Scientific Poster

1
 
Distribution Of Fecal Coliform Bacteria in A
Central California Coastal Stream
Tim Viray, Eric Fung, and Christine Case Biology
Department, Skyline College, San Bruno CA

• Results
• Fecal contamination was found in sites 3, 4, and
  5 (Figures 3 and 4), which indicates that the
  source of contamination is nearer the estuary
  than the headwaters.
• No coliforms were found in plant and soil samples
  collected at sites 3, 4, and 5.
• Enteroccocus bacteria are present and abundant in
  the sites where fecal contamination was found
  (Figure 4).
• Higher coliforms counts were found during periods
  of rainfall suggesting stormwater runoff as the
  source of contamination (Figure 5).

Abstract Pillar Point is a popular recreation
area and one of the most contaminated beaches
along the central California coast. This study
was undertaken to locate the source of fecal
contamination at Pillar Point. Identifying the
source of fecal contamination in coastal creeks
is important for protecting the health of
swimmers and the coastal ecosystem. Frenchmans
Creek is the only stream that drains the Coast
Ranges into the ocean at Pillar Point. The creek
flows from coastal sage scrub, through rural and
suburban watersheds, to the ocean. We conducted a
systematic survey of water, soil, and vegetation
along the 4-km creek from headwaters to estuary.
Coliform and Enterococcus bacteria were used as
indicators of fecal contamination. Total coliform
and fecal coliform bacteria were counted using
the multiple-tube method. A membrane-filtration
test was used to determine enterococcal numbers
in the samples. Fecal contamination begins
approximately 0.8 km upstream from the estuary
heavy contamination was detected at three of the
sites investigated. In these sites, total
coliforms exceed 2400/100 mL and enterococci
exceed 80/100 mL. Fecal coliforms (from mammals)
were found at these sites. Coliform counts are
being performed on soil and aquatic vegetation to
determine whether these are reservoirs for fecal
coliform bacteria or the fecal coliforms are from
land-based anthropogenic sources.

• Materials Methods
• Water samples were collected along Frenchmans
  Creek from headwaters to the estuary between
  April and July 2011 (Figure 2).
• Samples were collected by washing 480 mL plastic
  bottles and collecting approximately 240 mL of
  the creeks water.
• Soil and plant samples were also collected around
  the area where water samples were collected and
  placed in zip-lock bags.
• Coliform counts were performed on water, plant,
  and soil samples using the multiple-tube method
  with lauryl-sulfate lactose broth.
  Methylumbelliferone glucuronide (MUG) agar
  incubated at 440.5C was used for the confirming
  test (2).
• The membrane filter technique was used on the
  water sample to determine enteroccoci on
  Enterococcus Agar and E. coli on Endo Agar (2).

• Discussion Conclusion
• During the summer and fall season, local farmers
  raise the dam between sites 3 and 4 (Figure 2) to
  provide irrigation water.
• The water level was raised by 1520 feet, which
  covered multiple smaller water runoffs that could
  be possible sources of the contamination.
• We cannot confirm the exact location of the
  contamination but we have narrowed the source to
  sites 4 and 5.
• We confirmed that soil or riparian vegetation
  are not reservoirs for the fecal bacteria, which
  infers that the contamination is from land-based
  anthropogenic sources.
• The higher coliform counts found during periods
  of rainfall suggest that stormwater drainage
  contributes to contamination of the creek.

Aim To determine the source of fecal
contamination into Frenchmans Creek.
Future Studies Locating storm drains or sewage
cross-connections along the creek can be done to
verify whether these factors contribute to the
contamination. Sampling at the tunnel/storm
drain that links to a florist warehouse/green-hous
e. This runoff from the florist could be the
source of the contamination. This site is between
sample sites 4 and 5.

• Background
• Pillar Point is listed as one of the 10 most
  polluted beaches in San Mateo County (1).
• Illnesses associated with fecal pollution
  include skin rashes, respiratory infection,
  meningitis, gastroenteritis, and hepatitis (1).
  These illnesses are transmitted by water contact
  sports and from consuming marine animals.
• Transfer of pathogenic bacteria among fishes
  and other marine organisms can directly affect
  humans (4).
• Fecal contamination at Pillar Point Harbor
  threatens commercial fishing and recreation (7).
• Frenchmans Creek (Figure 1) is a major
  contributor to the fecal distribution of Pillar
  Point (1).
• Coliforms are aerobic or facultatively
  anaerobic, gram-negative, non-endospore-forming,
  rod shaped bacteria that ferment lactose to form
  gas within 48 hr of being placed in lactose broth
  at 35-37C. Fecal coliforms are found in the
  human intestines. They produce the enzyme
  ?-glucuronidase when put on a methylumbelliferyl-?
  -D-glucuronide at 44.5C. Total coliforms include
  fecal coliforms as well as coliforms that grow at
  35-37C (3).
• Escherichia coli and enteroccoci are used as
  indicator organisms for fecal contamination
  because they are found in the intestines of
  warm-blooded animals (5).
• E. coli can survive in waterways in the
  biofilms that form on some most surfaces (6).
• Enterococci are facultatively anaerobic,
  gram-positive cocci in Lancefield group D. They
  can also be found in soil, water, food, and are a
  significant component of human intestinal
  microbiota (3).
•  

Literature Cited 1. Brennan, S,. August 2010.
Ten most polluted beaches in San Mateo County.
Coastsider. http//coastsider.com (5 June
2011).  2. Clesceri, L. S. and A. E. Greenberg,
and A. D. Eaton (eds). Standard methods for the
examination of water and wastewater, 20th
ed. Washington, D. C. American Public Health
Association, 1999.  3. Holt, J. G. (ed.) Bergey's
Manual of Determinative Bacteriology, 9th ed.
Baltimore Williams Wilkins, 1994.  4. National
Research Council (U.S.). From Monsoons to
Microbes Understanding the Oceans Role in Human
Health. National Academy Press, Washington D.C.,
1999.  5. OBrien, D. 2011. A Better To Track
Salmonella and E. coli in Waterways.
Agricultural Research Magazine 206 8.  6. Perry,
A. 2011. E. coli Alive and Well, Probably in a
Streambed Near You. Agricultural Research
Magazine 211 20.  7. Pillar Point Harbor.
1998-2004. San Mateo County Harbor District.
http//www.smharbor.com/pillarpoint/ (29 July
2011).

• Acknowledgements
• Skyline MESA and SACNAS for supporting our
  project
• Colleagues with whom we worked countless hours
  during the entire spring and summer semesters  
• Pat Carter for providing us with all the
  materials we need to do our experiment well
• Professor Christine Case who inspired us to do
  our best and pushed us to go beyond ourselves to
  get better.