Source tracking of fecal indicator bacteria: Bacteroides in Hilo Bay, Hawaii

I have extracted bacterial DNA from 240 filtered water samples from Hilo Bay, Hawaii estuaries in order to determine whether or not fecal indicator bacteria (FIB) Bacteroides were present and whether their source was from human feces. Primers were used for amplifying genes from known sequences using: General Bacteroides 32F primer, Human-associated Bacteroides HF183F, and Cattle-associated Bacteroides primer CF128F. The General primer was used first to identify if Bacteroides FIB was present. If the marker was amplified, then I tested the same DNA sample against the Human-associated primer. One hundred and twenty six of 240 samples (52.5%) were positive for general Bacteroides. Of the positive samples, 118 of 126 (93.6%) tested positive for the Human-associated marker, through primer sets HF183F/708R. I also tested the positive samples against the Cattle-associated primer and all samples tested (100%) negative. Since human feces should not be present in estuarine waters, it is important to positively and accurately identify the source of pollution so that remediation can take place. Human FIB poses a serious public health risk as well as disrupts the natural ecosystem of the marine waters.