Enterotoxigenic Escherichia coli (ETEC) is an important cause of diarrhea and
septicemia (toxic, blood-borne infection) in neonatal and recently weaned swine. A
better understanding of the pathogenesis of enteric and septicemic colibacillosis is
needed before more effective therapeutic and preventative measures can be
developed. One aspect that is poorly understood is the mechanism by which bacteria
spread from the intestine to the blood and other organs; this process has been termed
translocation. Studies in laboratory animals have shown that translocation may be
reduced by the presence of nonpathogenic indigenous bacteria, similar to the bacteria
commonly found in probiotic preparations, in the intestine. Because the feeding of
probiotics is a management strategy currently available to producers, we sought to
determine whether the feeding of probiotic bacteria would reduce translocation of ETEC
bacteria and the severity of enteric and septicemic colibacillosis in the gnotobiotic piglet
model.
In the present study, Lactobacillus acidophilus and Enterococcus faecium strains
were isolated from a commercial probiotic product for swine. In vitro competition
experiments and in vivo challenge experiments were conducted with the probiotic
strains and two serotype O8:K87:NM:F4ac ETEC challenge strains. The two ETEC
strains included hemolytic strain WAM2317 and an isogenic nonhemolytic mutant,
WAM2335. Neither probiotic bacterial strain was inhibitory to the growth of either ETEC
strain in in vitro competition experiments. In vivo challenge experiments were
conducted. Principal gnotobiotic piglets from 3 to 7 days of age were fed daily, 1-2 x
109
colony-forming-units (CFU) each of the L. acidophilus and E. faecium strains,
whereas controls were fed sterile culture broth. Principals and controls were challenged
at 9 days of age by feeding 1-2 x 109
CFU of WAM2317 or WAM2335. Severe weight
loss and septicemia occurred only in phenotype A piglets, i.e., those susceptible to
ETEC bacterial adherence due to binding of K88 (F4) fimbria. Microscopic examination
of the small intestines of these pigs indicated that epithelial cells lining the villi had
E Escherichia coli ( ผู้เชี่ยวชาญ ) เป็นสาเหตุสำคัญของอาการท้องร่วง และภาวะโลหิตเป็นพิษ ( พิษ เลือด
ที่เกิดการติดเชื้อในทารกแรกเกิด และเมื่อเร็วๆ นี้ ) ลูกสุกร a
ความเข้าใจในพยาธิกำเนิดของโรคท้องร่วง และเป็นเลือดที่มีประสิทธิภาพมากขึ้นและผู้ที่ต้องการก่อน
มาตรการเชิงป้องกัน สามารถพัฒนาได้ One aspect that is poorly understood is the mechanism by which bacteria
spread from the intestine to the blood and other organs; this process has been termed
translocation. Studies in laboratory animals have shown that translocation may be
reduced by the presence of nonpathogenic indigenous bacteria, similar to the bacteria
commonly found in probiotic preparations, in the intestine. Because the feeding of
probiotics is a management strategy currently available to producers, we sought to
determine whether the feeding of probiotic bacteria would reduce translocation of ETEC
bacteria and the severity of enteric and septicemic colibacillosis in the gnotobiotic piglet
model.
In the present study, Lactobacillus acidophilus and Enterococcus faecium strains
were isolated from a commercial probiotic product for swine. In vitro competition
experiments and in vivo challenge experiments were conducted with the probiotic
strains and two serotype O8:K87:NM:F4ac ETEC challenge strains. The two ETEC
strains included hemolytic strain WAM2317 and an isogenic nonhemolytic mutant,
WAM2335.หรือโปรไบโอติกแบคทีเรียสายพันธุ์ถูกยับยั้งการเติบโตของเชื้อในการทดลองการแข่งขันผู้เชี่ยวชาญ
หลอดแก้ว ในการทดลองที่ท้าทายโดยมี
ดำเนินการ ตัว gnotobiotic หลักจาก 3 ไป 7 วัน อายุเลี้ยงทุกวัน 1-2 x
อาณานิคมสร้าง 109 หน่วย ( CFU ) แต่ละวันมี L . จากสายพันธุ์
ในขณะที่การควบคุมได้รับวัฒนธรรมที่เป็นหมัน ซุป Principals and controls were challenged
at 9 days of age by feeding 1-2 x 109
CFU of WAM2317 or WAM2335. Severe weight
loss and septicemia occurred only in phenotype A piglets, i.e., those susceptible to
ETEC bacterial adherence due to binding of K88 (F4) fimbria. Microscopic examination
of the small intestines of these pigs indicated that epithelial cells lining the villi had
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