|BRIEF RESEARCH ARTICLE
|Year : 2015 | Volume
| Issue : 4 | Page : 299-301
Microbial evaluation of bottled water marketed in North India
Bhawna Sharma1, Satinder Kaur2
1 MSc Student, Department of Biotechnology, Sri Guru Gobind Singh College, Chandigarh, India
2 Assistant Professor, Department of Biotechnology, Sri Guru Gobind Singh College, Chandigarh, India
|Date of Web Publication||17-Nov-2015|
Assistant Professor, Sri Guru Gobind Singh College, Sector 26, Chandigarh, Punjab and Haryana
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Drinking unsafe and unhygienic water can cause waterborne diseases such as diarrhea and typhoid. The present study describes the microbial evaluation of bottled water sold in North India. The samples were analyzed for total viable count and coliforms and susceptibility to different antibiotics. Though free of coliforms, the samples had a total viable count ranging from 0.01 × 10  cfu/mL to 2.40 × 10  cfu/mL and in 17% of the samples, total viable count was much higher than specified by the Bureau of Indian Standards (BIS), Government of India. Among the samples, 6.5% also showed fungal growth. On checking the sensitivity of bacteria isolates to different antibiotics, most of the strains were found to be resistant to a number of antibiotics. It can thus be concluded that the consumption of bottled water with a high viable count and that was bacteria-resistant to different antibiotics may have an effect on the health of the consumers, especially immune-compromised individuals.
Keywords: Antibiotic susceptibility, bacteria, coliforms, microbial quality, viable count
|How to cite this article:|
Sharma B, Kaur S. Microbial evaluation of bottled water marketed in North India. Indian J Public Health 2015;59:299-301
Bottled water is any potable water, which is sealed in food-grade bottles for human consumption.  Recently, in India, there has been an increase in the consumption of bottled water due to the nonavailability of safe municipal water.  However, studies conducted revealed that most of the samples of bottled water were unfit for human consumption. ,,,, The microorganisms most frequently found were Pseudomonas, A. hydrophila, Escherichia coli, Flavobacterium, and Mycobacterium. , The present study was conducted to evaluate the microbial quality of bottled water available in North India.
A total of 46 bottles of uncarbonated mineral water samples belonging to 24 brands, with different production (bottling) dates and batch number were purchased randomly from January 2013 to March 2013, from different local retail stores in Chandigarh, Himachal Pradesh, and Delhi.
Bacteriological analysis: The samples were analyzed for total viable count by spread plate technique and coliforms by using the standard five-tube most probable number (MPN) method. 
For the detection of fungus, potato dextrose agar (PDA) media was used and was identified by staining with lactophenol cotton blue.
Forty-two bacterial isolates were selected randomly for antibiotic sensitivity testing against eight antibiotics using standard methods. 
In the present study, bottled water samples were evaluated for microbial contamination and the results were compared with the standards drafted for total viable count and coliform count by the Bureau of Indian Standards (BIS), Government of India.  BIS prescribed the viable count limit at 100 cfu/mL and there is zero tolerance for coliforms in 250 mL of water.
Out of the 46 samples analyzed, 19 samples showed bacterial growth and out of these in 8 (17%) samples, the cfu/mL value exceeded the limit of 100 cfu/mL set by BIS. Around 2% of the samples showed bacterial counts higher than 1,000 cfu/mL. The highest value of total viable count was found to be 2.40 × 10  cfu/mL in 2.17% of the samples. Coliforms were not detected in any of the samples.
A total of 50 bacterial isolates were isolated by picking up morphologically different colonies from nutrient agar (NA) plates. The bacterial isolates were characterized by morphological and biochemical tests following Bergey's Manual of Determinative Bacteriology, 1994. They were found to belong to the genera Bacillus, Staphylococcus, Corynebacterium, etc. Out of these, Gram-positive genera such as Corynebacterium and Staphylococcus were found to be dominant [Table 1]. Antibiotic sensitivity of different bacterial isolates was also observed [Table 2]. Most of them were resistant to antibiotics such as cloxacillin, penicillin, ampicillin, tetracycline, and erythromycin.
|Table 1: Bacterial isolates of different genera present in bottled drinking water|
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|Table 2: Antibiotic susceptibility of different bacterial isolates present in bottled water|
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Fungi were also isolated from three (6.5%) samples of bottled water and were identified as Aspergillus spp. and Mucor spp.
Bottled water is generally considered of good quality for drinking but if not properly protected during bottling and transit, it could be a subject of contamination.  The samples analyzed in the present study were able to meet the standards set by BIS only in the case of coliforms but not in the case of viable count. However, the bacteriological quality of the samples was better than that reported by Gangil et al.,  Radhakrishna,  Uravashi et al., and Jeena et al.
Characterization of bacterial isolates revealed that the genera Corynebacterium, Staphylocoocus, Acinetobacter, and Pseudomonas were predominant. The presence of Corynebacterium and Staphylococcus has also been reported earlier by Jeena et al. Similarly, Reddy  detected Bacillus, Pseudomonas, and Acinetobacter. The genus Corynebacterium is a heterogeneous group of species comprising human and animal pathogens. Some species of Corynebacterium such as renale can grow on nutrient agar.  Corynebacterium renale has been identified as a potential zoonotic bacterial pathogen. 
Isolation of Staphylococcus from the bottled water samples in the present study indicate lack of personal hygiene among the personnel involved in the operations in some of the bottling facilities as this bacterium is present in the nasal mucosa and in cuts and wounds on the skin in humans. Similar results have been reported by Jeena et al.
Increasing drug resistance among bacteria isolated from noncarbonated mineral water is another major concern.  In the present study, the maximum resistance was observed against cloxacillin followed by penicillin. High levels of antibiotic resistant bacteria in bottled drinking water have been reported earlier by Jeena et al. These bacteria can act as reservoir of resistant plasmids, which they can freely exchange with possible pathogens in the intestine.
Aspergillus spp. and Mucor spp. were also detected in some of the samples in the present study. Aspergillus has also been detected by Reddy.  The presence of fungi in drinking water can cause health problems because of the production of mycotoxins. 
From the present study, it can thus be concluded that the microbial quality of some brands of the bottled water samples available in North India is not as per BIS recommendations, which may have an effect on the health of the individuals consuming it. The isolation of potentially pathogenic microorganisms such as Staphylococcus spp. and Pseudomonas spp. indicated that bottled water is unsafe. Therefore, it is necessary to improve the processing and bottling operations to completely eliminate them.
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Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2]