E. coli diversification within their ecological niches was studied
phenotypically through phage typing. Three water sites which were
ecologically variable (well, river and drainage) were selected for isolation
of E. coli by multiple tube fermentation technique and identification
through biolog system. Three isolates were designated as E. coli-EGl, E.
coli-EG2 and E. coli-EG3 to represent their source from well, river and
drainage, respectively. Spot test and plaque assay were adopted for
discriminating among such isolates and showed sensitivity for E. coli-EGl
and E. coli-EGly but quantitatively E. coli-EGl exceeded E. coli-EGl as,
105 and 103 PFUs respectively. The image processing and numerical
analysis for plaque assay data revealed small variations in mean, median,
standard deviation and number of pixels. The last was the most important
as it indicated no far extent in sensitivity of E. coli-EGl as compared to E.
coli-EGl. The differential behavior towards phage infection was attributed
to mutational effect caused by environmental stress and exerted the role for
the generation of new phenotypes which had fundamentally evolutionary
impact. From our knowledge a first automated image processing method
used for evaluation of plaques number based on scale and rotation
invariant analysis of optical transforms was applied here.
Key words: Image processing, Bacteriophage, Bacteria. |
