Research Projects 

Germs and Worms

Ever since I was a kid I enjoyed exploring dirt and worms.  My sisters enjoy tormenting me by telling everyone  how they couldn't keep me away from worms when I was little.  Apparently I liked to put them in my mouth.  Well, I don't believe this story one bit.  I have the sneaking suspicion that she they were the ones who put the worms in my mouth and blamed me so they wouldn't get in trouble. Anyway,  I seemed to develop this strange fascination with slimy things that live in soil, most especially bacteria,  nematodes, fungi, protists and earthworms.  Notice that with the exception of worms all of these organisms are microscopic.  I can "blame" my sisters for this too.  When I was 10 they convinced my mother  that I really wanted a microscope for Christmas.  So I received a microscope instead of a parrot, which was what I had originally requested.  I was the only 10 year old on my block with a microscope. I used that scope to look at everything from sea monkeys to dental plaque.   Boy were the other kids disappointed when I showed them what sea monkeys really looked like up close and magnified.  

For the first 2 years of college I thought I wanted to be a medical doctor.  I decided to do rounds with my brother-in-law, who was a neurologist in Philadelphia at the time.  I spent 2 days with him and I WAS BORED TO DEATH.  I realized that an MD's job included very few of the aspects of science that  I actually enjoyed. Very few MDs have the time to do research and most MDs who do research have a Ph.D. as well as an MD.  Most doctors are trained to follow standard procedures and rarely have the opportunity to use creative approaches to solve problems. I realized that if I pursued an MD as my terminal degree then I simply wouldn't feel fulfilled.  Soon after  I discovered that practicing medicine was not for me, I discovered the the world of Microbiology.

 I worked on an independent research project with my Microbiology professor (Dr. Sid Crow) at Georgia State.  He was studying "Sick Building Syndrome".  Sick building syndrome is a phenomenon in which occupants of a building suffer from acute health effects (i.e. acute allergies,  asthma, headaches, skin irritation, etc.) that are linked to the amount of time spent in the building.  Usually no specific illness or cause can be attributed to the health effects, but typically bacterial and fungal colonization of building walls and HVAC systems is involved.  In my research project I studied the effects of  relative humidity on the germination of Rhizopus spores. 

After I graduated from Georgia State with a BS in Biology and emphasis in Environmental Biology, I studied Microbiology at  the University of Georgia.  I did not have a clear idea what research I wanted to pursue at UGA, but I knew that I liked environmental microbiology.  I worked with Dr. Barney Whitman in the Microbiology department at UGA.  He helped me to develop my doctoral dissertation project in Microbial Ecology.  

Some of my research involved investigating bacterial communities found in no-till agricultural soil and in the alimentary canals of worms that live in that same soil.  Soil is a black box to soil microbiologists.  About 1,000 different species of prokaryotes exist in each gram of soil and less than 10% of all prokaryotes that live in soil have actually been identified.  This is simply do to the lack of  techniques that can be used to identify these organisms.  Worst yet, nobody really has a clear idea of  the purpose of most of these organisms to the soil ecosystem and how they contribute to soil health.  During my research I developed novel methods for studying these soil prokaryotes. Below is a listing of and links to some of my publications:

Furlong, Michelle A., David R. Singleton, David C. Coleman, and William B. Whitman.  2002.  Molecular and culture-based analyses of prokaryotic communities from an agricultural soil and the burrows and casts of the earthworm Lumbricus rubellus.  Applied and Environmental Microbiology 68:1265-1279

Singleton, David R., Michelle A. Furlong, Stephen L. Rathbun, and William B. Whitman.  2001.  Quantitative Comparison of 16S rRNA Gene Sequence Libraries from Environmental Samples.  Applied and Environmental Microbiology 67:4374-4376.  

Singleton, David R., Michelle A. Furlong, Aaron D. Peacock, David C. White, David c. Coleman, and William B. Whitman.  2002.  Solirubrobacter pauli gen. Nov., sp. Nov., a mesophilic bacterium within the Rubrobacteridae related to common soil clones.  Accepted August 2002 for publication by the International Journal of Systematic and Evolutionary Microbiology. In press.

During my first year at UGA I was "forced" to be a teaching assistant  for a general microbiology course.  This is usually how most first year graduate students in the sciences get money to go to school.  It is NOT a good idea to work a part time (or full) time job while attending graduate school and most program coordinators forbid it.  Most programs offer students the opportunity to be a TA and teach laboratories for a stipend and tuition waver.  The stipend is usually enough money to pay rent , bills and buy food.  I dreaded my TAship and did not want to do it.   During my first semester as a TA, however, I learned to love it and I won several teaching awards.

