%0 Journal Article
%T Phenotypic and genotypic characterization of enterotoxigenic Escherichia coli isolated from diarrheic calves in Argentina
%A Ana R. Moreira
%A Marcelo E. Sanz
%A Nora L. Padola
%A Ram¨®n A. Gonz¨¢lez Pasayo
%J Archive of "Open Veterinary Journal".
%D 2019
%R 10.4314/ovj.v9i1.12
%X Enterotoxigenic Escherichia coli (ETEC) is the most common and global cause of neonatal calf diarrhea, but there is a little information regarding calf ETEC strains in Argentina. In this study, five ETEC isolates from diarrheic dairy calves (2¨C10 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 presence of integron class 1 and 2. The five isolates were examined by polymerase chain reaction (PCR) for the presence of 18 bovine 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 ETEC pathotype. 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 PCR method. The AM resistance of the three isolates D242, D157, and D151-5 was determined by agar disk diffusion method for 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 the dfrA17-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 in dairy calves in Argentina. This finding may be used for diagnostic and therapeutic purposes
%K Antimicrobial resistance
%K Dairy cattle
%K Escherichia coli
%K Neonatal diarrhea
%K Virulence gene
%U https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6500866/