INVESTIGADORES
RAJAL Veronica Beatriz
artículos
Título:
Evaluation of concentration efficiency of the Pseudomonas aeruginosa phage PP7 in various water matrixes by different methods
Autor/es:
HUGO R. POMA; VERÓNICA B. RAJAL; MARÍA D. BLANCO FERNÁNDEZ; PATRICIA A. BARRIL; MIGUEL O. GIORDANO; GISELA MASACHESSI; LAURA MARTÍNEZ; MARIA B. ISA; MARIA C. FREIRE; GABRIELA RIVIELLO-LÓPEZ; DANIEL CISTERNA; SILVIA NATES; VIVIANA A. MBAYED
Revista:
ENVIRONMENTAL MONITORING AND ASSESSMENT
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2013 vol. 185 p. 2565 - 2576
ISSN:
0167-6369
Resumen:
Enteric viruses monitoring in surface waters
requires the concentration of viruses before detection
assays. The aim of this study was to evaluate different
methods in terms of recovery efficiencies of bacteriophage
PP7 of Pseudomonas aeruginosa, measured by
real-time PCR, using it as a viral control process in
water analysis. Different nucleic acid extraction methods
(silicaguanidinium thiocyanate, a commercial kit
(Qiagen Viral RNA Kit) and phenolchloroform with
alcohol precipitation) exhibited very low recovery
efficiencies (0.084.18 %), being the most efficient
the commercial kit used for subsequent experiments.
To evaluate the efficiency of three concentration methods,
PBS (as model for clean water) and water samples
from rivers were seeded to reach high (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 and two river samples, respectively)
than adsorptionelution with negatively charged membranes
(1.00±1.34, 2.79±2.62 and 0.05±0.08 % for
HC in PBS and two river samples, respectively) and
polyethylene glycol precipitation (15.95±7.43, 4.01±
1.12 and 3.91±0.54 %, for HC in PBS and two river
samples, respectively), being 3.250.4 times more
efficient than the others for PBS and 2.7252 times
for river samples. Efficiencies also depended on the
initial virus concentration and aqueous matrixes composition.
In consequence, the incorporation of an internal
standard like PP7 along the process is useful as a
control of the water concentration procedure, the
nucleic acid extraction, the presence of inhibitors and
the variability of the recovery among replicas, and for
the calculation of the sample limit of detection. Thus,
the use of a process control, as presented here, is crucial
for the accurate quantification of viral contamination.