Current Research

Soil Bacteria

My first research project involves developing novel culture methods for isolating soil bacteria.  This research is important because only a small percentage of the bacteria present in the soil have actually been cultured and described in the literature.  One might say we are sitting on a goldmine since most of the antibiotic producing bacteria that we know of today are actually inhabitants of soil.  So far we have developed a culture method that was capable of culturing a much higher percentage of bacteria than any previous method.    Using this method we cultured several novel species of bacteria.  I am in the process of publishing this data so I cannot describe the method here.  More on this later (after we publish) 

Students who worked on this project:

Caroline Doty is now in the process of sequencing the 16S rRNA genes from several of the bacterial isolates there were cultured using this method.  This will allow us to determine the putative identity of each isolate and determine if any of the isolates are novel species.  I will need undergraduates in the future to assist with this part of the project.  

Hypolithic Bacterial Communities

A common habitat for microorganisms in deserts is the lower surfaces of stones, at the stone-soil interface.  This habitat is termed hypolithic and it provides protection for the microorganisms from environmental extremes characteristic of the soil and upper stone surfaces.  In the Chihuahuan Desert of North America microorganisms colonize three different geological substrata:  calcite, gypsum and chalcedony.  These differ in chemical and mineralogical compositions.  This project involves studying and comparing the microbial communities under these three different substrata.  Preliminary 16S rRNA sequence data from microbial communities under calcite illustrate a diverse community of prokaryotes including Proteobacteria and cyanobacteria.   

Students who worked on this project:

Fecal Coliform Source-Tracking

This project involves investigating fecal coliform contamination in the watershed surrounding CCSU.  The research group is attempting to trace the source of fecal coliforms found in Jesters Creek and Swan Lake by analyzing their antibiotic resistance patterns. this project involves 3 steps.

Step 1: Taking Water and Fecal Samples
Water samples are collected in sterile containers and transported back to the lab on ice.

Step 2:  Processing Samples and Counting Coliforms
Each water sample is diluted in sterile buffer and filter through a 0.2 um pore filter.  The filter collects any particles larger than 0.2 um; therefore it collects any fecal coliforms present in the water sample.  The filters are then placed in mFC media (media used to grow fecal coliforms).  Any fecal coliforms present on the filter will form a blue colony forming unit (CFU).  After 24 hour incubation the blue CFUs are counted on the filters and a simple formula is used to determine the number of fecal coliforms present in each milliliter of water.

Step 3:  Fecal Coliform Library
Each colony is sub-cultured in EC media (media used to grow fecal coliforms).  The EC culture is then placed into cryoplates  (plates with 96 separate wells used to freeze biological specimens) with 15% glycerol and is frozen at -80 ºC.  These colonies are used later in the "Source Tracking Experiment".

Step 4:  Collecting Fecal Samples
In order to trace the source of the fecal coliform contamination fecal samples found surrounding the bodies of water must be collected.  For instance, we found fox, possum, and dog feces and a sewage pipe near Jester's creek and we found goose feces and a sewage pipe near Swan Lake in 2002.   Each sample is suspended in sterile saline and inoculated in EC media.  The EC cultures are streaked for isolation on EC plates  and isolated colonies are collected and frozen as described above.

Step 5:  Antibiotic Resistance Patterns and Source Tracking
Each isolate from step 3 and 4 is transferred to several different plates with various concentrations of various antibiotics.  The antibiotic resistance/sensitivity for each coliform on each antibitoic is recorded and this data is used to construct antibiotic resistance patterns (ARPs) for each coliform.  The ARPs for the coliforms from the water samples are then compared statistically to the ARPs for the coliforms from each suspected fecal contaminator (i.e. goose or human for Swan Lake).

The antibiotics used in this experiment are those that are typically used to treat illness in the animals that are the suspected fecal contaminators.   If a coliform came from a dog then we would expect to see that coliform is likely to be resistant to antibiotics commonly used to treat infections in dogs, however it is less likely to be resistant to antibiotics that are used to treat humans and not dogs.  Hence all of the coliforms that are associated with a specific animal, like a dog, will have a similar resistance pattern and this pattern can be used to trace any given coliform found in a body of water to that particular animal.  For instance, if we find coliforms in Jester's Creek that have antibiotic resistance patterns that are similar to those of human coliforms then we can assume that the fecal coliform contamination came from a human source (broken sewage pipe).

Runoff:  Water draining from terrestrial surface to a stream.

    Each blue colony represents a fecal coliform CFU.  How many do you see?

Students who worked on this project

Melissa Hammond:  (Fall 2001; Spring 2002)-->see Melissa's PowerPoint--Melissa is currently employed by Clayton County Water Authority

Shane Savage:  Summer 2002--Shane is currently attending Morehouse School of Medicine

Melina Rada:  (Summer 2002)

Maggie Mills: Summer 2003, Summer 2004  Maggie's PowerPoint

MyHang Nguyen:  Summer 2004 MyHang's PowerPoint--MyHang is currently attending Mercer University Pharmacy School

Cheryl Bettis:  Summer 2004 Cheryl's PowerPoint

Kalette Hayes:  Summer/Fall 2004

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Future Plans

I am looking for a student to help characterize and identify some of the isolates we have obtained from the soil.

I am also interested in starting an experiment to investigate preferential feeding behavior of Lumbricus rubellus (earthworms).

If you are interested, or if you just have any questions, you can email me at MichelleFurlong@mail.clayton.edu.