Typing of Pseudomonas aeruginosa strains isolated from Greek water samples by three typing methods: serotyping, Random Amplified Polymorphic DNA (RAPD) and Pulsed Field Gel Electrophoresis (PFGE).

The study of various types of Pseudomonas aeruginosa strains isolated from water environments is of paramount importance from a public health point of view, due to their ubiquity and pathogenicity. Molecular (Random Amplified Polymorphic DNA and Pulsed Field Gel Electrophoresis) and phenotypical (serotyping) typing methods were applied to environmental P. aeruginosa strains. The typeability and discriminatory power of the methods were studied and compared. The two molecular methods managed to type a number of P. aeruginosa strains which were non-serotypeable due to their rough phenotypes. According to our results, the combination of phenotypic and genotypic methods increased the reliability of the results, yielding several different clones that seem to circulate in Greek water environments.

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.

In this study ten laboratories in Greece compared the performance of reference method TTC Tergitol 7 Agar (with the additional test of beta-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.

KPC-2-producing Klebsiella pneumoniae infections in Greek hospitals are mainly due to a hyperepidemic clone.

To verify the presence of Klebsiella pneumoniae carbapenemase-producing (KPC-producing) Klebsiella pneumoniae in Greece, we asked 40 Greek hospitals participating in the Greek System for the Surveillance of Antimicrobial Resistance (GSSAR) to apply a combination of the modified Hodge test plus EDTA synergy test on all K. pneumoniae clinical isolates obtained from February 2008 which displayed reduced susceptibility to carbapenems (MIC of imipenem > or = 1 mg/L). The presence of the blaKPC gene was confirmed by PCR and sequencing. This procedure revealed the presence of KPC-2 in isolates from 173 patients in 18 hospitals during a period of 11 months. Of these, 166 isolates belonged to a single pulsotype a fact consistent with possible epidemic spread, whereas the remaining seven isolates were further classified into four different pulsotypes. BlaKPC-2 gene was found to be transferable by conjugation in the four pulsotypes other than the prevailing one. The emergence of a new carbapenemase gene in Greece, where high resistance rates to carbapenems in K. pneumoniae due to the spread of the VIM type metalloenzyme have been observed, emphasises the urgent need for the implementation of public health measures in the field of infection control and antibiotic consumption. It also underlines the need to supplement surveillance systems based on susceptibility data with the surveillance of resistance mechanisms.