibiotics Work.”  Key messages of such campaigns include using antibiotics only when needed and NOT for viral infections like colds or the flu; using them only as prescribed by a physician, or, for animals, under veterinary care; and disposing of unused medications through a take-back program or through proper landfill disposal, but NOT by flushing.

Thanks to Emily Garner and other Virginia scientists for tackling water-related challenges posed by the complex world of bacteria and other microbes.

For more Virginia water sounds, music, and information, visit us online at, or call us at (540) 231-5463.  Virginia Water Radio is produced by the Virginia Water Resources Research Center, part of Virginia Tech’s College of Natural Resources and Environment.  Thanks to Stewart Scales for his banjo version of Cripple Creek to open and close the show.  In Blacksburg, I’m Alan Raflo, thanking you for listening, and wishing you health, wisdom, and good water.


The information in this episode was based on Emily Garner’s report to the Virginia Water Resources Research Center (Water Center) on her Ph.D. research project, “Effect of storm events on transport of antibiotic resistance genes in surface water and sediment: Implications for watershed management.”  Ms. Garner’s research is supported in part by a 2014 grant from the Water Center.

Thanks to Cully Hession, Virginia Tech Department of Biological Systems Engineering, for providing a recording of Stroubles Creek in Blacksburg, Va., during flooding.

Virginia Tech graduate student Emily Garner sampling in the Cache la Poudre River near Fort Collins, Colorado, in December 2013 as part of her research project, “Effect of storm events on transport of antibiotic resistance genes in surface water and sediment: Implications for watershed management.”  Photo courtesy of Emily Garner.

One branch of Stroubles Creek on the Virginia Tech campus in Blacksburg, during high water from stormwater runoff on September 29, 2015.

Logo for Virginia Department of Health’s campaign to increase public awareness of antibiotic resistance, accessed online at, 11/10/15.


From the U.S. Centers for Disease Control and Prevention
, “Antibiotic/Antimicrobial Resistance,” online at

On Microbes
(specific link: “Microbes are organisms too small for the eye to see and are found everywhere on Earth.  There are many types of microbes: bacteria, viruses, fungi, and parasites.  While most microbes are harmless and even beneficial to living organisms, some can cause disease among humans, other animals, and plants.  These disease-causing microbes are called pathogens; ...  All types of microbes have the ability to develop resistance to the drugs created to destroy them, becoming drug-resistant organisms.”

How Resistance Happens and Spreads
(specific link: “The use of antibiotics is the single most important factor leading to antibiotic resistance around the world.  Simply using antibiotics creates resistance.  These drugs should only be used to manage infections.”

Trends in Drug Resistance
(specific link: “Antibiotics are among the most commonly prescribed drugs used in human medicine and can be lifesaving drugs.  However, up to 50% of the time antibiotics are not optimally prescribed, often done so when not needed, incorrect dosing or duration. ... Because of the link the between antibiotic use in food-producing animals and the occurrence of antibiotic-resistant infections in humans, antibiotics that are medically important to treating infections in humans should be used in food-producing animals only under veterinary oversight and only to manage and treat infectious disease, not to promote growth.  The other major factor in the growth of antibiotic resistance is spread of the resistant strains of bacteria from person to person, or from the non-human sources in the environment.”

Biggest Threats
(specific link: “In 2013, CDC published a report outlining the top 18 drug-resistant threats to the United States.  These threats were categorized based on level of concern: urgent, serious, and concerning. ...”

Urgent: Clostridium difficile, Carbapenem-resistant Enterobacteriaceae (CRE), Neisseria gonorrhoeae.

Serious: Multidrug-resistant Acinetobacter; Drug-resistant Campylobacter; Fluconazole-resistant Candida; Extended Spectrum Enterobacteriaceae (ESBL); Vancomycin-resistant Enterococcus (VRE); Multidrug-resistant Pseudomonas aeruginosa; Drug-resistant non-typhoidal Salmonella; Drug-resistant Salmonella Serotype Typhi; Drug-resistant Shigella; Methicillin-resistant Staphylococcus aureus (MRSA); Drug-resistant Streptococcus pneumonia; Drug-resistant Tuberculosis.

