Journal of
Toxicology and Environmental Health Sciences

  • Abbreviation: J. Toxicol. Environ. Health Sci.
  • Language: English
  • ISSN: 2006-9820
  • DOI: 10.5897/JTEHS
  • Start Year: 2009
  • Published Articles: 208

Full Length Research Paper

Fast monitoring of water distribution system with portable enrichment unit – Measurement of volatile compounds of coliforms and Salmonella sp. in tap water

Elias Hakalehto1*, Anneli Heitto2, Lauri Heitto3, Tarmo Humppi 4, Kari Rissanen5, Ari Jääskeläinen5, Heikki Paakkanen6 and Osmo Hänninen7
1Department of Biosciences, University of Eastern Finland, FI-70211 Kuopio, Finland. 2Finnoflag Oy, FI-70101 Kuopio, Finland. 3Environmental Research of Savo-Karjala Oy, FI-70150, Finland. 4PVTT (Finnish Defence Forces Technical Research Centre), FI-34111 Lakiala, Finland. 5Samplion Oy, FI-70101 Kuopio, Finland. 6Environics Oy, FI-50101 Mikkeli, Finland. 7Department of Physiology, University of Eastern Finland, FI-70211 Kuopio, Finland.  
Email: [email protected]

  •  Accepted: 24 June 2011
  •  Published: 31 August 2011

Abstract

The aim of the study was to clarify if microbe enrichment cultures and monitoring of volatiles released by them could speed up the detection of indicator bacteria in water samples. The combination of Portable Microbe Enrichment Unit (PMEU) cultivation and ChemPro100i® chemical detector were used to detect the hygiene indicating bacteria. When the water distribution network of Kuopio city was studied in early summer, more than 20 early warnings of heterotrophic bacterial growth were registered during one month from lake water and 9 sampling points in 350 km of tube lines compared to only one alarm of coliformic growth from the same samples when solely the ColilertTM system was used. The results from the PMEU were used in repairs. After adding mixed cultures of Klebsiella and Escherichia coli strains to the tap water the first alarm of the microbe growth in the enrichment culture could be achieved in 4 to 8 h. The results obtained showed that the combination of the PMEU with ChemPro100i®  could also be used in the detection of a single Salmonella cell from a millilitre of tap water after about 10 h enrichment in the selective Rappaport Vassiliadis Soy (RVS) broth. In conclusion, besides instantaneous enrichment of coliformic bacteria, also controlling total heterotrophic bacterial loads with option for pathogen screening is recommended for household water monitoring.

 

Key words: Water distribution, bacterial detection, Portable Microbe Enrichment Unit (PMEU), volatile sensing, Escherichia coli, Klebsiella, Salmonella, tap water, Rappaport Vassiliadis Soy (RVS) medium, Scentrion, Colilert.

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