Prevalence and characteristics of Shiga toxin-producing &ITEscherichia coli&IT in finishing pigs: Implications on public health
Prevalence and characteristics of Shiga toxin-producing &ITEscherichia coli&IT in finishing pigs: Implications on public health
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DOI：
10.1016/j.ijfoodmicro.2017.10.017
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发表时间：
2018-01-02
影响因子：
5.4
通讯作者：
Funk, Julie A.
中科院分区：
文献类型：
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作者：
Cha, Wonhee;Fratamico, Pina M.;Funk, Julie A.
产滋贺毒素大肠杆菌（STEC）是重要的食源性致病菌，可引起出血性结肠炎和溶血性尿毒综合征等严重疾病。为了研究STEC在肥育猪中的流行病学，并检查它们对人类STEC感染构成的潜在风险，我们在三个肥育场进行了纵向队列研究。随机选择6个队列的猪（2个队列/研究中心，20头猪/队列），并在肥育期内每两周采集一次粪便样本（n = 898）。82头猪（68.3%）至少排出一次STEC，各研究中心（50-97.5%）和队列（15-100%）之间STEC阳性猪的比例各不相同。分别从研究中心C和A的两头猪中回收到具有临床意义的血清型O 157：H7（stx（2c），eae）和O26：H11（stx（1a），eae）。分离的最常见血清型为O 59：H21（stx（2 e）），其在位点B中特别流行，因为其从所有STEC阳性猪（n = 39）中回收。每个队列显示不同的STEC脱落模式，这与流行的血清型相关。猪STEC的中位散毒持续时间为28天，与我们之前的研究一致。然而，在至少排出一次O 59：H21的猪中，与其他组群相比，组群B2中的猪具有42天的显著更长的排出持续时间（P < 0.05）。与先前的研究一致，Stx 2 e是育肥猪中最常见的stx变体（93.9%）。据报道，Stx 2 e与猪水肿病显著相关，然而，在人类中的致病性需要进一步研究。尽管如此，我们的研究结果证实，猪是人类STEC感染的重要宿主，并且队列中的循环血清型和研究中心管理因素可能会显著影响STEC的患病率。STEC分离株的分子特征和流行病学研究，以确定在猪中散毒的风险因素是非常必要的，以进一步解决公共卫生的重要性，并制定缓解策略。
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 (stx(2c), eae ) and O26:H11 (stx(1a), eae), were recovered from two pigs at sites C and A, respectively. The most common serotype isolated was O59:H21 (stx(2e)), 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.