الفهرس 
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Abstract
In spite of the importance and popularity of swimming pools in our life, they have
been identified as posing some public health risks to users due to either chemical or
microbiological contamination.
MF is a useful technique for the majority of water quality laboratories as it is a
relatively simple method to use. Many samples can be processed in a day with limited
laboratory equipment by a technician with basic microbiological training. (4)
Addition of fluorogenic and chromogenic substrates to cultivation media (agar and
liquid media) to detect the enzymatic activity of TC and E.coli have increased the
sensitivity and the rapidity of the classical methods for estimating the microbial
contamination of water .These methods detect the presence of β-D galactosidase and β-Dglucuronidase
activities in TC and E.coli respectively.
The present study aimed to compare between chromogenic medium and conventional
media for enumeration of TC and E.coli in some swimming facilities in Alexandria.
The study was carried out during two month period, from the beginning of June 2014
to the end of July 2014, on a total of 120 water samples from 10 different swimming pools
(Three indoor pools designated as A, B and C and seven outdoor pools designated as D, E,
F, G, H, I and J). Twelve samples were collected from each pool.
All water samples were subjected to the following procedures :
A. Enumeration of TC and E.coli by MF using chromagar ECC and m. Endo LES media.
B. Physical and chemical Examination for measurement of pH, temperature and residual
chlorine.
The results of this study can be summarized as follow:
1. According to the Egyptian standards , the highest percentage of acceptable samples
was for E.coli parameter (97.5% and 94.2%) using m. Endo LES and chromagar ECC
media respectively. The corresponding figures for TC were (71.7% and 54.8%)
respectively.
2. The complying percentages of residual chlorine and pH were (42.5% and 31.7%)
respectively.
3. All mean values of TC (CFU/100 ml) recovered on m.Endo LES agar were lower than
those recovered on chromagar ECC with statistical significance.
4. Regarding E.coli (CFU/100 ml), chromagar ECC agar recovered higher mean values
than those recovered on m.Endo LES after verification with no statistical significance
5. The two tested media (Chromagar ECC and m.Endo LES) showed 79.2% , 96.7%
agreements regarding TC and E.coli recovery rates respectively.
6. A significant negative correlation was found between TC recovery rates of chromagar
Summary and Conclusion
60
ECC and m.Endo LES media and residual chlorine (p <0.001).
7. A negative correlation between E.coli recovery rates of chromagar ECC and m.Endo
LES media with residual chlorine. These results were statistically significant in case of
m.Endo LES medium where p=0.020 but not significant in case of chromagar ECC
(p= 0.079).
8. pH was positively correlated with E.coli recovery rates of chromagar ECC and a
negatively correlated in case of m.Endo LES medium with no significant difference.
9. Positive correlations between TC recovery rates of chromagar ECC and m.Endo LES
media with pH. These results were statistically significant in case of chromagar ECC
where p= 0.009 and not significant in case of m.Endo LES (p= 0.120).
10. chromagar ECC recovered 5.4 , 1.5 times TC, E.coli as m.Endo LES agar
respectively.
It can be concluded from the study that:
1. According to the Egyptian standards most of the examined swimming pool water
samples were considered unacceptable.
2. Residual chlorine and pH were good operational indices in the quality control of
swimming pool water.
3. chromagar ECC agar is a potential alternative media for detection of coliforms and
E.coli because it has the advantages of being sensitive, selective and specific .