Coliphages as Fecal Pollution Indicators of

the Guavate River Basin, Puerto Rico

LEYDA VILLAGRASA

JOHN L. RIVERA MELENDEZ

Introduction What are coliphages?

•Phages that infect E.coli

Where are coliphages found?

•Anywhere E.coli thrives

What is E. coli?

•Bacteria found in warm blooded animal feces

Why are Coliphages important?

Used as E.coli indicator. E.coli is used to evaluate Salmonella in fresh water systems.

3.4 million people die from fresh water pollution due to Salmonella. Used to indicate how contaminated a fresh water system is. 780 million people don’t have access to uncontaminated and drinkable water. Drinking contaminated fresh water can lead to many symptoms, one being diarrhea which is the second leading cause of death among children around the world.

Related Investigations

1) Visible light has a negative effect in the number of E.coli

2) Survival of E.coli is prolonged if water is 25 C or more and survival is )decreased if temperature is 5 C or less. (Wislo, 2000) )

Problem

Will different areas of the Guavate river with factors, such as light, fast flow and stagnant(no flow),affect the amount of coliphages?

Hypothesis The different factors of each area will affect the quantity of coliphages.

Purpose of the experiment

Identifying coliphages by taking samples from the Guavate river basin, each sample having a different factor.

By doing this we can know if E.coli is present in the fresh water system and therefore fecal pollution.

Identify the number of plaque forming units of coliphages in the samples per area.

Procedure Before taking samples: Water conditions were verified to see if E. coli could survive in this river.

Area Hour Temperature PH Dissolved oxygen Conductivity Turbidity

Control 9:18 a.m. 20.7°C 7.91 8.4 mg/L 124.7 1.44 NTU

Stagnant water 9:07 a.m. 21°C 6.88 .7 mg/L 129.7 1.60 NTU

High flow 9:26 a.m. 20.8°C 7.87 8.42 mg/L 125 1.99 NTU

High light exposure

9:35 a.m. 21.6°C 7.59 8.06 mg/L 8.06 2.06 NTU

Guavate River basin

Procedure Sample Collection:

Sample 1: Control group

Sample 2: Stagnant water

Sample 3: Fast flow water

Sample 4: High light exposure

Samples on ice at 4°C

http://zyklon1985.blogspot.com/

2007_06_01_archive.html

Lab Procedure:

Aseptic technique

Labeling and dividing plates into groups

Single layer plaque assays

Incubation

Counting of viral plaques

http://www.youtube.com/watch?v=bRadiLXkqoU

Results

Plates divided into groups Control group results Groups 4: High light exposure

ResultsSample PFU’s per sampleSample 1: Control 1.67pfu/50mL

Sample 2: Stagnant water .67pfu/50mLSample 3: Fast flowing water .67pfu/50mL

Sample 4: High light exposure 34.7pfu/50mL

Conclusion

The different factors such as light, fast flowing water and stagnant water can affect the amount of coliphages found.

The area with high light exposure revealed the highest quantity of plaque forming units, there by showing more coliphages.

Future Works 1) Compare with the end of the river that discharges into the ocean.

2) Compare with a river that is in an urban area like San Juan. This way other factors like air contamination or salt can be taken in consideration.

References R. Wcisło, R.J. Chróst, 2000, Survival of Escherichia coli in Freshwater , http://www.google.com.pr/url?sa=t&rct=j&q=&esrc=s&frm=1&source=web&cd=2&ved=0CDAQFjAB&url=http%3A%2F%2Fwww.pjoes.com%2Fpdf%2F9.3%2F215-222.pdf&ei=m1h1U_TqO4iqsQTB-4GICw&usg=AFQjCNFnVeh_3r0MA4JzOABehhtTUW2w4w, extracted May 17,2014

Hatfull GF, Cichon P, Foley A, Ford M, Gonda R, Houtz J, Hryckowian A, Kelchner V, Pelluda M, Serra D. et al. 2006,Exploring the Mycobacteriophage Metaproteome: Phage Genomics as an Educational Platform,http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.0020092

Science Education Alliance. 2012. SEA-PHAGES Resource Guide. Howard Hughes Medical Institute; Chevy Chase, MA.

Todar K. 2012 , Todar’s Online textbook of bacteriology.http://textbookofbacteriology.net/phage.html , extracted May 1,2014

Acknowledgements

Mrs. Jennifer Paredes Lopez

Dr. Javier Arce

RISE Program