Smith David R, Moxley Rodney A, Klopfenstein Terry J, Erickson Galen E
Department of Veterinary and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska 68583-0905, USA.
Foodborne Pathog Dis. 2009 Sep;6(7):885-92. doi: 10.1089/fpd.2009.0299.
We tested the efficacy of vaccinating all cattle within a region of a cattle feedlot using a two-dose regimen of a vaccine against type III secreted proteins of Escherichia coli O157:H7. Cattle (n = 504) were randomly assigned to 63 pens (8 steers/pen) within 3 treatment regions of the feedyard. All pens within each region were assigned: (1) two doses of vaccine (ALLVAC), (2) two doses of adjuvant as placebo (NOVAC), or (3) commingled vaccination (HALFVAC), four of eight cattle in each pen receiving two doses of vaccine, and the others adjuvant. Binary outcomes were (1) fecal shedding of E. coli O157:H7 42, 63, and 84 days postvaccination (dpv), (2) hide contamination 42, 63, and 84 dpv, and at the abattoir 85 dpv, and (3) colonization of the terminal rectal mucosa at the abattoir 85 dpv. For each outcome, multilevel logistic regression tested the effect of regional vaccination (ALLVAC vs. NOVAC), and compared commingled vaccinated versus placebo-treated cattle within HALFVAC pens. For fecal shedding, regional vaccine efficacy of ALLVAC compared to NOVAC pens was 63% (OR = 0.34, p = 0.0009), similar to vaccine efficacy of 52% for vaccinated cattle compared to placebo-treated cattle within HALFVAC pens (OR = 0.48, p = 0.014). For hide contamination, vaccine efficacy was 55% for regional vaccination of cattle in ALLVAC pens compared to NOVAC pens (OR = 0.43, p = 0.014). However, commingling vaccinated and placebo-treated cattle was not protective of hide contamination (OR = 0.67, p = 0.33). Colonization of cattle at the abattoir was not different among vaccinated and placebo-treated cattle (p = 0.63). We concluded that the two-dose vaccine regimen effectively reduced E. coli O157:H7 fecal shedding and hide contamination, and that vaccination of cattle within regions of the feedyard provided greater protection against hide contamination than commingling vaccinates and nonvaccinates.
我们使用针对大肠杆菌O157:H7Ⅲ型分泌蛋白的两剂次疫苗接种方案，对一个肉牛饲养场区域内的所有牛进行了疫苗接种效果测试。牛（n = 504）被随机分配到饲养场3个处理区域内的63个围栏中（每个围栏8头阉牛）。每个区域内的所有围栏被分配为：（1）两剂疫苗（ALLVAC），（2）两剂作为安慰剂的佐剂（NOVAC），或（3）混合接种（HALFVAC），每个围栏中的8头牛中有4头接受两剂疫苗，其他牛接受佐剂。二元结局包括：（1）接种疫苗后42、63和84天（dpv）时大肠杆菌O157:H7的粪便排菌情况，（2）接种疫苗后42、63和84天以及屠宰时（85 dpv）牛皮的污染情况，以及（3）屠宰时（85 dpv）终末直肠黏膜的定植情况。对于每个结局，多水平逻辑回归分析测试了区域接种（ALLVAC与NOVAC）的效果，并比较了HALFVAC围栏中混合接种与接受安慰剂处理的牛。对于粪便排菌情况，与NOVAC围栏相比，ALLVAC的区域疫苗效力为63%（OR = 0.34，p = 0.〇〇〇9），类似于HALFVAC围栏中接种疫苗的牛与接受安慰剂处理的牛相比52%的疫苗效力（OR = 0.48，p = 0.014）。对于牛皮污染情况，与NOVAC围栏相比，ALLVAC围栏中牛的区域疫苗效力为55%（OR = 0.43，p = 0.014）。然而，混合接种与接受安慰剂处理的牛并不能预防牛皮污染（OR = 0.67，p = 0.33）。接种疫苗与接受安慰剂处理的牛在屠宰时的定植情况没有差异（p = 0.63）。我们得出结论，两剂次疫苗接种方案有效减少了大肠杆菌O157:H7的粪便排菌和牛皮污染，并且在饲养场区域内对牛进行接种比混合接种和未接种提供了更好的抗牛皮污染保护。
