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watermicrohistory
History of water testing in developing countries using the Colilert 10 ml presence/absence test and the E. coli Count Petrifilm as test items of a Portable Microbiology Laboratory.
Date(s): 1987-2003. Album by Bob Metcalf. Photos by Bob Metcalf. 1 - 110 of 110 Total. 1475 Visits.
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The presence of the bacterium Escherichia coli indicates recent fecal contamination of water.

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First step: gas from lactose broth at 35°C.

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2nd step: 2nd lactose broth incubated at 44.5°C +/- 0.2°C. Gas produced by 'thermotolerant coliforms'

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Most strains of E. coli produce gas at 44.5°C

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But so do environmental coliform bacteria like this Klebsiella sp. The thermotolerant coliform test is not specific for E. coli.

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The burden of collecting and using firewood to cook food for ~2.5 billion people in developing countries

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Tree cutting leads to deforestation and land degradation

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Barbara Kerr and Sherry Cole developed a practical solar box cooker in 1976.

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Regular solar cooking in Sacramento since 1978.

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Solar cooking in Sacramento, California, June, 1991

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Bolivia, 1987, teaching how to build and use a solar box cooker. No simple water test available.

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Guatemala, January, 1998.

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Built solar box cookers but no simple water test available.

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In 1988, a new approach to test for E. coli is announced. Colilert, a defined substrate test

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Colilert was available as a dry powder in glass tubes to test 10 ml of water. Made by Access Medical Systems, CT.

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IDEXX took over production of Colilert from ACCESS in 1993.

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January, 1989, Sierra Leone. With Colilert, water testing could be included with building solar box cookers.

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First solar box cooker made in Sierra Leone

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Cake baked in solar box cooker for 2 hours

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Fish soup & rice solar cooked

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Distribution of Colilert tubes to 41 workshop participants to sample home water source.

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Tubes can be incubated next to one's body to obtain next day results.

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Body incubation of Colilert tubes

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Next day results.

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Clear = no coliform bacteria. Yellow (ONPG+) = coliform bacteria present, possibly E. coli

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Shine a long-wavelenth UV light on tubes. Blue fluorescence = MUG (+), E. coli is present (right tube). MUG (-), E. coli not present.

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39 of 41 tubes were ONPG + (yellow), coliform bacteria present, perhaps E. coli.

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26 of 41 samples were MUG (+), indicating the presence of E. coli.

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Bamako, Mali, 1991. 33 water samples, 19 ONPG (+), 12 MUG (+).

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Noukchott, Mauritania, 1991. 24 urban water samples were inoculated into Colilert tubes

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Solar box cooker made at workshop.

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Of 24 urban samples, 20 were ONPG (+), 12 were MUG (+)

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Nepal, 1993. Colilert results from this source were ONPG (+), MUG (-).

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Solar box cookers in Nepal, 1993.

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Colilert results, urban and rural water sources tested

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22 total sources tested. 21 ONPG (+), 9 MUG (+)

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Somali women returning from 8 hour journey to collect wood, Dadaab refugee camp, Kenya, 1995

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Refugee children returning with sticks after a long journey.

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Introduction of the simple Cookit solar cooker. Foods cooked inside clear plastic bags.

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Cookit among refugee dwellings.

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Refugee family with Cookit.

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Solar cooking works!

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Testing borehole water with Colilert. ONPG (+), MUG (-)

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In 1995, E. coli Count Petrifilms were available to test 1 ml.

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To use Petrifilm, label sample source and time

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Add 1 ml of water sample to nutrient circle

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Use flat side of plastic spreader to gently distribute 1 ml over entire circle

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Petriflms covered with firm cardboard enables incubation on one's body. Invisible bacteria to develop into visible colonies in 12-16 hours.

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Results usually in 12-18 hr. E. coli = blue colonies with gas. Coliforms from environment = red with gas.

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First use of E. coli Count Petrifilm on raw camel milk in Dadaab refugee camp

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Inoculated Petrifilms with 1 ml. Incubated on body between cardboard pieces to obtain overnight results.

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Next day results. > 200 E. coli/ml before pasteurization.

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Colilert and Petrifilm tests correlate with risk of disease, WHO Guidelines for Drinking Water Quality, 2nd Edition.

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Colilert and Petrifilm results also correlate with MSF treatment guidelines in emergencies.

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Students at California State University, Sacramento, who contributed to water pasteurization work

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Heating water to 65°C will pasteurize water and make it safe to drink.

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Water Pasteurization Indicator (WAPI). When water reaches 65°C (149°F), wax melts and falls to the bottom. Water is pasteurized.

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Article on Cookit and WAPI to pasteurize water, 1999

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Water Pasteurization Indicator used by Dadaab refugees who received Cookit solar cookers.

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Fuelwood problems in Meatu District, Tanzania, 2000

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Water source, Meatu District, Tanzania

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Sampling water source, Meatu District

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Removing water sample for Colilert and Petrifilm tests, Meatu District

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Water source, Meatu District

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Water seller collecting water in Meatu District

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Components of the Portable Microbiology Laboratory to test water in Meatu District

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Materials for 25 water tests in gallon-sized plastic bag to make a Portable Microbiology Laboratory.

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Any table becomes a laboratory to test village water sources

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Testing numerous water sources in Meatu District

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Results from one village. 1 ml removed from Colilert tube for separate incubation.

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Results of Meatu water tests.

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Demystifying microbiology, teaching community about bacteria and water testing

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Topics covered include bacteria size, growth, E. coli as indicator, Colilert & Petrifilm tests, WHO disease risk guidelines

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Village chiefs and village health workers in 3 day workshop.

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Next day results. Most local water sources from dry riverbed were high/very high risk.

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Village chief knows that MUG+ Colilert means that E. coli was in the town's river water source, unsafe water

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Health worker finds >10 E. coli on Petrifilm, a very high risk of disease

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Water testing workshop for Saka Saka village. Boniphace will translate into Kiswahili.

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Two water sources in Saka Saka. From a pump (green bucket) and an open stream (yellow bucket).

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Adults will sample either pump or stream water

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Mixing inoculated Colilert tubes, to incubate overnight

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Inoculating Petrifilms

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Next morning demonstration of solar cooking, solar water pasteurization

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Read results: Pump water yellow, MUG -, no E. coli. Stream yellow and MUG+, E. coli present.

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Examining Petrifilms

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Petrifilm results are clear.

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Stream water (front) with ~100 E. coli colonies on each Petrifilm, very high disease risk. Pump water (back) with environmental coliforms,no E. coli, low disease risk.

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All villagers see results of grossly contaminated stream water, no E. coli contamination of pump water.

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Solar cooked rice in 2 hr

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Providing a year's supply of water testing materials to Saka Saka health workers to monitor pump water

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After only an afternoon and a morning session, Saka Saka village understands the microbiology of water testing.

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Competence in water microbiology is established in the village.

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Guest House (hotel) in Meatu District

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River water provided for guests

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After testing river water, collect for solar pasteurization

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Heating river water in Cookit to pasteurize

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Temperature >60°C in 2 hours

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WAPI wax melted, water is pasteurized

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Evidence-based microbiology that contaminated water has been pasteurized.

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Poster at 2001 American Society for Microbiology Annual Meeting

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Poster at 2003 American Society for Microbiology Annual Meeting

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Poster at 2005 American Society for Microbiology Annual Meeting

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Water testing booklet published by UN-Habitat, 2010.

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