Title: Prevalence and characterization of enterotoxigenic Escherichia coli isolated from non-diarrheic pigs in Argentina

MOREDO FA; PIÑEYRO PE; MÁRQUEZ GC; SANZ M; COLELLO R; ETCHEVERRÍA A; PADOLA NL; QUIROGA MA; PERFUMO CJ; GALLI L; LEOTTA GA

FOODBORNE PATHOGENS AND DISEASE

MARY ANN LIEBERT INC

Lugar: New York; Año: 2015

1535-3141

Abstract: In order to determine the prevalence of ETEC in non-diarrheic pigs, 990 animals from 11 pig farms were sampled. Using end-time PCR, ETEC were detected in 150 (15.2%) animals. From the positive samples 43 strains were isolated (28.7%). Out of the 43 ETEC+ strains, 39.5% were resistant to multiple antimicrobials and 18.6% of them carried intI2 gene. The genotypes rfbO157/estII/aidA and estI/estII were the most prevalent, 32.5% and 25.0%, respectively. The estII gene was identified most frequently (90.7%), followed by estI (34.9%), astA (25.6%) and eltA (11.6%). The genes coding the fimbriae F5, F6 and F18 were detected in single isolates each one. The aidA gene was detected in 20 ETEC+ strains associated with estII gene. ETEC belonged to 9 different serogroups, and 35.0% of them belonged to serotype O157:H19. Isolates were grouped by ERIC-PCR into 5 clusters with 100.0% similarity. In this study we demonstrated that numerous ETEC+ genotypes cohabit and circulate in swine population without clinical manifestation of ND or PWD, in different production stages. We also showed numerous MAR patterns in ETEC+ non-diarrheic animals, occasionally associated with the presence of intl2. Moreover, a risk factor analysis demonstrates an association of a few environmental variables with the presence of specific genotypes. The information generated in this study is important not only for diagnostic and epidemiological purposes, but also to understand the dynamics and ecology of ETEC in pigs in different production stages. This information can be directly applied to prevent clinical signs of ND and PWD and associated economic losses.