Fille 2693(14).qxd Microbial Contamination of Water in Around Dhaka City Sahana Parveen*, M. Shakir Uddin Ahmed and Tania Nasreen Food Microbiology Section, Institute of Food Science and Technology, Bangladesh Council of Scientific and Industrial Research, Dhaka, Bangladesh. Abstract A total of 109 water samples were collected from around Dhaka city and examined for microbial con- tamination. Samples were collected in sterilized screw capped glass bottles, transported to the labora- tory in cold and processed within 6 hours of their collection. All river water, pond water and household water were found heavily contaminated with coliform, faecal coliform, E. Coli and Salmonella where- as tube well water and bottled water was devoid of faecal coliform, E. Coli and Salmonella. A signifi- cant correlation between total number of total coliform and percentage of Salmonella was also investi- gated. It is suggested that water must be boiled before use. Key Words: Water contamination, Total coliform, Faecal coliform, Salmonella Bangladesh J. Sci. Ind. Res. 43(2), 273-276, 2008 Short Comuunication Introduction Safe drinking water and adequate environ- mental sanitation are preconditions for health and for success in the fight against poverty, hunger and child deaths. Worldwide in 1995, contaminated water and food caused more than 3 million deaths, of which more than 80% were among children under age five (WHO 1996). Globally, the World Health Organization (WHO) estimates that 1.8 million people die each year from diar- rhoeal diseases. Faechem (1980) reported that at least one and a half thousand million people worldwide used polluted water. This problem is more acute in developing coun- tries where higher incidence of water-borne diseases are reported. In India, more than 70% of the epidemic emergencies are either water borne or are water related (Khera, et al 1996). Among waterborne diseases of bacte- rial origin typhoid, bacillary dysentery and diarrhoea are common in Bangladesh. Although a substantial amount of work has been carried out on common water borne pathogens in Bangladesh, unfortunately a lit- tle information is available. For this a study was conducted to estimate the quality of var- * Corresponding author BCSIR Avaiable online at www.babglajol.info BANGLADESH JOURNAL OF SCIENTIFIC AND INDUSTRIAL RESEARCH E-mail: bjsir07gmail.com 274 Microbial Contamination of Water 43(2) 2008 ious sources of water and the prevalence of waterborne pathogens. Materials and Methods Sample collection A total of 109 water samples were collected from the entire region of the city of Dhaka. Samples of river water (18), Pond water (18), Household Water (45), Tubewell water (19), Bottled water (9) were collected. Samples were collected in sterilized screw capped glass bottles, transported to the labo- ratory in cold and processed within 6 hours of their collection. Methodology All of the water samples were analyzed by standard methodologies recommended by the American Public Health Association (APHA 1995). To assess the microbial load, indicator parameters, viz. heterotrophic plate count (HPC), Total fungus count (TFC), Total Coliform count (TCC), Faecal Coliform count (FCC), Salmonella and E. Coli were studied. HPC was enumerated on plate count agar (PCA) by standard plate count, TFC were on potato dextrose agar (PDA) by spread plate technique; TCC, FCC and E. Coli were determined by the most probable number (MPN) method. Isolation of Salmonella was carried out on enrichment method. For Salmonella, 100 ml of water sample was enriched 24 hours at 37OC in 100ml of double strength lactose broth, then 1 loopful of 24 hours culture was transferred to 10 ml selenite broth and incubated 24 hours at 37OC in an incubator. One loopfull overnight culture from selenite broth was streaked on bismuth sulphite agar (BSA) and incubated 24 hours at 37OC. From each sam- ple three typical colonies were biochemical- ly confirmed. Results and Discussion Table I summerized the water samples with source , type and microbial parameters. In River water 18 1.12x105 4.93x102 2.4x104 2.4x104 3.49x102 100 Pond water 18 4.43x105 3.02x103 2.4x104 2.4x104 2.12x102 100 Household water 45 2.30x105 9.3x101 1.70x102 1.70x102 1.40x102 84.37 Tubewell water 19 1.8x102 0.1x101 1.0x101 N.F N.F N.F Mineral water 09 3.50x102 1.93x103 N.F N.F N.F N.F Table I. Microbial contamination of different type of water in Dhaka. N= Number, HPC = Heterotrophic plate count, TFC= Total fungus count, TCC= Total coliform count, FCC=Faecal Coliform count, Water samples Counts (geometric mean) N TFC(counts/ ml) HPC(counts /ml) TCC(counts /100ml) FCC(counts /100ml) E.Coli(cou nts/100ml) Salmonella (%) Parveen, Ahmed and Nasreen 275 comparison to tubewell water and bottled water, river water, pond water and household water showed more pathogenic contamina- tion. All river water, pond water and house- hold water were heavily contaminated with Coliform, Faecal coliform, E. Coli and Salmonella whereas tubewell water and bot- tled water were devoid of Faecal Coliform, E. Coli and Salmonella. There was no remarkable difference in pathogenic organ- ism among river water, pond water and household water. Geldreich (1994) reported that the rate of salmonella isolation is related to faecal coliforms. Our findings was also similar with that result. From this study we had found that there was a correlation between total coliform and the presence of Salmonella species. Among the different sources of water the correlation was signifi- cant in case of river water, pond water and household water (Fig. 1). The presence of coliform, Faecal coliform, E. Coli and Salmonella in a majority of these samples showed that contamination was widespread. However, except for some samples, most drinking water samples were found to be devoid of any pathogenic organism. It is con- tended that contamination is mainly due to disposal of waste in river and pond, unhy- gienic conditions related to washing in uten- sils and bathing. Household water may be contaminated with connecting the supplied pipe line with sewerage system. The Dhaka city is also over crowded which seem to the cause of contamination. 0 20 40 60 80 100 1 2 3 4 % of Salmonella Number of TCC (Log base 2) 1. River water 2. Pond water 3. Household water 4. Tube well water Fig. 1: Relationship between TCC and % of Salmonella. Salmonella 276 Microbial Contamination of Water 43(2) 2008 Conclusion The data presented here may serve as a base- line to which all future data may be com- pared. Studies in this respect are also war- ranted to safeguard ourselves against water- borne pathogens and suggested to boil the water before use. Acknowledgement Financial support from Institute of Food Science and Technology, Bangladesh Council of Scientific and Industrial Research, Dhaka is gratefully acknowl- edged. References American Public Health Association (APHA) (1995) Standard methods for examination of water and wastewater. 19th edition. American Public Health Association, Washington, D.C.USA. Faechem, R.G. (1980) Bacterial standards for drinking water quality in developing coun- tries. Lancet. 2:255-56. Geldreich, E.E. (1998) The bacteriology of water. In: Colier, L., Balows, A.and Sussman, M. (Eds.), Microbiology and microbial Infections. 9th ed. Arnold publication, London. Khera, A.K. Jain, D.C. Dutta, K.K. (1996) Microbial contamination of various water sources in Delhi. J. Commun. Dis. 28:129- 38. WHO (1996) The World Health Report. Fighting Diseases, Fostering development. Geneva. Available at: http://www.who.int/whr/ 1996/en/. WHO (1997) Guidelines for drinking water qual- ity. Vol 3: Surveillance and control of com- munity supplies. The World Health Organisation, Geneva. Available at: http://www.who.int/water_sanitation_healt h/dwq/gdwq3rev/en/. Received : August 29, 2007; Accepted : January 17, 2008