Research Article
Presence of Escherichia coli or Coliform Bacteria in Drinking Water Sources as Indicator to Other Fecal Contamination
Mutaz Mohamed Ahmed Elshiekh* and Eman Abd-Alla Gism-Alla Alamin
Corresponding Author:
Received: March 07, 2019; Accepted: March 20, 2019;
Citation: Elshiekh MMA & Alamin EAG. (2019) Presence of Escherichia coli or Coliform Bacteria in Drinking Water Sources as Indicator to Other Fecal Contamination. J Microbiol Microb Infect, 1(1): 5-13.
Copyrights: ©2019 Elshiekh MMA & Alamin EAG. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

The main objective of this research project is to find a best source for drinking water with low concentration of E. coli and to predict a better treatment method(s) to produce low contaminated water in order to achieve best conditions for reasonable public health in Omdurman (Sudan) through guiding people to use adequate and decontaminated drinking water. Coliforms are good indicator of potential of water contamination. Testing for coliform bacteria is faster and cheaper than testing for specific organisms and pathogens. Water is important for life of human and animals hence purity of water from pathogenic microorganism is very important public health goal.

Random samples from different water drinking sources were tested and cultured for the presence and/or concentration of E. coli. These samples were River Nile, surface water collected water from Almanara Company (treated by chlorine) before entering to the water dispenser system, Almanara normal house hold water after entering the dispenser system, Wells water and Mineral bottled water (treated by ozone) from three different industrial water treatment companies, these were Mizo, Cristal and Anhar. Sample from each water sources was cultured separately in the microbiology lab at Ahfad University for Women for coliform and E. coli. Surface water collected directly from the river Nile (neither decontaminated by chlorine, ozone) was found to be the most contaminated water with the E. coli, Almanara house hold water after entering the water dispensers system was found to be next in terms of contamination. Collected water from the tankers of Almanara before entering the dispenser system occupies the third position concerning the degree of contamination indicating that the dispensers system was already contaminated with the E. coli. Well water (treated with chlorine) and industrial Mineral bottled water (treated with ozone) were found to be coli form and E. coli decontaminated samples. Finally we concluded that drinking water contamination depends on the water source and the type of water decontamination treatment method.

Results were evaluated and recommendations were drawn.


Keywords: Public health, Contamination, E. coli, Bacteria, Pathogens, Ozonation




In living organisms, water acts as a temperature buffer and a solvent, is a metabolite and creates a living environment. Water is an effective and necessary solvent in living organisms.

Source of water

Surface water: Surface water is water in a river, lake or fresh water wetland. Surface water is naturally replenished [1].

Under river flow: Throughout the course of a river, the total volume of water transported downstream will often be a combination of the visible free water flow together with a substantial contribution flowing through rocks and sediments that underlie the river and its floodplain called the hypothetic zone [1].

Groundwater: Groundwater is fresh water located in the subsurface pore space of soil and rocks.

Water contamination

When we think of contaminated water we tend to focus on many different things. These can be chemicals from industrial plant, heavy metals from pollution and sewage release. One of largest concern is to find pathogens in drinking water; some of these microbes are bacteria. Drinking water that is not properly treated or traveled through piping system may create an environment of contamination.


Coliforms are Enterobacteriaceae organism distributing worldwide and found on soil, water and plant. They are also present as part of normal flora intestinal of humans and animals. Member of this family move by peritrichous flagella or they may be non-motile without any flagella also they are aerobic and facultative anaerobic and grow readily on ordinary media.

Human diseases caused by enterobacteriaceae organism: Some members of the family such as salmonella species always cause human disease such as diarrhea. In addition another group of Enterobacteriaceae organisms, which are found as normal commensally in humans but become pathogenic when they acquire virulence factor genes through plasmid bacteriophages or Pathogen city islands, E. coli associated with gastroenteritis in the human is one such example [2,3].

Classification of E. coli:

Order: Enterobacteriales

    Family: Enterobacteriaceae

        Genus: Escherichia

            Species: coli

Escherichia: It’s one of Enterobacteriaceae which are animal and human pathogen. This genus consists of five species: E. coli, Escherichia ferguson, E. bermanii, E. vulneris and E. blatted.

A.      E. coli: It's an aerobe and it's most common important types that concourse disease to human in enteric disease [4,5].

B.      Culture of E. coli: Fermented sugar with production of acid and gas or acid only reduce nitrate to nitrite and are catalase positive but oxidize negative, the oxidize test is important test by which the member of the Enterobacteriaceae can be distinguished from many other fermentative and non-fermentative gram negative bacilli. Member of the family show every wide biochemical and antigenic heterogeneity among them self. E. coli are aerobe and facultative anaerobe.

C.      E. coli gives bright pink flat colonies due to lactose fermentation condition. In liquid broth culture gives turbid growth with deposit, which disperses completely on shaking.

1.       Pathology of E. coli infection: Many diseases caused by E. coli examples are:

1-       Urinary tract infection: caused by E. coli normally found in the feces.

2-       Gastroenteritis related to contaminated food, water with fecal E. coli.

3-       Infant diarrhea caused by Enteropathogenic caused by E. coli in tropical countries.

4-       Septicemia caused by entering E. coli to blood stream and cause toxicity.

5-       Neonatal meningitis.

D.      Laboratory diagnosis: Laboratory diagnosis is generally based on isolation of E. coli by culture and separation of E. coli from other different clinical specimen. Samples were collected from urine, feces, blood and CSF.

E.       Prevention and control: General good hygiene for food, water in taking and handling use, good cooking all types of meets and boiling water in proper ways [6].

