INIQUI   05448
INSTITUTO DE INVESTIGACIONES PARA LA INDUSTRIA QUIMICA
Unidad Ejecutora - UE
artículos
Título:
Evaluation of concentration efficiency of the Pseudomonas aeruginosa phage PP7 in various water matrixes by different methods
Autor/es:
RAMIRO POMA Y VERONICA B. RAJAL; BLANCO FERNANDEZ, MARIA DOLORES; PATRICIA A. BARRIL; MIGUEL O. GIORDANO; GISELA MASACHESSI; LAURA C. MARTINEZ; MARIA B. ISA; MARIA C. FREIRE; GABRIELA RIVIELLO LOPEZ; DANIEL CISTERNA; SILVIA V. NATES; VIVIANA A. MBAYED
Revista:
ENVIRONMENTAL MONITORING AND ASSESSMENT
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2012
ISSN:
0167-6369
Resumen:
Enteric viruses monitoring in surface waters requires theconcentration of viruses before detection assays. The aim of thisstudy was to evaluate different methods in terms of recoveryefficiencies of bacteriophage PP7 of Pseudomonas aeruginosa,measured by real-time PCR, using it as a viral control process inwater analysis. Different nucleic acid extraction methods (silica?guanidinium thiocyanate, a commercial kit (Qiagen Viral RNA Kit)and phenol?chloroform with alcohol precipitation) exhibited verylow recovery efficiencies (0.08?4.18 %), being the most efficientthe commercial kit used for subsequent experiments. To evaluatethe efficiency of three concentration methods, PBS (as model forclean water) and water samples from rivers were seeded to reachhigh (HC, 106 pfu ml−1) and low concentrations (LC, 104 pfu ml−1)of PP7. Tangential ultrafiltration proved to be more efficient(50.36 ± 12.91, 17.21 ± 9.22 and 12.58 ± 2.35 % for HC in PBS andtwo river samples, respectively) than adsorption?elution withnegatively charged membranes (1.00 ± 1.34, 2.79 ± 2.62 and 0.05 ±0.08 % for HC in PBS and two river samples, respectively) andpolyethylene glycol precipitation (15.95 ± 7.43, 4.01 ± 1.12 and3.91 ± 0.54 %, for HC in PBS and two river samples, respectively),being 3.2?50.4 times more efficient than the others for PBS and2.7?252 times for river samples. Efficiencies also depended on theinitial virus concentration and aqueous matrixes composition. Inconsequence, the incorporation of an internal standard like PP7along the process is useful as a control of the water concentrationprocedure, the nucleic acid extraction, the presence of inhibitorsand the variability of the recovery among replicas, and for thecalculation of the sample limit of detection. Thus, the use of aprocess control, as presented here, is crucial for the accuratequantification of viral contamination.