the summer of 2002 I worked in the invasions lab under the supervision of
Cathleen Coss. I also worked closely with Tone Rawlings and Al Prioleau.
This summer I learned information about Vibrio cholera and the
types of plankton it grows on. My project was to analyze the abundance of Vibrio
cholera present on specific types of plankton and worm larvae, and to
do a comparison between the different types. This experiment was conducted
in Baltimore as well as in the SERC invasions lab during the summer months
of July and August of 2002. The samples of water were collected from Fells
Point in Baltimore, Maryland using an 80-micron tow. Two tows were
supposed to be drawn for four consecutive days in order to establish
consistency. Once back at the lab the samples were treated with MgCl,
protoslo, or seltzer water in order to slow down plankton activity. I
looked specifically for Acartia and worm larvae and tried
separating three replicates of 50 of each type for the experiment. The
three replicates were to be used for direct plating, PCR (polymerase chain
reaction), and DVC. For direct plating, the replicate sample was
homogenized and directly plated onto a TCBS plate, which is specific for Vibrio
cholera growth. About 100 microliters of this homogenized replicate
was used for serial dilutions, which were also plated onto TCBS plates.
All of the plates were incubated for 4-6 hours at 37 degrees Celcius.
For PCR, the next replicate was placed in microcentrifuge tubes and
spun down in the centrifuge. I had to pipette off the water at the top of
the tube after centrifugation, label the tubes then place them in –70
degrees Celcius. For DVC, the sample was viewed under a fluorescent
microscope to do a cell count.
cholera is an
inhabitant of riverine and estuarine environments and is alos pathogenic
to humans. During my experiment I was to look for Vibrio cholera 01
and Vibrio cholera 1039 strains, which are etiological agents of
epidemic cholera. I was to see which type of plankton carried the largest
amount of Vibrio cholera and which strain it carried.
In addition to my project, this summer I participated in some seining, and
tethering with other members of my lab.