Host specific differences in fatty acid methyl ester profiles of indicator organisms as a new tool for microbial source tracking.

The objective of this study is to test the hypothesis that indicator organisms isolated from different host categories, i.e., from human and animal, would have distinctly different whole-cell fatty acid profiles that can be used to track sources of microbial pollution. The FAME profiles fecal coliforms (FC) isolated from feces of poultry, bovine, swine, waterfowl, deer and sewage samples were investigated. Stool samples from several individuals within each host category were collected and cultured on selective and differential media. A known source library was constructed with 314 FC isolates cultured from five possible sources of fecal pollution; 99 isolates from sewage; 29 from bovine; 29 from poultry; 50 from swine; 46 from waterfowl; and 61 from deer. Whole-cell fatty acids were extracted from isolated FC and quantified by a gas chromatograph with flame ionization detector (GC/FID). A linear discriminant function differentiated FC isolates of human origin from those of livestock and wildlife origin at 99% accuracy. The same discriminant function was used to predict sources of 37 FC isolates cultured from water samples taken from a well-protected natural pond where the only significant source of fecal matter was known to be waterfowl. As expected, 81% of the pond isolates were classified as wildlife while the remaining 19% were identified as livestock. These results provide evidence that the FAME profiles of indicator organisms show statistically significant host specificity and have the potential to be used as a phenotypic Microbial Source Tracking (MST) tool.

Main Author: Duran, Metin.
Other Authors: Haznedaroglu, Berat.
Language: English
Published: 2005
Online Access: