Escherichia coli O157:H7 EDL933 has a strong virulence to Bama miniature pigs by injection and fails to colonize to their gastrointestinal tracts

Abstract

Detection of Shiga toxin-producing Escherichia coli O157:H7 from commercially grown pigs has been reported.
Furthermore, the E. coli O157:H7 colonized model of pig has been established and E. coli O157:H7 could be
transmitted from infected donor pigs to naïve pigs directly and indirectly. In the present study, we want to know
whether any E. coli O157:H7 strain can colonize to the alimentary tract of pig and the virulence of E. coli
O157:H7 to pig by injection. Bama miniature pig was infected with E. coli O157:H7 EDL933 strain orally, but the
organism could not be recovered from the feces and did not cause any tissue damage. Nevertheless, this
pathogen introduced serious clinical symptoms and pathological injuries by injection, especially the nervous
system and the injected pig exhibited severe neurological symptoms, including synclonus tremens, ataxia,
head-pressing and recumbency, etc. The pig did not excrete urine and feces and the abdomen became
tympanous. These data suggested that only certain E. coli O157:H7 strains could colonize to the GIs of pigs
involved mechanisms that related to various factors. However, the organism has strong virulence to pig by
injection mode and it is a risky pathogen to human health.