Kitchen B J, Kwee W S, Middleton G, Andrews R J
J Dairy Res. 1984 Feb;51(1):11-6. doi: 10.1017/s0022029900023268.
Changes in the level of the tissue damage marker enzyme, N-acetyl-beta-D-glucosaminidase (NAGase) in quarter fore milks were found to be related to the presence and types of pathogenic bacteria present and to somatic cell counts (SCC). Minor pathogens (coagulase-negative staphylococci, Corynebacterium bovis) elicited a mild SCC increase (from a mean of 243 X 10(3)/ml in healthy quarters to 504 X 10(3)/ml in infected quarters) with marginal tissue damage (mean NAGase activity increased from 21 in healthy quarters to 28 in infected quarters). Major pathogens (i.e. Staphylococcus aureus, Streptococcus agalactiae, Str. dysgalactiae and Str. uberis) caused more severe tissue damage (mean NAGase of 48) and SCC increases (mean, 2803 X 10(3)/ml). The NAGase test could also be used effectively on composite milk samples where regular monthly NAGase analysis was able to identify correctly 74% of animals having infected quarters. The possibility of combining SCC and NAGase data in order to give a more definite diagnosis of bovine mastitis is discussed.
研究发现，四分之一前乳中组织损伤标志物酶——N-乙酰-β-D-氨基葡萄糖苷酶（NAGase）水平的变化与存在的病原菌种类以及体细胞计数（SCC）有关。次要病原菌（凝固酶阴性葡萄球菌、牛棒状杆菌）引起体细胞计数轻度增加（从健康乳腺的平均243×10³/ml增至感染乳腺的504×10³/ml），组织损伤轻微（NAGase平均活性从健康乳腺的21增至感染乳腺的28）。主要病原菌（即金黄色葡萄球菌、无乳链球菌、停乳链球菌和乳房链球菌）导致更严重的组织损伤（NAGase平均为48）和体细胞计数增加（平均为2803×10³/ml）。NAGase检测也可有效用于混合乳样，每月定期进行NAGase分析能够正确识别74%有感染乳腺的动物。本文讨论了结合体细胞计数和NAGase数据以更明确诊断牛乳腺炎的可能性。
