MICROBIOLOGY'S NICHE IN FARM COUNTRY

"Bacterial antibiotic resistance is a leading health care concern of the 21 st century."


UMM biology professor Timna (Odegaard) Wyckoff (UMM '94) begins all her grant proposals with the above statement.   For her, the need for more research in antibiotic resistance is obvious.

"The main causes of death used to be diarrhea, TB and other infectious diseases," says Wyckoff.   "Then better sanitation and antibiotics replaced those top killers with cancer and heart disease.   Now, antibiotic resistance is creating a new threat.   But the public's awareness of the dangers of antibiotic resistance didn't really begin until a decade ago."

Not long after taking a teaching position at UMM in August of 2001, Wyckoff began looking for a new area of research.   Her previous research wasn't a good fit at a small liberal arts college.   "Medical microbiology and biochemistry are competitive areas of big bucks and big universities," she notes.  

Wyckoff decided that at UMM, she could fill a useful niche by giving her microbiology research a local slant. "Since resistance to antibiotics fascinates me and I'm in a rural setting, why not find a way to apply that interest to agriculture?" she says.

Antibiotics are obviously a good thing because they help people live longer.   But bacterial resistance creates a paradox.   Each time antibiotics are used, resistant strains of the bacteria survive.   Humans are becoming aware of the reasons why they should only use antibiotics when needed, but often don't know how those drugs are used on livestock.

"Most people don't know that half of our country's antibiotic use is not for humans," Wyckoff points out.

Conventional farmers use antibiotics on their livestock for three reasons:

1) Therapeutic.   When an animal has a bacterial infection, it is treated with an antibiotic

2) Preventative. Antibiotics are given to animals in the absence of infection to prevent it

3) Growth Promoters.   One fourth of all antibiotic use is as a growth promoter in livestock

"Almost all conventional livestock in the U.S. get antibiotics for growth although we don't know exactly how it works," Wyckoff says.   "Yet growth promoters are being banned in many countries including Denmark and, more recently, all of the European Union."

Wyckoff's research focuses on dairy cows because growth-promoting antibiotics are not used on milk cows.   Only therapeutic and prophylactic antibiotics are used. She wants to compare the antibiotic resistance of bacteria found in cows at conventional dairy farms to those at organic dairy farms.  

In dairies, mastitis (inflammation of the mammary gland) is the biggest reason for antibiotic use.   Antibiotics are introduced directly into the udder.   Wyckoff uses her research assistants to help her gather milk samples from conventional and organic dairies and then they look for one type of bacteria associated with mastitis: Staphylococcus .

"It was in July, 2004 when I decided to do this research," Wyckoff recalls.   "My students came that fall thinking we would resume our former projects and instead, I told them we're going out to dairies to milk cows!"

Students work on all the stages of the research:

* Collect samples

* Isolate the staph bacteria

* Identify bacteria to the species level

* Determine the bacteria's resistance profile

A year after beginning this project, Wyckoff and her students are still collecting data.

"Our preliminary results suggest that bacteria on conventional farms are a bit more resistant than those on organic farms," she reports. "The students presented posters on our results for UMM's Undergraduate Research Symposium last spring."

This fall, Wyckoff will use her semester leave to explore some of the questions that have surfaced in her research of bacterial antibiotic resistance associated with dairy cows.

"I'd like to know why different types of bacteria seem to show up at conventional vs. organic dairies.   On organic farms, we see strains of Staphylococcus that are more susceptible to antibiotics," she observes.

"I also want to look at transitioning organic dairies.   Once the selective pressure is gone, how long does it take for susceptible strains to out-compete the resistant strains of staph ?"

With questions like this to still answer, it looks like Wyckoff and her students will be milking cows for some time to come!


Timna Wyckoff outside her "staph" room.

 

 

 


"Antibiotics?? I'd rather eat grass!"

 

 

 


Timna streaks bacteria onto a petri plate

 

 


The obvious source of sample collection

 


Transferring broth from bottle to test tube

 

Go Back To Newsletter Homepage Go To Biology Discipline Home Page

Share your comments and ideas about the newsletter 


The University of Minnesota is an equal opportunity educator and employer.

University of Minnesota Online Privacy Statement
©2005 by the Regents of the University of Minnesota
Edited and maintained by Carol Ford(fordcj@morris.umn.edu)
Last Modified: Friday, September 28, 2007
Page URL: http://www.morris.umn.edu/academic/science/news/biol2.html