Bacteroides HF183 Research Articles

Sourcing faecal pollution: A combination of library-dependent and library-independent methods to identify human faecal pollution in non-sewered catchments

Library-dependent (LD) (biochemical fingerprinting of Escherichia coli and enterococci) and library-independent (LI) (PCR detection of human-specific biomarkers) methods were used to detect human faecal pollution in three non-sewered catchments. In all, 550 E. coli isolates and 700 enterococci isolates were biochemically fingerprinted from 18 water samples and compared with metabolic fingerprint libraries of 4508 E. coli and 4833 enterococci isolates. E. coli fingerprints identified human unique biochemical phenotypes (BPTs) in nine out of 18 water samples; similarly, enterococci fingerprints identified human faecal pollution in 10 water samples. Seven samples were tested by PCR for the detection of biomarkers. Human-specific HF134 Bacteroides and enterococci surface protein ( esp) biomarkers were detected in five samples. Four samples were also positive for HF183 Bacteroides biomarker. The combination of biomarkers detected human faecal pollution in six out of seven water samples. Of the seven samples analysed for both the indicators/markers, at least one indicator/marker was detected in every sample. Four of the seven PCR-positive samples were also positive for one of the human-specific E. coli or enterococci BPTs. The results indicated human faecal pollution in the studied sub-catchments after storm events. LD and LI methods used in this study complimented each other and provided additional information regarding the polluting sources when one method failed to detect human faecal pollution. Therefore, it is recommended that a combination of methods should be used to identify the source(s) of faecal pollution where possible.

Identification of human fecal pollution sources in a coastal area: a case study at Oostende (Belgium)

From April to June 2001, a monitoring study at Oostende (Belgium) was conducted to obtain an insight into fecal pollution impairing water quality at this coastal area. Eight sampling sites were selected based on the historically low water quality at these sites compared to the remainder of the area. Indicator organisms such as fecal coliforms, Escherichia coli and fecal streptococci were monitored by plating. A real-time PCR assay for quantification of the human-specific HF183 Bacteroides 16S rRNA genetic marker was used to detect human fecal pollution at the sampling sites. Human fecal pollution was detected at all sampling sites. However, the frequency of detection ranged from 30-100% and the amount of human-specific Bacteroides markers recorded varied between the sampling sites. Concentrations of 10(7) human-specific Bacteroides markers per 1 to levels below the detection limit of the real-time PCR assay were recorded. Our results indicate that human fecal pollution is a re-occurring problem in certain areas. Of all the environmental parameters monitored during the study, only rainfall was strongly related to the detection of the indicator organisms and the human-specific Bacteroides marker.