Diagnosis of bovine intramammary infection (IMI) has traditionally been based on bacterial culture, but currently IMI can also be detected with DNA based methods, such as multiplex real-time PCR. The aim of this study was to describe the elimination of bacteria in experimentally induced IMI on the quarter level, using conventional bacterial culture (BC) and multiplex real-time PCR. Two coagulase-negative staphylococcal species, Staphylococcus epidermidis and Staphylococcus simulans, were experimentally inoculated into 14 healthy quarters of 8 dairy cows during 4 consecutive study periods. Intramammary infections were followed with 20 milk samplings per each quarter. Milk somatic cell count was monitored to evaluate the inflammation process in the quarters. Four quarters cured spontaneously during the study period according to the culture. The PCR detected staphylococcal DNA from these quarters for several days after they were defined as cured in BC. Agreement between BC and PCR results varied from substantial to almost perfect agreement for the first 36 h postchallenge, decreasing to moderate levels toward the end of the sampling period. Based on this study, we recommend collecting possible follow-up samples to assess the bacteriological cure from IMI not until 2 to 3 wk after the onset of mastitis or after the quarter milk somatic cell count has normalized when PCR is used.

牛乳房内感染（IMI）的诊断传统上是基于细菌培养的，但是目前也可以使用基于DNA的方法（例如多重实时PCR）来检测IMI。这项研究的目的是描述使用传统的细菌培养（BC）和多重实时PCR在四分之一水平上消除实验诱导的IMI中的细菌。两种凝固酶阴性葡萄球菌种类，表皮葡萄球菌和模拟葡萄球菌在连续的4个研究阶段中，分别对8头奶牛的14个健康区进行了实验接种。乳房内感染之后每季度进行20次牛奶采样。监测牛奶的体细胞计数以评估宿舍的炎症过程。在研究期间，根据文化，四分之四会自发治愈。在将它们定义为在BC中治愈后，PCR连续几天检测了这些区域中的葡萄球菌DNA。攻击后的最初36小时，BC和PCR结果之间的一致性从基本一致到几乎完美一致，在采样期结束时降低到中等水平。根据这项研究，