INVESTIGADORES
MALIRAT Viviana
artículos
Título:
Characterization of foot-and-mouth disease virus from outbreaks in Ecuador during 2009?2010 and cross-protection studies with the vaccine strain in use in the region
Autor/es:
MARADEI E; PEREZ BEASCOECHEA, C.; MALIRAT, VIVIANA; SALGADO G.; SEKI, C; PEDEMONTE, A; BONASTRE, P.; D'ALOIA, R; LA TORRE, J.L.; MATTION, N; RODRIGUEZ TOLEDO, J.; BERGMANN I.E.
Revista:
VACCINE
Editorial:
ELSEVIER SCI LTD
Referencias:
Lugar: Amsterdam; Año: 2011 vol. 29 p. 8230 - 8240
ISSN:
0264-410X
Resumen:
During the years 2009 and 2010 relevant epidemic waves of foot-and-mouth disease (FMD) serotype O
occurred in Ecuador, representing a great drawback for the last stages of the ongoing eradication program
in South America. This study describes the molecular and antigenic characterizations of 29 isolates collected
from various regions in the country and their relationship to the vaccine strain. The phylogenetic
tree derived from sequences spanning the complete VP1 protein showed that, despite the widespread
origin of the viruses, they were all related among themselves and to previous isolates occurring in 2008,
with around 10% difference with the vaccine strain O1/Campos. The high level of sequence conservation
among different isolates in the various regions of Ecuador pointed to a common origin, suggesting animal
movements as possible sources of viral spread. Monoclonal antibody profiling grouped the isolates
in two major reactivity patterns which differed from that of the vaccine strain. Both profiles showed loss
of reactivity with the same four MAbs, three of them with neutralizing properties. Additional sites were
lost in the profile representing most of the 2010s viral samples. Levels of protective antibodies induced
by the vaccine against the field strains assessed by in vitro vaccine matching studies also pointed to an
increased temporal pattern of loss of a protective response. Moreover, results obtained with in vivo challenge
in the protection against podal generalization test in cattle, clearly indicated lack of appropriate
protection of the Ecuadorian field strains by the vaccine virus in use, which in the case of a 2010 variant
was observed even after revaccination.
origin of the viruses, they were all related among themselves and to previous isolates occurring in 2008,
with around 10% difference with the vaccine strain O1/Campos. The high level of sequence conservation
among different isolates in the various regions of Ecuador pointed to a common origin, suggesting animal
movements as possible sources of viral spread. Monoclonal antibody profiling grouped the isolates
in two major reactivity patterns which differed from that of the vaccine strain. Both profiles showed loss
of reactivity with the same four MAbs, three of them with neutralizing properties. Additional sites were
lost in the profile representing most of the 2010s viral samples. Levels of protective antibodies induced
by the vaccine against the field strains assessed by in vitro vaccine matching studies also pointed to an
increased temporal pattern of loss of a protective response. Moreover, results obtained with in vivo challenge
in the protection against podal generalization test in cattle, clearly indicated lack of appropriate
protection of the Ecuadorian field strains by the vaccine virus in use, which in the case of a 2010 variant
was observed even after revaccination.