The workshop aimed to give a basic knowledge of Escherichia coli (E. coli) bacteria as an indicator for fecal contamination in water, and methods for Detection and Quantification of E. coli and Coliform Bacteria in Water Samples. Building upon this knowledge and using guided prompts, participants brainstormed how to create an agar on which only coliform bacteria will grow and how to differentiate between E. coli and other coliforms based on their enzymes. Finally, participants filtered surface water (river water and pond water), carried out a serial dilution (10^-1,10^-2,10^-3,10^-4,10^-5) and placed 1 ml of each dilution on ENDO agar media that differentiates E. coli from other coliforms using an enzyme unique to E. coli. The resulting data are used to determine if the water meets the Governmental standards for safe E. coli contamination limit on freshwater.

Intended Audience:

Local community representatives

Learning Objectives:

At the completion of this activity, each learner will be able to:

  1. Know how E. coli bacteria could be used as an indicator for fecal contamination in water, and methods for Detection and Quantification of E. coli and Coliform Bacteria in water samples.
  2. Differentiate and enumerate colonies of E. coli and coliforms on agar media.
  3. Interpret water quality standards for freshwater in terms of numbers of colonies of E. coli allowed per sample of water.

Laboratory analysis Specific Precautions:

  1. All samples sent for microbiological analyses must always be collected in sterile containers provided
  2. always leave an air space of at least 2.5 cm between the surface of the liquid and the container lid. This helps to produce a homogenized sample for laboratory analysis;
  3. The necessary aseptic conditions must be respected when a sample is collected (e.g. use a rubber gloves and mask, avoid inserting fingers or other objects in the mouth or on the lid of the container and minimize exposure of the container to air at the time of sampling); This is also intended to avoid E.coli contamination to the sampling personel.
  4. Carefully close all containers tightly after sampling;
  5. make a detailed record of all samples as soon as possible after sampling;

Workshop summary:

The workshop was attended by 4 lifepatch members and 9 people from the local communities (Greentech:4, Otakatik Creative:2, IDEA:1, Bangun Indonesia:1, Tourism Academy: 1) and one local person from the northern area of Yogyakarta. Most of them have been joining the river project before. More people from the Greentech community joined us at the end of workshop and follow the discussion after we finished the E. coli analysis. Their motivation to come was because as they have already been a part of the JRP project, they wanted to know how we carry out the test and the background of conducting an E. coli analysis in the water sample.

At the beginning of the workshop, I explained the reason of using E. coli as an indicator bacteria for water quality analysis. Further, I gave an introduction of the lab equipment we will use during the workshop and how we will carry out the E. coli analysis. Before we began to take the water sample from the river and pond, I told the participants to use the rubber gloves and masks that we gave to them. The water sampling process was guided by Agus Tri Budiarto (Timbil). Most of the audience had never done those kinds of analyses before, as they come from different backgrounds. One workshop attendee was an older gentleman (about 60 years old) that came to the workshop riding a bicycle for almost 15 km. He is a very curious old man who actively asked many questions during the workshop. Most of the workshop attendees paid a lot of attention to the technical process of E. coli analysis and were willing to further continue this kind of workshop with the community. With people from tourism academy, we are planning to carry out a swab test to analyze the E. coli in children’s hands from the “HS (Home Schooling) Mandiri” Elementary School which managed by GAFATAR (Gerakan Fajar Nusantara) Non-governmental organization, with whom they have a collaboration program.

To accomodate the further collaboration, we offered the workshop attendees to freely use our lab facility for E. coli analysis for non commercial purposes. Especially for the swab test plan, we will provide the ready use ENDO agar media in petridishes and invite the Elementary school children to come to the lifepatch headquarters and carry out a swab test and give some basic knowledge of how to avoid E. coli contamination.


E.coli test results using plate count methodes showed that the river water sample were positively contaminated by E.coli at the rate of  5 x 103 CFU/ml, the presence of E.coli colony indicated by the appearance of red colored colony with a metalic sheen.  The results also showed that the pond water sample were clean from E.coli contamination (Fig 1).

 EcoliTestResultMedFig 1. E.coli Test Results

ENDO agar media contains Lactose which serves as a carbohydrate source. Lactose positive colonies exhibit a red color caused by the aldehyde reaction with the Sodium Sulfite and Basic Fuchsin. The development of a metallic sheen on ENDO agar media occurs when the organism produces aldehydes with the fermentation of Lactose. Lactose non-fermenting bacteria form clear, colorless colonies.


3 thoughts on “Quantification Of Escherichia Coli Contamination In Water

  1. Pingback: Determination of E.coli Bacteria in Children Hands by Swab Test | biodesign for the real world

  2. Pingback: DIY incubator | biodesign for the real world

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