TY - JOUR
T1 - Characterization of a novel and genetically different small infective variant of Piscirickettsia salmonis
AU - Verónica Rojas, M.
AU - Olivares P., Jorge
AU - del Río, Rodrigo
AU - Marshall, Sergio H.
N1 - Funding Information:
We thank a grant to S.H.M and M.V.R. from Dirección de Investigación y Estudios Avanzados, Pontificia Universidad Católica de Valparaíso, Chile.
PY - 2008/5
Y1 - 2008/5
N2 - We report a novel genetically different small infective variant of the fish pathogen Piscirickettsia salmonis (sP.s). sP.s variants were recovered both from ageing post-infected CHSE-214 culture cells as well as from naturally infected fish. The ITS region of sP.s variants, although sharing a common core sequence, is different from the ITS of the prototype strain LF-89 from which they originate. Thus, sP.s can be selectively amplified with sequence-specific discriminatory set of PCR primers. Transcriptionally, sP.s are fully active as shown by reverse transcription PCR analysis. Immunologically, sP.s is specifically recognized by antibodies against standard P. salmonis. Structurally, atomic force microscopy shows that sP.s. is well below (<0.2 μm) the standard range size described for this pathogen (0.5-1.5 μm). Functionally, although sP.s is infective their in vitro progeny is a hundred percent identical to the LF-89 prototype strain. In summary sP.s, represent selectable infective variants of the LF-89 strain and not new strains, probably resulting from a survival strategy of the bacteria in response to limiting growth conditions. In this frame, sP.s could be responsible of horizontal infection of fish in the field.
AB - We report a novel genetically different small infective variant of the fish pathogen Piscirickettsia salmonis (sP.s). sP.s variants were recovered both from ageing post-infected CHSE-214 culture cells as well as from naturally infected fish. The ITS region of sP.s variants, although sharing a common core sequence, is different from the ITS of the prototype strain LF-89 from which they originate. Thus, sP.s can be selectively amplified with sequence-specific discriminatory set of PCR primers. Transcriptionally, sP.s are fully active as shown by reverse transcription PCR analysis. Immunologically, sP.s is specifically recognized by antibodies against standard P. salmonis. Structurally, atomic force microscopy shows that sP.s. is well below (<0.2 μm) the standard range size described for this pathogen (0.5-1.5 μm). Functionally, although sP.s is infective their in vitro progeny is a hundred percent identical to the LF-89 prototype strain. In summary sP.s, represent selectable infective variants of the LF-89 strain and not new strains, probably resulting from a survival strategy of the bacteria in response to limiting growth conditions. In this frame, sP.s could be responsible of horizontal infection of fish in the field.
KW - Cell size reduction
KW - Genetic variant
KW - New infective form
KW - Piscirickettsia salmonis
UR - http://www.scopus.com/inward/record.url?scp=42049119374&partnerID=8YFLogxK
U2 - 10.1016/j.micpath.2007.10.012
DO - 10.1016/j.micpath.2007.10.012
M3 - Article
C2 - 18166333
AN - SCOPUS:42049119374
VL - 44
SP - 370
EP - 378
JO - Microbial Pathogenesis
JF - Microbial Pathogenesis
SN - 0882-4010
IS - 5
ER -