Oldham E R, Daley M J
Agricultural Research Division, American Cyanamid Company Princeton, NJ 08543-0400.
J Dairy Sci. 1991 Dec;74(12):4175-82. doi: 10.3168/jds.S0022-0302(91)78612-8.
A recombinant mucolytic protein, lysostaphin, was evaluated as a potential intramammary therapeutic for Staphylococcus aureus mastitis in dairy cattle. Lysostaphin, a product of Staphylococcus simulans, enzymatically degrades the cell wall of Staphylococcus aureus and is bactericidal. Thirty Holstein-Freisian dairy cattle in their first lactation were infected with Staphylococcus aureus (Newbould 305, ATCC 29740) in all quarters. Infections were established and monitored for somatic cell counts and Staphylococcus aureus colony-forming units 3 wk prior to subsequent treatment. Infected animals were injected through the teat canal with a single dose of recombinant lysostaphin (dose response 1 to 500 mg) or after three successive p.m. milkings with 100 mg of recombinant lysostaphin in 60 ml of sterile phosphate-buffered saline. Animals were considered cured if the milk remained free of Staphylococcus aureus for a total of 28 milkings after last treatment. Kinetic analysis of immunologically active recombinant lysostaphin demonstrated that a minimum bactericidal concentration was maintained in the milk for up to 36 to 48 h after a single infusion of 100 mg of recombinant lysostaphin. The cure rate of quarters receiving recombinant lysostaphin (100 mg in sterile phosphate-buffered saline, administered over three consecutive p.m. milkings) was 20% compared with 29% for sodium cephapirin in saline and 57% for a commercial antibiotic formulation, respectively. An improved formulation of recombinant lysostaphin may prove to be an effective alternative to antibiotic therapy for bovine mastitis.
一种重组溶菌蛋白——溶葡萄球菌酶，被评估为奶牛金黄色葡萄球菌乳腺炎的潜在乳房内治疗剂。溶葡萄球菌酶是模仿葡萄球菌的产物，能酶解金黄色葡萄球菌的细胞壁并具有杀菌作用。30头处于第一个泌乳期的荷斯坦 - 弗里生奶牛的所有乳腺象限均感染了金黄色葡萄球菌（纽博尔德305，美国典型培养物保藏中心29740）。在后续治疗前3周建立感染并监测体细胞计数和金黄色葡萄球菌菌落形成单位。感染动物通过乳头管注射单剂量的重组溶葡萄球菌酶（剂量范围为1至500毫克），或者在连续三个下午挤奶后，在60毫升无菌磷酸盐缓冲盐水中注射100毫克重组溶葡萄球菌酶。如果在最后一次治疗后总共28次挤奶的牛奶中均未检测到金黄色葡萄球菌，则认为动物已治愈。对具有免疫活性的重组溶葡萄球菌酶的动力学分析表明，单次输注100毫克重组溶葡萄球菌酶后，牛奶中可维持最低杀菌浓度长达36至48小时。接受重组溶葡萄球菌酶（100毫克溶于无菌磷酸盐缓冲盐水中，在连续三个下午挤奶时给药）治疗的乳腺象限治愈率为20％，相比之下，头孢匹林钠盐水溶液的治愈率为29％，商业抗生素制剂的治愈率为57％。重组溶葡萄球菌酶的改良制剂可能被证明是治疗牛乳腺炎的抗生素疗法的有效替代方案。
