CIVETAN   23983
CENTRO DE INVESTIGACION VETERINARIA DE TANDIL
Unidad Ejecutora - UE
artículos
Título:
Phenotypic and genotypic characterization of enterotoxigenic Escherichia coli isolated from diarrheic calves in Argentina
Autor/es:
GONZALEZ PASAYO R; MOREIRA AR; SANZ M; PADOLA NL
Revista:
Open Veterinary Journal
Editorial:
Faculty of Veterinary Medicine, University of Tripoli
Referencias:
Lugar: Tripoli; Año: 2019 vol. 9 p. 65 - 73
ISSN:
2226-4485
Resumen:
Enterotoxigenic Escherichia coli (ETEC) is the most common and global cause of neonatal calf diarrhea, but there is alittle information regarding calf ETEC strains in Argentina. In this study, five ETEC isolates from diarrheic dairy calves(2?10 d old) from Buenos Aires and Cordoba, Argentina were characterized on the basis of virulence gene (VG) pattern,O:H serotyping, hemolytic phenotype, phylogenetic group affiliation, antimicrobial (AM) resistance profile, and presenceof integron class 1 and 2. The five isolates were examined by polymerase chain reaction (PCR) for the presence of 18bovine VGs and showed the following genotypes: F5+/F41+/sta+ (D242), F5+/sta+ (D158), F5+/sta+ (D157), F5+ (D151-9), and F5+/iucD+ (D151-5). These VGs confer pathogenic potential and most of them are associated with the ETECpathotype. The five isolates showed a non-hemolytic phenotype, belonged to five different serotypes: O101:H−, O141:H−,O60:H−, ONT:H10, and ONT:H−, and were assigned to the phylogenetic group A by the quadruplex Clermont PCRmethod. The AM resistance of the three isolates D242, D157, and D151-5 was determined by agar disk diffusion methodfor 24 AMs and they exhibited a multi-resistance phenotype (resistance to four different AM classes: Cephalosporins,Penicillins, Macrolides, and Ansamycins). In addition, class 1 integrons were found in the isolate D151-5 containing thedfrA17-aadA5 gene cassette and in the bovine ETEC reference strain FV10191 containing the dfrA1-aadA1 gene cassette.The present study revealed for the first time the occurrence of multi-resistant ETEC associated with neonatal diarrhea indairy calves in Argentina. This finding may be used for diagnostic and therapeutic purposes.