Salmonella and
Campylobacter
prevalence in stream networks of the Satilla River Basin (SRB)
were monitored monthly from August 2007 to August 2009 to study relationships between
these pathogens and land use, presence of poultry houses and wastewater treatment plant
(WWTP) discharge.
Salmonella
and
Campylobacter
were detected at all 10 stream sites and the
three sites at the sole wastewater treatment plant (WWTP) in the study area. In all, 43% (129/
299) and 62% (96/156) of samples were positive for
Salmonella
and
Campylobacter
, respectively,
with detection frequency increasing in downstream sites with more poultry production and
influence of WWTP discharge. Both
Salmonella
and
Campylobacter
detection frequencies were
positively associated with the number of poultry houses in the subwatersheds, but agri-
cultural land use as a proportion of the watershed was not a significant predictor of either
pathogen. Fecal indicator bacterial levels were assessed and evaluated for their ability to
predict the presence of pathogens. Of those examined, enterococci was most predictive; of
the 129 samples positive for
Salmonella
, 88% (113/129) were detected when enterococci were
above EPA single sample threshold (61 CFU 100 ml
-1
); and of the 96 samples positive for
Campylobacter
, 90% (86/96) were detected when enterococci levels exceeded this level.
Comparatively,
Escherichia coli
concentrations were above EPA single sample thresholds in
38% (49/129) of the positive
Salmonella
samples. Detection of the pathogens throughout the
watershed indicated that there was potential for waterborne transmission especially in
downstream areas that were more likely to have recreational users.