Prevalence and characteristics of Shiga toxin-producing Escherichia coli in finishing pigs: Implications on public health

Wonhee Cha, Pina M. Fratamico, Leah E. Ruth, Andrew S. Bowman, Jacqueline M. Nolting, Shannon D. Manning, Julie A. Funk

Research output: Research - peer-reviewArticle

Abstract

Shiga toxin-producing Escherichia coli (STEC) are important food-borne pathogens, which can cause serious illnesses, including hemorrhagic colitis and hemolytic uremic syndrome. To study the epidemiology of STEC in finishing pigs and examine the potential risks they pose for human STEC infections, we conducted a longitudinal cohort study in three finishing sites. Six cohorts of pigs (2 cohorts/site, 20 pigs/cohort) were randomly selected, and fecal samples (n = 898) were collected every two weeks through their finishing period. Eighty-two pigs (68.3%) shed STEC at least once, and the proportion of STEC-positive pigs varied across sites (50–97.5%) and cohorts (15–100%). Clinically important serotypes, O157:H7 (stx2c, eae) and O26:H11 (stx1a, eae), were recovered from two pigs at sites C and A, respectively. The most common serotype isolated was O59:H21 (stx2e), which was particularly prevalent in site B as it was recovered from all STEC positive pigs (n = 39). Each cohort showed different patterns of STEC shedding, which were associated with the prevalent serotype. The median shedding duration of STEC in pigs was 28 days, consistent with our prior study. However, among pigs shedding O59:H21 at least once, pigs in cohort B2 had a significantly longer shedding duration of 42 days (P < 0.05) compared to other cohorts. Stx2e was the most commonly observed stx variant in finishing pigs (93.9%), in accordance with the previous studies. Stx2e has been reported to be significantly associated with edema disease in pigs, however, the pathogenicity in humans warrants further investigations. Nonetheless, our findings affirm that pigs are an important reservoir for human STEC infections, and that the circulating serotypes in a cohort and site management factors may significantly affect the prevalence of STEC. Molecular characterization of STEC isolates and epidemiological studies to identify risk factors for shedding in pigs are strongly warranted to further address the significance to public health and to develop mitigation strategies.

LanguageEnglish (US)
Pages8-15
Number of pages8
JournalInternational Journal of Food Microbiology
Volume264
DOIs
StatePublished - Jan 2 2018

Profile

Shiga toxin-producing Escherichia coli
finishing
public health
swine
Shiga-Toxigenic Escherichia coli
Swine
Public Health
serotypes
Serogroup
duration
infection
Escherichia coli Infections
hemolytic uremic syndrome
swine diseases
sheds
colitis
food pathogens
cohort studies
edema
epidemiological studies

Keywords

  • Cohort
  • Finishing pigs
  • Prevalence
  • Shedding duration
  • Shiga toxin-producing Escherichia coli

ASJC Scopus subject areas

  • Food Science
  • Microbiology

Cite this

Prevalence and characteristics of Shiga toxin-producing Escherichia coli in finishing pigs : Implications on public health. / Cha, Wonhee; Fratamico, Pina M.; Ruth, Leah E.; Bowman, Andrew S.; Nolting, Jacqueline M.; Manning, Shannon D.; Funk, Julie A.

In: International Journal of Food Microbiology, Vol. 264, 02.01.2018, p. 8-15.

Research output: Research - peer-reviewArticle

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