Objective:

Determine the frequency of diarrheagenic Escherichia coli pathotypes colonizing swine.

Materials and methods:

E. coli strains isolated of fecal samples from 280 swine, produced for local consumption, in a semi-technical farm of Morelos state (central Mexico), were tested to identify the diarrheagenic E. coli pathotypes by multiplex PCR. Pulsed-field gel electrophoresis (PFGE) were determined for the study of genetic diversity between pathigenic E. coli strains.

Results:

Of the 521-diarrheagenic E. coli isolates examined, 50 (9.6%) were positive for at least one virulence gene in 42 different animals. Thus, 15% (42/280) of the swine in this farm were colonized with pathogenic E. coli. Among the E. coli isolates, the pathotype EPEC (6.5%) was the most frequently, followed by EHEC (2.3%), ETEC and EIEC (0.4%). The study of genetic diversity, carried out by PFGE of 40 representative isolates, revealed 25 distinct restriction profiles clustered in 21 groups (A-U).

Conclusions:

In this study, four different E. coli pathotypes were found among swine colonized by E. coli in this farm. Thus, these swine are reservoirs for these virulent bacteria and there is potential risk of causing diarrhea in swine and in the population consuming the meat.