Omar, A., Abbas, A., El batouti, G. (2002). Assessment of Bacteriological Quality of Egyptian Bottled Water. Journal of High Institute of Public Health, 32(2), 192-210. doi: 10.21608/jhiph.2002.206457
Abeer A. Omar; Aleya A. Abbas; Gihan A. El batouti. "Assessment of Bacteriological Quality of Egyptian Bottled Water". Journal of High Institute of Public Health, 32, 2, 2002, 192-210. doi: 10.21608/jhiph.2002.206457
Omar, A., Abbas, A., El batouti, G. (2002). 'Assessment of Bacteriological Quality of Egyptian Bottled Water', Journal of High Institute of Public Health, 32(2), pp. 192-210. doi: 10.21608/jhiph.2002.206457
Omar, A., Abbas, A., El batouti, G. Assessment of Bacteriological Quality of Egyptian Bottled Water. Journal of High Institute of Public Health, 2002; 32(2): 192-210. doi: 10.21608/jhiph.2002.206457
Assessment of Bacteriological Quality of Egyptian Bottled Water
Microbiology Department, High Institute of Public Health, Alexandria University, Egypt
Abstract
With the significant increase in bottled water consumption over the last decade, there has been a growing concern over the microbiological quality of such products. Hence the present investigation aimed at assessment of the bacteriological quality of bottled water as well as to study the effect of some factors [refrigeration and storage] on its quality. The study included 300 bottled water samples of five Egyptian brands and were designated A, B, C, D and E [60 bottles each]. In addition, 65 tap water samples were collected to compare their hygjenic quality with that of bottled water. A 150 bottles were purchased unrefrigerated from the shelves while the other 150 bottles were purchased refrigerated. All the bottled water samples were subjected to determination of heterotrophic plate count [HPC] using the standard pour plate method and determination of most probable number [MPN] of Total coliforms [TC], fecal coliforms [FC], Escherichia coli [E.coli], Pseudomonas aeruginosa [P.aeruginosa] and Staphylococcus aureus [S.aureus] using multiple tube dilution technique [MTD]. All tap water samples were subjected to determination of HPC and enumeration of TC and E.coli. After initial examination, 150 bottled water samples [75 unrefrigerated and 75 refrigerated, equally divided between the 5 brands] were refrigerated for 2 days and re-examined to evaluate changes in HPC during this period. According to the Egyptian guidelines for purified natural bottled water No. 1589/2000, and for drinking water No. 108/ 1995, the examined bottled and tap water samples respectively were classified into acceptable or unacceptable. The results revealed that, 185 bottled water samples [61.7%] were considered acceptable and 115 [38.3%] were unacceptable while the corresponding figures for tap water were 81.5% and 18.5% respectively. Brand B gave the highest percentage of unacceptable samples [55%] while brand D gave the lowest percentage [8.3%]. Regarding the HPC at 22°c, the majority of the examined samples [81.7%] were acceptable with an HPC < 100 cfu/ml compared to 18.3% unacceptable ones with an HPC ranging from 101 ->10 cfu/ml. At 37°c, 70.7% of the bottled samples were acceptable with an HPC < 50 cfu/ml compared to 29.3% unacceptable ones with an HPC ranging from 51-10 cfu/ml. The percentage of bottled water samples that contained TC, FC, E.coli, P.aeruginosa and S.aureus constituted 13.7%, 8.0%, 2.3%, 5.7% and 10.7% respectively. The percentage of unacceptable samples of the unrefrigerated bottles constituted 54.0%, compared to 22.7% only for the refrigerated bottles. The majority of bottled water samples had the same or decreased HPC after storage at 4°C for 2 days [46.0% and 41.3% respectively]. Moreover, only 9.3% of the refrigerated samples showed increase in HPC compared to 16% of the unrefrigerated bottles. A higher percentage of unacceptable bottled water samples was found during the "4-6" months storage time than during the "1-3" months storage time [52.5% and 33.2% respectively]. Tap water gave a higher percentage of acceptable samples than bottled water ones as regards HPC at 22°C [87.7% to 81.7%] and at 37 C [89.2% to 70.7%] respectively. The frequency of isolation of TC from tap water samples was slightly higher [18.5%] than from bottled water [13.7%] while tap water samples were completely free from FC and E.coli. From the present study, it could be concluded that: tap water was of better bacteriological quality than bottled water. The presence of total coliforms and or E. coli in bottled water may indicate contamination of the source water. The presence of elevated HPC, P.aeruginosa and S. aureus may indicate non compliance with GMP in the bottling plant. Refrigeration of bottled water maintains or minimizes the bacterial growth. Storage of bottled water favors the multiplication of bacteria [when present] especially if it is stored at ambient room temperature. Hence, the continuous systematic monitoring of bottled water for evidence of contamination at the source or during the bottling process should be employed. S.aureus should be included as one of the parameters for assessing the hygienic quality of bottled water. Bottles should be purchased at a time as close as possible to the production date. Finally, bottled water should be purchased refrigerated and kept this way once it is bought and opened.
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