Hogan J S, Weiss W P, Smith K L, Todhunter D A, Schoenberger P S, Sordillo L M
Department of Dairy Science, Ohio State University, Wooster 44691, USA.
J Dairy Sci. 1995 Feb;78(2):285-90. doi: 10.3168/jds.S0022-0302(95)76636-X.
Efficacy of an Escherichia coli (O111:B4) J5 bacterin was tested in an experimental challenge trial. Nineteen cows were vaccinated with an E. coli J5 bacterin, and 10 cows were injected with a placebo containing adjuvant only. Vaccine and placebo were administered at drying off, 30 d after drying off, and within 48 h after calving. Cows were challenged approximately 30 d after calving by intramammary infusion with a smooth heterologous strain of E. coli previously shown to cause mild clinical mastitis. Vaccination with the J5 bacterin reduced duration of IMI and local signs of clinical mastitis. Concentrations of BSA in milk 24 h after challenge were greater in control cows than in cows vaccinated with J5. The SCC at 7 d postchallenge were greater for cows vaccinated with the placebo than for cows vaccinated with J5. Bacterial counts were lower for cows vaccinated with the placebo than for cows vaccinated with J5 at 3, 6, and 9 h postchallenge. In contrast, cows vaccinated with J5 had lower bacterial counts at 2, 3, and 4 d postchallenge than did cows vaccinated with placebo. Systemic signs of clinical mastitis were relatively mild and similar between treatment groups. Rectal temperature, DMI, and milk production did not differ between control and cows vaccinated with J5 following challenge.
在一项实验性攻毒试验中测试了大肠杆菌（O111:B4）J5菌苗的效力。19头奶牛接种了大肠杆菌J5菌苗，10头奶牛注射了仅含佐剂的安慰剂。在干奶期、干奶期后30天以及产犊后48小时内分别给予疫苗和安慰剂。在产犊后约30天，通过乳房内注入先前已证明可引起轻度临床乳腺炎的光滑异源大肠杆菌菌株对奶牛进行攻毒。接种J5菌苗可缩短隐性乳房炎的持续时间以及临床乳腺炎的局部症状。攻毒后24小时，对照奶牛乳汁中牛血清白蛋白（BSA）的浓度高于接种J5菌苗的奶牛。攻毒后7天，接种安慰剂的奶牛的体细胞计数（SCC）高于接种J5菌苗的奶牛。攻毒后3、6和9小时，接种安慰剂的奶牛的细菌计数低于接种J5菌苗的奶牛。相反，攻毒后2、3和4天，接种J5菌苗的奶牛的细菌计数低于接种安慰剂的奶牛。临床乳腺炎的全身症状相对较轻，且各治疗组之间相似。攻毒后，对照奶牛和接种J5菌苗的奶牛的直肠温度、干物质采食量（DMI）和产奶量没有差异。