Presence of E. coli or coliform as indicator to other fecal contamination

Certain bacteria can be used as good indicator organisms of the potential contamination in particular situations and used to evaluate the general quality of water. The presence of bacteria commonly found in human feces or animal waste product and the greater risk for exposure to pathogenic organisms. The total number of coli form discharged by a normal person ranged from 100 to 400 billion per day, some animals discharge much more, coliform bacteria (e.g. E. coli), in the surface water is considered as a common indicator of fecal contamination. For this reason, sanitation programs often test water for the presence of these organisms to ensure that drinking water systems are not contaminated with feces. This testing can be done using several methods which generally involve taking samples of water or passing large amounts of water through a filter to sample bacteria, then testing to see if bacteria from that water grow on selective media such as MacConkey agar. Alternatively, the sample can be tested to see if it utilizes various nutrients in ways characteristic of coliform bacteria [7].

Water treatment techniques

Ozonation and chlorination:

Ozonisation: It is chemical water treatment technique based on the infusion of ozone into water .The gas composed of three oxygen atoms (O3) which is one of the most powerful oxidant. Chlorination is another type of advanced oxidation process, involving the production of very reactive oxygen species able to attack a wide range of organic compound and all microorganisms [8].



Water: Different source of water were used, these sources are River Nile, Manara water collected directly from municipal water supply, water from wells and Industrial treated water from different water treating companies, and these are Mizo, Anhar and Crystal.

Reagents: MacConky broth, EMP, distilled water, cotton and Aluminum foil.

General method

Different portions from each water sample were cultured for presence and concentration of E. coli separately, these portions were 1, 0.1, 0.01 mL.

Culture process was done in two different media, MacConky broth for coli form and EMP selectively for E. coli; these media were prepared prior to the process of culture. Evaluation of gas during the culture indicates to present of coli form bacteria whereas change in color of EMP indicates growth and presence of E. coli.

Media preparation

MacConky broth: 63 g of MacConky broth was weighed using sensitive balance and dissolved in 630 mL distilled water. 10 ml of MacConky media was transferred to 63 test tubes separately. Durham tubes were linked to the test tubes to detect gas evaluation. The test tubes were then closed by cotton and aluminum foil to prevent loss of volume during autoclaving process. The test tubes were then sterilized by autoclaving for 15 min at 121°C.

EMP (ethylene blue): 18.7 g of EMP powder was weighed using sensitive balance and dissolved in 500 mL distilled water in a conical flask. The conical flask was closed by cotton to prevent loss of volume; the EMP was sterilized by autoclaving for 15 min at 121°C. The prepared media was cooled and poured into 9 ml disposable Petri dishes using aseptic technique. The media was allowed to stand at room temperature for further use.

Inculcation of sample in MacConky broth: Different portions (1 ml, 0.1 ml and 0.01 ml) from water sample containing MacConky broth were inoculated separately for 2 days at 37°C. Each portion was cultured three times to obtain better results.

Inculcation of sample in EMP selective media: MacConky broth was sub cultured after 2 days of incubation into EMP agar using striking method, then inculpated at 37°C for 48 h.


Drinking water sample from several different sources usually used in Omdurman (Sudan) were cultured for E. coli. These sources were water from Almanara (water treating governmental company) before pumping to the houses, Almanara water after pumping, water from the wells, water from non-running river Nile and there different industrial water treated companies; these are Mizo, Anhar and Crystal.

E. coli is considered to be the major cause of water contamination and mixing with human feces. Culturing takes place in two media; the MacConky Broth for general contamination and (EMB) Eosin Methylene Blue selectively for E. coli. Gas evaporation and change in color were used as evidences for growth and contamination in MacConky broth whereas green metallic sheen or pink colony was the evidences for growth of E. coli in EMB.

Concerning industrial water samples, no change in color and no gas production in MacConky broth and no even green metallic sheen or colony in EMB were detected. This is expected since they are well purified and decontaminated using ozone (Tables 1-6).

The non-running river Nile show pronounced change of color and clear gas evaluation in MacConky Broth beside clear green metallic sheen and colony growth in EMB, during culturing (Tables 7 and 8). Also this is expected since water from non-Running River Nile was not decontaminated by any water treatment methods. Water obtained from the well showed no contamination (Tables 9 and 10) indicted by color change or gas evaluation in MacConky Broth or growth formation in EMB.

 Comparing Almanara water samples after and before pumping and reaching houses through the water pump line system, it was found that water before pumping is less contaminated than water after pumping (Tables 11 and 12) and entering dispenser lines (Tables 13 and 14) which indicates that water pump lines have a considerable degree of contamination. Results were statistically calibrated and elaborated (Table 15).


Better recommendations were elaborated and used to evaluate the general quality of water and Strategies to improve household stored drinking water quality in post-disaster situations [9]. In many areas of the developing world, drinking water is collected from unsafe surface sources outside the home and is then held in household storage vessels. Drinking water may be contaminated at the source or during storage; strategies to reduce waterborne disease transmission must safeguard against both events. We describe two-component prevention strategies which allow an individual to disinfect drinking water immediately after collection (point-of-use disinfection) and then to store the water in narrow-mouthed, closed vessels designed to prevent recontamination (safe storage). New disinfectant generators and better storage vessel designs make these strategies practical and inexpensive. This approach empowers households and communities that lack portable water to protect themselves against a variety of waterborne pathogens and has the potential to decrease the incidence of waterborne diarrheal disease. Other suggestion is to boil the water before consumption in case of emergency situation. Also resins may be used as a traditional method to improve water quality.


Severe water infection occurs as results of poverty and poor educational knowledge of water treatment methods.

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