 |
Water Science & Technology—WST Vol 61 No 1 pp 67–76 © IWA Publishing 2010 doi:10.2166/wst.2010.781
Equivalency testing of TTC Tergitol 7 agar (ISO 9308-1:2000) with five culture media for the detection of E. coli in water samples in Greece
A. Mavridou, E. Smeti, G. Mandilara, P. Boufa, M. Vagiona-Arvanitidou, A. Vantarakis, G. Vassilandonopoulou, O. Pappa, V. Roussia, A. Tzouanopoulos, M. Livadara, I Aisopou, V. Maraka, E. Nikolaou and G. Mandilara
Technological Educational Institution of Athens, Ag Spyridona, Aigaleo 12210, Greece E-mail: amavridou@teiath.gr
Water Supply & Sewerage Company of Athens, 156, Oropou street, Galatsi 11146, Greece E-mail: esmeti@eydap.gr; ginamicro@eydap.gr
Central Public Health Laboratory, 196, Alexandras Av, Athens 11521, Greece E-mail: kedy@otenet.gr
Aristoteleion University, University Campus, Thessaloniki, Greece E-mail: vayona@med.auth.gr
Democritus University of Thrace, Alexandroupolis 68100, Greece E-mail: avantar@med.upatras.gr
National School of Public Health 196, Alexandras Av, Athens 11521, Greece E-mail: olpap79@yahoo.gr; avatopou@nsph.gr; gmandil@nsph.gr
Centre of Water and Food Analysis, 46, Alexander street, Thessalonika 55133, Greece E-mail: atzouano@yahoo.gr
Hellenic Center for Marine Research, Gournes Pediados, P.O. Box 2214, Heraklion, Greece E-mail: moshoula@imbc.gr
Municipal Enterprise for Water Supply and Sewage of Heraklion, 1, Vironos street, Heraklion, Greece E-mail: deyah-b@her.forthnet.gr
Municipal Enterprise for Water Supply and Sewage of Chania, 29 Kydonias street, Chania 73135, Greece E-mail: vmaraka@yahoo.com
General Chemistry, General Chemical State Laboratory of Rhodes, 17, Haritou street, Rhodes 8510, Greece E-mail: xyrhod@rho.forthnet.gr
Ministry of Health, 17, Aristotelous street, Athens 10187, Greece E-mail: ymp@mohaw.gr
* Equally contributed.
ABSTRACT
In this study ten laboratories in Greece compared the performance of reference method TTC Tergitol 7 Agar (with the additional test of b-glucuronidase production) with five alternative methods, to detect E. coli in water, in line with European Water Directive recommendations. The samples were prepared by spiking drinking water with sewage effluent following a standard protocol. Chlorinated and non-chlorinated samples were used. The statistical analysis was based on the mean relative difference of confirmed counts and was performed in line with ISO 17994. The results showed that in total, three of the alternative methods (Chromocult Coliform agar, Membrane Lauryl Sulfate agar and Trypton Bilex-glucuronidase medium) were not different from TTC Tergitol 7 agar (TTC Tergitol 7 agar vs Chromocult Coliform agar, 294 samples, mean RD% 5.55; vs MLSA, 302 samples, mean RD% 1; vs TBX, 297 samples, mean RD% -2.78). The other two alternative methods (Membrane Faecal coliform medium and Colilert 18/ Quantitray) gave significantly higher counts than TTC Tergitol 7 agar (TTC Tergitol 7 agar vs MFc, 303 samples, mean RD% 8.81; vs Colilert-18/Quantitray, 76 samples, mean RD% 18.91). In other words, the alternative methods generated performance that was as reliable as, or even better than, the reference method. This study will help laboratories in Greece overcome culture and counting problems deriving from the EU reference method for E. coli counts in water samples.
Keywords: equivalency testing; Escherichia coli; Greece; microbiological methods; water
Full article (PDF Format)
eProduct: Buy this article for £24.00 (IWA MEMBER PRICE: £18.00)
All prices include VAT. For customers where VAT should not be applied, the VAT amount will be removed upon payment
|
|
|
