INLAIN   20354
INSTITUTO DE LACTOLOGIA INDUSTRIAL
Unidad Ejecutora - UE
artículos
Título:
Phage adsorption on Enteropathogenic and Shiga Toxin-Producing Escherichia coli strains: influence of physicochemical and physiological factors
Autor/es:
TOMAT, DAVID DAMIÁN; CASABONNE, CECILIA; QUIBERONI, ANDREA DEL LUJÁN; BALAGUÉ, CLAUDIA
Revista:
FOOD RESEARCH INTERNATIONAL
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2014 vol. 66 p. 23 - 28
ISSN:
0963-9969
Resumen:
Bacteriophages have proved to be useful tools against
pathogenic Escherichia coli strains. The first step in the phage life cycle is the adsorption
to the host cell surface. In the present
work, three Myoviridae phages (DT1,
DT5 and DT6) were used to characterize the adsorption process on three
pathogenic E. coli strains, namely
two Shiga-toxin producing E. coli
(STEC) and one enteropathogenic E. coli
(EPEC), in several conditions found on food. The influence of Na+, Mg2+,
temperature, pH, periodate, proteinase K and physiological cell state on phage
adsorption was investigated. The three
phages evaluated showed high adsorption rates at pH 7.5 and 5.7 while they were
moderate at
the lowest pH evaluated (4.5). Sodium or magnesium ions were not indispensable for the adsorption of
the three phages evaluated. Specifically, phage particles were adsorbed either
in the presence or absence of Mg2+, while increasing Na+
concentration resulted in lower adsorption values for all the systems
evaluated. Regarding temperature, phage adsorption was slightly affected
at 4°C and
50°C,
while it reached its maximum at 37°C.
Adsorption rates decreased after the thermal inactivation of cells, though,
when chloramphenicol (as protein-synthesis inhibitor) was used, adsorption
values on treated and untreated cells were similar. In addition, periodate was
able to decrease phage adsorption, thus suggesting the receptors were
carbohydrates in nature. All these results showed that the adsorption process
was only partially affected and most conditions are suitable for the completion
of the first step in the phage life cycle. Therefore, phages evaluated in this
study can be used to prevent foodborne diseases on several food matrices since they
are active in a wide range of environmental conditions.