Starzyk, Marvin J.
M.S. (Master of Science)
Department of Biological Sciences
Due to the increased use of polluted bodies of water for recreational purposes, a study was undertaken to determine the sources of contamination. Water and sediment samples were taken from the Rock River and its tributaries between Byron and Oregon, Illinois, in September and November, 1973. Utilizing 'Standard Methods' procedures, MPN calculations were employed to determine fecal streptococci concentrations. Data on fecal coliforms was obtained from Mitchell (1974). Pfizer Selective Enterococcus Agar was also used to confirm and enumerate fecal streptococci with the intent of developing a fecal streptococcus test that would have a shorter incubation period. Media used to characterize and speciate group D streptococci were also evaluated using fecal streptococci isolates from water and sediment samples. Pfizer Selective Enterococcus Agar was shown to be 95% effective in confirming the presence of group D streptococci and its use shortened the fecal streptococcus test to a maximum of 36 hours. In addition, Bile-Esculin Agar (Difco) was shown to be the best medium for establishing an organism as a group D streptococcus. Due to the low concentrations of fecal coliforms and fecal streptococci in river water samples, the FC/FS ratio was shown to be of little value in determining sources of contamination. High concentrations of fecal coliforms and fecal streptococci from sediment samples gave more credibility to the FC/FS ratios. The actual distribution of group D streptococcal species in the rivers and streams was also shown. High concentrations of all Division II species (S. faecium, S. faecium var. casseliflavus, and S. faecium var. durans) were found in the water and sediment samples with S. faecium var. durans comprising 50% of the total number of isolates. Low concentrations of Division I group D streptococci (S. faecalis and varieties) were found while only one isolation of Division III group D streptococci (S. bovis and S. equinus) was made.
Ator, Linda Louise, "The distribution of the group D streptococci in the rivers and streams of Northern Illinois" (1974). Graduate Research Theses & Dissertations. 5457.
Northern Illinois University
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