CIVETAN   23983
CENTRO DE INVESTIGACION VETERINARIA DE TANDIL
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Distribution of serine protease espP subtypes among verotoxigenic Escherichia coli isolated in Argentina
Autor/es:
SANSO, A. M.; BUSTAMANTE, A.V.; FRANCI, T.; PARMA, A. E.; LUCCHESI, P. M. A.
Reunión:
Simposio; 8th INTERNACIONAL SYMPOSIUM ON SHIGA TOXIN (VEROCYTOTOXIN) - PRODUCING Escherichia coli INFECTIONS; 2012
Resumen:
Introduction and Objectives: Infections by verotoxigenic Escherichia
coli (VTEC) range from mild, self-limiting diarrhea to severe diseases
such as hemorrhagic colitis (HC) and hemolytic uremic syndrome
(HUS). Ruminants and derived foods are the main sources of
human infections. Epidemiologic studies have shown that virulence
factors other than verotoxins may also contribute to its pathogenicity
in humans, including the plasmid-encoded serine protease EspP.
EspP belongs to the serine protease autotransporters of Enterobacteriaceae
(SPATE) family, and contributes to the adherence to bovine
primary rectal cells and colonization of the bovine intestines. Moreover,
degradation of human coagulation factor V via EspP could
contribute to the mucosal hemorrhage observed in HC patients. Five
espP alleles with different proteolytic activities have been identified
and some authors have demonstrated that subtype a is associated
with highly pathogenic serogroups.Infections by verotoxigenic Escherichia
coli (VTEC) range from mild, self-limiting diarrhea to severe diseases
such as hemorrhagic colitis (HC) and hemolytic uremic syndrome
(HUS). Ruminants and derived foods are the main sources of
human infections. Epidemiologic studies have shown that virulence
factors other than verotoxins may also contribute to its pathogenicity
in humans, including the plasmid-encoded serine protease EspP.
EspP belongs to the serine protease autotransporters of Enterobacteriaceae
(SPATE) family, and contributes to the adherence to bovine
primary rectal cells and colonization of the bovine intestines. Moreover,
degradation of human coagulation factor V via EspP could
contribute to the mucosal hemorrhage observed in HC patients. Five
espP alleles with different proteolytic activities have been identified
and some authors have demonstrated that subtype a is associated
with highly pathogenic serogroups.(VTEC) range from mild, self-limiting diarrhea to severe diseases
such as hemorrhagic colitis (HC) and hemolytic uremic syndrome
(HUS). Ruminants and derived foods are the main sources of
human infections. Epidemiologic studies have shown that virulence
factors other than verotoxins may also contribute to its pathogenicity
in humans, including the plasmid-encoded serine protease EspP.
EspP belongs to the serine protease autotransporters of Enterobacteriaceae
(SPATE) family, and contributes to the adherence to bovine
primary rectal cells and colonization of the bovine intestines. Moreover,
degradation of human coagulation factor V via EspP could
contribute to the mucosal hemorrhage observed in HC patients. Five
espP alleles with different proteolytic activities have been identified
and some authors have demonstrated that subtype a is associated
with highly pathogenic serogroups.a is associated
with highly pathogenic serogroups.
Material and Methods: Since espP has been found in a high prevalence
and there are few data about de distribution of espP subtypes
among VTEC strains from different origins, our aim was to investigate
the ocurrence of the subtypes a, b, c, d, and e in espP-positive
Argentine strains. Determination of espP alleles was done by PCR in
182 isolates belonging to 44 serotypes from cattle, food and humans.Since espP has been found in a high prevalence
and there are few data about de distribution of espP subtypes
among VTEC strains from different origins, our aim was to investigate
the ocurrence of the subtypes a, b, c, d, and e in espP-positive
Argentine strains. Determination of espP alleles was done by PCR in
182 isolates belonging to 44 serotypes from cattle, food and humans.a, b, c, d, and e in espP-positive
Argentine strains. Determination of espP alleles was done by PCR in
182 isolates belonging to 44 serotypes from cattle, food and humans.
Results: Some serotypes harbored only one espP subtpype whereas
others presented more than one allele. The a subtype was found in
serotypes O26:H11, O38:H39, O103:NM, O103:H2, O118:H16,
O145:NM, O146:NM, O157:H7 and O177:NM, whereas b subtype in
O8:H16, O20:H19, O39:H49, O79:H19, O113:NM, O113:H21,
O117:H7, O141:H8, O174:H21, O178:H19, O185:H7 and several
ONT strains with different H antigen.Some serotypes harbored only one espP subtpype whereas
others presented more than one allele. The a subtype was found in
serotypes O26:H11, O38:H39, O103:NM, O103:H2, O118:H16,
O145:NM, O146:NM, O157:H7 and O177:NM, whereas b subtype in
O8:H16, O20:H19, O39:H49, O79:H19, O113:NM, O113:H21,
O117:H7, O141:H8, O174:H21, O178:H19, O185:H7 and several
ONT strains with different H antigen.a subtype was found in
serotypes O26:H11, O38:H39, O103:NM, O103:H2, O118:H16,
O145:NM, O146:NM, O157:H7 and O177:NM, whereas b subtype in
O8:H16, O20:H19, O39:H49, O79:H19, O113:NM, O113:H21,
O117:H7, O141:H8, O174:H21, O178:H19, O185:H7 and several
ONT strains with different H antigen.b subtype in
O8:H16, O20:H19, O39:H49, O79:H19, O113:NM, O113:H21,
O117:H7, O141:H8, O174:H21, O178:H19, O185:H7 and several
ONT strains with different H antigen.
Conclusions: Subtyping of the espP gene revealed an association
among O serogroups and particular espP subtype(s). Also, despite
that in previous studies espP a was present particularly in isolates
from HUS patients, we found that some VTEC strains isolated from
reservoir animals or foods also contained this espP allele. Particularly
interesting is the observation that serogroup O103, considered
to be highly pathogenic and reported in previous studies as negative
for espP, resulted espP+ and carried the allele a.Subtyping of the espP gene revealed an association
among O serogroups and particular espP subtype(s). Also, despite
that in previous studies espP a was present particularly in isolates
from HUS patients, we found that some VTEC strains isolated from
reservoir animals or foods also contained this espP allele. Particularly
interesting is the observation that serogroup O103, considered
to be highly pathogenic and reported in previous studies as negative
for espP, resulted espP+ and carried the allele a.a was present particularly in isolates
from HUS patients, we found that some VTEC strains isolated from
reservoir animals or foods also contained this espP allele. Particularly
interesting is the observation that serogroup O103, considered
to be highly pathogenic and reported in previous studies as negative
for espP, resulted espP+ and carried the allele a.a.