Vancomycin-resistant Staphylococcus aureus; Erythromycin-resistant Group A Streptococcus; Clindamycin-resistant Group B Streptococcus.[Please note: The watershed processes discussed in this Virginia Water Radio episode are not necessarily connected to the spread of antibiotic resistance for each of the organisms or groups listed above.]

From the Virginia Department of Health
, “Antibiotic Resistance,” online at
“Antibiotics are drugs used to treat bacterial infections.  Antibiotics are often taken when they are not needed for colds and flu.  This causes the bacteria to become resistant, which means the drugs used to treat bacterial infections no longer work or can take longer to work.  Almost all common bacterial infections in the U.S. and worldwide are becoming resistant to antibiotics.  Resistant bacteria can cause serious illness and may be spread from one person to another.
“To address this growing public health threat the Virginia Department of Health is partnering with community and professional organizations around the state to increase awareness for the growing resistance to antibiotic medications.  The campaign's key messages are [the following]:
• Antibiotics are not effective in treating viral infections like colds, flu and bronchitis.
• Antibiotics should be taken exactly as prescribed and only when prescribed by a physician.
“Taking antibiotics inappropriately does more harm than good and promotes bacterial resistance. Resistant bacteria can stay in your body or spread to others in your family and community. They can cause severe illnesses that are difficult and expensive to treat.”


Michigan State University, College of Veterinary Medicine, “Antimicrobial Resistance Learning Site,” online at

U.S. Food and Drug Administration, “FACT SHEET: Veterinary Feed Directive Final Rule and Next Steps,” June 2, 2015, online at

U.S. Centers for Disease Control and Prevention (CDC), “Antibiotic/Antimicrobial Resistance,” online at

Virginia Department of Health, “Antibiotic Resistance,” online at

World Health Organization, “Drug resistance,” online at


All Water Radio episodes are listed by category at the Index link above (

This is the second in a series of episodes on Water Center-supported student research.  The first was Episode 259 (3-30-15), “Red-winged Blackbird Research Follows Connections among Hormones, Avian Malaria, Aquatic Habitats, and Mercury” (4 min./8 sec.), online at

Another episode on student research (not, in this case, supported by the Water Center), is Episode 280 (9-7-15), “Oysters, Nitrogen, and the Chesapeake Bay—Part 2” (4 min./41 sec.), online at

Other episodes on topics related to this episode are the following:

Medication disposal | EP107 – 4/16/12
Wastewater treatment plants | EP72 – 7/25/11
Stormwater | 
EP182 – 10/7/13


This episode may help with the following Virginia’s 2010 Science Standards of Learning (SOLs):

Grades K-6 Living Systems Theme

4.5 - ecosystem interactions and human influences on ecosystem.

6.7 - natural processes and human interactions that affect watershed systems; Va. watersheds, water bodies, and wetlands; and water monitoring.

Life Science Course

LS.6 - ecosystem interactions, including the water cycle, other cycles, and energy flow.
LS.11 - relationships between ecosystem dynamics and human activity.
LS.12 – genetic information and DNA.

Earth Science Course

ES.8 - influences by geologic processes and the activities of humans on freshwater resources, including groundwater and major watershed systems in Virginia.

Biology Course

BIO.4 – life functions in different organism groups, including human health, anatomy, and body systems.
BIO.5 – inheritance, protein synthesis, DNA structure, DNA technology.
BIO.8 - dynamic equilibria and interactions within populations, communities, and ecosystems; including nutrient cycling, succession, effects of natural events and human activities, and analysis of the flora, fauna, and microorganisms of Virginia ecosystems.

The episode may also help with the following Virginia 2008 Social Studies SOLs:

Civics and Economics Course

CE.9 – public policy at local, state, and national levels.

World Geography Course

WG.10 - cooperation among political jurisdictions to solve problems and settle disputes.

Government Course

GOVT.9 – public policy at local, state, and national levels.
GOVT.16 – role of government in Va. and U.S. economies, including examining environmental issues and property rights.

Virginia’s SOLs are available from the Virginia Department of Education, online at