Abstract:
Contamination of drinking water sources remains a big challenge and many people
lack access to safe potable water. In Njoro Sub-county the main water sources are rivers,
man-made wells (protected and unprotected), boreholes, rainwater and springs (protected and
unprotected). Although Escherichia coli (E. coli) is an indicator organism for fecal
contamination of water, some E. coli strains have acquired the ability to cause intestinal
(gastroenteritis) and extra intestinal diseases in humans. This study aimed at determining the
Physico-chemical parameters and microbiological quality (using E. coli as indicator
organism) in water used for drinking in Njoro Sub-county. Water samples were collected
from drinking water sources and household storage containers. E. coli was isolated and
quantified using the Compartmental Bag Test kit (CBT). The Physico-chemical properties
were measured to determine water quality at points of collection and use, respectively.
Characterization of pathogenic E. coli strains was done using a published multiplex-PCR
protocol (mPCR). All data was imported into SAS 9.1 statistical software package for
analysis. Numerical variables were summarized using arithmetic means and frequencies. The
means were subjected to One way ANOVA and compared using Least Significant difference
(LSD) at p= 0.05. Turbidity and electrical conductivity were above the WHO recommended
levels in the water samples. E. coli was detected in 62.36% (n=111) of all the sampled
drinking water in the sources and household storage containers. In total, 53.15% (n=59) of
the E. coli positive samples were positive for pathogenic strains. However, only 38.98%
(n=23) of the samples had different combinations of virulence strains. This indicated that the
majority of drinking water were contaminated with the organic and inorganic matter at
sources, during storage and handling and hence the need for frequent water quality
monitoring and treatment to minimize contamination
